Efficacy of different protocols in synchronization of estrus in sows

Abstract

A study was conducted on Large White Yorkshire (LWY) sows at a private piggery farm in Kunigal, Karnataka, to evaluate the efficacy of various estrus synchronization protocols. Sows, weaned on the 45th day after farrowing, were randomly assigned into four groups: Group I (n = 10) as the control; Group II (n = 10) received oral letrozole for five days; Group III (n = 10) received a single 10 µg buserelin acetate injection intramuscularly on the fifth day; and Group IV (n = 10) received both 5 mg letrozole orally followed by a 10 µg buserelin injection intramuscularly. Group I exhibited a 100% response to estrus, and mean weaning-to-estrus interval of 5.90±0.23 days and an estrus duration of 56.4±1.66 hours. These findings suggest that natural estrus post-weaning yields superior reproductive outcomes compared to synchronization protocols in LWY sows.