Effect of insulin administration during follicular growth on serum glucose and hormone profiles in ewe lambs

Abstract

Twenty ewe lambs received either 0 or 1 IU of Lente insulin kg −1 body weight from day 12 of the estrous cycle until 24 h after estrus. Blood samples were collected at 15-min intervals for 6 h after treatment on days 12, 14 and 16 of the estrous cycle. Following insulin injection, serum insulin was elevated (P < 0.05) and was accompanied by a decrease in serum glucose levels. Insulin treatment did not affect (P > 0.10) luteinizing hormone secretory characteristics, ovulation rate, or subsequent litter size. Key words: Insulin, glucose, sheep, luteinizing hormone