Dietary fat supplementation for dairy cows in early lactation injected with somatotropin

• Main Author: Marty, Bruno Josef
• Format: Others
• Language: en
• Published: McGill University 1990
• Subjects: Dairy cattle > Feeding and feeds.; Bovine somatotropin.
• Online Access: http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59537

Dairy cows fed diets supplemented with 2.5% calcium-salt fatty acids (CSFA) (DM basis) during early lactation produced more 4% FCM than cows fed the control diet. Feeding this diet also increased whole lactation performance. Supplementing diets with 1.25% CSFA or animal fat did not increase production performance of cows. Dietary fats were used directly for greater milk production and, based on unchanged body condition scores, did not alleviate body fat mobilization. Changes in the milk fat content and composition due to fat supplemented diets were negligible. A slight decrease in milk protein and SNF percentage was observed with CSFA but not with animal fat feeding. Palatability of the diets was good and DM intake was not impaired. Feeding animal fat at 1.25% and CSFA up to 2.5% of the DM does not impair forage digestibility and nitrogen balance. Dietary fat increased plasma triglyceride (TG) and cholesterol concentration. Injection of 10.3 mg d$ sp{-1}$ or 350 mg 14d$ sp{-1}$ of recombinant bovine somatotropin (rbST) did not change 4% FCM production or milk composition at any stage of lactation.