REPRODUCTIVE EFFICIENCY AND ENDOCRINE PROFILE IN PRIMIPAROUS EWES IN GOOD BODY CONDITION SUPPLEMENTED WITH BYPASS FAT

Abstract

Objective: To evaluate the effect of the addition of bypass fat in primiparous ewes in good body condition (CC 3) on the reproductive variables and serum levels of insulin (INS) and progesterone (P4).
Design/methodology/approach: A completely randomized design was used. Forty-four primiparous ewes were randomly distributed in two experimental groups: 1) In the AGS group (n=22) ewes added with 75 g of bypass fat during a period of 25 d; 2) in the SGS group (n=22) ewes without additional fat. Estrus synchronization was performed using the CIDR device for 11 d, and ewes in estrus were served. To determine serum concentrations of P4 and INS, blood samples were collected every 48 h during supplementation.
Results: Estrus onset and presentation were not different. No differences were found in gestation and prolificacy, nor changes for the mean P4 in serum. Serum INS concentrations showed differences during the synchronization d 8-14.
Limitations of the study: The addition of 75 g of bypass fat in ewes with BC 3 does not have effects on reproductive variables, therefore, is recommended to use it in ewes with low BC.
Findings/conclusions: The addition of bypass fat in primiparous ewes in BC 3 does not change P4 concentrations; however, it causes variations in the concentrations of INS in blood serum without modifying the response in the reproductive variables.