Diallel Cross Analysis for Growth Traits in Improved Normal Feathered and Naked Necked Nigerian Indigenous Chickens

This study was carried out to evaluate the crossbreeding effect on the growth traits of normal feathered and naked necked improved Nigerian indigenous chicken FUNAAB alpha. One hundred (100) experimental birds aged forty (40) weeks, comprising 20 cocks and 80 hens were used. The birds were arranged in four (4) genetic groups GG1, (NF X NF), GG2 (NN x NN), GG3 (NN X NF) and GG4 (NF X NN) with each genetic group having 5 sires and 20 dams, (a mating ratio of one cock to 4 hens). Mating was carried out using artificial insemination to produce one hundred chicks. The traits monitored were body weight (BW), body length (BL), chest girth (CG), wing length (WL), leg length (LL), shank length (SL), and shank circumference (SC). The data obtained from these traits at hatch, week 4, week 8, week 12 and week 16 were subjected to multivariate analysis of variance. The results indicated that there were significant (P˂0.05) differences in body weight among the four genetic groups. At hatch NF X NN had the highest body weight (42.60g) as compared to 37.69, 36.96 and 38.22 for NF X NF, NN X NN and NN X NF respectively. A similar trend was observed at weeks 4, 8 and 16 with NF X NN cross having a higher body weight than the other genetic groups. No significant (P˃0.05) variation was noticed in body weight among the four genetic groups at 12 weeks of age, only numerical differences existed. The heterosis estimates for body weight from day old to 16 weeks of age were positive and higher in the main cross (NFXNN) than in the reciprocal cross (NNXNF). A similar trend was noticed in all the other traits. The results showed that the main cross (NFXNN) had strong and positive additive effect at all ages (2.25, 34.10, 67.08, 16.93 and 52.44) while the reciprocal cross (NN X NF) had weak and negative additive effect at all ages (-1.49, -10.13, -36.94, and -0.92) except for week 12 that was positive 0.62. It was observed further that the reciprocal effects for body weight at week 8 and 16 were strong and high 67.58 and 67.06. The result showed that the specific combining abilities for body weight and body length were all positive for the main (NF X NN) cross but negative in the reciprocate (NN X NF) cross for all ages. In view of the performance in body weight, chest girth and body length in this experiment, the combination of normal feathered and naked necked genes as sires and dams, respectively, is recommended to bring about genetic improvement in all the studied traits.