Effect of a prolonged release formulation of recombinant bovine somatotropin on plasma concentrations of hormones and metabolites, and milk production in dairy cows.
The effect of a prolonged release formulation of recombinant DNA derived bovine somatotropin (rbST) on the plasma concentrations of growth hormone (GH), insulin-like growth factor-I (IGF-I), insulin, glucose, blood urea nitrogen (BUN) and nonesterified fatty acids (NEFA), and milk production in lactating dairy cows was studied. Eight cows were divided into two equal groups. One group was the noninjected control, and cows in the other group received a single subcutaneous injection of 640 mg rbST. Plasma GH levels in the rbST-treated cows were higher than in the control cows for 10 days after the injection. Plasma IGF-I concentrations were significantly higher in the rbST-treated cows than in the control for 14 days after the treatment. In the rbST-treated cows, the plasma concentrations of insulin and glucose tended to be higher than those in the control until 7 days after the injection. Also, plasma NEFA levels were higher in the rbST-treated cows for 10 days. In contrast, plasma BUN levels were significantly lower in the rbST-treated cows for 17 days after the treatment. For 28 days after the injection, the mean daily milk yield in rbST-treated cows was 4.5 kg (21.2%) more than that in the control cows. In the rbST-treated cows, a highly positive correlation was observed between the mean daily milk yield and the mean plasma concentration of IGF-I throughout the postinjection period.(ABSTRACT TRUNCATED AT 250 WORDS)
Hodate
K
K
Department of Animal Physiology, National Institute of Animal Industry, Ibaraki, Japan.
Ozawa
A
A
Johke
T
T
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001806:Blood Urea Nitrogen; D002417:Cattle; D003692:Delayed-Action Preparations; D004435:Eating / Q000187:drug effects; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D013006:Growth Hormone / Q000097:blood / Q000494:pharmacology*; D006728:Hormones / Q000097:blood*; D007328:Insulin / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007774:Lactation / Q000187:drug effects*; D008894:Milk Proteins / Q000096:biosynthesis; D011247:Pregnancy; D011994:Recombinant Proteins / Q000494:pharmacology
D001786:Blood Glucose; D003692:Delayed-Action Preparations; D005230:Fatty Acids, Nonesterified; D006728:Hormones; D007328:Insulin; D008894:Milk Proteins; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone