Induction of estrus as a strategy to improve the economic efficiency of the sheep flock

Abstract

Productivity and profitability in sheep production systems are strongly influenced by the reproductive capacity of the flock.

Objective: To evaluate the use of reproductive biotechnologies (e.g., the induction of estrus) and its impact on the economic efficiency and the productive and reproductive performance of technified sheep production systems, during the seasonal anestrus.

Design/Methodology/Approach: Four-hundred recently weaned (60 days postpartum) ewes of the Katahdin breed were randomly divided into two treatments: T1 = natural mating (n= 200) and T2 = induction of estrus (n=200). Estrus was induced through the application of intravaginal sponges, impregnated with 20 mg of chronolone, plus the injection of 400 IU of Equine Chorionic Gonadotropin. The aim was to evaluate the reproductive and economic efficiency of the flock.

Results: The induction of estrus during the seasonal anestrus recorded increases (p<0.001) in prolificacy (32%), fertility (86%), and kilograms of lamb weaned per year per ewe (48%), while decreases (p <0.05) were recorded in the number of open days (25%), calving interval (11%), cost per open days (23%), and the kilograms of lamb required per ewe per year (10%).

Study Limitations/Implications: The constant variations in the price of supplies and services caused changes in the economic indicators.

Findings/Conclusions: The use of reproductive biotechnologies (such as estrus induction) has a positive impact on production units, improving their profitability.