Genetic improvement of egg production traits in Dokki -4 strain 1- correlated responses heritability, genetic and phenotypic correlations for egg production and egg quality traits
Abstract: Dokki-4 is a local strain selected for improving egg number during the first 90 days of laying. Genetic changes were estimated as deviations from its unselected control line per generation. This study was conducted to determine the effect of selection for two generations for egg production and- egg quality. The results of selection for egg number during the first 90 days of laying showed:
- Average egg number during the first 90 days of laying of the base, first, and second generation were 43.9, 52.7 and 61.9 eggs for the selected line and 43.6, 44.8 and 46.1 eggs for control line, respectively. The cumulative realized response and expected response after two generations were 15.5 and 5.3 eggs, respectively.
- Selected line pullets matured earlier than those of the control line by -6.9 and -8.7 days for the first and the second generation. Also, the realized cumulative response after tow generations was 7.5 days.
- Average duration period of the first 10 eggs of the base, first and second generations were 26.4, 24.4 and 22.2 days for selected line. The selected pullets decreased in the duration period of first 10 eggs than those of the control line by -2.05 and -2.19 days for the first and second generations.
- Egg number till 45 and till 65 weeks of age were increased in the selected line compared with the control line during two generations by 21.1 and 25.9 eggs respectively.
- Selected line had significantly better egg mass and feed conversion during the first 90 days of laying, till 45 and 65 weeks of age than the control line.
- Selected pullets had better egg quality characteristics (thicker shell, higher shell and yolk percentages, and Haugh Units) when compared to the pullets of the control line.
Most traits studied affected significantly (P<0.01) by generation.
- Heritability estimates for egg number during the first 90 days of laying, till 45 and till 65 weeks of age for selected line based on sire component of variance over two generation were 0.21, 0.19 and 0.23, respectively.
- Negative genetic and phenotypic correlations were found between egg number and body weight at sexual maturity, age at sexual maturity, duration period of the first 10 eggs, feed conversion while positive correlations were found between egg number and egg mass. As for the quality of the eggs shape index and shell thickness were found negative with egg number and yolk%, albumen %, shell % and Huagh Units were positive with egg number.
Generally, selection for egg number during the first 90 days of laying of Dokki-4 strain of chickens was able to increase egg number. This improvement was associated with early sexual maturity, high egg mass and better feed conversion. However, more studies are needed, in this strain (Dokki-4) to improve economic characteristics constantly.
Keywords: Correlated responses, heritability, correlations, egg production.
Publication year 2013
Pages 345-362
Availability location معهد بحوث الانتاج الحيوانى-شارع نادى الصيد- الدقى- الجيزة
Availability number
Organization Name
City الاسكندرية
serial title Egyptian Poultry Science Journal
ISSN 1110-5623
Author(s) from ARC
External authors (outside ARC)
    حسن حسن يونس جامعة كفر الشيخ
Agris Categories Animal husbandry
AGROVOC
TERMS		 Egg production. Heritability. Selection responses.
Proposed Agrovoc correlations;egg number;Genetic changes;egg quality;second generation;first generation;
Publication Type Journal
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