A clinical study of anestrus buffaloes in southern Nepal.

Anestrus is one of the most important reproductive disorders in dairy buffaloes. The clinical features of anestrus in buffaloes, however, have not been well described. The objectives of this study were to describe the causes of anestrus in buffaloes and their reproductive performance after treatment under field conditions in southern Nepal. Of 135 anestrus buffalo cows, 61.4% had true anestrus with ovarian dysfunction and 33.3% had silent ovulation. In 111 buffalo heifers, 76.6% were in true anestrus and 18.9% had silent ovulation. The duration of anestrus after calving was longer than 6 months in 83% of buffalo cows and 61.5% of the buffalo cows had durations longer than 10 months. The interval between the last breeding and diagnosis of anestrus was more than 5 months in 67.4% of cows and heifers. Treatment of anestrus with prostaglandin F(2)alpha in cows and heifers with a corpus luteum resulted in higher pregnancy rates within one (P<0.01) and two months (P<0.05) after treatment as compared with treatment with a vitamin/mineral mixture. Buffalo cows and heifers with inactive ovaries bearing a dominant follicle were also successfully treated with gonadotropin releasing hormone, resulting in higher pregnancy rate within one month after treatment (P<0.05). In conclusion, the predominant cause of anestrus in dairy buffaloes in this region was true anestrus with inactive ovaries, and the duration of anestrus after calving as well as breeding was extremely long. Routine reproductive examination and adequate hormone treatment may improve the reproductive performance of these buffaloes.