Genetic and phenotypic correlation coefficients of quantitative traits in two chicken genotypes

This study was carried out to estimate genetic and phenotypic correlations of morphometric traits of a newly developed Nigerian poultry breed (FUNAAB Alpha) and Noiler chickens. A total of 300 unsexed day-old-chicks comprising 150 each of the two genotypes were raised for eighteen weeks. Superior individuals (4 cocks and 20 hens per genotype) from first phase were selected based on weight to constitute parents of 100 birds per genotype raised in second phase for 12 weeks. Body weight, and linear body measurements (body circumference, breast girth, thigh length, shank length and wing length) were taken on weekly basis. Growth data were analysed using Generalized Linear Model of SAS and least significant difference (LSD) test was used to separate significant means for the genotypes. Computed variances and covariances (PROC MIXED DATA) were used to estimate genetic and phenotypic correlations. Results showed that Noiler chicken had higher (p<0.05) body weight and linear body measurements from 10 to 18 weeks with average weight of 2079.55 g compared with 1895.29 g for FUNAAlpha. Positive genetic correlations were observed among the traits of interest in both FUNAAlpha and Noiler with the latter having higher genetic correlation coefficients which ranged between 0.573 (TL x SL) and 0.953 (BG x BC) at week 12. Sexual dimorphism favoured male birds in all the traits measured. The implication of these results is that it is important to know both the effect of the trait actually being selected and its effect on the other traits. Genetic correlations result from pleiotropic effects of genes on multiple traits or from chromosomal linkage of genes affecting different traits. It estimates the degree to which the traits studied are affected by the same genes (Pleiotropic) or pairs of genes.