Impact of chronic heat stress on physiological and productive performance of buffalo dams during the dry period under climatic conditions in the Nile Valley

The present study was conducted at Bani Sweif Governorate (The middle area of the Nile Valley). The experimental work was carried out at Seds Experimental farm affiliated with the Animal Production Research Institute (APRI), Agricultural Research Center (ARC). The main objective of this work was to study the impact of exposure of buffalo dams to direct solar radiation at late pregnancy (Two months dry period) on physiological and productive performance. Also, to study the Comprehensive Climate Index (CCI) under Egyptian conditions with the higher solar radiation that characterizes the Nile Valley in comparison with the temperature-humidity index (THI) which is still the proper indicator of animal stress under the environmental conditions in Egypt. Ten buffalo dams were available for the study. The animals were randomly divided into two groups. The first group was exposed to direct solar radiation, while the second group was under shade; Weekly measurements and blood samples were taken from (July to August) in the morning before feeding and watering. The results showed that the correlation coefficient between THI and with CCI Index under direct solar radiation in Egypt from July to August months was (0.84). The (THI) is still the best indicator of animal stress under environmental conditions in Egypt. The average daily milk decreased by 0.800 Kg and the average birth weight by 10 Kg and decreased of quality of colostrum this increased value of THI by 10. Its recommended buffalo animal of climatic change under any environmental conditions adapted and we can maintain milk and meat production from buffaloes with bad environmental conditions with climatic change.