Effects of genetic polymorphisms on egg production in indigenous Noi chicken

Abstract

Noi is a popular backyard chicken breed in the Mekong Delta of Viet Nam but egg production is still limited. The aim of the present study was to evaluate the genetic potential of candidate genes involved in egg yield of Noi chicken. Hens were individually stalled for daily egg record in 20 weeks. Feather samples were collected for DNA extraction and genotyping by PCR-RFLP method. Five genes namely DRD2 (Dopamine receptor 2), IGF-I (Insulin-like growth factor I), NPY (Neuropeptide Y), VIP (Vasoactive intestinal polypeptide) and VIPR-1 (Vasoactive intestinal peptide receptor 1) were used in this study. It was shown that at all loci there were two alleles and three genotypes, of which allele frequencies of DRD2/BseGI, VIP/VspI and VIPR-1/HhaI polymorphisms were of great discrepancy. In addition, significant associations between genotypes and egg numbers were found (PDraI, VIPR-1/TaqI and VIPR-1/HhaI loci had highest production with 50.9, 49.8 and 50.4 eggs/hen/20 laying weeks, respectively. The results provide an option for breeding selection of Noi chicken towards improving egg production.