Nutrition, Feeding, and calves: Evaluation of Ruminally Protected Methionine and Lysine Or Blood Meal and Fish Meal as Protein Sources For Lactating Holsteins

摘要

Forty lactating Holstein cows averaging 55 days in milk were used in randomized block designed experi- ment to evaluate the effectiveness of ruminally pro- tected Met and Lys compared with that of ruminally undegradable protein for supporting lactation. Cows were fed total mixed diets for 15 wk. Diets were formu- lated to be isonitrogenous with the same base ingredi- ents resulting in base crude protein percentage of 15.5. Supplemental crude protein supplied by urea, soybean Meal, or a 50:50 (wt/wt) mixture of fish and blood meal Increased total dietary nitrogen to 18.0/100 of diet DM.