The main aim of this research was to estimate the genetic and phenotypic parameters for productive and reproductive traits of Esfahan native chickens. Traits included body weights at hatch (BW1), 8 weeks of age (BW8), 12 weeks of age (BW12), and at sexual maturity (WSM)], age at sex maturity (ASM), egg number (EN), average egg weight (AEW) in the first 12 weeks of production, and egg production...

The objective of the present study was to estimate heritability values for some performance and egg quality traits of native fowl in Isfahan breeding center using REML and Bayesian approaches. The records were about 51521 and 975 for performance and egg quality traits, respectively. At the first step, variance components were estimated for body weight at hatch (BW0), body weight at 8 weeks of a...

the objective of the present study was to estimate heritability values for some performance and egg quality traits of native fowl in isfahan breeding center using reml and bayesian approaches. the records were about 51521 and 975 for performance and egg quality traits, respectively. at the first step, variance components were estimated for body weight at hatch (bw0), body weight at 8 weeks of a...

The effect on thermotolerance of the incompletely dominant frizzle (F) gene, which causes feather curling and feather mass reduction, was investigated in 281 laying hens that were homozygous for the frizzle mutation (FF), heterozygous (FN), or normally feathered (NN). One-half of the birds were kept under standard conditions (22°C) and half were exposed to high ambient temperatures (32°C) betwe...

The first objective of this study on broiler breeders was to investigate the genetic basis of variability in hatchability over age using a longitudinal model. Weekly percentage hatch of fertile and hatch of set eggs were available for 23,250 dams mated to 3,106 sires of the same age between the 28th and 54th week of life. Hatch of set was very highly correlated with fertility and showed a simil...

The objective of the current study was to estimate genetic and phenotypic correlations among feather pecking (FP) behavior and stress response, immune response, and egg quality parameters. These traits have been measured in an F2 cross, coming from a cross between a high and a low FP line of laying hens. Heritabilities (h2) of stress response (32 wk), primary immune response to keyhole limpet h...

The present study was conducted to investigate the effects of four different levels of dietary probiotic (protexin) on productive traits and egg quality of broiler breeder hens. One hundred sixty female 64-week-old broiler breeders (Hubbard classic) were involved in this experiment. The birds were randomly assigned to control Group A (unsupplemented diet), Group B (0.25% protexin supplemented d...