Effect of Heat Stress on Reproductive and Productive Traits in Baladi and Crossbred Goat Does under Subtropical Conditions

This experiment was conducted to study the effect of heat stress on some reproductive and productive performance in purebred and crossbred female goats under both of hot (summer season) and mild climatic (winter season) conditions. Forty mature female goats (20 Baladi and 20 crossbred (50% Zaraibi x 50% Baladi) used in this research. Results- cundity were higher in experimental does during mild climate conditionsthan hot climate conditions. Birth weight recorded higher values inmild climate conditions in comparison with hot climate conditions. Concerningto breed, reproductive traits were higher in crossbred goat doescompared with purebred goat does. Crossbred goat does showed higher(P<0.01 or P<0.0001) in all productive traits than Baladi goat does. Cortisolhormone concentration showed lower (P<0.0001) concentration undermild climate conditions than hot climate conditions during differentstages of estrous cycle, pregnancy and postpartum periods. On the otherin crossbred goat does compared with purebred does during differentstages of estrous cycle, except diestrous period. Similar trend was foundduring pregnancy and postpartum periods (P<0.01 or P<0.0001). It could-productive and productive traits of goats and in the same time, crossbredwas better than purebred goats.