Genetic variation and parameters of feed efficiency traits in Boran cattle in Kenya

The aim of this study was to evaluate the effect of fixed factors on measures of feed efficiency and estimate genetic parameters for feed efficiency for the Boran cattle in Kenya. A total of 1348 records of birth weight and weaning weight were used to derive pre weaning measures of feed efficiency. The traits derived were pre-weaning daily gain (ADG), weaning weight adjusted to 205 days (WA205), Kleiber Index at 205 days (KI205), and relative growth rate (RGR). The fixed effects model included effects of sex, parity, year-season of birth or weaning and dam weight at weaning. A maternal genetic effects model was fitted to estimate the genetic parameters for the traits. All fixed effects except parity and dam age at weaning significantly influenced the studied traits. Direct heritability estimates for WA205, kg, ADG, kg/day, KI205, kg/kg0.75, RGR were 0.05±0.02, 0.27±0.02, 0.13±0.02 and 0.21±0.02 while the maternal heritability estimates were 0.04±0.02, 0.29±0.02, 0.10±0.02 and 0.23±0.02, respectively. The genetic correlations between direct and maternal genetic effects for the traits were -0.18±0.05, -0.30±0.04, 0.9±0.05 and -0.72±0.04, respectively. This study has provided genetic parameters for measures of feed efficiency for the improved Boran cattle in Kenya. The parameters can be used to incorporate the traits in the selection programmes with the aim of reducing the cost of feed leading to improved profitability as well as reduction in methane (CH4) gas emission. Key words: Boran Cattle, climate change, greenhouse gases, kleiber index, relative growth rate