Effects of nutrition and feeding on dairy cattle health
2019
Kida, K. (Obihiro University of Agriculture and Veterinary Medicine, Obihiro-city, Hokkaido (Japan). Center of Animal Science and Agriculture)
Dairy cow’s nutrition and disease were discussed from three perspectives. The basis of nutritional management is maximizing dry matter intake (DMI), and above all, it is important to eliminate as much as possible eating-inhibiting factors. DMI requirements are determined by the weight and milk yield of dairy cows, but their physical intake limits vary with the length of fiber that can pass through the omasum. Length that passes through the omasum folds is 1.18 - 4 mm, in order to increase the intake of TMR, it is also important to shorten the length of the fiber. As the impact of rottened silage on dairy cow performance, according to increasing VBN concentration, blood and milk urea nitrogen increased and polymorphonuclear leukocyte (PMN) reactive oxygen (ROS) production increased. This suggests that ammonia derived from altered feed also affects the innate immune system of dairy cows, and that oxidative stress caused by ROS derived from leukocytes is a factor in the development of infectious diseases such as mastitis. In cows fed high VBN diet within 2 weeks prior to insemination, the pregnancy rate decreased, suggesting that oxidative stress related to high ammonia absorption from the rumen could impair pregnancy formation. Daily increases in concentrates were given to postpartum dairy cows in 2 different rates, and a significant decrease in the rumen acetate / propionic acid ratio and an increase in lipopolysaccharide (LPS) were observed in the cows given concentrates rapidly. Feeding of concentrates to prevent SARA during early lactation should be reached the maximum after 5 weeks postpartum.
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