Prolactin haplotypes and their effect on body weight and egg production in the KU line of Betong chicken

Abstract

Body weight and egg production need to be considered for the selection of parents in the KU line of Betong chicken. The allele, genotype and haplotype frequencies were determined of single nucleotide polymorphisms in the 5’-flanking region (5FA) of the prolactin (PRL) gene and the effect was estimated of haplotypes on body weight at age 16 wk (BWT), hen weight at first egg (WFE), age at first egg (AFE), first egg weight (FEW) and egg number at age 42 wk (ENO) in Betong chicken (KU line). Data and blood samples were collected from 297 hens. Haplotypes in 5FA of the PRL gene were identified using polymerase chain reaction and restriction fragment length polymorphism with the CViQI and AluI restriction enzymes. The results showed that at site -358 in 5FA of the PRL gene, the frequency of the deletion (D) allele was higher than that of the insertion (I) allele, at site -2161 the frequency of the G allele was higher than that of the C allele and at site -2402 the frequency of the T allele was higher than that of the C allele. Five haplotypes were found and haplotype DDGGTT had the highest frequency (0.667). The effects of PRL haplotypes were not significant for all traits. Therefore, the five haplotypes identified would not be useful for selection programs aimed at improving body weight and egg production in the KU line of Betong chicken.