Sexual dimorphism of Fulani ecotype chicken in Danbatta Local Government, Kano State, Nigeria

Abstract

This study was conducted to characterize the quantitative traits of Fulani ecotype chicken in Danbatta Local Government, Kano State. A total of 300 matured and randomly selected Fulani ecotype chickens (152 males and 148 females) with average weights of 1.5 and 1.0 kg, respectively were used for this study. Sixteen biometric characters and four morphological indices were investigated. Biometric traits and indices were tested for normality with Shapiro-Wilk’s test (p>0.05) and by visual inspection of the histograms. Levene’s test was used to confirm the homogeneity of variances (p>0.05). Due to the non-normality of the distribution of the data, the non-parametric Kruskal-Wallis H test was performed to compare mean ranks of biometric traits and morphological indices based on sex. Mann–Whitney U test was used for pairwise comparisons of mean ranks. Pearson’s coefficients of correlation were computed for all the traits. The multivariate principal component (PC) was employed to identify the combination of variables that best separate the sexes. A multiple regression procedure using a stepwise variable selection was used to obtain models of estimation of Body Weight (BW) from biometric measurements based on the sex of the birds. Sex significantly influenced (p<0.01) all the biometric traits and morphological indices investigated in this study. The male Fulani chickens had higher body weight, head length, head thickness, wattle length, neck length, neck circumference, wing length, wing span, body length, trunk length, keel length, chest circumference, thigh length, thigh circumference, shank length and shank thickness. The male Fulani chicken also recorded higher massiveness (5.75 vs. 4.15) and condition index (12.24 vs. 7.69) compared to females. However, female Fulani chicken had higher stockiness (100.36 vs. 81.49) and long-leggedness (27.74 vs. 23.16) compared to males. There were strong and positive phenotypic correlations of biometric traits and morphological indices of Nigerian indigenous Fulani chicken based on sex. Three PCs each were extracted for male and female chickens. Nine regression models each were obtained for male and female chickens, which could be used to predict the body weight of birds, especially in rural areas.