Evaluation of Growth and Efficiency-Related Traits of Different Levels of Boer X Central Highland Crossbred Goats

Abstract

The objective of this study was to evaluate the growth and efficiency-related traits of the Boer x Central Highland goats. Besides, genetic and non-genetic factors affecting growth and efficiency-related traits (Kleiber ratios) were identified. Data were collected for nine years and a general linear model procedure of SAS was employed to detect the significance of fixed effects. The overall least-squares mean live weight at birth, 3-, 6-, 9- and 12 months of age were 2.52±0.01, 9.81±0.13, 13.8±0.15, 17.8±0.19, and 20.5±0.29 kg, respectively. The average weight gains from birth to 3 months, 3 to 6, 6 to 9 and 9 to 12 months of age were 80.3, 37.5, 41.9, and 31.2 g day-1, respectively. Exotic gene level, dam genotype, birth type, season and year of kidding had a significant effect on growth traits. The overall least-squares mean of Kleiber ratio from birth to 3 months, 3 to 6 months, 6 to 9 months, and 9 month to yearling age were 13.99±0.11, 5.23±0.14, 4.66±0.16, and 2.95±0.18 g/kg0.75, respectively. Parity, birth type, blood level, season and year of birth had a significant influence on the expression of efficiency-related traits (Kleiber ratios) in different growth phases. In terms of growth performance and efficiency-related traits, F2 and F3 crossbreds did not show any benefit over F1 crossbreds. Furthermore, increasing Boer blood level above 50% would be meaningless under the existing minimal input production system. Therefore, besides to improving the management of goats, producing the first filial generation would be ideal for medium to high input production systems.