Plasma Levels of Growth Hormone, Insulin and Plasma Protein-Bound Iodine in Finishing Cattle

Abstract

Growth hormone, insulin and PBI were measured in plasma samples from 30 yearling steers fed finishing rations. Insulin and PBI were measured in samples from 24 yearling heifers. Feeding of finishing rations had no effect on concentration of plasma GH. Levels of plasma insulin gradually increased while the animals were fed finishing rations. Feeding stilbestrol increased plasma GH (P<.01) in steers, increased plasma insulin in steers and heifers and had no effect on PBI. The cattle fed stilbestrol gained more weight (P<.05) and had larger pituitary glands (P<.01) than did control animals. Correlations between levels of plasma hormones and weight gain tended to be positive with insulin and negative with GH. Copyright © 1970. American Society of Animal Science . Copyright 1970 by American Society of Animal Science