Use of bovine somatotropin in the tropics: the effect of sometribove on milk production in western, eastern, and southern Africa.
Seven field studies conducted in western, eastern, and southern Africa to determine the effect of a prolonged-release formulation of bovine somatotropin (bST) administered at 14-d intervals on milk production of indigenous, crossbred, and purebred cows are described. Studies in Gambia showed that 334 mg of a prolonged-release formulation of bST increased milk production of N'Dama cattle by 205 ml/d, which represented a 22% increase in milk production, and increased the body weight gain of calves. In small dairy units in Zimbabwe, 500 mg of a prolonged-release formulation of bST increased milk production of crossbreds from 8.0 to 10.0 kg/d. Milk production response of crossbred cows in Kenya increased 2.5 kg/d after the lower dose rate (334 mg); no further increases were observed when the dose rate was increased to 500 mg. A study with Holsteins showed that delaying treatment of 500 mg of a prolonged-release formulation of bST from 90 to 120 or 150 d postpartum resulted in similar milk production responses of 3.5, 3.4, and 3.2 kg/d, respectively. The milk production response (6.1 kg/d) recorded in another study with Holsteins was attributed to an excellent plane of nutrition and delayed treatment initiation. For nonpregnant cows that were classified to be culled, the prolonged-release formulation of bST was efficacious and could potentially be used to extend lactation.
Phipps
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Centre for Dairy Research, University of Reading, England.
Hard
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Adriaens
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D000351:Africa, Eastern; D000353:Africa, Southern; D000354:Africa, Western; D000818:Animals; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D005260:Female; D013006:Growth Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D007774:Lactation / Q000187:drug effects*; D014329:Tropical Climate
D013006:Growth Hormone; C108583:sometribove