PHENOTYPIC VARIANT IN GROWTH AND DEVELOPMENT AMONG MALE AND FEMALE ARBOR ACRES CHICKEN STRAINS
Abstract
The performance of broiler birds is determined by its genotype and environmental factors which are determinants of variations in the phenotype. A total of fifty (50) day-old Arbor Acres broiler chicken were used for the study. Body weight (g) were measured using a digital sensitive scale while the linear body measurements (cm); wing length (WL), shank length (SL), thigh length (TL), comb length (CL), back length (BL), breast girth (BG) and keel length (KL) were measured with the aid of a measuring tape. The experiment lasted for 28 days. Data collected were subjected to one-way analysis of
variance (ANOVA) to generate the variance components using SAS statistical package. The variance components were subsequently used to generate the genetic parameters. The results showed that male chickens (237.10g) were superior in body weight to female chickens at 2 weeks (231.55g), though some of the linear traits (WL, TL and CL) were better in female chickens. The results of the body weight for female chickens (569.92g) were superior at the 4th week than the male chickens (545.23g). The heritability estimates was highest in BG and KL for female chickens while SL presented the
highest value of 0.71 and the lowest value of 0.50 in male and female chickens respectively. Amongst the linear body measurements, SL (0.68cm) and BL (0.68cm) had the highest repeatability value in male chickens while repeatability value was highest in CL (0.66cm) amongst the linear measurements in male chickens. It was concluded that male chickens perform better than female chicken early in life. Arbor Acre chickens could be effectively selected on the basis of KL at 2 weeks, and SL and KL at 4 weeks because their heritability was moderate to fairly high for improved performance and
significant genetic gain in subsequent generations.