EFFECT OF SELECTION FOR BODY WEIGHT ON EGG PRODUCTION, EGG QUALITY, FERTILITY AND HATCHABILITY TRAITS in EL-SALAM CHICKEN STRAIN IN EGYPT

Abstract

This work was carried out at Sakha Poultry Production Research Station, Animal Production Research Institute, Ministry of Agriculture, during two successive generations in order to estimate the correlated response in egg production, egg quality and hatch traits to selection for body weight at 12 weeks of age in El-Salam chicken strains. Traits under taken were body weight, egg number, egg weight, egg mass, egg quality, fertility. Heritability, genetic and phenotypic correlations among studied traits were estimated. The means of body weight at 12 week of age in El-Salam chicken strain in the base, first and second generations for males were 868.3, 903.6 and 942.9 g and for females were 838.6, 868.3 and 881.3g for selected line, respectively. Moreover, males and females in the selected line were heavier than corresponding birds in the control one for all generations. After two generations selected for body weight, selected line was significantly higher body weight than control line by 85.4 and 33.6g in average means 9.8% and 4.0% superiority for male and female respectively. Selection to the weight of the body lead to the delayed age at sexual maturity, as well as increased body weight at sexual maturity and the period until the first ten eggs. Means of egg number and feed conversion were significantly reduced by generations. Moreover, egg weight and egg mass for selected line were significantly heavier than those of the control one. As generational succession caused significant improvements on Haugh units, it decreased egg shape index, shell thickens, albumen and yolk percentages. Furthermore, egg shape index and shell percentage were significantly (P<0.05) affected by lines. Also, data showed no significant interactions between generations and lines on all of tested egg quality traits. Reproductive performance as fertility and hatchability percentages were significantly (P≤0.05) reduced by -2.9 vs. -0.6% after progress two generation of selection, but not affected by lines separately or as combination with generations. Heritability estimated for body weight at 12 week of age were 0.67 based on sire variance component (h2s). Negative genetic and phenotypic correlations were found between body weight at 12 week of age with egg number, egg mass, fertility, hatchability, egg shape index, yolk%, shell% and shell thickens, while the positive effect were found for body weight at sexual maturity, age at sexual maturity, the period until the first 10 eggs, egg weight, feed conversion, albumen % and Hough unit.