LIVER VITAMIN A STORAGE IN FATTENING CATTLE FOLLOWING INTRARUMINAL OR INTRAMUSCULAR INJECTION OF VITAMIN A.
The effect of intramuscular or intraruminal injection of 1 million I.U. of an emulsifiable vitamin A preparation upon liver vitamin A stores in fattening steers was investigated. Pre-injection liver stores were 52 mcg vitamin A/gm fresh liver. At 7 days post-injection, these stores had increased to an average of 88 mcg vitamin A/gm fresh liver. Thereafter, the liver vitamin A stores declined until at 73 days post-injection they were approximately 28 mcg vitamin A/gm fresh liver. During depletion the pre-injection liver vitamin A levels were reached between 30-35 days post-injection. The method of administration had little effect on repletion of liver vitamin A stores; however, the steers injected intramuscularly showed a slightly slower depletion of liver vitamin A, than those injected intraruminally. Very little difference was observed in average daily weight gains between the two methods of vitamin A administration.
D000818:Animals; D001835:Body Weight; D002417:Cattle; D007267:Injections; D007273:Injections, Intramuscular; D008099:Liver / Q000502:physiology*; D008660:Metabolism; D012417:Rumen; D014801:Vitamin A
D014801:Vitamin A
CATTLE; INJECTIONS, INTRAMUSCULAR; LIVER FUNCTION; METABOLISM; RUMEN; VITAMIN A