Effect of Direct Fed Microbials on Concentrations of Glucose and Insulin in Plasma and Animal Performance

Abstract

Sixty-two Angus x Hereford heifers were used to determine the effects of feeding direct fed microbials for 8 wk prior to the breeding season on concentrations of insulin and glucose in plasma, animal performance and reproductive performance. Treatments were a pelleted low starch diet (control) and the control diet plus 5 g of a mixture of propionibacteria strains P169, P5 and XP-yeast (Diamond V). Feeding propionibacteria P169, P5, and XP-yeast for 8 wk prior to the breeding season did not influence concentrations of insulin and glucose in plasma and animal and reproductive performance in beef heifers. Heifers born in spring of year 1997, 1998 and 2003 were used to evaluate the percentage of mature body weight at puberty. Heifers will attain puberty at approximately 56 % of mature body weight (5 to 7 yr of age). Puberty occurred at 74 % of their 2.5 yr weight.