Genetic analysis of growth, production and reproduction traits afterlong-term selection in Rhode Island Red chicken

Abstract

In present investigation, 325 single-hatched RIR chicks that has undergone 30 generation of selection based on 40-week part-period egg production were evaluated for growth and layer economic traits using least-squares analysis of variance. Overall least-square means of body weight at 16, 20, 40 and 64 weeks of age were 1362.6±21.4g, 1791.6±24.5g, 2184.6±26.2g and 2433.8±34.2g, respectively. Males were significantly heavier than females (P£0.001) at all ages. Least-square means of age at sexual maturity, egg weight at 28, 40 and 64 weeks of age, egg number up to 40 and 64 weeks of age were 134.5±0.9days, 44.8±0.3g, 47.73±0.4g, 51.5±0.7g, 118.3±1.2eggs and 214.5±4.8eggs, respectively. Heritability estimates were high for growth and low to medium for layer economic traits. Genetic and phenotypic correlations among body weights were high and positive. The egg production up to 40 weeks revealed high and positive genetic (0.89±0.15) as well as phenotypic (0.63) correlations with egg production up to 64 weeks suggesting the its usefulness as selection criterion for genetic improvement of annual egg production.

Evaluation of Production Traits in Gramapriya Female Line Chicken Under Intensive System of Rearing

“…Whereas genetic and phenotypic correlation among BW 64 and EP 64 was very low and negative than the value reported [13]. Genetic and Phenotypic correlation between EW 64 and EP 64 was negative and very low compared with values reported in Naked neck chicken [13] and in RIR pure strain [43]. This clearly indicates that improvement in egg weight will result in reduced egg production.…”

Genetic Analysis of Egg Production Traits in Luhua Chickens: Insights from a Multi-Trait Animal Model and a Genome-Wide Association Study

“…The heritability of Start-EW in Luhua chickens was 0.30, which was similar to Japanese quail (0.26) [ 24 ]. The heritability of EW43 in Luhua chickens was 0.21, lower than EW40 in the Giza M-2 line local broiler breeders (0.39–0.42), but higher than the Rhode Island red chicken (0.09) [ 25 , 26 ]. However, compared to most of other local breeds in China, the heritability of EW-43 in Luhua chickens was found to be slightly lower, which might be a common characteristic of the local breed; moreover, heritability seemed to decrease with age [ 27 ].…”

Fold changes in relative mRNA expression of immune response genes in lymphoid tissues of Rhode Island Red chicken

“…RIR birds (12: 6 of either sex) were randomly chosen at 6-8 weeks of age, maintained at experimental layer farm of this institute in deep litter system and provided ad lib. feed and water, and standard management and vaccination practices (Rahim et al 2016). Three lymphoid tissues, viz.…”