University of Khartoum

Egg Characteristics, Genetic and Phenotypic Relationships of Body Weight at Various Ages in Indigenous Chicken.

Egg Characteristics, Genetic and Phenotypic Relationships of Body Weight at Various Ages in Indigenous Chicken.

Show full item record

Title: Egg Characteristics, Genetic and Phenotypic Relationships of Body Weight at Various Ages in Indigenous Chicken.
Author: Mobarak Fadl El Moula, Suliman
Abstract: The objectives of this research were to study the productive and reproductive traits of the indigenous chicken under relatively improved management and the genetic and phenotypic parameters of body weight estimates at biweekly intervals from hatching to 8 weeks of age. The experiment was conducted using 40 cockerels and 120 pullets randomly chosen from rural areas. Each cockerel was randomly assigned to mate with three pullets in a rotation pattern. Egg production of individually caged pullets was recorded on a daily basis, weighed and incubated to obtain ten consecutive hatches at weekly intervals. Fertility, hatchability and embryonic mortality were regularly recorded. Chicks of each hatch were graded, identified, weighed and reared in brooder up to 8 weeks of age. The total number of hatched chicks was 2842. However, only 960 chicks (469 males and 491 females), progeny of 40 sires and 108 dams, were used in the genetic analysis. Body weights were taken from hatch to 8 weeks of age at biweekly intervals. Chick mortality was regularly recorded. Feed consumption and feed efficiency of the parent stock were also recorded. Heritability of body weight at different ages was estimated from sire, dam and sire plus dam components of variance for sex combined and separately for each sex. The genetic, phenotypic and environmental correlations between body weights at various ages were also estimated. The average egg production per hen per week and during 76 days was 3.4 and 37, respectively, whereas the average hen-day and hen-housed production during 10 weeks were found to be 49.0 and 48.2%, respectively. The average egg weight was 40.6±4.3 g with CV equal 11.2%. The results indicated that egg weight was significantly affected by season. The average fertility was 91.5%, while the average hatchability of all eggs set and of fertile eggs were 80.7 and 88.5%, respectively. The early and late embryonic deaths were 3.2 and 1.5%, respectively. The average feed consumption per bird per day and the average feed efficiency per dozen egg were 89.4 g and 2.2 kg, respectively. The average final weight of males and females parent stock were 1636±239.5 and 1272±289.5 g, respectively. Body weight of male chicks at hatch, 2, 4, 6 and 8 weeks of age were 28.0±2.6, 55.0±8.6, 112.2±23.4, 189.2±37.2 and 310.1 ±51.1 g, respectively. The corresponding weights of females were 27.9±2.4, 51.9±7.9, 102.7±22.7, 171.5±37.3 and 271.8±52.1, respectively. Hatch effect on body weight was significant (P<0.01) at all ages. Sex affected body weight significantly (P<0.01) at 2, 4, 6 and 8 weeks of age, with males being heavier than females indicating the presence of sexual dimorphism. There was significant hatch x sex interaction (P<0.01) in 4 and 8 week body weights. The effect of sire on body weight was only significant (P<0.0l) at 6 and 8 weeks of age, whereas the dam effect was significant (P<0.0l) at hatch, 2 and 4 weeks of age. Heritability estimates at various ages ranged from low (0.04±0.l0) to high (0.97±0.11). Estimates from paternal half-sibs at hatch, 2 and 4 weeks of age were non-estimable due to negative covariances. Heritability estimates from paternal half-sibs for females and males at 6 weeks were 0.13±0.11 and 0.04±0.l0, respectively. The corresponding estimates at 8 weeks were 0.31±0.14 and 0.19±0.13, respectively. The genetic correlations were positive and high in magnitude, whereas the phenotypic correlations were also positive but relatively lower than the genetic correlations and exhibited a general decreasing trend with increased time interval between weighings. The environmental correlations in most cases were positive and high.
URI: http://khartoumspace.uofk.edu/handle/123456789/13987
Date: 2015-06-22


Files in this item

Files Size Format View

This item appears in the following Collection(s)

Show full item record

Share

Search DSpace


Browse

My Account