Managerial and Nutritional Strategies to Minimize Lactational and Reproductive Losses in Heat-Distressed Dairy Cows

Abstract

Heat stress (HS) is a welfare issue and has detrimental effects on lactation and reproduction. When environmental temperature exceeds 25 °C or when thermal-humidity index exceeds 75, cows exhibit HS signs. Feed intake, milk production, and fertility decrease and immune system is compromised in heat-distressed dairy cows. Managerial approaches cover barn design (stocking density, ventilation, shading, and sprinkling water) and animal’s handling and mating (synchronization and timed-artificial insemination), which are intended to cool down the cow. Nutritional approaches are intended to reduce heat production by the body and covers access to unlimited clean and fresh water, feeding at night, increasing feeding frequency, feeding fat, reducing forage percentage and increasing concentrate, K, Na, and Mg percentages in the ration, balancing protein fractions, modifying particle size, formulating alkaline diet, and supplementing cow with buffer and yeast cultures. In conclusion, both managerial and nutritional approaches help maintain body temperature so that lactation and reproduction potential can be achieved during hot weather