Insulin-like growth factor I during growth in bulls.
In 10 bulls, changes in blood plasma concentrations of insulin-like growth factor I (IGF1) were studied during rearing and during the ensuing growth period. IGF1 continuously increased from 32 micrograms/l at the age of 15 d to 194 micrograms/l at the age of 307 d together with body weight. However, IGF1 was not related to daily rate of gain, which remained fairly constant during the growth period. An age-dependent increase was also observed for blood levels of insulin, thyroxine and triiodothyronine. The data suggest that insulin and thyroid hormones may be causally related to the age-dependent increase in IGF1 levels.
Ronge
H
H
Université de Berne, Institut de Zootechnie, Switzerland.
Blum
J
J
D000375:Aging / Q000097:blood*; D000818:Animals; D002417:Cattle / Q000097:blood* / Q000254:growth & development*; D007334:Insulin-Like Growth Factor I / Q000097:blood*; D008297:Male; D013002:Somatomedins / Q000097:blood*
D013002:Somatomedins; D007334:Insulin-Like Growth Factor I