An experiment was conducted to determine whether ahemeral lighting (AH) could be used to obtain increased egg weight and poult weight and otherwise normal reproductive performance in Large White turkey hens lit as early as 26 wk of age. The experimental design utilized a 2 x 2 factorial arrangement of treatments that evaluated two light cycle lengths (24 h, control and 28 h, ahemeral) at two he...

Hatchability is a very important trait in a breeding program which has a great economical impact on franchise hatcheries. The variability between and within strains raises the question whether reproductive performance can be improved by selection within lines. The aim of this study is to analyse the genetic background of the hatchability and its correlations between egg quality and production t...

An experiment was conducted to determine the effect of time of oviposition, generally representing different positions in the normal egg laying sequence, on egg weight loss during storage and incubation, and on fertility and fertile hatchability of eggs from mid-lay (42 wk) and old (67 wk) broiler breeders. A total of 1,800 eggs (900 eggs per flock age) were collected during 10 consecutive days...

1. Experiments were conducted to study the effects of dietary vicine (2, 6-diamino-4, 5 dihydroxy pyrimidine-5 (beta-D-glucopyranoside)) and supplemental vitamin E on the performance of laying hens and growing chicks, haemolysis of erythrocytes than birds fed on a control diet. 3. Vicine when fed to laying hens had a very dramatic effect. It depressed food consumption, egg weight, fertility and...

This experiment was designed to evaluate the effect of naked neck (Na) and frizzle (F) genes on eggshell ultrastructure at different intervals of incubation period. 81 eggshell samples (9 samples/ genotypes/ incubation studied intervals) were taken before incubation period, at 12 days of incubation period and after hatching. Before incubation period, the present results showed that the presence...

The current study investigated the effect of short-term selection for four week body weight (BW) on performance of divergent lines of Japanese quail and their crosses. The mean of BW at hatching time, one, two, three and four week oldand BW at sexual maturity time, age at sexual maturity, number of eggs (from 50 to 100 days old), mean of egg weight, percentage of fertility and hatchability in e...

Recent trends occurring in broiler primary breeding companies are described. The structure and operation of broiler primary breeder companies are described from pedigree elite populations, through great-grandparent and grandparent generations, down to the parent stock. The relatively low value of fertility and hatchability, compared with yield and feed efficiency as selection traits, is assesse...