GROWTH PERFORMANCE OF CROSSBRED DAIRY CATTLE AT ASELLA LIVESTOCK FARM, ARSI ETHIOPIA

Abstract

Genetic and non-genetic factors affecting growth traits and growth performance at 50% and 75% upgrading levels were studied, in the Arsi
highland, Ethiopia. The traits studied were: weight at birth, 6, 12, 18,24 and 36 months. The analyses were carried out using Harvey's Mixed Model Leastsquares and Maximum Likelihood Computer Program. The breed groups compared were: 112 Friesian 112 Arsi (FIFA), 112 Friesian 112 Zebu (FIFZ), 112 Friesian 114 Jersey 1/4 Arsi (F(JxA», 3/4 Friesian 114 Arsi (75%FA) and 3/4 Friesian 114 Zebu (75%FZ). The 75% FA were significantly heavier than FIFA at birth, 6 and 30 months. No significant differences were found between FIFZ and 75%FZ at all ages. The differences between F(JxA) and FIFA were not significant except at 6 months. The 75% FA were significantly heavier than the F(JxA) at birth, 30 and 36 months. However, 75 % FA were significantly lighter than 75% FZ at 12 and 36 months. No significant effect of sex were observed at birth, though males were slightly heavier. Parity of the dam did not
show significant influence ,on body weight except at birth and 24 months. Year of birth of the calf did not have significant effect except at 12 months. The effect of season of birth was significant at birth and 12 months. Animals born during the main rains were the heaviest at birth. Heritability estimates for weights at birth, 6, 12, 18 and 24 months were: O.20±0.15, O.14±0.23, O.04±0.21, 0.68±0.34 and 0.33 ±O.29, respectively. From the results obtained, it may be concluded that the management 'and feeding conditions at Asella Livestock Farm would warrant the limitation of upgrading level to 50% exotic inheritance. The smaller weights for the three-breed crosses, i.e., (F(JxA), may be advantageous