Discrimination of the Nigerian local turkeys into breeds using linear body measurements
Turkey is one of the poultry species that is declining in Nigeria due to its importation as frozen turkey. In this study, a total of 78 day-old random-bred Nigerian local turkey poults were used to generate another 232 day-old poults to discriminate Nigerian local turkey based on linear body measurements. Three phenotypic classes (Black, White and Spotted) were obtained as base population and used to generate F progeny. Experimental design was 1 a randomized complete block (RCBD) with phenotypic class as major factor of interest and hatch as block. Linear body measurements (LBMs), namely body length (BDL), shank length (SHL), keel length (KLL), breast width (BW), wing length (WGL) and drumstick length (DSL) were significantly different at weeks 7, 9, 11 and 19. There were two discriminant functions. The variance ratio (eigenvalue) of each of the two discriminant functions were not significant (p>0.05). The percentage of the total variance explained was 87.7% and 12.3% for the two functions respectively. Group centroids for the phenotypic classes were 7.210, -1.254 and -5.956 for Black, White and Spotted turkeys respectively. The magnitudes and signs of the group centroids indicate that the three phenotypes are distinctly different from one another when BDL (weeks 7, 11, 13 and 15), WGL (weeks 7, 9 and 11), KLL (weeks 7, 9 and 15) and SHL (weeks 11 and 21) are used as the discriminating factors. The study shows that linear body measurement is a reliable classification criterion for discriminating among the phenotypes, which are therefore, correctly described as different breeds/strains. Therefore, for rapid improvement in local turkeys and breed development, these linear body traits could be used to enhance its discrimination, classification and appropriate grouping into breeds. The present findings could assist in the design of long-term genetic improvement programmes for local turkey breeding and production in Nigeria.
Keywords: local turkey, linear body measurements, discrimination.