Quantitative Genetic Parameters for Growth Traits in Nigerian Indigenous Cattle Breeds

This study estimates quantitative genetic parameters including heritability, genetic correlations, and breeding values for growth traits in Nigerian indigenous cattle breeds, providing the genetic data needed to design effective breeding programmes. Indigenous Nigerian cattle breeds including the Bunaji, N'Dama, Keteku, and Kuri represent important genetic resources adapted to tropical conditions, but quantitative genetic characterisation essential for structured improvement programmes is lacking for most breeds. This study uses mixed model methodology applied to performance data from 1,840 cattle of four indigenous breeds recorded at the National Animal Production Research Institute Shika, Ladoke Akintola University of Technology Ogbomoso, and University of Maiduguri research herds spanning 12 years. Growth traits analysed include birth weight, weaning weight at 205 days, yearling weight at 365 days, and post-weaning daily gain. The restricted maximum likelihood method using animal model is applied to estimate heritability and genetic correlations using ASREML software. Breeding values are estimated and ranked for selection. Findings reveal that heritability estimates for birth weight, weaning weight, and yearling weight average 0.28, 0.34, and 0.42 respectively across breeds, suggesting moderate to high genetic control suitable for mass selection. Genetic correlations between growth stages are positive and high (0.68 to 0.84), indicating that selection for weaning weight will improve later growth performance. Bunaji cattle show the highest estimated breeding values for yearling weight. The study contributes original quantitative genetic parameters for four Nigerian breeds and recommends a structured national breed improvement programme based on the identified selection response potentials.

Keywords: quantitative genetics, indigenous cattle, heritability, breeding values, Nigeria.