Modeling the reproductive performance of the local goat population in Tunisian arid regions

Abstract

This study aims to illustrate the qualitative and quantitative action of aridity factors and management methods on the reproductive performance of local goats. A total of 462 kidding resulting from the mating of 11 buks and 185 goats were collected during the period 1999-2014. Two traits were chosen to analyze reproductive performance : litter size and the interval between two successive kidding. The fixed factors included in the model are the age and the parity of the goat and the interaction year × Month of kidding. The means of IMB and TP are respectively 13.85 ± 5.20 months and 1.33 ± 0.49 kids. Young females showed relatively poorer reproductive performance than older goats, indicating possible conflicts between growth requirements and food availability. It seems to have a general increase in TP as the parity progresses to the fifth parity. A large IMB value was observed for the second parity then it tends to decrease. The reproductive cycle of goats is essentially subject to the effects of factors that act on pastoral resources and climatic stress. The genetic variability detected in the studied population allows to hold expectations for the implementation of selection programmes for fertility traits in this local breed.