Effect of Breeding Method on Calf Sex Ratio at Birth in Sahiwal, Crossbred and Gangatiri Cattle

The present study evaluated the effect of breeding method on the calf sex ratio (M:F) at birth in Sahiwal, Gangatiri, and crossbred cattle maintained at the Faculty of Veterinary and Animal Sciences, BHU. Calving records from 2020–2026 were classified with respect to semen type (sex-sorted or conventional) and breeding method (artificial insemination [AI] or natural breeding). Of the 187 recorded calvings, 118 (63.1%) resulted from farm breeding, whereas 69 (36.9%) were from animals purchased in pregnant condition. Among the recorded calvings, 78.1% were from Sahiwal, 13.4% from Gngatiri and 8.6 % from crossbred cattle. Sex-sorted semen through AI was predominantly used in Sahiwal and crossbred cattle, whereas Gangatiri cattle were primarily bred through natural service. The sex-sorted semen resulted in a markedly female-biased sex ratio, with 93.58% female calves. In contrast, conventional semen produced a comparatively balanced sex ratio, with 35.71% male and 64.29% female calves in Sahiwal and crossbred cattle. However, natural service in Gangatiri cattle resulted in a nearly balanced sex ratio, comprising 48.15% male and 51.85% female calves. Statistically Fisher’s exact test revealed no significant association between breeding method and calf sex, when breeding was done by artificial insemination using conventional semen versus natural service (P = 0.546). However, a statistically significant association was observed between use of sex-sorted semen and natural service (P = 0.006), as well as between sex-sorted and conventional semen (P = 0.012), with respect to calf sex. Overall, the calf sex ratio at birth was 19.49% male and 80.51% female. The pronounced female bias was associated with the extensive use of sex-sorted semen, particularly in Sahiwal cattle, indicating its potential utility for targeted herd replacement and genetic improvement of dairy herds. Key words: Sex sorted semen, Natural service, Calf Sex ratio, Sahiwal, Gangatiri