γ BST 의 유우에 대한 안정성 연구 I. γ BST가 우유중 미량광물질 조성에 미치는 영향

Studies on the safety of recombinant bovine somatotropin in dairy cow I. Effects of recombinant bovine somatotropin on mineral composition in milk of dairy cows

Effects of recombinant bovine somatotropin$({\gamma}BST)$ on mineral composition of milk were investigated in Twenty-five multiparous Holstein dairy cows. Recombinant BST was administered by two different routes; intramusculary(12.5mg and 25mg/day) and subcutaneously (500mg and 750mg) in sustained-release vehicle every 2 weeks beginning 4 week postpartum and continuing for 7 months. Milks were collected 0,1,2,3,5 and 7 months after beginning of treatments in control and ${\gamma}BST$-administered groups. Mineral composition, such as Ca, Pi, Na, K, Mg, Zn, Fe and Mn, in milk were not affected by the administration of ${\gamma}BST$ regardless of dose and dosage forms. It is concluded from the observations of these experiments that the dose and dosage forms of ${\gamma}BST$ employed in this work might not affect milk mineral composition in dairy cows under the normal sanitary condition and adequate nutrient balance.