Traditional system of goat management. III. Reproductive performance of SRD (non-descript) does and kid mortality

The reproductive performance of 50 adult SRD does maintained in native caatinga pasture at a stocking rate of 1 to 1.5 ha/head/year was evaluated. Two bucks were used in natural matings from September 1978 until December 1980. A total of 93 kiddings and 28 abortions occurred. Three pregnancies occurred before initiation of the experiment. From the 90 parturitions, 57.7%, 35.6%, 1.1% and 5.6% bore singles, twins, triplets and undetermined, respectively. The flock showed an overall prolificacy of 1.38. From the initial flock, 15 (30%), 28 (56%), 5 (10%) and 2 (4%) does presented one, two, three and zero kiddings, respectively, during the period of study. Neither gestation length nor kidding interval were influenced by type of birth. Length of open period was influenced by season of the year when data were classified by season and kidding status at the open period. Combination of kidding type at previous and following kiddings showed a significant influence (P < 0.05) on the length of the open period. Animals that kidded first singles and then singles or twins showed a shorter open period than animals that firstly kidded twins and then aborted at the following pregnancy (109 vs 188 days). The peak of kid mortality occurred between 7 and 112 days of age. Kid mortality appears not to be influenced by sex or type of birth. Overall kid mortality was 76%. The age at death of kids was influenced by season and sex as well as by their interaction. Males born during the rainy season survived longer than any other class studied.