Vol. 8, Issue 2 (2019)

Author(s):
GN Purohit, Pankaj Thanvi, Munesh Pushp, Mitesh Gaur, Chandra Shekher Saraswat, Atul Shanker Arora, Surya Prakash Pannu and Trilok Gocher

Abstract:
Estrus synchronization and timed inseminations can overcome two distinct problems of buffalo breeding: poor overt estrus expression and seasonality of breeding. Evidence is accumulating that, similar to cattle, the synchronization of estrus in buffalo is dependent on the presence of dominant follicle (DF) and corpus luteum (CL) on the ovary. Approaches for estrus synchronization govern either the progression of DF to ovulation following luteolysis (prostaglandins PG) or regression of a DF, followed by growth of a new DF that progresses to ovulation (progestins and GnRH). The use of prostaglandins for estrus synchronization has led to estrus rates (ER) of 60-80% and conception rates (CR) of 12.5%-60% in buffalo heifers and ER of 70-100% and CR of 40-80% in adult buffaloes. Such an approach has the disadvantage of poor response in postpartum anestrus buffaloes and buffalo heifers with absence of CL and follicular growth. Moreover, the effects are suboptimal during the non-breeding season and during nutritional inadequacies. Progestagen treatments are more useful in buffalo heifers and adult buffaloes during the non-breeding season when combined with estradiol, eCG, prostaglandins and GnRH/hCG. A slightly longer duration (12-14 d) of progesterone therapy is suggested during the non-breeding season along with estradiol at the time of progesterone implant insertion, as this effectively regresses large follicles and/or initiates a new follicular growth. Such therapies effectively produce additional pregnancies during the unfavourable season, which is clearly advantageous. The ovsynch is the most commonly used GnRH based estrus synchronization protocol used in buffaloes with conception rates of up to 60% during the breeding season however, during the non-breeding season and in buffalo heifers the conception rates are suboptimal (11-20%). The nutritional status of buffaloes appears important before initiating estrus synchronization. In conclusion, estrus and ovulation can be effectively synchronized in buffaloes using ovsynch protocols during the breeding season; however during the non-breeding season progestagen based protocols in combination with estradiol, eCG, PG and GnRH are a better option for timing insemination and planning calvings.