Progress 04/01/99 to 09/30/04
Outputs
Sixty-six Holsteins were blocked by parity and expected calving date and randomly assigned within block to one of six diets. Dietary treatments were fed from 25 days prepartum to 100 days in milk. Treatments were arranged as a 3 x 2 factorial design. Cows received no soybeans, soybeans beginning at calving, or soybeans for the duration of the study. Soybeans were fed raw, cracked beans at feeding rates of 1.9 and 2.8 kg DM per cow per day during pre- and postpartum periods, respectively. RPC was top-dressed once daily at a rate of 0 or 15 g dietary choline per cow per day. Cows were individually fed diets as total mixed rations using electronic feeding gates that allowed daily measurement of feed intake. Body weights and body condition scores were measured weekly throughout the study. Cows were milked twice daily and milk yields were measured electronically. DMI measured during the pre- and postpartum periods were not different. Feed intake of all diets decreased
during the last 3 days of gestation, but recovered quickly after calving. Feeding soybeans starting at calving improved milk yield during early and peak lactation. However, feeding soybeans during the prepartum period decreased milk yield. Changes in body weight and body condition score reflected normal changes for lactating dairy cows during these phases of production. Milk fat percentage was not different due to diet. Analysis of milk protein percentage included a significant interaction between the feeding of soybeans and RPC. Cows fed soybeans for the entire duration of the study had lower milk protein percentage when choline was added to the diet. These results indicate that soybeans can be fed at the start of lactation and give the cows an advantage of added dietary energy. Feeding soybeans during the prepartum period should be limited to less than 4 pounds to reduce the potential negative impact of the fat intake. No differences were measured in ovarian structure (size or
number of follicles). Feeding soybeans at the start of lactation improved the fatty acid and overall lipid balance and led to an increase in blood progesterone.
Impacts
High producing dairy cows are at increased risk of metabolic disorders and disease during the periparturient period. Hypocalcemia (low blood calcium) not only results in loss of milk production, but this condition also predisposes the cow to other disorders such as ketosis, displaced abomasum, retained fetal membranes and metritis. Anionis salts have been used to prevent hypocalcemia, but the salts have a negative affect on feed intake. The decrease in feed intake occurs during a period that the cow experiences a loss of appetite at the same time the animal is experienceing an increase in energy requirement. The use of sulfur and sulfur based anionic salts were found to improve calcium status while maintaining feed intake. This resulted in an increased milk production and imporved health, supporting increased production efficiency and higher profitability.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
The objective of this study was to determine the effect of a commercially available anionic salt supplement providing multiple sources of sulfur and chlorine fed during late gestation on intake, health, and production of Holsteins. Twenty-six mature cows were pair by expected calving date, lactation number, milk production potential, and body weight. Cows within pair were then randomly assigned to one of two diets. The dietary treatments were control (C) and supplemental anionic salt (A). Cows were fed the experimental diets as TMR via electronic feeding gates. Control diet was formulated to achieve a Dietary Cation-Anion Difference (DCAD) of +20 mEq/100 g dry matter. Control diet was predicted to provide 70g of calcium per cow per day. The treatment group was fed 454g per cow per day of a commercially formulated anionic salt supplement which lowered the DCAD level to -10 mEq/100 g dry matter. Treatment diets were formulated to provide a daily intake of 150g of
calcium per cow per day. Diets were fed 30 days prior to expected day of calving. At calving, cows were fed standard lactation TMR for the first 6 weeks of lactation. Feed intake was measured daily. Urine pH was monitored twice each week using an electronic pH meter. Blood samples were collected weekly prepartum as well as on day -3 and day of calving. Postpartum blood samples were collected on day 1, 3, 7, 10 and 14 of lactation and then weekly until day 42. Blood samples were analyzed for Ca and NEFA. Daily milk yields and weekly milk component data were also collected. These data were analyzed for significance using SAS PROC MIX method. Cows fed anionic salts had lower urine pH compared to control cows (6.78 vs. 8.29; P<0.0001). Blood calcium was higher for anionic salt fed cows compared to control cows (8.70 vs. 8.53 g/dl; P=0.061). Plasma NEFA were lower for cows fed anionic salt diet (292 vs. 402 millieq/l; P < 0.01). Milk was greater over time for cows fed anionic salts versus
control cows (P = 0.0434). Supplementation with a commercially available anionic salt supplement providing multiple sources of sulfur and chlorine improved calcium and energy balance associated with significant increase in milk production
Impacts
High producing dairy cows are at increased risk of metabolic disorders and disease during the periparturient period. Hypocalcemia (low blood calcium) not only results in loss of milk production, but this condition also predisposes the cow to other disorders such as ketosis, displaced abomasum, retained fetal membranes and metritis. Anionis salts have been used to prevent hypocalcemia, but the salts have a negative affect on feed intake. The decrease in feed intake occurs during a period that the cow experiences a loss of appetite at the same time the animal is experienceing an increase in energy requirement. The use of sulfur and sulfur based anionic salts were found to improve calcium status while maintaining feed intake. This resulted in an increased milk production and imporved health, supporting increased production efficiency and higher profitability.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
The use of energy for milk production by dairy cows has compromised fertility. Additionally, the period around calving is characterized by a period of negative energy balance. Feeding additional fat and vitamins may improve energy balance and fertility in high-producing dairy cows. This experiment examined the effects of feeding soybeans and rumen protected choline to dairy cows during the transition period on milk production and reproduction. Cows fed choline consumed less feed and produced more milk without losing more body weight or body condition compared to cows not fed choline. Blood parameters indicated that cows fed choline were in better energy balance. Cows fed choline also had improved reproductive function. Choline may be used to improve efficiency of energy use for milk production and reproduction of dairy cows. Cows fed soybeans before calving had lower feed intake and milk yield than cows fed soybeans at the beginning of lactation. Feeding soybeans did
improve energy balance. Changes in plasma lipids during the transition period were characterized. Although cows fed soybeans had increased plasma lipids, there was no change in reproductive function. Soybeans can be used as an energy supplement for lactating dairy cows, but feeding should be started at calving.
Impacts
Improved use of vitamins and soybeans will improve the feeding management of dairy cattle. Improved health and reproduction while achieving higher levels of milk yield will imporve the profitiability of commercial dairy farms.
Publications
- Scheer, W.A., M.C. Lucy, M. Kerley, and J.N. Spain. 2002. Effects of feeding soybeans and rumen protectes choline during late gestation and early lactation on performance of dairy cows. J. Dairy Science 85(SUppl.1):276. (abstract).
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Progress 01/01/00 to 12/31/00
Outputs
Dairy cattle experience a significant physiological, endocrine, and metabolic transition during the periparturient period. Associated with these changes is a dramatic change in nutrient demand associated with initiation and maintenance of lactation. The changes in nutrient requirements require a significant alteration of the diet fed to the cows during the prepartum and early postpartum phases of production. A primary challenge that must be addressed is the nutritional management strategies employed for these cows during the periparturient period. One key objective of the dietary management scheme is to adapt ruminal microorganisms during late gestation in preparation for the high starch diet fed during early lactation. While adapting the ruminal microflora, pre and postpartum diets and their combination of feeding sequence should minimize the risk of ruminal acidosis stimulating feed intake and concurrently stimulating growth of ruminal mucosa tissue. An in vitro
study has been designed to investigate the effects of source of dietary carbohydrate used in prepartum diets on ruminal fermentation. A single flow continuous culture system is being used to simulate rumen fermentation. The fermentors are maintained at 39C with continuous purging with carbon dioxide. Peristaltic pumps supply a constant infusion of artificial salivary buffer to control pH while establishing a flow rate of 3% per hour. Eight dietary treatments include four different combinations of carbohydrate sources with or without supplemental live yeast culture. Treatment combinations of carbohydrate sources and yeast are arranged as a 4x2 factorial arrangement of a complete block. All dietary ingredients are combined as a total mixed diet and fed at a rate of 30g per day. Fermentors are fed 10g per day at 0700, 1500, and 2300 hours. Experiment design includes three 7-d replicates including a 4 day adaptation phase followed by a 3 day sampling period. Fermentor pH is measured at
0700 before morning feeding and then 2, 4, and 6 hours after morning feeding. Effluent discharge is collected during the 3 day sampling period of each replicate. Effluent samples will be analyzed for DM, OM, N, ADF, NDF, ash and purines. On the final day of each replicate, fermentors will be stopped by adding 40 ml of a formaldehyde solution (37%). Fermentor contents will be blended using a commercial blender to stimulate the release of particulate-associated bacteria. Differential centrifugation will be used to isolate microorganisms for measurement of DM, OM, N, ash, and purines. Results of this study will be used to develop recommendations for formulation of diets to be fed to dairy cattle during the last four weeks of gestation.
Impacts
Results of this study will improve the dietary management strategies employed for the formulation of diets to be fed to periparturient dairy cows. Improved nutritional management of dairy cattle during this critical production phase will improve animal health, milk production, and reproduction. Improved animal health and increased milk production coupled with decreased animal health, culling, and breeding costs will improve economic sustainability of the dairy farm enterprise.
Publications
- No publications reported this period
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Progress 01/01/99 to 12/31/99
Outputs
Two studies were conducted to investigate the role of polyunsaturated fatty acids supplied from raw soybeans would affect milk production and reproduction of lactating holstein cows during early lactation. A fermentation study was conducted using ruminally fistulated lactating holsteiins. A concurrent production study was initiated using 90 early lactation holstein cows. Diets fed to the fistulated cows included a control diet compared to diets containing cracked raw soybeans, ground raw soybeans, or an extensively hydrogenated rumen inert fat. A 4 x 4 Latin Square design was used with each cow being fed all four diets during one of four 20 d experimental periods. Dry matter intake, mikl production, and milk compositionwere not different due to diet. VFA concentrations in the rumen were also not different due to dietary treatment. The production study utilized three diets similar to the fistulated cow study. A control diet, cracked raw soybeans and rumen inert fat
diet were fed to cows 2 wks after calving. Milk yied was lowest for cows fed the rumen inert fat, but when evaluated as a percentage of body weight, there were no differences in milk production. Dry matter intake followed a similar trend as milk yield and was explained by differences in body weight. Cows receiving the cracked bean diet maintained higher feed intake and milk production during periods of heat stress during the summer. Animals were synchronized to evaluate the effects of fat source and supplementation on reproductive performance. There were no differences in reproductive performance of cows due to dietary treatment.
Impacts
Dairy cows fed raw soybeans had similar ruminal and ovarian function. Cows fed cracked soybeans during the summer were found to maintain higher feed intake and milk production.
Publications
- Mowrey, A., M.C. Lucy, and J.N. Spain. 1999. Rumen fermentation and reproductive performance of lactating dairy cows fed raw soybeans. J. Dairy Sci. 82(Suppl.1):66. (abstract)
- Mowrey, A., M.C. Lucy, and J.n. Spain. 1999. Reproductive performance and production characteristics of early lacation dairy cows fed raw soybeans. J. Dairy Sci. 82(Suppl.1):67. (abstract)
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Progress 01/01/98 to 12/31/98
Outputs
Microbial protein provides to the lactating dairy cow a significant portion of the amino acids that flow to the absorptive sites of the small intestines. Bacterial protein has an amino acid profile that more closely matches the one required by the cow. To maximize the flow of microbial amino acids to the intestines, it is necessary to provide the ruminal microflora with sufficient amounts of protein and energy as well as necessary co-factors. In order to support maximal milk protein production, the cow must be supplied with adequate amounts of the essential amino acids. Methionine and lysine have been found to be the first limiting amino acids in the diets typically fed to lactating dairy cows. Therefore, high producing cows not only rely on microbial amino acids but also on the dietary amino acids that escape ruminal degradation to reach the intestine intact as dietary amino acids. Protein supplemented to the escape the rumen should complement the amino acid profile
of microbial protein to support maximum production of milk and milk protein. In this study, four multi-cannulated Holstein steers were used in a 4x4 Latin square arrangement of treatments to describe the site and extent of digestion including total tract digestibility of four experimental diets. Treatment diets had been screened using continuous culture to estimate relative amino acid flow available for digestion at the small intestine. The four diets tested in this study using in vivo measurements included: 1) 14 percent crude protein and 45% undegraded intake protein; 2) 16 percent crude protein and 39% undegraded intake protein; 3) 16 percent crude protein and 45% undegraded intake protein; and 4) 18 percent crude protein and 39% undegraded intake protein. Cows were fed experimental diets as a total mixed diet twice daily. Each of the four 10 day feeding periods included a 7-day adaptation phase followed by a 3-day collection and sampling phase. Total volatile fatty acid
concentrations and molar percentages of individual volatile fatty acids were not different due to dietary treatment. Ruminal ammonia increased with increasing level of crude protein in the diet and agreed with previous results generated using the continuous culture system. The nitrogen and amino acid composition of bacteria did not differ due to dietary treatment. Level or source of protein did not affect microbial amino acid, total duodenal amino acid, and ileal amino acid flows. The apparent absorption of amino acids in the small intestine was similar for all dietary treatments. Increasing the level of crude protein above 14% did not enhance the microbial yield or fermentation efficiency. Total nitrogen flow was not affected by level of protein. These results may be attributed to the low dry matter intake and reduced rate of passage which allowed extensive degradation of dietary protein in the reticulorumen. Microbial amino acid was also similar for all treatments. Increasing level
of crude protein above 14 percentage of the dietary dry matter did not alter the flow of digestible amino acids in cannulated steers.
Impacts
(N/A)
Publications
- Costas, M.E., J.N. Spain, M.S. Kerley, and J.E. Williams. 1998. The effect of level and source of protein on ruminal fermentation, microbial efficiency and amino acid flow and digestibility in steers. Journal of Dairy Science 81(Suppl.1):332 (abstract).
- Costas, M.E. 1997. Effects of Level and Source of Protein on Ruminal Fermentation, Flow and Digestibility of Amino Acids. Masters Thesis. University of Missouri. Columbia, MO.
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Progress 01/01/97 to 12/31/97
Outputs
Four multi-cannulated Holstein steers were used in a 4 x 4 Latin square to describe the site and extent of digestion and total tract digestibility of four diets: 14 percent CP and 45 percent UIP; 16 percent CP and 39 percent UIP; 16 percent CP and 45 percent UIP and 18 percent CP and 39 percent UIP. Each 10 day period consisted of a 7 day adaptation phase followed by a 3 day sampling phase. Total VFA production and molar proportions of each VFA were not affected by diet. Ruminal ammonia N increased with increasing levels of protein. The N and AA composition of bacteria did not differ due to treatments. Microbial AA, duodenal AA and ileal AA flows were not affected by level or type of protein. The apparent absorption of AA in the small intestine were similar for all treatments. Lysine and methionine flow and apparent absorption, as a percent of total essential AA, did not differ with increasing levels of protein. Increasing the level of CP above 14 percent did not
enhance microbial yield or fermentation efficiency. Total N flow was not affected by level of protein because of the low dilution rate which resulted in extensive ruminal fermentation and deamination of the supplemental protein. Microbial AA flow was not affected. Increasing the level of CP above 14 percent did not alter flow of digestible amino acids in cannulating steers.
Impacts
(N/A)
Publications
- Costas, M.E., J.N. Spain, M.S. Kerley and J.E. Williams. 1997. Effect of level and source of protein on amino acid flow. J. Dairy Sci. 80
- Costas, M.E., J.N. Spain, M.S. Kerley and J.E. Williams. 1997. Effect of level and source of protein on ruminal fermentation and microbial efficiency. J. Dairy Sci. 80 (Suppl. 1):141.
- Underwood, J.P., J.N. Spain, J.E. Williams and M.C. Lucy. 1997. Effects of mineral source on growth and reproduction of beef and dairy heifers. J. Dairy Sci. 80 (Suppl. 1):187.
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Progress 01/01/96 to 12/30/96
Outputs
Fifty lactating dairy cows were assigned to one of 5 diets in a randomized complete block design. Control diet included alfalfa hay, corn silage, high moisture corn, cracked corn and soybean meal. Treatment diets included:F30, 30% replacement of hay with a combination of soyhulls, corn gluten feed, and wheat midds; F60, 60% replacement of hay; C30, a 30% replacement of corn and soybean meal; C60, a 60% replacement of corn and soybean meal. Diets were fed for 56 days. Body weight, condition score, feed intake, were not different due to diet. Milk fat percent was lowest for F60 (p<.000 ) with a trend for lower milk fat percent for F30(p<.14) compared to control, C30, and C60. Milk and 4% FCM yields were not different. A concurrent study was conducted with five fistulated cows in a 5x5 Latin Square to characterize ruminal fermentation changes in response to diets. Diets fed during five 14 day periods were the same described above. Total concentrations of volatile fatty
acids were not different. Percentage acetate was highest for control and C60 diet. Percentage propionate was highest for F60 diet (p<.001). Acetate:propionate (p<.0001) ratio was highest for control and C60 diets. In situ digestibility of alfalfa hay DM was increased for C30 and C60 diets (p<.0001). These data show fibrous by-products can be used to replace forage o dairy cows. Fermentation was altered with a corresponding shift in milk fat concentration. Milk and milk component yields were not affected.
Impacts
(N/A)
Publications
- Mowrey, Amy. 1996. The Effects of Feeding Fibrous By-Product Feeds to Lactating Dairy Cattle. Master's Thesis. University of Missouri-Columbia.
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Progress 01/01/95 to 12/30/95
Outputs
Utilization of dietary nitrogen is an important aspect affecting the long term sustainability of dairy farm enterprises. Encapsulated amino acids provide an opportunity previously unavailable to dairy nutritionists to provide specific amino acids that may be limiting milk protein synthesis without overfeeding dietary protein. These amino acids should allow for the reduction of total crude protein in the diet while maintaining total flow of these amino acids to the small intestine. There is need to compare the influence of amino acid source on intestinal digestibility. Dairy cattle (n=3) with duodenal and ileal cannulae were used in a 3x3 Latin Square to measure the affect of protein and amino acid source on post-ruminal flow and intestinal digestibility of amino acids. Diets included soybean meal, blood meal/fishmeal, or urea with rumen protected amino acids Lys and Met. Urea diets had lowest microbial N flow and microbial efficiency. Total amino acid flow to the
duodenum was lower for the urea diet. Total Lys and Met and intestinal digestibilities of the amino acids were the same. Rumen protected amino acids maintained flow of amino acids to the intestine. Follow-up studies are underway. An in vitro experiment using 4 levels of protein and three levels of UIP will be used to describe the diets that support maximum microbial efficiency and amino acid flow to the duodenum. This study will be followed by an in vivo study to describe intestinal digestiblity of diets to optimize amino acid flow.
Impacts
(N/A)
Publications
- Hess, BW, JN Spain, MS Kerley, ME Costas, JE Williams. 1995. Effects of replacing soybean meal with a blood/fish meal combination or urea. J. Dairy Sci.
- Abstract (In press). Hess, BW, JN Spain, MS Kerley, ME Costas, JE Williams. 1995. Compa.
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Progress 01/01/94 to 12/30/94
Outputs
Feed costs represents 50 percent of the cost of producing milk. In addition, excessive nutrient load impacts waste nutrient management. Research has been conducted to evaluate interactions of carbohydrates and protein feeding on milk production by dairy cows. A study was conducted to evaluate the effect of supplemental protein source on milk production and milk composition. Amino acids, methionine and lysine, were fed encapsulated in fat to protect from microbial degradation in the small intestine. Milk production and milk composition was not different due to dietary protein supplementation. These results indicated rumen protected amino acids could be used to support milk production at levels supported by supplemental bloodmeal and fishmeal. Currently, the effect of dietary protein on site of digestion and flow of protein/amino acids is being studied. Dairy cattle (n = 3) with duodenal and ileal cannulae are being used to measure protein flow in lactating cows fed
different protein sources. Results will describe N flow in the GI tract. By better understanding and dietary impact on N flow in the cow will allow more accurate ration/diet formulation which can be used to reduce N wasted in excretion.
Impacts
(N/A)
Publications
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Progress 01/01/93 to 12/30/93
Outputs
SEE MO-ASRB0142 and MO-ASHC0143.
Impacts
(N/A)
Publications
- No publications reported this period.
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