In genetic improvement programmes for beef cattle, the effect of selecting for a given trait or index on other economically important traits, or their predictors, must be quantified to ensure no deleterious consequential effects go unnoticed. The objective was to compare live animal measurements, carcass composition and plasma hormone and metabolite concentrations of male progeny of sires selec...

Growth and carcass data of Angus cattle were used to estimate heritabilities and genetic and environmental correlations between growth and carcass traits by means of a Bayesian data augmentation (DA) algorithm. Records were taken on 739 Angus steers from 31 sires, during 10 years of a designed progeny test. The cattle were entirely fed on grass during their lifelong. Growth traits evaluated wer...

An experiment was conducted to investigate the effect of short-term selection for 4 week breast weight (4wk BRW), and to estimate genetic parameters of body weight, and carcass traits. A selection (S) line and control (C) line was randomly selected from a base population. Data were collected over two consecutive hatches for four generations. A total of 1 135 records from 156 sires and 218 dams ...

Heritabilities of and genetic correlations between additive direct and maternal genetic effects for calf market weight, and additive direct genetic effects for carcass traits, were estimated for Japanese Black cattle by REML procedures under 2-trait animal models. Data were collected from calf and carcass markets in Hyogo and Tottori prefectures and analyzed separately by prefecture. Calf marke...

The current research was conducted to estimate the heritability coefficients and the genetic correlations for performance and carcass and body composition traits in a single sire broiler line. The performance traits analyzed were BW at 38 d, ultrasound records of pectoral muscle depth, feed intake, feed conversion ratio, and BW at 42 d. The carcass traits analyzed were eviscerated BW, breast we...

Quantitative trait loci (QTL) were identified for traits related to carcass and meat quality in Scottish Blackface sheep. The population studied comprised a double backcross between lines of sheep previously divergently selected for carcass lean content (LEAN and FAT lines), comprising nine half-sib families. Carcass composition (600 lambs) was assessed non-destructively using computerised tomo...

Design of breeding programs requires knowledge of variance components that exist for traits included in specific breeding goals and the genetic relationships that exist among traits of economic importance. A study was conducted to evaluate direct and correlated genetic responses to selection for intramuscular fat (IMF) and to estimate genetic parameters for economically important traits in Duro...

Marker-assisted selection holds promise because genetic markers provide completely heritable traits than can be measured at any age in either sex and that are potentially correlated with traits of economic value. Theoretical and simulation studies show that the advantage of using marker-assisted selection can be substantial, particularly when marker information is used, because normal selection...

This genome-wide association study (GWAS) was conducted to identify major loci that are significantly associated with carcass weight, and their effects, in order to provide increased understanding of the genetic architecture of carcass weight in Hanwoo. This genome-wide association study identified one major chromosome region ranging from 23 Mb to 25 Mb on chromosome 14 as being associated with...

Artificial selection in closed populations can fix or differentiate alternative alleles of loci associated with selected traits. Two closed chicken populations, A and B, originating from Jiuwu, a Chinese native breed, were bred for more than 10 generations. We compared progeny from reciprocal crosses (AB and BA) under free range (trial 1) and cage and pen (trial 2) systems. Traits measured incl...