Estimation of Genetic Parameters, Inbreeding Trend and its Effects on Production and Reproduction Traits of Native Fowls in Fars Province

Abstract

In this study, the data and pedigree records of the native fowls collected by Fars Native Fowls Breeding Center during 1990-2004 were analyzed. A pedigree file collected on 30855 hens and roosters was used to calculate the inbreeding coefficients and its trend and its effect on production and reproduction traits. The average of inbreeding coefficient for all birds was 0.002% ranging from 0 to 14.8%. In this population, 14% of the birds were inbred with an average inbreeding coefficient of 0.019%. The Inbreeding coefficient was considered as covariate to estimate its effect on economic traits including body weight in 12 weeks (BW12), egg number during 12 weeks (EN), mean egg weight between 28 to 32 weeks (MEW) and Age of Sexual Maturity (ASM). Results showed that inbreeding does not have a significant effect on the traits under study (p > 0.05). Moreover, heritability, genetic and phenotypic correlations between traits was estimated through a multiple traits animal model procedure by restricted maximum likelihood using ASREML software. The estimated heritabilities were 0.53, 0.47, 0.57 and 0.22 for body weight in 12 weeks (BW12), Age of Sexual Maturity (ASM), mean Egg Weight (EW) and Egg Number (EN), respectively. Because of relatively high heritabilities of productive and reproductive traits, it is possible to achieve more genetic gains in these traits using appropriate genetic selection.

Investigating the genetic determination of clutch traits in Chinese local chicken breed

“…Estimates of genetic parameters for clutch related traits revealed that the afe had the highest heritability estimate (0.76). In the literature, the afe has been reported as a trait with moderate heritability (0.36-0.55) [4,[21][22][23], which is in agreement with our estimates. Our results also showed that the number of clutches had a moderate heritability estimate (0.36), which is similar to related studies showing that the heritability of the number of clutches and average clutch length is around 0.15-0.68.…”

Genetic and Phenotypic Trend and Inbreeding Effects for Sexual and Egg Production Traits of Iraqi Local Chickens

“…result of the selection of birds with high egg production and with ideal age at sexual maturity on the one hand and introduced ideal environmental conditions as possible on other hand. In this regard, many researchers [22,23] proposed that selecting hens with less age at sexual maturity would increase egg production.…”

“…Generally, inbreeding has an effect on egg production and egg mass but its effect was negative on the sexual traits of Iraqi local chicken. Shad et al [23] and Tongisri et al [21] conclude that the rate of inbreeding with reasonable or low levels had no detrimental effect on the performance or vigor of Iranian or Thai native chickens. A high level of inbreeding rate may affect negatively some traits but could affect positively on some other traits .…”

Genetics and genomics of egg production traits in poultry species

“…Grown pullets start laying eggs when the length of the day increases which, in the production industry, is supplemented with artificial light stimulation. However, there is also a strong genetic component for age at maturity, typically measured as age at first egg, with estimates of heritability reported to be moderate (0.36-0.55; Niknafs et al, 2012;Wolc et al, 2010Wolc et al, , 2011aShad et al, 2013). Age at first egg has an optimum dependent upon breed and production system.…”