Hyperthermal and Nutritional Effects on Milk Production, Udder Health and Reproduction of Dairy Cows

Effect of Heat Stress on Cattle: A Review

“…Hence, maintaining the proper temperature for the cows is critical for maintaining their high productivity and overall health. The adaptive mechanisms of the cows become unsuccessful in eliminating the excess heat produced when the upper critical temperature is exceeded [5,8]. Therefore, the manual actions should be adopted in such situations in order to remove the excess heat load.…”

“…Nutritional management is another aspect that should be considered in mitigation of heat stress. According to literature, there were clear evidences to state that it is essential to modify the feed for cattle during hot seasons [6,8,[83][84][85] . The rations should be reformulated to account for the reduced dry matter intake (DMI), increased nutrient requirement, dietary heat increment and by avoiding the provision of excess nutrients as increase metabolic rates may increase the risk of heat stress [5].…”

“…The upper critical air temperature is the air temperature which is at which the animal increases the heat production due to its body temperature increment as a result of inadequate evaporative heat loss is reported to range from 25-26 °C for dairy cattle, irrespective of their previous acclimatization and milk production [5][6][7]. Air temperature, relative humidity, solar radiation, precipitation, and air movement are the major environmental factors affecting the occurrence of heat stress in animals [1], and out of these, the elevated air temperature can be considered as the leading factor responsible for the heat stress in cattle [8]. On the other hand, breed, age, lactation stage, level of milk production, levels of feed and water intake, feed composition, and body condition score are also considered as the other factors of heat stress [5,7].…”