This study was carried out to investigate the effect of different concentrations of selenium nanoparticles (Se-NPs) in the Beltsville Thawing Solution (BTS) extender on the semen quality and fertility of Hampshire crossbred pigs. For the study, semen was collected from four boars (10 ejaculates/boar) by the gloved hand method. Each ejaculate was extended @ 1:2 with the BTS extender and split into four aliquots. The control (C) samples were without the supplementation of Se-NPs, whereas the other three were supplemented with 0.5 (T1), 1 (T2), and 2 μg ml⁻¹ of Se-NPs (T3) and stored at 15°C in a BOD incubator. Extended semen was evaluated at 0 (immediately after dilution), 24, 48, 72, and 96 h of storage for sperm motility, live sperm, plasma membrane integrity, acrosome integrity, DNA integrity, and mitochondrial membrane potential (MMP). The mean percentage of sperm motility, live sperm, and sperm with intact plasma membrane and acrosome, and MMPs were significantly (p < 0.01) higher in all treated groups in comparison to control at 24, 48, 72, and 96 h of storage. Sperm with intact DNA in all treated groups increased significantly at 48 (p < 0.05), and 72 and 96 (p < 0.01) h of storage in comparison to the control group. The concentration of 1 μg ml⁻¹ of Se-NPs was found to be the best among other concentrations. In each group, 10 sows were artificially inseminated with the liquid semen preserved for 72 h at 15°C. Supplementation of 1 μg ml⁻¹ of Se-NPs yielded the highest conception rate in comparison to other groups. In conclusion, supplementation of 1 μg ml⁻¹ of Se-NPs in the BTS extender resulted in the best semen quality and conception rate during the short-time liquid preservation of boar semen.

Highland pastoralism provides economic sustainability to the tribal livelihoods and is endemic to the yak-rearing tracts of India. Transhumant pastoralists of Arunachal Pradesh (in India) have centuries-old deep socio-religious and economic connections with this unique bovine species. As a result of their conservation efforts, Arunachali was recognized as the first and is still the lone breed (to date) of yaks in the country. A survey was conducted on the pastoral production system in the region to enable the phenotypic characterization of yaks and to understand the prevailing husbandry practices. Arunachali yaks are medium-sized bovines that are predominantly black with dense and long hairs hanging down the body and are docile in temperament. They have a convex head with horizontal ears and distinctly curved horns with pointed tips. The average milk yield is 0.98–1.04 kg milk/day with 7.45% fat and 11.5% SNF and the peak milk yield/day is 1.1–1.6 kg. The average ages of clipping of coarse hairs and down fibres are 12–18 months and 12 months, respectively, with average yields of 1.5 kg and 0.5 kg/clipping/animal, respectively. Value addition of yak milk and fibre presents a unique opportunity for the economic rejuvenation of yak pastoralism. However, winter feed scarcity, inbreeding, extreme climate events and the non-availability of essential services are still major challenges for yak production in the country. Our findings acknowledge that pastoral sustainability is critical for the conservation of yaks and yak rearing. This calls for pastoralism-centric governance and research efforts in the highlands to curb the declining population and to put Indian yaks on the road to sustainability.