ABSTRACT 

This experiment evaluated the production performance of three chicken strains in the humid tropics. Three hundred (300) day-old chicks, 100 each of Arbor Acre broiler (AAB), Noiler hybrid (NOH) and Yoruba ecotype chicken (YEC) were randomly replicated five (5) times with 20 birds per replicate in a Completely Randomized Design (CRD). Measurements were done in two phases 0-8 and 10-16 weeks. Body weight(BWT) and linear body parameters; body length(BL),keel length(KL),breast width(BWD),drumstick length(DL) shank length(SL), wing length(WL),body depth(BD) were measured fortnightly. Average daily feed intake (ADFI), average daily weight gain (ADWG), feed conversion ratio (FCR) and percentage mortality, carcass cut-parts and internal organ proportions were evaluated. Data obtained were analyzed using the SAS (2011) package for analysis of variance procedures and significant means separated using Duncan’s multiple Range Test.  Phenotypic correlations of body weight and linear body traits, live weight and carcass traits, as well as correlations among linear traits and repeatability estimates for weeks 4, 8, 12 and 16 were also done. Results obtained showed significant strain (P <0.05) effects for  Arbor Acre broiler over  other strains in final body weight at 16 weeks of age, Arbor Acre broiler (AAB) maintained strain superiority (P<0.05) in almost all the performance traits evaluated, average daily weight gain: AAB (35.24), NOH (6.24) and YEC (4.90), average daily feed intake: AAB (149.41), NOH (75.40) and YEC (68.79), feed conversion ratio: AAB (4.24), NOH (12.07) and YEC (13.82) except in percentage mortality where Noiler hybrid performed better (P<0.05) with 6% mortality. In carcass evaluation, Arbor Acre broiler maintained its superiority in both phases of (0-8) and (9-16) weeks of age, dressed percent: AAB (71.91%, 83.62%), NOH (53.96%, 78.36%), YEC (62.08%, 76.89%) and dressed weight: AAB (1131.67g, 3380.00g), NOH (600.00g, 1780.00g), YEC (460.00g, 1330.00g). Noiler hybrid and Yoruba ecotype strains performed better (P<0.05) in drumstick and wing. Yoruba Ecotype chicken had higher (P<0.05) shank length (6.57 cm) in week 9-16. Correlations between body weight and linear traits, live weight and carcass traits showed highly significant and positive associations. High to moderate associations were observed between live weight and internal organs in the Yoruba ecotype followed by the Arbor Acre broiler strain whereas low association was observed in the Noiler hybrid. Regression of body weight and linear body traits indicated that quadratic model produced better (P<0.05) coefficients of determinations (R² %) for Arbor Acre with higher accuracy of prediction in 10-16 weeks of age.  Repeatability estimates of body parameters for 4, 8, 12 and 16 weeks of age showed that both Arbor Acre and Noiler hybrid had the highest repeatability estimates of 71.33 ± 4.38 and 72.96 ± 4.38 for body length and drumstick respectively in the 16^th week of age and Yoruba ecotype with the highest estimate of 99.99 ± 5.18 in the 12^th week for drumstick. The results of this study revealed that AAB maintained superiority and showed significant values in body weight and linear body traits as well as other traits measured among the strains except for internal organ proportions where the Yoruba ecotype chicken maintained superiority. Noiler hybrid (NOH) and Yoruba ecotype chicken (YEC) have the potentials to be reared in humid tropics with improved management system.