<div>Background: Standard estrus synchronization regimens resulted in variable outcomes in buffaloes. The present study evaluated ovarian and fertility responses following presynchronization in Heatsynch protocol administered in postpartum buffaloes.&nbsp; 
 
Methods: In group-I (Presynch-Heatsynch group, n=30), PGF2&alpha; was administered on days -14 and -2. Then, GnRH analogue, PGF2&alpha; (Cloprostenol) and Estradiol benzoate were administered on day 0, 7 and 8, respectively followed by fixed-time artificial insemination (FTAI) 48 hours later. In group-II (Heatsynch group, n=30), rest protocol was same, except that first two PGF2&alpha; injections were not administered.&nbsp; 
 
Result: The progesterone concentrations differed (P&lt;0.01) between the two groups on days -2, 0 and 7. Post-treatment, progesterone profiles were also higher in pregnant compared to non-pregnant buffaloes in both the groups except on day 10. CL diameter differed (P&lt;0.01) between groups on days -2, 0 and 7. It was larger in pregnant than non-pregnant buffaloes on day 7 in both the groups. Dominant follicle diameter remained larger on days -2, 0 and 8 in group-I than -II. Buffaloes getting pregnant had a larger (P&lt;0.01) dominant follicle size on the day of FTAI in group-I than of group-II. Ovulatory response of 93.33 and 90.00% was observed in group-I and II. The conception rate was higher (66.66 vs. 40.00%; P&lt;0.05) in group-I than Group-II. Presynchronization improved reproductive efficiency in Heatsynch treatment and may aid for better fertility in buffaloes.</div>

Presynch-Heatsynch: A New Approach to Improve Ovarian and Fertility Responses in Water Buffalo (Bubalus bubalis)