Gestation length, birth weight and growth rates of pure-bred indigenous goats and their crosses in Kenya

Abstract

Data on gestation period of 701 indigenous East African and Galla does and pre- and postweaning growth of 810 pure-bred and cross-bred kids were analysed by least squares statistical analysis. Breeds of kids were East African, Galla, Toggenburg × East African, Toggenburg × Galla, Anglo-Nubian × East African and Anglo-Nubian × Galla. Average gestation length was 149 days and was significantly (P < 0·05) affected by type of birth of the kid, year–month of kidding, and age of dam. Does carrying twins had shorter gestation length than does carrying singles. Sex and breed of kid did not have significant effect on gestation length.

Significant (P < 0·05) factors affecting birth weight, weight at 30, 60, 90, 120, 150, 210 and 270 days of age, and preweaning growth rate were breed and sex of kid, type of birth, year–month and age of dam. Male kids grew faster and were heavier than females. Kids born single were heavier and grew faster than twin-born kids. Kids from dams less than 3 years old weighed less than kids from older dams. Cross-bred kids had higher preweaning growth rates than indigenous pure-bred kids. The Anglo-Nubian × Galla cross was heaviest while the East African ranked lowest. The results point to importance of cross-breeding with temperate breeds to increase growth rates of indigenous goats. Comparison of Toggenburg and Anglo-Nubian sires for cross-breeding showed both buck breeds produced kids with roughly equal growth rates. Evaluation of indigenous Galla and East African dams for cross-breeding showed Galla dams produced heavier kids than East African but preweaning growth rates were not significantly different.