| HSP70-2 is well accepted as an indicator of heat stress. The purpose of this study was to investigate the physiological responses to heat stress of differential genotypes of HSP70-2 in dairy cattle. Thirty two female Holstein Friesian (HF) crossbred heifers, 2-3 years of age, 266 ± 5.6 kg body weight were placed outdoor with partial roof. Blood samples were collected to do genotyping of HSP70-2 using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Ambient temperature, relative humidity and physiological responses, including rectal temperature, respiration rate, sweating rate, pulse rate, skin temperature, and N/L ratio were examined at 06.00, 14.00, 18.00 and 22.00. Genotyping revealed that there were 14 and 18... |
