Estimation of genetic parameters for carcass traits in Japanese quail using Bayesian methods

Abstract

The aim of this study was to estimate genetic parameters of some carcass characteristics in the Japanese quail. For this aim, carcass weight (C w ), breast weight (B w ), leg weight (L w ), abdominal fat weight (AF w ), carcass yield (C P ), breast percentage (B P ), leg percentage (L P ) and abdominal fat percentage (AF P ) were measured on approximately 500 quails (offspring of 60 sires and 180 dams). Gibbs sampling (GS) under a multi-trait animal model was applied to estimate heritability and genetic correlations. Genetic analyses were performed using MTGSAM (Multiple Trait Gibbs Sampling) software. Heritability estimates for all the traits were low to moderate. Point estimates (means of marginal posterior densities) of heritabilities for C w , B w , L w , AF w and C P , B P , L P , AF P were 0. 42, 0.36, 0.34, 0.40 and 0.11, 0.18, 0.12, 0.29, respectively. Genetic correlations between the carcass parts (C w , B w , L w , AF w ) were high and positive, ranging from 0.65 to 0.87. Direct selection for total carcass weight would increase its component traits. There were moderate to high negative genetic relationships between AF P and L P (-0.27), AF P and B P (-0.34), and AF P and C P (-0.89). Therefore, a decreasing AF P in quail could be reached by direct selection for higher C P .________________________________________________________________________________

Effects of Breeder Age on Genetic Parameter Estimates of Slaughter and Carcass Traits in Japanese Quail

“…In the study, a heritability estimation (0.36) for CW was found lower than the values reported by Vali et al (2005) In the study, the heritabilities estimated for CY in the flocks obtained when the breeders were at 12, 16, and 20 weeks of age (0.16, 0.11, and 0.15, respectively) and the heritability estimated when all flocks were evaluated collectively (0.14) were found at a low level. The findings concerned were found in agreement with the heritabilities estimated for CY by Vali et al (2005) Similarly, the heritabilities estimated for BRY and LY were also found in agreement with the findings by most researchers (Toelle et al, 1991;Vali et al, 2005;Narinç et al, 2010;Lotfi et al, 2011;Akbernejad et al, 2015). The heritability for AFY was estimated as 0.16 for the flocks obtained at different breeder ages but as 0.18 when all flocks were taken into consideration.…”

“…In the study, the genetic correlations between AFW and BW, between AFW and CW, between AFW and BRW, and between AFW and LW were estimated as positive and at moderate to high levels. These results are parallel with the findings by a large number of researchers (Akşit et al, 2003;Narinç et al, 2010;Lotfi et al, 2011).…”

“…The heritability for AFY was estimated as 0.16 for the flocks obtained at different breeder ages but as 0.18 when all flocks were taken into consideration. The literature contains estimations of low to moderate heritabilities for AFY in quails, which is in agreement with the results of the study (Akşit et al, 2003;Narinç et al, 2010;Lotfi et al, 2011).…”

“…The heritabilities of CW were found at high levels (0.40-49), but the general heritability was found moderate (0.36) in the flocks obtained at different breeder ages in the study. Various researchers reported that the heritability estimates for BW and CW in poultry were at moderate and high levels (Toelle et al, 1991;Gaya et al, 2006;Narinç et al, 2010;Daikwo et al, 2013). In the study, a heritability estimation (0.36) for CW was found lower than the values reported by Vali et al (2005) In the study, the heritabilities estimated for CY in the flocks obtained when the breeders were at 12, 16, and 20 weeks of age (0.16, 0.11, and 0.15, respectively) and the heritability estimated when all flocks were evaluated collectively (0.14) were found at a low level.…”

“…Constant age weights were used as the criterion for selection in most of the selection practices carried out in Japanese quails. The carcass traits were also indirectly developed with the method of selection employed so due to the high heritabilities for the constant age weights and owing to the high genetic correlations between these traits and the slaughter and carcass traits (Narinç et al, 2010). However, the genetic correlations between slaughter weight and the traits of carcass ratio, breast ratio, and leg ratio (when all data were evaluated) were estimated as -0.42, -0.31, and -0.44, respectively.…”