bSTH and IGF‐I Levels in Blood and Milk of Black and White Dairy Cows before and after Application of Recombinantly Derived Bovine Somatotropin

Publisher Website
Google Scholar
Abstract
In an 8 week trial period six black and white dairy cows were injected with Optiflex®, a slow release formulation of recombinantly derived bovine somatotropin (BST). Three cows each were injected at two-weeks (BST-14) or four weeks (BST-28) intervals. The dosage was 640 mg BST per injection. Average milk yield increased by 18. 3% and 13. 8% in groups BST-14 and BST-28 respectively. Blood plasma levels of bSTH and IGF-I increased till day 10 post-injection; thereafter they declined, except IGF-I levels in group BST-14 which persisted continuously elevated with minor variations. No bSTH above detection level could be assayed in the milk of treated animals. The IGF-I level in milk was slightly elevated after BST-application but stayed within the normal range.