Phenotypic characterization of chicken inbred lines that differ extremely in growth, body composition and egg production traits

Abstract

The development of phenotypically and genetically divergent inbred chicken lines as simplified genetic models facilitates the identification of genes and contributes to the elucidation of gene functions. In this study, we characterized a New Hampshire (NH) population with its partial inbred derivative, New Hampshire inbred (NHI), and a White Leghorn inbred line (WL77). Both NHI and WL77 lines were inbred after selection for high meat yield or low egg weight, respectively. The inbreeding levels in NHI and WL77 are about 86 % and 100 %, respectively. Animals of the NHI line grew twice as fast, were about two times as heavy at 20 weeks, and deposited 9.3 times as much fat as WL77. NHI females reached sexual maturity, indicated by age at first egg, earlier, had a 35 % higher egg production ratio, and their eggs were on average 6 g heavier compared to WL77 females. The NHI and WL77 lines were extremely different for most traits, which makes them suitable for cross-bred experiments to map quantitative trait loci and identify genes contributing to the observed differences.

Fine mapping of a distal chromosome 4 QTL affecting growth and muscle mass in a chicken advanced intercross line

“…Measurement methods for the above body composition traits were described previously (Goraga et al . ).…”

“…The characterization of parental inbred lines NHI and WL77 as well as the generation of the F 2 population (NHI × WL77) have been described previously (Goraga et al . ; Nassar et al . ).…”

Quantitative trait loci segregating in crosses between New Hampshire and White Leghorn chicken lines: IV. Growth performance

“…The inbreeding levels in NHI and WL77 lines were 86 and 99% respectively (Goraga et al . ). These lines could harbour line‐specific alleles contributing to the extreme traits that differ from chickens that were used for other mapping experiments.…”

“…The inbreeding coefficient in the NHI line was 86% at the time the cross‐bred experiment was performed (Goraga et al . ). This could also affect potential QTL and genetic background interaction effects.…”

Quantitative trait loci segregating in crosses between New Hampshire and White Leghorn chicken lines: II. Muscle weight and carcass composition

“…We used the dual purpose line New Hampshire (NHI), which had been selected for high meat yield at the age of 20 weeks, and the layer line White Leghorn (WL77), which had been selected for low egg weight during the laying period (Goraga et al . ). NHI chickens had about twice as heavy breast muscles and 2.4 times heavier drumsticks–thighs than WL77 chickens did.…”