Long-term evaluation of a prolonged-release formulation of N-methionyl bovine somatotropin in lactating dairy cows.
Eighty Holstein cows (first, second, or third lactation) were used to evaluate the efficacy of a prolonged-release formulation for sometribove (n-methionyl bovine somatotropin). Cows were fed ad libitum a complete mixed diet and milked twice daily. Cows were allocated randomly by parity to two treatment groups receiving 500 mg sometribove in a prolonged release formulation or excipient at 14-d intervals starting at 60 +/- 3 d postpartum and continuing for 36 wk. Treatment with sometribove increased FCM yield to a similar extent (11.4%, +3.1 kg/d) in primiparous and multiparous animals. Milk content of lactose, fat, ash, and Ca was not affected, but protein and phosphorous were slightly greater (less than 5%) in milk from sometribove-treated cows. Within a 14-d injection interval, animals treated with sometribove displayed a cyclic pattern in milk yield, but a similar pattern was not evident in feed intake.
Bauman
D E
DE
Department of Animal Science, Cornell University, Ithaca, NY 14853-4801.
Hard
D L
DL
Crooker
B A
BA
Partridge
M S
MS
Garrick
K
K
Sandles
L D
LD
Erb
H N
HN
Franson
S E
SE
Hartnell
G F
GF
Hintz
R L
RL
D000818:Animals; D002417:Cattle / Q000502:physiology*; D003692:Delayed-Action Preparations; D004032:Diet; D005260:Female; D013006:Growth Hormone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D019382:Human Growth Hormone; D007774:Lactation / Q000187:drug effects*; D011247:Pregnancy; D013997:Time Factors
D003692:Delayed-Action Preparations; D019382:Human Growth Hormone; D013006:Growth Hormone