Growth Performance of Indigenous X Exotic Crosses of Chicken and Evaluation of General and Specific Combining Ability under Sudan Condition

Abstract

Two thousand three hundred and fourty six chickens, line X tester crosses were obtained from fifteen consecutive hatches at weekly interval. Testers were exotic cockerels; Rhode Island Red (RIR), Bovans (BO) and Egyptian Fayoumi (FO), while lines were indigenous hens; large Baladi (LB), Bare-neck (BN) and Betwil (BT). The nine genetic groups of crosses were reared up to 18 weeks of age in litter opened-house system. Significant differences (DMRT 5%) for average body weight of different crosses were obtained at hatching, 2, 14, 16 and 18 weeks of age. Biweekly average weight gain showed similarity in growth pattern of the various crosses. Sex affected body weight insignificant at hatching, whereas the differences were significant (P< 0.05) at 2 weeks of age and highly significant (P< 0.01) for the subsequent ages. Hatching effect was found to be highly significant (P< 0.01) on body weight at various ages; however, sex X hatch interaction was found to be significant (P< 0.05) at day old and disappeared thereafter. The average live weight at 18 week of age for the nine groups was adjusted for hatching and sex effects. There were significant differences (P< 0.05) of lines and testers, however, line X tester interaction was not significant for 18 weeks body weight. The estimated general combining ability (gca), thus the additive gene effect, was relatively high for both lines (-42.03, 19.90 and 22.13) and testers (-36.74, 10.74 and 26.00). On the other hand the specific combining ability (sca), which involves dominance, over dominance and epistasis effects, was found to be minor in both positive and negative values for the nine groups, ranging from -14.66 to 17.37. The general combining ability estimated was of high value and seemed to be much important than specific combining ability for body weight at 18 weeks of age.