Prevention of Milk Fever by Application of Dietary Cation-Anion Balance Concept

Milk fever (hypocalcemia) in dairy cows is caused by an acute deficiency of blood calcium, usually immediately before or after calving. It is often more common in mature cows. Both clinical and subclinical hypocalcemia can seriously affect cow health, including dystocia, retained placenta, prolapsed uterus, displaced abomasum, and left abomasal displacement. Limiting the calcium intake of non-lactating cows by changing forage can help prevent milk fever, but is often not practical. A more practical strategy is decreasing the dietary cation-anion difference (DCAD) in dry cow diets for 10 days to 3 weeks just before calving. DCAD is the sum of the positively-charged ions sodium and potassium minus the sum of the negatively-charged ions chloride and sulfur and can be decreased by adding anionic (sometimes called acidogenic) salts to the diet. Problems to consider are toxicity, palatability, the offsetting effects of other elements of the cow's diet, and avoiding feeding this diet to lactating cows. Supplemented by references, DCAD tables, and formulation instructions. 8 pages

Effects of intraruminal infusions of propionate and butyrate with two different protein supplements on milk production and blood metabolites in dairy cows receiving grass silage-based diet

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Fermentation and Utilization of Grass Silage

The decision to utilize particular forages in support of dairy production should be based on a number of key factors, such as available land base, type of manure management, soil type and topography, climate, and availability of purchased forages and feeds. Because of the complexity and environmental concerns existing in the dairy industry today, decisions about forage and manure management should include whole farm analysis with the aid of computer software. The chemical composition and digestibility of grass are affected more by stage of maturity than by other management factors, such as species, DM, or type of harvest system. The decline in digestibility of nutrients in first growth forage is approximately .55 to .68%/d and is dependent on the method of estimation. The decline in digestible DMI in first growth is .3 to .5%/d. The use of silage additives has become an integral part of forage management, and improvements in DMI and milk production are documented. Particle size and type of harvest equipment significantly affect eating behavior and efficiency of milk production. Wilting of silage results in an increase in DMI and efficiency of microbial protein production

Effect of Whole Cottonseed, Gossypol, and Ruminally Protected Lysine Supplementation on Milk Yield and Composition

To determine whether the gossypol content of the diet affected availability of dietary Lys, 4 cows with ruminal and duodenal cannulas and 16 intact cows in early lactation were assigned to diets containing either glanded cottonseed, glanded cottonseed plus 15 g/d of ruminally protected Lys, glandless cottonseed, or glandless cottonseed plus 15 g/d of ruminally protected Lys. The experimental design was a 4 × 4 Latin square design with 3-wk experimental periods. Gossypol concentrations in plasma were lower when cows were fed glandless cottonseed. Lysine supplementation increased the flow and percentage of Lys in duodenal digesta and increased the concentration of Lys in plasma. Neither type of cottonseed nor Lys supplementation affected dry matter intake. Yields of milk and fat-corrected milk from cannulated cows were not affected by diet, but yields from intact cows were increased by Lys supplementation. For both cannulated and intact cows, Lys supplementation increased the percentage of milk protein, and milk protein yield was increased by Lys in intact cows. Dietary gossypol did not affect the response to Lys, indicating that dietary gossypol had little or no effect on the availability of Lys for dairy cows