Livestock production in central Mali: weight at first conception and ages at first and second parturitions in traditionally managed goats and sheep

Abstract

SUMMARYResults relating to a 4-year study of early reproductive traits in traditionally managed flocks of indigenous goats and sheep under semi-arid conditions are reported. Mean weights (least-squares estimates) at first conception of 16·9 kg for goats and 23·4 kg for sheep were recorded, and animals raised under the better environmental conditions of the irrigated rice system had a 2·2 kg advantage at this stage over animals raised under the rainfed millet system. Animals from young and old dams were heavier at first conception than those born of middle-aged dams. Neither season of birth nor type of birth (single or multiple) had any effect on weight at first conception. Age at first parturition was 443 days and at second parturition was 709 days. Animals born of young and of old dams were later at both first and second parturitions than those born of middle-aged dams while age at first parturition was younger for those animals reared in the rice system. Age at first parturition was within the range normally found for these types of animals under these environmental and social conditions. An early first parturition, even with a high death rate of offspring, may contribute to a greater total lifetime production than a later parturition with a lower death rate.