Effect of melatonin on follicular development parameters in a fixed-timed artificial insemination programme in water buffalo

It is well known that buffaloes have seasonal anoestrus and the use of melatonin reduces effects season in reproduction, articularly among sheep goats. This study evaluates on water to increase pregnancy rates a fixed-time insemination programme. The was conducted an Argentinian buffalo herd, located Corrientes Province, during unfavourable reproductive season. Artificial cycles were performed September December 2018. Sixty animals selected, administered 29 females at dose 18 mg/50 kg. Ten days after implant, ovulation synchronization started. Animals inseminated with frozen semen single bull. Pregnancy evaluated by ultrasound 35 insemination. rate two repetitions 34.62% for 6.4% (P=0.007). No significant differences found parameters associated follicular development formation corpus luteum. Analysis replicates showed there no statistically effect ovarian response regarding analysed parameters. There also (17.85% vs. 20.68%; P=0.15), or treatment control. In conclusion, this not able demonstrate as reported other authors. Other factors, such environmental conditions subtropical areas species specificities, may more endocrinology. These factors should be improve results fixed-timed artificial programmes.