Progress 11/01/11 to 10/31/16

Outputs
Target Audience:Dairy scientists and researchers, dairy nutrition and mangement consultants, and dairy farmers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Numerous seminars and invited presentations to dairy producers and nutritonists across the US were given on water quality and nutrition during the life of this project. The research in this project contributed new knowledge and content for those presentations. How have the results been disseminated to communities of interest?Through seminars and invited presentations and conference proceedings for professional dairy nutritionists and farmers. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Research addressed the nutrition and quality of drinking water for dairy cattle. Phase 1 focused on drinking water quality for lactating dairy cows; Phase 2 addressed drinking water quality for young calves (28 to 83 d of age, pre- and post-weaning). Majority of iron (Fe) naturally occurring in drinking water drawn from underground wells is in the potentially more bioavailable ferrous (Fe2+) valence. In contrast, the majority of Fe in feedstuffs is of the ferric (Fe3+) valence, and poorly absorbed by ruminants. Therefore, Fe from drinking water potentially could have a greater impact on the animal's Fe status, potential risk of Fe toxicity, and oxidative stress compared with feed Fe. Excessive ferrous iron in drinking water presents the risk to impact animal health and productivity negatively. Phase 1 (cows), Experiments 1 and 2. Effects of abomasally dosed ferrous (Fe2+) or ferric (Fe3+) iron on short-term iron status of lactating dairy cows. Our objective was to evaluate short-term effects of abomasally infused Fe2+ and characterize potentially differences in short-term effects of Fe2+ versus Fe3+ when administered at concentrations to simulate total daily Fe intake from high-Fe drinking water. In each experiment, 6 mid-lactation Holstein cows were assigned in a replicated 3 x 3 Latin Square balanced for treatment sequences. Treatments in Experiment 1 were 0, 0.75 and 1.5 mg of Fe from ferrous lactate [Fe(C3H5O3)2] per kg body weight (BW). Treatments were calculated to approximate 0, 4.5 and 9 mg Fe/L concentrations typically found in drinking water, but pulse-dosed directly in abomasum in 1 L of deionized water. Experiment 2 differed only in treatments administered: 0 mg Fe and 1.5 mg Fe/kg BW of either ferrous (FeSO4) or ferric sulfate [Fe2(SO4)3]. In each experiment blood samples were taken at 0 h (before dosing) and hourly for 12 h post-dosing; and, liver biopsies were taken at 0, 18 and 36 h post-dosing. There were no effects of either Fe concentration or valence on blood serum Fe, unsaturated Fe binding capacity, percent Fe saturation, or serum Zn concentrations. In Experiment 1, cows infused with 0.75 mg/kg BW of ferrous lactate had greater serum total Fe binding capacity and hepatic Cu concentrations. Cows infused with 1.5 mg Fe/kg BW had greater serum alpha-tocopherol concentrations. In Experiment 2, there was a tendency for cows administered ferric sulfate to have lower serum Fe than those infused with no Fe or ferrous sulfate. Cows infused with ferrous sulfate had lower serum Cu concentrations compared with those dosed with other treatments. Overall, various Fe treatments did not influence short-term Fe status, suggesting that it may take chronic, longer-term exposure to excessive Fe in drinking water, or greater Fe dosages or concentrations to impact Fe status and productivity of lactating cows. Phase 1 (cows), Experiments 3, 4, 5, and 6. Preference and drinking behavior of lactating dairy cows offered water with different concentrations, valences, and sources of Fe were evaluated. Drinking water can contain high concentrations of Fe, mainly of the ferrous (Fe2+) valence. Current recommended upper tolerable concentration of Fe in drinking water for cattle (0.3 mg/L) comes from guidelines for human palatability, but cattle may be able to tolerate greater concentrations. Our objective was to determine effects of varying concentrations of ferrous (Fe2+) or ferric (Fe3+) iron and Fe-salt source on lactating dairy cows' preferences for and drinking behavior of water offered ad libitum. In four separate experiments, cows were offered pairs of water treatments for 22-h periods and water intake and drinking behavior were recorded. In Experiment 3 treatments were: 0, 4, or 8 mg of total recoverable Fe/L from ferrous lactate; total recoverable iron is detected after treatment of the water sample with nitric acid. Cows exhibited no preference between water with 0 or 4 mg Fe/L, but water intake was less with 8 compared with 0 or 4 mg Fe/L. Also, cows spent less time drinking water containing 8 mg Fe/L. Total time spent drinking correlated positively with water intake when pooled across treatments. In Experiment 4, treatments were: 0 or 8 mg Fe/L from either ferrous sulfate (FeSO4) or ferric sulfate [Fe2(SO4)3]. Water intake did not differ among treatments. In Experiment 5, treatments were: 0 or 8 mg Fe/L from either ferrous chloride (FeCl2) or ferric chloride (FeCl3). Again, cows exhibited no preference among treatments. In Experiment 6, treatments were: 0 or 8 mg Fe/L from ferrous lactate [Fe(C3H5O3)2], ferrous sulfate (FeSO4) or ferrous chloride (FeCl2). Cows preferred to drink water without added Fe, but did not exhibit any preference among waters containing the Fe sources with different anionic moieties. Cows spent less time drinking and drank less frequently when offered water containing 8 mg of total recoverable Fe/L from ferrous chloride compared with ferrous lactate or ferrous sulfate. Water intake correlated positively with both drinking duration and frequency when pooled across treatments in Experiment 6. Overall, our results indicate that upon first exposure to drinking water with varying iron concentrations, lactating dairy cows tolerate concentrations of Fe up to 4 mg/L from ferrous lactate without reducing water intake; however, water intake was reduced with 8 mg of total recoverable Fe. Preference was not influenced by Fe valence or Fe source. Results indicate that lactating dairy cows tolerate Fe concentrations up to 4 mg Fe/L without reduced water intake, but 8 mg Fe/L reduced water intake; however, we did not test concentrations of 5, 6 or 7 mg Fe/L. Overall our results indicate that total recoverable Fe concentration (after treatment of the water sample with nitric acid) of up to 4 mg Fe/L did not affect negatively the drinking water preference of lactating dairy cows when compared with water containing no added Fe. However, water intake was less with total recoverable Fe of 8 mg Fe2+/L. Additionally, cows did not exhibit a preference comparing ferrous and ferric Fe in water, and did not have a preference for Fe source comparing ferrous salts of lactate, sulfate or chloride. Drinking duration was negatively impacted by greater Fe concentration and was dependent on source. This research illustrates that potential effects of excess Fe in drinking water on productivity and health of lactating dairy cows could be due, at least in part, to reduced water intake resulting from reduction in palatability and normal consumption of drinking water.

Publications

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:dairy farmers, dairy scientists, dairy nutritionists, university students Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?About 30 undergraduate students and 1 graduate student received extensive training and experience in animal science research. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?Completion of data analysis, interpretation and writing from the two preference experiments and the follow-up performance study will be done. The M.S. student will present and defend the graduate thesis. The primary practical question from the work is if drinking water for young calves with more than 0.3 parts per million of dissolved iron reduces water intake thus reducing feed intake, growth and health; and (or) if the growth performance, iron status and health may be affected by a mechanism other than reduction in water intake. The information from this work will be shared with communities of interest such as dairy farmers and nutritionists.

Impacts
What was accomplished under these goals? Our recent research demonstrated that young dairy calves could distinguish (differentiate) the presence increasing concentrations of dissolved iron (ferrous lactate) in their drinking water offered ad libitum. Post-weaned calves (approximately 65 to 85 days of age) demonstrated a moderate to substantial agreement in ranking of treatments by Kendall's Coefficient of Concordance (which tests for normalcy and agreement among calves). In general the greater to concentration of iron the less water was consumed. The degree of agreement was slightly less but still detectable in pre-weaned calves (approximately 35 to 55 days of age) and still consuming milk replacer (without added iron). Primary objective in two the experiments was to determine if pre- and post-weaned calves could differentiate and rank among free-choice drinking waters offered simultaneously and containing 20, 12, 8, 4, 2 or 0 parts per million of ferrous iron from ferrous lactate. Small graded amounts of lactic acid were added to equalize the pH among treatments. A non-parametric experimental design was used to achieve preference ranking over the 20-day experimental periods. Each separate experiment involved simultaneous offering of six drinking waters each with one of the six iron concentrations in period 1; the most preferred treatment per each calf was determined by the most drinking water consumed. Then the most preferred treatment within calf was removed in the next period through four successive experimental periods. Thus, each calf provided its own ranked preference. Daily intake of milk replacer (for the younger calves) and calf starter in each experiment also was quantified. All data were combined and analyzed for each experiment (within age group). In a longer term follow-up study the growth, iron status, and health of pre-weaned dairy calves offered twice daily free-choice drinking water and milk replacer with varying ferrous iron concentrations was being tested. Increasing ferrous iron concentrations (0, 2, 4, 8, and 12 parts per million) in drinking water and the water used for milk replacer were hypothesized to reduce growth and increase blood iron, pack cell volume, and iron protein saturation. Sixty calves of both sexes started the study at 28 and finished at 56 days of age in a randomized complete block design consisting of the five iron treatments and 12 replicates. Each calf was assigned randomly to one of five drinking water and milk replacer solutions containing a specific concentration of iron for the entire study. Drinking water and milk replacer intake were measured three times per day and starter feed intake once per day. Calves were weighed and measured (wither height, heart girth, hip width, and body length) once per week to monitor growth. Three blood samples are taken via jugular puncture at 08:00 hour on days 0, 14 and 28 of the study. Blood was analyzed for serum iron, packed cell volume, and iron binding protein saturation. Growth and blood data collection from this study have been completed and currently are being analyzed by ANOVA using the MIXED procedure (SAS, version 9.1.3; SAS Institute Inc., Cary, NC).

Publications

• Type: Journal Articles Status: Published Year Published: 2014 Citation: Contreras-Govea, F. E., V. E. Cabrera, L. E. Armentano, R. D. Shaver, P. M. Crump, D. K. Beede, and M. J. VandeHaar. 2014. Constraints for nutritional grouping in Wisconsin and Michigan dairy farms. J. Dairy Sci. 98: 1336  1344.

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: dairy farmers, dairy scientists, dairy nutritionists, dairy students Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? All the data from both Studies 1 and 2 have been collected and data analysis is underway. The practical implications and impact of results of these studies is forthcoming. The central practical question is if drinking water with greater than typically recommended (0.3 parts per million iron) may affect drinking preference, water intake, health, and growth performance of young dairy calves.

Impacts
What was accomplished under these goals? Effects of iron in drinking water on preference, growth, and iron status of pre- and post-weaned dairy calves. Drinking water (generally well water in most commercial dairy farms) with greater than 0.3 parts per million iron may affect drinking preference, water intake, health, and growth performance of young calves. The 0.3 parts per million often listed for livestock is actually the upper threshold guideline for “good quality” for palatability for humans published by the World Health Organization (2006). This research aims to determine if pre-weaned and early post-weaned dairy calves exhibit preference for free-choice drinking water with varying iron concentrations; and, to determine if drinking water with varying iron concentrations affects growth performance and iron status of dairy calves. Study 1 and 2. Drinking water preference of pre-weaned and post-weaned calves offered water with graded ferrous iron (Fe+2) concentrations. Hypothesis: dairy calves will progressively discriminate against drinking water with increasing ferrous iron concentrations of 0, 2, 4, 8, 12, and 20 parts per million. Objective: to determine pre- and post-weaned dairy calves exhibit differential preference when graded concentrations of ferrous iron are present in the drinking water. Experimental: In each Study 1 (pre-weaning with milk replacer) and 2 (post-weaning using a different group of calves) six Holstein calves of either or both sexes were used. The experimental design was a non-parametric preference ranking design lasting 20 days. In the first of five total experimental periods, six buckets contained drinking water with one of six iron treatment concentrations (0, 2, 4, 8, 12, or 20 parts per million). Treatments were randomly placed (daily) on the long each sides of each calf’s individual pen. Experimental drinking water solutions with different concentrations of iron were made using ferrous lactate and distilled water; small graded amounts of lactic acid were added to make all treatments iso-lactate. Fresh pre-weighed drinking water treatments in new buckets replaced the previous treatment buckets at time of feedings (morning, afternoon and evening) after milk replacer has been consumed (calves had access to drinking water 24 hours daily). At these times, buckets (previously weighed empty) for water, calf starter pellets, and milk replacer (milk replacer fed in Study 1, but not in Study 2) were weighed and changes in weight were recorded as intake. Starter pellets were weighed after each 24-hour period (every morning) and recorded as daily starter intake. Water buckets with treatment solutions were re-randomized each morning (08:00 hour) in each experimental period. In period 1, all six treatments were provided in a completely random order each day for the first 6 days separately for each calf. At the end of the 6th day, the drinking water treatment with the greatest total consumption over the previous 6-day period was removed and replaced with an empty bucket. The 5 remaining treatments, as well as an empty bucket to replace the 6th treatment, were re-randomized within the bucket holders in Period 2. The previous steps were repeated with 5 treatments provided for 5 days, 4 treatments provided for 4 days, 3 treatments provided for 3 days, and 2 treatments provided for 2 days (Period 5). An empty bucket replaced each removed treatment(s) bucket in the successive periods to keep spatial relationships within the pen the same among all periods. All the data from both studies have been collected and data analysis is underway. Day 1 intakes (total water consumed during first 24 hours) from each bucket will be used to rank the calf’s initial preference to drinking water with varying concentrations of iron using the Kruskal-Wallis test. Friedman statistical test is used to determine agreement of preference among all successive treatment periods (i.e., 6-, 5-, 4-, 3-, and 2-day periods). Kendall’s coefficient of concordance will be used to test for normalcy and agreement among calves. Study 3: Growth performance of pre-weaned calves offered drinking water and milk replacer with varying ferrous Fe concentrations. Hypothesis: increasing ferrous iron concentrations (0, 2, 4, 8, and 12 parts per million) in drinking water and the water used for milk replacer will reduce growth and increase blood iron, pack cell volume, and iron protein saturation. Objective: to determine if pre-weaned calves show biological responses (growth performance and (or) blood iron, PCV, and blood iron protein saturation) to increasing iron concentrations in drinking water and that used in preparation of milk replacer (0, 2, 4, 8, and 12 parts per million). Experimental: Sixty calves of both sexes and 28 days of age will be used in a randomized complete block design consisting of five iron treatments and 12 replicates. Calves are on study 28 through 56 days of age. Calves of each sex are blocked (bull block or heifer block) as available chronologically and within block assigned randomly to one of five drinking water and milk replacer solutions with different ferrous iron concentrations (0, 2, 4, 8, or 12 parts per million). Calves are assigned to the same treatment for the entire study. Iron concentrations are varied using ferrous lactate and all treatments are iso-lactate using graded additions of lactic acid as needed. Milk replacer feedings are made using respective solutions containing the iron treatments. Milk replacer (containing the iron treatments) is fed three times per day and drinking water and starter are placed inside the hutches. New drinking water treatment solutions will be offered at each feeding (three times a day) and water intake and milk replacer intake will be recorded at each of these times. Starter intake will be measured once per day at 08:00 hour. Calves are weighed and measured (wither height, heart girth, hip width, and body length) once per week to monitor growth. Three blood samples are taken via jugular puncture at 08:00 hour on days 0, 14 and 28 of the study. Blood is analyzed for serum iron, packed cell volume, and iron binding protein saturation. Study 3 is on going; about half the calves have completed the study. Data will be analyzed by least-squares analysis of variance using the MIXED procedure (SAS, version 9.1.3; SAS Institute Inc., Cary, NC).

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: Genther, O. N., and D. K. Beede. 2013. Preference and drinking behavior of lactating dairy cows offered water with different concentrations, valences, and sources of iron. J. Dairy Sci. 96:1164-1176.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Hollmann, M., W. J. Powers, A. C. Fogiel, J. S. Liesman, and D. K. Beede. Response profiles of enteric methane emissions and lactational performance during habituation to dietary coconut oil. J. Dairy Sci. 96: 1769-1781.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Shire, J. A., and D. K. Beede. DCAD Revisited: Prepartum Use to Optimize Health and Lactational Performance. Proc. Southwest Nutrition and Management Conf. pp 1  18.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Shire, J. A., and D. K. Beede. Revisiting Prepartum DCAD: Reducing Hypocalcemia in Transition Cows. Proc. Penn. Dairy Cattle Nutr. Workshop. pp 15 - 22.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Beede, D. K. What Can We Do about Water Quality? Proc. Penn. Dairy Cattle Nutr. Workshop. pp 53 - 58.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Shire, J. A., and D. K. Beede. Influence of DCAD on Lactational Performance: A Review of Some Practical Considerations. Proc. Penn. Dairy Cattle Nutr. Workshop. pp 91 - 98.
• Type: Book Chapters Status: Published Year Published: 2013 Citation: Beede, D. K. 2013. Animal Agriculture: How Can It Be Sustainable In the Future? (Chapter 18). In: Sustainable Animal Agriculture. E. Kebreab, ed., CABI Publishing, CAB International, Wallingford, Oxfordshire, OX10 8DE, UK. pp. 284-311. ISBN-13: 978 1 78064 042 6
• Type: Other Status: Published Year Published: 2014 Citation: Shire, J. A., and D. K. Beede. Hypocalcemia is more than a low calcium problem. Hoards Dairyman (February 10) 159 (3): 81.

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: dairy farmers, professional dairy nutritionists and management consultants, veterinarians, animal science educators, researchers and extension and outreach personnel, and the general public Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? The majority of iron (Fe) naturally occurring in drinking water is in the ferrous (Fe2+) state, and if present in great enough concentrations (perhaps greater than 4 to 10 ppm), could negatively affect iron status and potentially cause toxicity. We evaluated the short-term effects of ferrous lactate infused into the abomasum on iron status of mid-lactation dairy cows given amounts to simulate total daily iron intake from high- iron drinking water. There were no effects on blood serum Fe, unsaturated iron-binding capacity (UIBC), total iron-binding capacity (TIBC), percent iron saturation, α-tocopherol, and Cu concentrations, as well as for liver Fe, Cu and Zn. Results indicate that infusion of ferrous iron at rates used in this study do not have major impacts on short-term iron status of lactating dairy cows. Examination of longer term administration of ferrous iron in drinking water of lactating cows might provide useful information on the effects on lactating cows. How have the results been disseminated to communities of interest? Speaking engagements at Tri-State Dairy Nutrition Conference and Cornell Nutrition Conference on "What can we do about water quality?" What do you plan to do during the next reporting period to accomplish the goals? Studies will address the potenial water quality (excess iron) problems with pre and post weaned calves including drinking water preference and physiological responses to high iron in water.

Impacts
What was accomplished under these goals? We hypothesize that the majority of iron naturally occurring in drinking water is in the ferrous state, and if present in great enough concentrations, could negatively affect iron status and potentially cause toxicity. Our objective was to evaluate the short-term effects of ferrous lactate infused into the abomasum on iron status of mid lactation dairy cows given amounts to simulate total daily iron intake from high iron drinking water. Six mid-lactation Holstein cows were assigned in a replicated 3 by 3 Latin Square balanced for treatment sequences. There were 7 days between experimental periods. Treatments were: 1) 0 mg Fe; 2) 0.75 mg of iron from ferrous lactate per kg of body weight; and, 3) 1.5 mg of iron from ferrous lactate per kg body weight. Treatments were calculated to approximate 0, 4.5 and 9 parts per million iron concentrations in drinking water, respectively. All treatments were equal in lactate. Treatments were dosed in about 1 min directly into the abomasum via the ruminal fistula in 1 L of deionized water to avoid any potential ruminal impacts on iron valence. Blood samples were taken hourly prior to dosing via jugular catheter for 6 h, and post-dosing hourly for 12 h. Liver biopsies were taken at 0 (prior to dosing), 18 and 36 h of each period. Mean of the pre-dosing blood samples was used as a covariate for each dependent variable in statistical analysis. There were no treatment by time interactions for serum Fe, unsaturated iron-binding capacity (UIBC), total iron-binding capacity (TIBC), percent iron saturation, α-tocopherol, and Cu concentrations, as well as for liver Fe, Cu and Zn. There was no main effect of treatment on any response variables. There was an effect of hour pooled across treatments on serum iron, UIBC, percent iron saturation; and, for liver Cu and Zn concentrations. There was a treatment by time interaction for serum Zn concentration and a tendency for liver Cu concentration. Results indicate that infusion of ferrous iron at rates used in this study do not have major impacts on short-term iron status of lactating dairy cows.

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: Genther, O. N., and D. K. Beede. 2013. Preference and drinking behavior of lactating dairy cows offered water with different concentrations, valences, and sources of iron. J. Dairy Sci. 96:1164-1176.
• Type: Book Chapters Status: Accepted Year Published: 2013 Citation: Beede, D. K. 2013. Animal Agriculture: How Can It Be Sustainable In the Future? (Chapter 18). In: Sustainable Animal Agriculture. E. Kebreab, ed., CABI Publishing, CAB International, Wallingford, Oxfordshire, OX10 8DE, UK. pp. In Press (Accepted)

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: Effects of water iron concentration, valence and source on drinking water preference of lactating cows. Drinking water can contain high concentrations of Fe, mainly of the ferrous (Fe2+) valence. Current recommended upper tolerable concentration of Fe in drinking water for cattle (0.3 mg/L) comes from guidelines for human palatability, but cattle may be able to tolerate greater concentrations. Our objective was to determine the effects of varying concentrations of ferrous (Fe2+) or ferric (Fe3+) iron and Fe-salt source on lactating Holstein cows' preferences for drinking water offered as choices ad libitum. In four separate experiments, cows were offered pairs of water treatments for 22-h periods and water intake and drinking behavior were recorded. Data were analyzed by ANOVA. In Experiment 1 treatments were: 0, 4, or 8 mg of Fe/L from ferrous lactate [Fe(C3H5O3)2]. Cows exhibited no preference between water with 0 or 4 mg Fe/L, but water intake tended to be less with 8 compared with 0 or 4 mg Fe/L (P < 0.10). Also, cows spent less time drinking water containing 8 mg Fe/L (P = 0.01). Total drinking duration (r = 0.62) and frequency (r = 0.55) correlated positively with water intake (P < 0.05) when pooled across treatments. In Experiment 2, treatments were: 0 or 8 mg Fe/L from either ferrous sulfate (FeSO4) or ferric sulfate [Fe2(SO4)3]. Water intake did not differ among treatments. Treatments in Experiment 3 were: 0 or 8 mg Fe/L from either ferrous chloride (FeCl2) or ferric chloride (FeCl3). Again, cows exhibited no preference among the treatments. Treatments in Experiment 4 were: 0 or 8 mg Fe/L from ferrous lactate, sulfate, or chloride. Cows preferred water without added Fe (P < 0.05), but did not exhibit a preference among waters containing the Fe sources with different anionic moieties. Total drinking duration and frequency were less (P < 0.05) when offered water containing 8 mg of Fe/L from ferrous chloride compared with ferrous lactate or sulfate. Overall, our results indicate that upon first exposure to drinking water, lactating dairy cows tolerate concentrations of Fe up to 4 mg/L without reducing water intake; however, water intake was reduced with 8 mg Fe/L. Preference was not dependent upon Fe valence or Fe source in our studies. PARTICIPANTS: O. Genther - graduate research assistant TARGET AUDIENCES: Information important to US dairy farmers and nutritionists. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Drinking water of lactating dairy cows with concentrations of iron (Fe) of greater than 4 ppm reduced free water intake and affected the drinking behavior of cows. Overall, the ferrous form of Fe had more negative effects than the ferric form of water intake and consumption pattern. Significant numbers of dairy farms in the USA have drinking water with elevated iron. Presumably feed intake and milk production also would be reduced, but this has not been tested. It is not known if drinking water with iron concentrations between 2 and 4 ppm would be detrimental, as these concentrations have not been tested.

Publications

• Genther, O. N., and D. K. Beede. 2012. Effects of water iron concentration, valence and source on drinking water preference of lactating cows. J. Dairy Sci. (E-Suppl. 1) 95:102.
• Beede, D. K. 2012. What can we do about water quality Proc. Tri-State Dairy Nutr. Conf. pp. 17 - 22.
• Genther, O. N., J. A. Zyskowski, T. H. Herdt, and D. K. Beede. 2011. Effects of abomasal dosing of ferrous lactate in lactating dairy cows. J. Dairy Sci. (E-Suppl. 1) 94:126.
• Genther, O. N., J. A. Zyskowski, T. H. Herdt, and D. K. Beede. 2011. Effects of abomasal dosing of ferrous or ferric sulfate on short-term iron status of lactating dairy cows. J. Dairy Sci. (E-Suppl. 1) 94:768.

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: Saturated fatty acids (FA) reduce enteric methane emissions, but sometimes also reduce DMI and milk yield. We compared effects and explored possible mechanisms associated feeding saturated FA on lactational performance of early lactation Holstein cows were fed one or both of two sources of saturated FA, differing in predominant chain length. Dietary treatments were: 1) no added fat (CTRL); 2) 2.7% of dietary DM as saturated long-chain FA (Energy Booster 100; EB); 3) 2.7% CO; or, 4) a 2.7% mixture of equal parts EB and CO (intermediate = INT). Primiparous (PP; n = 31) and multiparous (MP; n = 36) Holstein cows 10 to 14 days in milk were fed one of the four dietary treatments for 16 wk in a continuous randomized complete block design. The basal diet (CTRL), containing corn and alfalfa silages (53% of DM), dry ground corn, soybean meal, plus mineral and vitamin supplement; it was formulated to contain 26.5% NDF (83% of NDF from forages), 17.6% crude protein, 29.6% starch, and 3.6% fat. Milk yield and DMI were recorded daily, and venous blood was collected weekly. Data were analyzed by least-squares ANOVA with main effects of dietary treatment, parity, time (repeated measures), and relevant interactions. Results reported differed at P < 0.05. Overall, cows fed CTRL had greatest DMI. Dietary fat source with greater chain length (Energy Booster 100) increased DMI linearly for multiparous cows (CO: 22.7; INT: 24.7; EB: 27.0 kg/cow per d), but in a quadratic fashion for primiparous cows (18.5; 21.0; 20.3 kg/cow per d). Similar responses and interactions of treatment by parity were observed for yields of solids-corrected milk and milk components. The CO treatment reduced milk fat (3.1%) and lactose (4.73%) concentrations compared with EB (3.8% and 4.92%), pooled across time and parity. Plasma glucose concentrations did not differ among treatments across the 16-wk experiment. However, fat source interacted with parity; INT resulted in the lowest glucose concentrations for primiparous cows, but greatest for multiparous cows. During wk 1 through 4 of the experiment, multiparous cows had lower plasma glucose than primiparous cows (52 vs. 58 mg/dL), which coincided with greater plasma beta-hydroxybutyrate concentrations (7.0 vs. 4.8 mg/dL) and non-esterified fatty acids concentrations (710 vs. 380 micro-equivalents/L) in multiparous cows. Body condition loss through wk 4 of lactation was greater for cows fed CO and CTRL than for those fed INT and EB. Overall, dietary CO reduced DMI compared with EB leading to a greater body FA mobilization in early lactation. The interaction of parity with dietary treatments for many dependent variables was particularly striking in this study. Coconut oil, although resulting in significant reductions in enteric methane emissions of lactation dairy cows in our previous studies, does not appear to be a likely commercial candidate for dietary use because of quite marked reductions in feed intake, milk yield and milk fat concentration. PARTICIPANTS: Major collaborator in this work was M. Hollmann, graduate research assistant, Michigan State University. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Coconut oil, a source of predominantly medium chain (C-12 and C-14) fatty acids, causes marked reduction in methane emissions, presumably due to effects on the rumen microbial ecosystem as well as reduced feed intake. However, lactational performance was detrimentally affected to the degree that coconut oil is not likely a viable commercial feed ingredient unless revenue from the lost milk production could be recovered by new revenue generation for the amount of methane reduction. Feeding dietary coconut oil (a natural source of mainly medium chain fatty acids) can result in significant reductions in enteric methane emissions in lactating dairy cattle; however, does not appear to be a likely commercial candidate for dietary use because of marked reductions in feed intake, milk yield and milk fat concentration.

Publications

• Beede, D. K., M. H. Hollmann, and M. S. Allen. 2011. Lactational response to corn distillers grains: A meta-analysis with focus on diet fermentability and protein quality. Proc. 72nd Minnesota Nutr. Conf. pp. 108-123.
• Hollmann, M., M. S. Allen, and D. K. Beede. 2011. Diet fermentability influences lactational performance responses to distillers grains: A meta analysis. J. Dairy Sci. 94: 2007-2021.
• Hollmann, M., M. S. Allen, and D. K. Beede. 2011. Dietary protein quality and quantity affect lactational responses to distillers grains: A meta analysis. J. Dairy Sci. 94: 2022-2030.
• Hollmann, M. and D. K. Beede. 2010. Source of dietary saturated fatty acids and parity influence dry matter intake and energy partitioning in Holstein dairy cows. J. Dairy Sci. 93 (E-Suppl. 1): 234.
• Hollmann, M., M. S. Allen, and D. K. Beede. 2011. Chain length of saturated fatty acids affects intake and ruminal turnover of NDF and chewing activity in lactating cows varying in milk yield. Abstract submitted for presentation at ASAS-ADSA Joint Meetings in New Orleans, LA, July 2011. J. Dairy Sci. (E-Suppl. 1):
• Hollmann, M., M. S. Allen, and D. K. Beede. 2011. Chain length of dietary saturated fatty acids affects meal patterns and plasma metabolite and hormone concentrations of cows varying in milk yield. Abstract submitted for presentation at ASAS-ADSA Joint Meetings in New Orleans, LA, July 2011. J. Dairy Sci. (E-Suppl. 1):
• Hollmann, M. and D.K. Beede. 2010. Limited suitability of dietary coconut oil to reduce enteric methane emissions from dairy cattle. Pg.112 in Proc. 4th Greenhouse Gases and Anim. Agric. Conf. Banff, Alberta, Canada.

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: This work addressed sub-objective 2 of the project: to optimize lactating and dry cow decision-making as it relates to animal health, nutrient utilization, milk production, reproduction, and profitability (cows). Dietary coconut oil (CO), a source of saturated, predominantly medium-chain fatty acids (FA), reduced enteric methane emissions, but also reduced DMI and milk yield in our earlier studies. Here, we examined lactational and metabolic performance of early lactation cows fed two sources of saturated FA, differing in predominant chain lengths. Dietary treatments were: no added fat (CTRL); 2.7% of dietary DM as saturated long-chain FA (Energy Booster 100; EB) or 2.7% CO; or, a 2.7% mixture of equal parts EB and CO (INT). Primiparous (PP; n = 31) and multiparous (MP; n = 36) Holstein cows 10 to 14 d postpartum were fed one of four treatments for 16 wk in a randomized complete block design. CTRL diet contained corn and alfalfa silages (53% of DM), dry ground corn, soybean meal, plus mineral and vitamin supplement; it was formulated to contain 26.5% NDF (83% from forages), 17.6% CP, 29.6% starch, and 3.6% fat. Milk yield and DMI were recorded daily, and blood was collected weekly. Main effects of diet, parity, time (repeated measures), and relevant interactions were tested by least-squares ANOVA. Reported values differed (P < 0.05). Overall, cows fed CTRL had the greatest DMI. Fat source with greater chain length increased DMI linearly for MP cows (CO: 22.7; INT: 24.7; EB: 27.0 kg/d), and quadratically for PP cows (18.5; 21.0; 20.3 kg/d). Similar interactions of treatment by parity were observed for yields of solids-corrected milk and milk components. CO reduced milk fat (3.1%) and lactose (4.73%) concentrations compared with EB (3.8% and 4.92%), pooled across time and parity. Plasma glucose concentration did not differ among fat treatments and CTRL across the 16 wk. Fat source interacted with parity; INT had the lowest glucose concentration for PP, but highest for MP. During wk 1 to 4 of study, MP had lower plasma glucose than PP (52 vs. 58 mg/dL), which coincided with greater plasma BHBA (7.0 vs. 4.8 mg/dL) and NEFA (710 vs. 380 micro eq/L) concentrations in MP. Body condition loss through wk 4 was greater for CO and CTRL than for INT and EB. Overall, dietary CO reduced DMI compared with EB leading to a greater FA mobilization in early lactation. PARTICIPANTS: D. K. Beede, Dept Animal Science, Michigan State University; and, M. Hollmann, Dept Animal Science, Michigan State University in graduate student training. TARGET AUDIENCES: The work reported was specifically targeted to dairy science/nutrition researchers and professional dairy nutritionists. PROJECT MODIFICATIONS: none

Impacts
Different staturated fatty acid sources, differing in chain length had marked effects on lactational performance and nutrient metabolism of dairy cows. Coconut oil reduced dry matter intake and milk yield to a greater extent than a commercial product with predominantly 18 carbon saturated fatty acid. Coconut oil, though causing significant reduction in enteric methane production, is not efficacious to lactational performance; therefore, its potential benefit in commercial dairy production is low.

Publications

• Hollmann, M. and D. K. Beede. 2009. Dietary coconut oil and animal fat blend decrease lactational performance of Holstein cows fed a high starch diet. Tri-State Nutrition Conf. page 167, Ft. Wayne, IN. (abstr).
• Hollmann, M. and D. K. Beede. 2009. Potential to reduce methane emission from dairy cattle in the U.S.: A life-cycle analysis. Graduate Academic Conference, Michigan State University, MI. http://www.msugac.com/ abstract.html (verified Dec. 10, 2009). (abstr).
• Hollmann, M. and D. K. Beede. 2010. Source of dietary saturated fatty acids and parity influence dry matter intake and energy partitioning in Holstein dairy cows. J. Dairy Sci. 93 (E-Suppl. 1): 232.
• Hollmann, M. and D. K. Beede. 2010. Limited suitability of dietary coconut oil to reduce enteric methane emission from dairy cattle. Proc. 4th International Conf. on Greenhouse Gases and Animal Agriculture, Banff, AB, Canada. Pp 112. (Abstr).
• Knowlton, K. F., D. K. Beede and E. Kebreab. 2010. Phosphorus and calcium requirements of ruminants. Pages 112-132 in Phosphorus and Calcium Utilization and Requirements in Farm Animals. D.M.S.S. Vitti and E. Kebreab, eds. CAB International, Walligford, UK.
• Hollmann, M., M. S. Allen, and D. K. Beede. 2010. Diet fermentability influences lactational performance responses to corn distillers grains: A meta-analysis. J. Dairy Sci. 94: (accepted). Hollmann, M., M. S. Allen, and D. K. Beede. 2010. Dietary protein quantity and quality affect lactational responses to corn distillers grains: A meta-analysis. J. Dairy Sci. 94: (accepted).
• Beede, D. K. 2009. Solving bad water problems for thirsty cows. Proc. Western Dairy Management Conf. Pp. 217-225.

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: An intensive study was done to examine the effects of dietary coconut oil (CO; source of medium-chain fatty acids) on enteric methane emissions. Twenty-four lactating Holstein cows in two blocks of 12 cows each were allocated randomly in a balanced design to 12 possible dietary treatment sequences in 2 periods of 35 d each. Dietary treatments were 0.0 (Control), 1.3, 2.7, or 3.3% CO, dry basis. Other dietary components included corn and alfalfa silages, ground dry corn, heat-processed soybean meal, soy hulls, wheat middlings, minerals, and vitamins. Control diet contained 16.5% crude protein (60% from RDP), 34% NDF (71% from forage), and 31% starch, dry basis. Cows were housed, fed, and milked individually in environmentally-controlled chambers from d 22 through 35. Air flux and respective temperature and relative humidity of each chamber were measured during a 5.5-min cycle every 3 h. Simultaneously, a photoacoustic analyzer detected methane concentrations in inlet and outlet air 3 to 6 times, adjusted to standard temperature and pressure. Methane emitted was computed from the difference in concentrations of inlet and outlet air, and flux. Subsequently, data were averaged within cycle and the average was weighted by the number of observations. Statistical analyses were conducted using mixed effects models, including the fixed effects of period, block, dietary treatment, potential carryover effects, day, and time of day, and relevant 2- and 3-way interactions; random effects were fitted to account for appropriate experimental units of each fixed effect factor. Methane emission (L/cow per day) was reduced by as much as 46% by increasing the concentration of CO in the diet (0.0 vs. 3.3% CO, linear decrease; P < 0.01). Similarly, methane emitted per kg feed dry matter consumed declined as much as 24%. However, daily dry matter intake, milk yield and fat-corrected milk yield also declined as dietary CO concentration increased. Expressed as the ratio of methane emitted per unit of fat-corrected milk produced, the ratio declined (compared with 0.0% CO) 6, 19, and 29% as dietary CO concentration increased from 1.3, 2.7, and 3.3%, respectively. Coconut oil also reduced milk fat concentration and yield, but had no effect on milk true protein concentration or yield. PARTICIPANTS: D. K. Beede, Michigan State University, Professor; W. Powers, Michigan State University, Professor; M. Hollmann, Michigan State University, PhD graduate research assistant. This work is part of the graduate training of M. Hollmann. TARGET AUDIENCES: The work reported was specifically targeted to dairy science/nutrition researchers and professional dairy nutritionists. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
These findings emphasize: 1) that it is possible to markedly reduce enteric methane emissions of lactating dairy cows; 2) that in the case of feeding coconut oil, feed intake and milk production also declined, at least partially accounting for the reduction in enteric methane emissions, and 3) that based on preliminary analysis more cows and replacements would be required to maintain the same national milk production, thus erasing much of the reduction in enteric methane emissions of individual cows and the national dairy herd.

Publications

• Hollmann, M., W. J. Powers, A. Fogiel, N. M. Bello, J. S. Liesman, and D. K. Beede. 2009. Increasing Dietary Concentration of Coconut Oil Reduces Enteric Methane Emission from Lactating Holstein Cows. J. Dairy Sci. 92: (Suppl 1.)343.

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: Coconut oil (CO), a potential dietary fat source containing a high proportion of medium-chain fatty acids is known to reduce methane production in the rumen. However, little is known about the impact of CO on lactational performance. Our objectives were to evaluate supplementation of dietary lipids in a high-starch diet fed to mid-lactation Holstein cows and to compare the incremental replacement of an animal fat blend (AFB) with CO. Thirty-two multiparous Holstein cows were adapted for 4 weeks to a basal diet (CONTROL) with 60% concentrate: 28% corn silage: 12% alfalfa silage and hay, dry basis. CONTROL was formulated to contain: 16.5% CP (10.1% RDP and 6.4% RUP), 27.4% NDF (67% of NDF from forage), 3.0% fat, and 36.8% starch, dry basis. During the last week of adaptation, performance variables were measured daily to use in covariate analysis of the experimental data. Cows were blocked by covariate milk yield and assigned to one of four iso-nitrogenous diets (n = 8 per treatment): CONTROL; 5% AFB; 2.5% AFB: 2.5% CO; or, 5% CO, dry basis. When fat was substituted for dry ground corn, corn gluten meal was added to maintain N content of all diets. Measurements of lactational performance and milk composition were monitored during 3 weeks of feeding treatment diets. However, dry matter intake and milk yield dropped 39% and 24%, respectively, within 3 days with 5% CO; those cows were removed from the study on d 6; their data were excluded from statistical analysis. Dry matter intake, unadjusted milk yield, energy-corrected milk yield, milk fat percentage and yield, milk protein yield, milk lactose percentage and yield, and solids-not-fat yield all were reduced by AFB or AFB-CO compared with CONTROL. Milk protein and solids-not-fat percentages were not affected by dietary fat inclusion compared with CONTROL. Cows responded similarly to AFB vs. AFB-CO, expect for milk fat percentage and yield; in which case each was depressed more by the mixture compared with AFB. In general in this preliminary study with a relatively high starch-diet supplementing relatively large amounts of fat from CO, AFB-CO, or AFB depressed dry matter intake, milk yield, and milk component yields and percentages. Additionally, replacing AFB partially with CO (the mixture) reduced milk fat content and yield even more. PARTICIPANTS: D. K. Beede, Michigan State University, Professor. M. Hollmann, Michigan State University, graduate research professor. This research work was part of the graduate training of M. Hollmann. TARGET AUDIENCES: At this stage of the project, the work targets mainly the dairy science research community. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
In this preliminary study assessing the effects of feeding coconut oil at 5% of the dry matter in a high starch diet to lactating dairy cows, dramatic negative effects of fat feeding on lactational performance occurred. We conclude that the 5% feeding rate is too great for practical feeding and would never be recommended for practical use. Lower feeding rates (e.g., less than about 4% of dietary dry matter) will be studied subsequently.

Publications

• Hollmann, M., and D. K. Beede. 2008. Dietary coconut oil and animal fat blend decrease lactational performance of Holstein cows fed a high starch diet. J. Dairy Sci. 91 (E-Suppl 1):331; J. Anim. Sci. 86: (E-Suppl 2):331.

Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: Increasing supply of corn distiller's grains (DG) has raised questions regarding the extent to which they can be used in dairy cow diets. A database was created of treatment means (n = 122) reported in 23 peer-reviewed journal articles published between 1982 and 2006. The database included 4% fat-corrected milk yield (FCM) response to DG treatment compared with control (no DG), DG (% of dietary DM), and various indicators of diet fermentability including forage type, concentration of cereal grain in DG diet, and grain fermentability. Forage type was classified as alfalfa (n = 27), corn silage (n = 49), or a mixture of each (n = 46), grain concentration was classified as high (> 20% of dietary DM; n = 34) or low (&#8804; 20 % of dietary DM; n = 13), and grain fermentability was classified as high moisture corn (HMC; n = 9) or dry corn (DC; n = 38); responses with diets including more than one grain source (n = 8) were eliminated from the analysis. Supplementation of DG ranged from 4.2 to 42% of dietary DM. Response to DG ranged from -5.0 to 5.6 kg/d for FCM (mean = 0.6 kg/d), but response was not related to DG concentration of diets (P > 0.15). Fat-corrected milk yield was affected by forage type (P < 0.001), percent grain (P < 0.01), and grain fermentability (P < 0.03); these three factors explained 56% of the variation in FCM from DG supplementation. Among forage types, FCM response to DG was greatest for alfalfa (2.6 kg/d), lowest for corn silage (-2.1 kg/d), and intermediate for the mixture (1.3 kg/d). Response of FCM to DG was greater when concentration of corn grain in the diet was low (1.5 kg/d) compared with high (-0.2 kg/d) and for DC (1.1 kg/d) compared with HMC (0.1 kg/d). Increasing fermentability of forages (corn silage > alfalfa), corn grain (HMC > DC), and increasing the grain concentration of diet resulted in lower and sometimes negative FCM responses to DG supplementation. Fat-corrected milk yield response to DG supplementation is likely greatest when diet fermentability is limited. PARTICIPANTS: D. K. Beede, principal investigator; M. Hollmann, graduate research assistant TARGET AUDIENCES: dairy producers; professional dairy nutritionists; commercial corn ethanol plant managers and owners

Impacts
This research illustrates that the milk yield response to inclusion of corn distiller's grains (with solubles) is dependent on the overall fermentability of the diet as defined by a) amount of corn grain in the diet, b) type of forage (alfalfa vs. corn silage). or c) high moisture corn in the diet. Increasingly (higher) ration fermentability had a negative effect on milk yield, and indicated that relatively low concentrations (<10% of DM) of corn distiller's grains can be used without deleteriously affecting lactational performance. Based this relationship, less corn distiller's grains with solubles can be included effectively in rations of lactating cows without depressing lactational performance; less than most commercial ethanol producers and dairy producers had hoped.

Publications

• Edgecomb, A., and D. K. Beede. 2007. Survey of Michigan dairy farmers perceptions about lameness. Michigan Dairy Review 12:3:4-5.
• VandeHaar, M. J., H. F. Bucholtz, D. K. Beede, M. S. Allen, and R. D Kriegel. 2007. Spartan dairy ration evaluator/balancer version 3: A user-friendly windows-based software program for dairy nutrition management. J. Dairy Sci. (Suppl. 1):604.
• Hollmann, M., D. K. Beede, and M. S. Allen. 2007. Increased diet fermentability reduces production response to corn distillers grains in lactating cows: A statistical analysis. J. Dairy Sci. 90(Suppl. 1):452.
• Beede, D. K., M. Hollmann, and H.F. Bucholtz. 2007. Tips for feeding corn distillers grains to dairy cattle. Michigan Dairy Review 12:1:10-11.

Progress 01/01/06 to 12/31/06

Outputs
The model approach of predicting P excretion from dairy cattle as (intake P - milk P) has been developed in this project and now is widely accepted in Michigan and the U.S.A. as a component of the "mass balance" approach to estimate the amount of P in manure for planning fertilization strategies and development of comprehensive nutrient management plans. The "RootZone" campaign/ publications in Michigan were produced and distributed embracing and using a portion of the research from the project. Also, in another line of research in the project it was demonstrated that feeding 0.21% phosphorus (P) (34 g of P/cow daily) prepartum is adequate for periparturient multiparous Holstein cows with high metabolic demands and genetic potential for milk production. Results from research work have been transferred to professional dairy nutritionists and dairy producers in Michigan and elsewhere to provide evidence that feeding late pregnant dry cows at the NRC (2001) recommendations for P is adequate to achieve normal metabolic performance in transition from pregnancy to lactation and to reduce ration P use and P excretion compared with previous practice that was common.

Impacts
Implemented P-prediction model developed and tested in research for field application to improve the accuracy of P management and comprehensive nutrient management planning compared with previous approaches (e.g., sampling and analysis of P in manure lagoons). This facilitated more precise and accurate feeding of P in dairy rations and increased the accuracy of and number of nutrient management plans (voluntary) written in Michigan. Ultimately, this work will reduce the amount of manure P excreted and reduce the risk of P being a pollutant in/from dairy farms in neighboring aquatic ecosystems.

Publications

• Beede, D. K. 2006. Evaluation of water quality and nutrition for dairy cattle. Proc. High Plains Dairy Conf. pp 129-153.
• Mussell, B. A., D. K. Beede, J. J. Domecq, W. B. Epperson, A. Ragavendran, N. T. Wright, and A. J. Zanella. 2006. Use of infrared thermography to non-invasively identify lesions in dairy cows. J. Dairy Sci. 89 (Suppl. 1): 143.
• Edgecomb, A. M., C. L. Wickens, A. J. Zanella, and D. K. Beede. 2006. Dairy farmers perceptions and attitudes about lameness. J. Dairy Sci. 89 (Suppl. 1): 411.
• Rozeboom, D., and D. K. Beede. 2006. Keep water-soluble phosphorus in the root zone. Proc. 2006 Great Lakes Manure Handling Expo, Keep It in the Root Zone (pp 2-3) and www.rootzone.msu.edu

Progress 01/01/05 to 12/31/05

Outputs
Objective was to compare the effects of different prepartum dietary phosphorus concentrations on periparturient metabolism and performance. Forty-two late pregnant multiparous Holstein cows were fed 0.21, 0.31, or 0.44% P (dry basis) for 4 wk before expected calving. After parturition, all cows were fed a common lactation diet (0.40% P). In the prepartum period, cows fed 0.21% P had lower blood serum P concentrations compared with cows fed 0.31 or 0.44% P. However, serum P concentrations of all cows were within the normal range (4 to 8 mg/dl) until the day of calving when average concentrations of cows in all treatments dropped below 4 mg/dl. From 3 to 14 d postpartum, serum P of cows fed 0.21% P was greater than that of cows fed 0.31 or 0.44% P. No cows presented or were treated for clinical hypophosphatemia in the periparturient period. Total serum Ca was lower before calving through 2 d postpartum for cows fed 0.44% P compared with those fed 0.21 or 0.31%. Prepartum dietary P treatments did not alter blood osteocalcin, hydroxyproline and deoxypyridinoline, indicators of bone metabolism, or concentrations of parathyroid hormone or 1, 25-dihydroxyvitamin D3. Energy-corrected milk yield and milk composition (first 28 d of lactation) were not affected by prepartum dietary P concentrations. It is concluded that feeding 0.21% P (34 g of P/cow daily in this experiment) prepartum is adequate for periparturient multiparous Holstein cows with high metabolic demands and genetic potential for milk production. No adverse effects on periparturient health, DMI, or 28-d lactation performance resulted.

Impacts
This research verifies the NRC (2001) phosphorus (P) feeding recommendations for late, pregnant (close-up) dairy cows, and indicates benefits of reduced P-feeding requirements and recommendations for professional dairy nutritionists and farmers in Michigan and across the United States. Compared with previous practices (typically over-feeding), the new practice reduces the amount of P excreted in manure during this stage of the lactation cycle (periparturient period) and improves the metabolic well-being of cows during the transition from pregnancy to lactation. Overall, the new practice improves the health of animals, the efficiency of milk production, and reduces risk of P-pollution to the environment, benefiting dairy farmers and society.

Publications

• Peterson, A. B., M. W. Orth, J. P. Goff, and D. K. Beede. 2005. Periparturient responses of multiparous Holstein cows fed different dietary phosphorus concentrations prepartum. J. Dairy Sci. 88:3582-3594.
• Pfeffer, E., D. K. Beede, and H. Valk. 2005. Phosphorus metabolism in ruminants and requirements of cattle (Chapter 7). In: Nitrogen and Phosphorus Nutrition of Cattle and the Environment. E. Pfeffer and A. Hristov, eds. CABI Publishing, CAB International, Wallingford, Oxfordshire, OX10 8DE, UK. pp 195-231.
• Sanchez, W. K., and D. K. Beede. 2005. Recent advances in the use of dietary cation-anion differences (DCAD) for transition dairy cows (Chapter 12). In: Recent Advances in Animal Nutrition 2004. P.C. Garnsworthy and J. Wiseman, eds. Nottingham University Press, Nottingham, NG11 0AX, UK. pp 201-222.
• Myers, Z. H., and D. K. Beede. 2005. Estimate of phosphorus (P) maintenance requirement of lactating dairy cows over a range of feed intake rates. J. Dairy Sci. 88(Suppl. 1):223.
• Myers, Z. H., and D. K. Beede. 2005. Evaluation of models to predict phosphorus (P) excretion of dairy cattle fed a range of P concentrations during different stages of the dry period and lactation. J. Dairy Sci. 88(Suppl. 1):247.

Progress 01/01/04 to 12/31/04

Outputs
The objectives were to evaluate the effect of varying dietary P concentrations on P balance and utilization of lactating and non-lactating Holstein cattle and to construct a dataset for future research to evaluate P excretion prediction models. A series of seven 30-day experiments were conducted. Experiments were designed so that P balance data were collected at various points of the lactation cycle. Experiments 1 and 2 were conducted with 21 pregnant nulliparous heifers at 57 and 28 days prior to parturition, respectively. Experiments 3 and 4 were conducted with 21 pregnant non-lactating primi- and multiparous cows at 59 and 30 days prior to parturition, respectively. Experimental treatments in Experiments 1 through 4 were diets with 0.19 (low; LP), 0.28 (moderate; MP), and 0.35% P (high; HP), dry basis. Experiments 5, 6, and 7 each consisted of 35 lactating primi-and multiparous cows. In Experiment 5 cows averaged 97 days in milk (DIM), in Experiment 6 cows averaged 183 DIM, and in Experiment 7 cows averaged 294 DIM. Experiments 5, 6, and 7 were designed to have different DIM so that DMI and MY theoretically would be different, so that P intake, utilization and excretion would differ for future modeling work. However, the dry matter intake (DMI) range desired did not occur. Therefore, DMI was restricted in Experiment 7 to the NEL intake required to support MY measured during the first 21 d of the experiment for any cow producing less than 25 kg/d. Cows producing greater than 25 kg/d were allowed to consume ad libitum. Dry matter intakes during the 5-d collection period for Experiments 5, 6, and 7 were 19.8, 19.3, and 17.8 kg/d, respectively. Treatment groups for Experiments 5, 6, and 7 were fed diets with 0.27 (T1), 0.36 (T2), 0.42 (T3), 0.46 (T4), and 0.52% P (T5), dry basis. In all experiments, fecal P concentration and fecal P excretion increased with increased dietary P concentration and ranged from 0.43 to 2.21% P, respectively, for Experiments 1 through 4 and 0.40 to 1.54, respectively, for Experiments 5 and 6. The effect of dietary P concentration on urine P concentration and excretion was small but inconsistent and averaged 0.0012% P and 0.82 g P/d for Experiments 1 through 4 and 0.0063% and 1.65 g P/d for Experiments 5 and 6. In general, P balance decreased with increased dietary P concentration in all experiments. Milk yield was not affected by dietary P content in Experiments 5 or 6 (P > 0.05). Three datasets will be constructed from the data collected in these experiments to use in subsequent research to evaluate various published models for predicting P excretion.

Impacts
This research provides new P excretion and balance data over a wide range of dietary P concentrations and intakes with cattle in different physiological states. These data are being used to model P excretion of non-lactating and lactating dairy cattle. The new data also are being used to test the accuracy, precision and bias of previously published P excretion models. The ultimate impact of this work is to predict P excretion from dairy cattle so that dairy farmers and dairy farm planners can use the results for nutrient management planning and to reduce P excretion into the environment.

Publications

• Beede, D. K. 2003. Dairy producers: Balancing phosphorus, your farms future. Michigan Dairy Review. 8(1):2-4.
• Beede, D. K. 2003. Real costs of byproduct feeds? Michigan Dairy Review. 8(1): 5.
• Beede, D. K., and A. B. Peterson. 2003. Optimal dietary phosphorus for close-up cows. Michigan Dairy Review. 8(4):20-22.
• Beede, D. K. 2003. Nutritional management of phosphorus for environmental sustainability in dairy and beef systems. Proc. California Animal Nutrition Conf. pp 56-63.
• Beede, D. K. 2003. Ration phosphorus management: Requirements and excretion. Four-State Applied Nutrition and Management Conf. pp 145-152. LaCrosse, WI, July 9, (MWPS-4SD16).

Progress 01/01/03 to 12/31/03

Outputs
This past year a focus of the project was to evaluate estimates of the phosphorus (P) maintenance requirement of lactating dairy cows. By definition, endogenous fecal P excretion of ruminants fed very near its true P requirement is the major component of the total P maintenance requirement. Inevitable fecal P includes endogenous fecal P plus unavailable dietary P excreted in feces. It is expressed as g of fecal P/kg of dry matter intake (DMI). The NRC (2001) set the P requirement for maintenance at a constant 1.2 g P/kg DMI. Twenty-one lactating Holstein cows with a wide range of milk yields and DMI rates (DMIR) were in the study. Additionally, some cows in mid- to late-lactation were restricted to 75 and 50% of their pre-trial ad libitum feed intakes to ensure a wide range of DMIR. Treatments, based on DMIR during the study, were 11.3, 15.3, and 25.1 kg/d, for Treatment 1 (T1), Treatment 2 (T2), and Treatment 3 (T3). All cows were fed the same low P diet (0.26% P, dry basis) so that total P intake was low relative to requirement. Phosphorus balances averaged 1.5 g/d among all cows on all treatments and were not different among treatments; nor, were balances different from zero. Average daily total inevitable fecal P excretion was 15.3, 18.2, and 26.3 g/cow and inevitable fecal P excretion (g/kg DMI) was 1.36, 1.19, and 1.04 for T1, T2, and T3, respectively; and, decreased slightly, but linearly with increasing DMIR. Regression equation to predict inevitable fecal P excretion across a range of DMIR was: (g/d) = [0.85 +/- 0.070 (g/d)] X DMI (kg/d) + [5.30 +/- 1.224 (g/d)]; (RMSE = 2.75 g/d; R2 = 0.90; P < 0.01). This equation can be used to estimate the inevitable fecal P component of the total P requirement for maintenance of lactating cows. It will be useful to validate this relationship with other independently collected data sets.

Impacts
This research basically confirms the new approach to determining and the estimate of phosphorus (P) maintenance requirement for lactating dairy cows (National Research Council, 2001). These new results help fine-tune the original estimate as a function of varying dry matter intake. These results can be used to help more precisely feed lactating dairy cows to reduce fecal excretion of P into the environment.

Publications

• No publications reported this period

Progress 01/01/02 to 12/31/02

Outputs
Few research results have been published on the effects of varying prepartum dietary P concentrations on cows during the periparturient period. We hypothesized that feeding 0.21% dietary P from 28 d prepartum until parturition is adequate to meet the requirements of the periparturient multiparous Holstein cow without adverse metabolic or production effects. The objective of this study was to compare the effects of varying prepartum dietary P concentrations on peripartum mineral element metabolism and lactational performance of multiparous Holstein cows. Forty-five nonlactating, pregnant multiparous Holstein cows were used in a randomized block design. Cows were blocked according to parity and expected calving date (ECD) to one of three prepartum dietary treatments. Diets containing 0.21, 0.31, and 0.44% P, dry basis, were fed for 28 d before parturition to 15, 13, and 14 multiparous Holstein cows, respectively. Blood from coccygeal vessels were collected at 0630 h (prior to feeding) every 3 d from 28 d prepartum until 10 d prepartum and daily until parturition. At parturition, blood samples were collected more frequently to better characterize temporal patterns of blood metabolites. Cows fed 0.21% P had lower prepartum serum P concentrations than cows fed 0.31 or 0.44% P. Neither total serum Ca nor plasma ionized Ca was altered by prepartum dietary P concentrations. Cows fed 0.21% P tended to have lower prepartum osteocalcin concentrations than cows fed 0.31 or 0.44% P, suggesting less bone formation. Neither pre- nor postpartum serum deoxypyridinoline concentrations were influenced by dietary treatment, suggesting no effect on bone resorption around parturition. Energy-corrected milk yield during the first 28 d of lactation was not affected by prepartum dietary P treatments. We conclude that a prepartum dietary P concentration of 0.44% was too high because it resulted in lower total serum Ca concentrations around parturition compared with 0.21 and 0.31% P. Cows fed 0.21% P consumed slightly above NRC 2001 requirements at 34 g of P/d. These cows fed 0.21% P prepartum had higher total serum Ca and plasma ionized Ca concentrations around parturition compared with 0.31 and 0.44% P. Energy-corrected milk yield during the first 28 d of lactation was not altered. We conclude that consuming 34 g of P/d (0.21% P in this experiment) was adequate to meet the needs of the periparturient multiparous Holstein cow.

Impacts
Dietary phosphorus (P) is often over-fed to late pregnant dry cows. This practice may result in metabolic disorders and compromise performance in the next lactation, and definitely increase excretion of excess phosphorus (P). This research clearly demonstates that feeding P at NRC (2001) recommendations (lower than typically fed) is adequate and will reduce excretion of excess P and improve periparturient health of multiparous Holstein cows.

Publications

• Peterson, A.B., Beede, D.K. 2002. Periparturient responses of multiparous Holstein cows to varying prepartum dietary phosphorus. J. Dairy Sci. (Suppl. 1) 85:187.

Progress 01/01/01 to 12/31/01

Outputs
Objective was to determine the effects on peripartum metabolic and health responses, and lactation performance of feeding graded concentrations of Ca without or with supplemental chloride for 3 wk before calving. Pregnant animals (n=420) in two research farms were blocked by parity and assigned randomly to one of five dietary treatments (trt). Postpartum parities were: 164 first; 82 second; and, 174 third and greater. Prepartum basal diet fed once daily was 18% alfalfa haylage: 42% corn silage: 40% concentrate. A mixture (16.7% of dietary DM) of HCl-treated, heat-extruded soybean meal (HCl-HESBM) and non-HCl-treated-HESBM was used to vary cation-anion difference (CAD; meq[(Na + K) - (Cl + S)]/100 g of dietary DM). Graded amounts of calcium carbonate were used to vary dietary Ca content. For the entire experiment, average analyzed Ca (%) and CAD of each trt were: (A) 0.47, +18; (B) 0.47, -4; (C) 0.98, -4; (D) 1.52, -4; and (E) 1.95, -4. Weekly urine pH measurements were used to adjust proportions of HCl-HESBM and non-HCl-treated-HESBM to maintain pH between 6.0 and 6.7 for B, C, D, and E. Urine pH the week before calving was 8.1 vs. 6.4, 6.6, 6.6, and 6.6 for A vs. B, C, D, and E (P<0.001). Prepartum DMI was greater for A, B, and C than for D and E (P=0.01). Caudal vein blood was collected within 24 h after parturition. Plasma ionized Ca was: 4.29 vs. 4.39, 4.43, 4.53, and 4.52 mg/dl for A vs. B, C, D, and E (P=0.02). Plasma Cl was higher for cows fed B, C, D, and E compared with A throughout the prepartum period (P < 0.001). Pre- or postpartum body condition and udder edema scores, cow BW, calf birth weight, and colostrum score were not affected by trt. Overall incidence rates (all parturitions) of ketosis (16.7%), retained placenta (12.2%), milk fever (7.7%), hypocalcemia (16.8%), abomasal displacement (10.3%), and mastitis (7.2%) were not affected by trt. Incidence of clinical milk fever was greater in third and greater parity cows in A vs. B, C, D, and E (P<0.08). Average postpartum DMI (19.8 kg/d) and milk yield (35.7 kg/d) through 70 DIM were not affected by trt. Overall, peripartum health and performance responses were optimum when the anion-supplemented diet (CAD = -4 meq/100 g of dietary DM) contained 0.98% Ca when supplemental Ca was from calcium carbonate.

Impacts
This new research information will help improve phosphorus and calcium utilization by transition dairy cows and reduce the incidience rates of metabolic disorders associated with phosphorous and calcium homeostasis around the time of calving in commercial dairy operations.

Publications

• Beede, D.K., T.E. Pilbeam, S.M. Puffenbarger, and R.J. Tempelman. 2001. Peripartum responses of Holstein cows and heifers fed graded concentrations of calcium (calcium carbonate) and anion (chloride) 3 weeks before calving. J. Dairy Sci. 84 (Suppl. 1):83.

Progress 01/01/00 to 12/31/00

Outputs
Pregnant cows ( n = 189) in two commercial dairy farms were randomly assigned to be fed energy-dense diets for either 3 or 6 wk before expected calving dates. Cows fed the diet for less than or equal to 26 d were designated the short (S) treatment group, and those fed greater than 26 d were the long (L) treatment group. Cows in L tended to have improved energy status during the first 2 wk postpartum, as indicated by lower plasma beta-hydroxybutyrate concentrations. Cow in L tended to gain more body condition during the late dry period. Total body condition loss from parturition through 6 wk postpartum was not different between treatments, but the rate of change varied over this period. Cows in S lost more body condition during the first 3 wk postpartum than cows in L. On farm 1 only, cows in L lost more body condition from 3 to 6 wk postpartum and had a higher incidence of metritis and a longer interval to first service than cows in S. Cows in L had higher milk protein content through 60 d in milk compared with cows in S. Additionally, cows in L in farm 1 produced 4.4 kg/d less milk, tended to have lower milk fat content and yields, and higher somatic cell counts through 150 d in milk than cows in S. Overall, increasing length of time cows were fed the energy-dense diet prepartum elicited significant changes in farm 1, but had little effect in farm 2. Based on these results, L treatment may improve energy status immediately postpartum, but long-term effects varied between farms, perhaps due to other unmeasured management differences.

Impacts
Results from this research will dairy cows suggest that a longer period of feeding of a high energy diet immediately before calving may improve energy status immediately postpartum. However, results were different in one commerical farm compared with the other, perhaps due to other unmeasured management differences.

Publications

• Mashek, D.G., and D.K. Beede. 2001. Peripartum responses of dairy cows fed energy-dense diets for 3 or 6 weeks prepartum. J. Dairy Sci. 84:115-125.
• Moore, S.J., M.H. VandeHaar, B.K. Sharma, T.E. Pilbeam, D.K. Beede, H.F. Bucholtz, J.S. Liesman, R.L. Horst, and J.P. Goff. 2000. Effects of altering dietary cation-anion difference on calcium and energy metabolism in peripartum cows. J. Dairy Sci. 83:2095-2104.

Progress 01/01/99 to 12/31/99

Outputs
With increased use of anion supplementation for late pregnant cows, the optimum dietary Ca% is unknown. Objective was to compare peripartum metabolic and health status, and lactation responses of late pregnant heifers and cows fed graded concentrations of dietary Ca with negative cation-anion difference (CAD; meq[(Na+K)-(Cl+S)]/100 g DM). Pregnant animals (n = 246) in two research farms were blocked by parity to one of five dietary treatments (trt) fed 19 d prepartum. Postpartum parity distribution was: 88 first; 50 second; and, 108 third and greater. Prepartum basal diet fed once daily was 18 alfalfa haylage: 42 corn silage: 40 concentrates. A mixture (16.7% of dietary DM) of HCl-treated, heated-extruded soybean meal (HCl-HESBM) and HESBM was used to set CAD. Graded amounts of CaCO3 were used to vary dietary Ca%. For the entire experiment (309 d), average analyzed Ca (%) and CAD of each trt were: (A) 0.47, +17.5; (B) 0.47, -4.7; (C) 0.99, -4.9;( D) 1.51, -4.7; and, (E) 1.94, -4.9. In (A), all HESBM and no CaCO3 were added; (B) had no added CaCO3. Weekly urine pH measurements were used to adjust proportions of HCl-HESBM and HESBM to maintain pH between 6.0 and 6.7 for B - E through time. Urine pH the wk before calving was: 8.1 vs. 6.3; 6.6; 6.6; and, 6.5 for A vs. B, C, D, and E (P < 0.01). Prepartum DMI was not affected by trt (12.6 kg/cow per d), but was affected by parity (P < 0.01). Caudal vein blood was collected within 24 h after parturition. Plasma ionized Ca was: 4.32 vs. 4.45, 4.50, 4.50, and 4.55 mg/dl for A vs. B, C, D, and E (P < 0.04). Plasma Cl was higher in B-E than A throughout the prepartum period. Pre- or postpartum body condition and udder edema scores, cow BW, calf birth weight, and colostrum score were not affected by trt. Overall incidence rates of ketosis (25.2%), retained placenta (8.5%), milk fever (6.1%), abomasal displacement (10.6%), or mastitis (5.7%) were not affected by trt. Postpartum DMI was not affected by trt (20.8 kg/cow per d), but was affected by parity (P < 0.01). Milk yield through 70 DIM was not affected by trt (35.1 kg/cow per d), but was affected by parity (P < 0.01).

Impacts
Results of this project indicate that periparturient calcium status was compromised without anion supplementation, but was not affected by varying dietary caclium concentration in diets with anion supplementation. Incidence of postpartum health disorders and feed intake and milk production were not afftected by dietary anion or calcium supplementation. Additional data are being collected to enlarge the dataset before accessing the impact. About 80 parturitions per treatment will be collected and evaluated before completion of the project.

Publications

• Rodriguez, L.A., T.E. Pilbeam, D.K. Beede, and J.P. Goff. 1999. High versus low dietary calcium with negative cation-anion difference prepartum: Effects on peripartum acid-base and calcium status. J. Dairy Sci. 82( Suppl. 1): 68.
• Beede, D.K., T.E. Pilbeam, and S.M. Puffenbarger. 1999. Varying dietary calcium concentration with negative cation-anion difference for late pregnant cows: Effects on peripartum acid-base and calcium status, feed intake, health, and lactational performance. J. Dairy Sci. 82(Suppl. 1):69.

Progress 01/01/98 to 12/31/98

Outputs
Objective was to determine if increasing dietary Ca concentration in a prepartum diet with negative dietary cation-anion difference (DCAD; meq [(Na+K)-(Cl+S)]/100 g of dietary DM) improved periparturient Ca status and mineral metabolism of multiparous Holstein cows. Twenty-two nonlactating, pregnant multiparous Holstein cows were assigned randomly to two dietary treatments 28 d before expected day of calving. Before parturition, totally mixed diets were 18% alfalfa silage, 42% corn silage and concentrates (dry basis). Dietary treatments had 0.48% or 1.98% Ca (supplemental CaCO3). The DCAD was( -11.2 meq/100 g of dietary DM) from the inclusion of extruded heat-treated soybean meal treated with hydrochloric acid. After parturition all cows were fed a totally mixed diet containing 21% alfalfa silage, 21% corn silage and concentrates, with 0.98% Ca. Plasma and urine samples were taken daily from 10 d before through 10 d after parturition. Dry matter intake was measured from d 21 prepartum through d 21 postpartum and was not affected by prepartum dietary treatments; however, there was a 30% decrease in DMI from wk 3 prepartum through wk 1 prepartum across both treatments. Cows fed 0.48% Ca had lower plasma pH and bicarbonate concentrations before parturition than cows fed 1.98% Ca prepartum. Cows fed 0.48% Ca had greater plasma Cl concentrations than cows fed 1.98% Ca prepartum. For both treatments, urine pH was lower the week before parturition (about 6.1) compared with the week after parturition (about 8.0). Incidence of clinical hypocalcemia tended to be greater in cows fed 1.98% Ca (36%; P < 0.12) compared with cows fed 0.48% Ca prepartum (9%). Incidence of subclinical hypocalcemia (iCa < 4.0 mg/dl) was greater for cows fed 1.98% Ca (64%; P < 0.03) compared with cows fed 0.48% Ca prepartum (18%). Cows fed 1.98% Ca had greater total plasma Ca from d -10 through d -1, but lower plasma Ca on the day of parturition compared with cows fed 0.48% Ca. Cows had similar plasma ionized Ca concentrations from d -10 through d -1 prepartum regardless of dietary Ca concentration; however, on the day of and the day after parturition, cows fed 1.98% Ca had lower plasma ionized Ca concentrations than cows fed 0.48% Ca prepartum. On d 0 cows fed 0.48% Ca averaged 4.44 mg/dl of plasma iCa compared with 3.68 mg/dl for cows fed 1.98% Ca prepartum. Also, cows fed 1.98% Ca prepartum had greater concentrations of parathyroid hormone and 1,25-dihydroxyvitamin D3 the day of calving and for 2 d after parturition. Peripartum plasma osteocalcin and urine deoxipiridinoline (indicators of bone formation and resorption, respectively) were not different due to prepartum dietary treatments, but each tended to be consistently lower over the entire sampling period for cows fed 1.98% Ca prepartum. Also, cows fed 0.48% Ca had greater plasma concentrations of hydroxyproline from d -10 through d 0 compared with cows fed 1.98% Ca prepartum. Feeding 1.98% Ca prepartum with negative DCAD prepartum increased alkalinity of the blood before parturition and affected Ca metabolism reducing bone Ca mobilization during the periparturient period.

Impacts
(N/A)

Publications

• Rodriguez, L.A. 1998. Periparturient responses of cows fed varying dietary cation-anion differences and calcium contents prepartum. PhD Diss., Michigan State University, East Lansing.

Progress 01/01/97 to 12/31/97

Outputs
Thirty-two multiparous nonlactating, nonpregnant Holstein cows were assigned randomly to treatments. Objective was to investigate responses over time of changing dietary cation-anion difference (DCAD; meq [(Na+K)-(Cl+S)]/100g of DM) with different anion sources and Ca content on dry matter and water intake, and urine pH. Total mixed diets were 20% alfalfa silage, 40% corn silage plus concentrates, dry basis. Dietary treatments were: C (control, no anion source, DCAD=+16.9); B (Bio-chlor); A (a mixture of MgCl2, NH4Cl and (NH4)2SO4 designed to match the anionic contribution of B); and H (HCl); DCAD of treatments with supplemental anions was -7.7. Factored with C, B, A, and H were dietary Ca concentrations of 0.50 and 2.10%, dry basis. Cows were fed C with 0.50% Ca for 14 d before starting treatments. Dry matter and water intake were measured for 7 d before, through 21 d after introduction of dietary treatments. Urine samples were collected daily from d 2 before, through d 7 after introduction of dietary treatments, and on d 14 and 21 of dietary treatment feeding. Pooled across Ca contents, cows fed C tended to have greater DMI than cows fed B, A and H (P<.10). DMI of cows fed H responded differently over time compared with cows fed A (P<.03; day by H vs A interaction). Pooled across anion sources, cows fed low Ca had greater DMI (P<.03) and water intake (P<.02) than cows fed high Ca. Pooled across Ca contents, there was an interaction of day by A vs H for water intake (P<.01). Urine pH of cows fed C remained at 8.0 to 8.2 across the treatment period (21d). Urine pH of cows fed B, A and H responded in a quadratic fashion (P<.01). From d 0 (pH=8.0) to d 2 urine pH dropped to 5.7 on average, and remained below 6.0 through d 7. On d 14 and 21, urine pH remained below 6.0 for H, rose to about 6.0 for A, and increased to 6.3 amd 6.7 for B. Ca content did not affect urine pH. Anion sources decreased urinary pH and tended to decrease DMI over time. High Ca diets decreased DMI across time.

Impacts
(N/A)

Publications

• Rordiguez, L.A., T.E. Pilbeam, R.J. Tempelman, and D.K. Beede. 1997. Responses over time to introduction of different anion sources and calcium concentrations by nonlactating, nonpregnant Holstein cows. J. Dairy Sci. 80(Suppl. 1):241. (Abstr.)