Body Composition of Cattle. I. Estimation of Body Fat From Measurement in Vivo of Body Water by Use of Antipyrine
Kraybill, H.F.; Hankins, O.G.; Bitter, H.L.
Journal of Applied Physiology 3(11): 681-689
Antipyrine given by vein is not toxic to cattle and is uniformly distributed over the body in about 2.5 hr. Measurements were made on 6 crossbred cows and heifers, 7 Hereford heifers and 7 steers on a high plane of nutrition, 2 heifers and 6 steers on a low plane, and 2 " discards ", of body water by sp. gr. and antipyrine dilution. Body fat was estimated from body water and the results were compared with separable fat and ether extract computed from dissection and analysis of the 9-10-11 rib cuts. The results were in excellent agreement. Body water, as a percentage of bodyweight after a 24-hr. fast and withdrawal of water for 10 hr., ranged from 63.3 for an immature steer with 13.9 per cent. fat to 43.9 for a heifer of 972 lb. and about 40 per cent. fat.