Abstract:
This study was conducted in HU poultry farm with the objective of evaluating and comparing production and reproduction performances, heterosis and combining ability up to the age at first egg laying for pure, straight and reciprocal crosses of Koekoek and White Leghorn poultry breeds. Two pure breeds of chickens namely Koekoek (KK) and White Leghorn (WH) were used in 2×2 diallel crossing experiment by AI mating system. From a total of 172 chickens (12 cocks and 160 hens), 3 cocks and 40 hens were used from each genotype for sire and dam line, respectively. Data of 288 chicks (144 males and 144 females) were randomly selected from 733 chicks after the 4th weeks and 72 chicks (36 males and 36 females) from each genotype with three replication were used for all measurements. The result showed that there were significant (p<0.05) differences in growth performance, body conformation measurements and feed conversion efficiency among genetic groups. The straight and reciprocal crosses were higher for growth performance traits, body conformation measurements and feed conversion ratio than pure genotypes and straight cross (WH ♂ × KK ♀) had the highest heterosis percentage for bodyweight traits, body conformation traits, feed conversion ratio than the other contemporary groups. Most results of GCA for pure G1 (KK ♂× KK ♀) were positive and had high estimations compared to that of GCA for pure G4 (WH ♂ × WH ♀). Also, the straight cross G3 (WH ♂ × KK ♀) had high positive SCA values compared to G2 (KK ♂ × WH ♀) cross. G3 (WH ♂ × KK ♀) revealed a higher FCR compared to other genotypes, except the pure G1 (KK ♂ × KK ♀) and recorded positive heterosis percentage. Positive maternal effects were verified for most of the growth and body conformation traits. Fertility percentages were higher for the pure genotype of White Leghorn (WH) with the value of 95.83% than the other contemporary groups. However, hatchability was significantly higher for straight (WH ♂ × KK ♀) (92.47%) and reciprocal crosses (KK ♂ × WH ♀) (94.63%), than the two pure genotypes. It was concluded that using White Leghorn as a sire line and Koekoek as a dam line resulted in G3 (WH ♂ × KK ♀) cross improved growth performance, early maturity and high adaptive traits in the studied periods.
