Relative Efficacy of Various Estrus Synchronization Protocols for Improving Fertility in Cyclic and Acyclic Buffaloes

Abstract

This study was undertaken in field conditions on 50 cyclic repeat breeder and 50 acyclic buffaloes to evaluate the efficacy of four standard estrus induction/ synchronization protocols, viz., Doublesynch (PG-GPG), Estradoublesynch (PG-GPE), Ovsynch (GPG), and Ovsynch Plus (eCG-GPG) (10 buffaloes in each protocol, and in controls) in terms of estrus induction response and conception rates at induced estrus with FTAI and overall of 3 cycles post-treatment. All repeat breeder and 90-100 % acyclic buffaloes under four protocols exhibited induced estrus within mean intervals of 69.80±3.44, 62.10±2.84, 61.45±1.34 and 64.00±1.25 h, and within 64.77±2.19, 62.50±1.39, 69.30±1.80 and 70.60±1.30 h, respectively, from PGF₂α injection. The conception rates obtained in cyclic/repeat breeder buffaloes at induced estrus (FTAI) and overall of three cycles post-treatment were 40 and 50 % with Doublesynch; 50 and 70 % with Estradoublesynch; 60 and 70 % with Ovsynch, and 60 and 60 % with Ovsynch Plus protocol, respectively. The corresponding conception rates in acyclic buffaloes were 50 and 60 %; 40 and 60 %; 30 and 80 %, and 50 and 70 %. Among 10 repeat breeder buffaloes each, 4, 3, 2 and 3 non-conceived buffaloes remained cyclic, while 1, 0, 1 and 1 became anestrus by 60 days post-induction/FTAI following use of Doublesynch, Estradoublesynch, Ovsynch and Ovsynch Plus protocols, respectively, whereas among 10 acyclic buffaloes each, 2, 2, 2 and 1 non-conceived buffaloes remained cyclic, while 2, 2, 0 and 2 again turned out to be anestrus by 60 days follow up. Among the untreated control cyclic and acyclic buffaloes (10 each), 3 and 2 buffaloes conceived over a period of 90 days follow up giving overall conception rates of only 30 and 20 %, respectively, as against 62.5 and 67.5 % in treated cyclic and acyclic buffaloes. It was thus concluded that all four protocols improved conception rates in repeat breeding and acyclic buffaloes by establishing regular cyclicity post-treatment. The maximal benefit was with Ovsynch and/or Estradoublesynch application in repeat breeders and Ovsynch and/or Ovsynch Plus in anestrus buffaloes.