High-resolution genomic analysis of four local Vietnamese chicken breeds.

In Vietnam, local chicken breeds account for over 70% of the national poultry population. Although these breeds are abundant, their productivity is low and their use is threatened by the extensive importation of foreign productive breeds. In this context, conservation programmes targeting several emblematic breeds have been established. The goal of these programmes was to characterize endangered breeds and maintain a pool of characteristic birds for preserving their genetic heritage. To contribute to these programmes, we comprehensively characterized four Vietnamese local chicken breeds (Dong Tao, Ho, Mia and Mong) at the genomic level using high-density single-nucleotide polymorphism (SNP) genotyping. Despite originating in geographically close areas, Dong Tao and Ho were evidently different from each other as well as from Mong and Mia, which shared a more recent common ancestor. The genomic inbreeding coefficient revealed high homozygosity amongst the four breeds (10%-20%). The observation of clear differentiation at the genomic level supported the presence of distinct breeds; nonetheless, the occurrence of crossbred birds in a presumably purebred sample demonstrated the need to apply genomic tools to unambiguously assign the birds to the correct breed. Moreover, the occurrence of substantial inbreeding and the presence of subgroups in certain breeds warranted attention to create future nuclei for use in the conservation of these local breeds.

Comparison of the Welfare of Gestation Sows Raised in Different Production Systems in North Vietnam.

Intensification and complexity of pig production systems may require different strategies for animal welfare improvement. We aimed to identify welfare issues of gestation sows and areas for improvement by comparing four production systems, including the smallholder pen-based system (SPS: 26 farms), smallholder stall-based system (SSS:14 farms), semi-intensive stall-based system (SES: 15 farms), and intensive stall-based system (ISS: 10 farms). Ten significant animal-based measures in the Welfare Quality® protocol were used for welfare assessment at the individual level. Stall-housed sows in SES and ISS faced more welfare problems where sows presented a higher prevalence of poor body condition (P < 0.001), wounds on body (P = 0.003), fear of humans (P < 0.001), and stereotypies (P < 0.001) than pen-housed sows in the SPS. Sows in the SPS presented the highest prevalence of panting (P < 0.001). Welfare improvement should be focused on minimizing the adverse effects of hot weather on sows in the SPS and SSS and redesigning a more welfare-friendly housing system that prevents sows from the risk of wounds on body and enables them to perform motivated behaviors in the SES and ISS.