Morphological traits and correlation between body weight and body size traits in Isa Brown and Illorin ecotype chickens

Abstract

Data collected in 2012 on 400 chickens were subjected to two-way analyses of variance to estimate body weight, morphometric traits as well as the correlation between body weight and morphometric traits in Isa Brown and Ilorin ecotype chickens. The studied morphometric traits were comb length, beak length, head length, neck length, body length, wing length, shank length, thigh length, toe length, breast length, and breast breadth. The results showed that genotype, sex and genotype × sex interaction significantly (P<0.05) affect body weight and morphometric trait measurements. Isa Brown chicken had a significantly higher (P<0.05) matured body weight than Ilorin ecotype birds. Isa Brown birds had higher (P<0.05) morphometric traits than Ilorin ecotype birds except for toe length. Male birds had higher body weight (P<0.05) and were also higher in most of the morphometric trait measurements than female birds. Interactions between genotype and sex were significant (P<0.05) for body weight and morphometric traits, except for breast length and breast breadth. Morphometric traits measured in young birds were significantly (P<0.05) correlated with body weight (0.68-0.95) except for wing length in Isa Brown and breast length in Ilorin ecotype chicken. Correlations between body weight and morphometric traits in adult Isa Brown birds were higher (0.27-0.95) than correlations between body weight and morphometric traits in Ilorin ecotype chicken (0.02-0.91). A significant negative correlation was obtained between body weight and beak length (-0.72) in Isa Brown and between body weight and wing length (-0.35) in Ilorin ecotype chicken. Morphometric traits measured on male birds were more highly correlated with body weight (0.68-0.95) than in female chickens, except for breast breadth. The present study showed that the two genotypes could be adequately characterised using morphometric indices. The study further revealed that morphometric indices like body length and comb length can be adequately used to predict body weight of birds in the two genotypes. However, the negative correlation obtained between body weight and wing length in Ilorin ecotype chicken requires further investigation to determine its basis for chicken adaptation