GENETIC STUDY OF EGG LAYING PERFORMANCE IN FOUR LOCALLY DEVELOPED STRAINS OF CHICKENS | ||||
Journal of Animal and Poultry Production | ||||
Article 1, Volume 25, Issue 6, June 2000, Page 3187-3195 PDF (651.57 K) | ||||
Document Type: Original Article | ||||
DOI: 10.21608/jappmu.2000.259377 | ||||
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Author | ||||
A. F. M. El-Labban, | ||||
Animal Production Research Institute, Agriculture Research Center, Ministry of Agriculture. | ||||
Abstract | ||||
A total number of 364 pedigreed pullets at sexual maturity was used randomly which contained 90 Mandarah (MN), 84 Golden Montazah (GM), 96 Silver Montazah (SM) and 94 Matrouh (MT) to study the genetic parameters of egg laying performance in four consecutive months in each strain. Results obtained are summarized as follows: 1- Matrouh pullets reached age at sexual maturity earlier than other strains, hence, they had lighter average body weight compared to other strains at this age. Moreover, Matrouh excelled other strains with respect to average weight of first egg and number of days in which the first 10 eggs were laid. 2- Matrouh strain surpassed other strains in average total egg mass, total egg number and rate of laying . 3- Percentages of variance components showed that maternal and sex-linked effects are considered important factors in determining traits of egg laying performance in these strains. 4- In general, traits of laying performance had relatively higher heritability estimates, which suggest that rapid improvement of egg production in these strains could be reached by within family selection. 5- Genetic and phenotypic correlations among total egg number and each of age at sexual maturity, body weight at sexual maturity, weight of first eggs and number of days in which the first 10 eggs were laid in all strains indicated that, when the pullet reached its sexual maturity at an early, it could have the ability to produce more number of eggs. Moreover, first egg weight and number of days in which the first 10 eggs were laid would be decreased. 6- Genetic correlations among total egg number and average egg mass indicated that genes which affect total egg number may, also, affect egg mass. | ||||
Keywords | ||||
Strains; variance components; heritability; correlations | ||||
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