Assessment of early sexual maturity in nondescript local pigs of northeast India: Testicular development, spermiogram and in vivo pregnancy

The tribal population of North Eastern India follow a unique practice of mating the sow with a male pig from its own litter to avoid maintenance of boar for breeding. In this system, it is claimed that the nondescript local male pigs, at very young age (around 3 months), impregnate the sow. There is no documented report available on this practice. The present study, therefore, was carried out to study the testicular development and early sexual maturity in nondescript local pigs and to compare with Hampshire and Large White Yorkshire (LWY) pigs. The weight and circumference of the testes were significantly (p < 0.05) higher in nondescript local pigs compared to Hampshire and LWY pigs, but the testicular length did not differ significantly. The epididymis weight and length of different segments also did not differ significantly between Hampshire and LWY pigs. However, the nondescript local pigs had significantly heavier (p < 0.05) epididymal weights at four and six months of age relative to the other two breeds. The testicular tissue per kg body weight was significantly higher (p < 0.05) in nondescript local pigs than the Hampshire and LWY pigs. The progressive motility of cauda epididymal sperm was 30.5 ± 5.6 and 70.5 ± 4.8% at two and three months of age, respectively while the corresponding live percent were 57.9 ± 7.2 and 82.6 ± 6.4 in nondescript local pigs. The nondescript local male pigs could mate and impregnate the females as early as 108.8 ± 8.0 days of age. It was inferred that the testicular growth was faster in nondescript local pigs compared to Hampshire and LWY pigs and the nondescript local male pigs have the capacity to mate and impregnate sows at 3–4 months of age.