Effects of heat stress on body temperature, milk production, and reproduction in dairy cows: a novel idea for monitoring and evaluation of heat stress — A review

Abstract

Heat stress exerts a substantial effect on dairy production. The temperature and humidity index (THI) is widely used to assess heat stress in dairy operations. Herein, we review the effects of high temperature and humidity on body temperature, feed intake, milk production, follicle development, estrous behavior, and pregnancy in dairy cows. Analyses of the effects of THI on dairy production have shown that body temperature is an important physiological parameter in the evaluation of the health state of dairy cows. Although THI is an important environmental index and can help to infer the degree of heat stress, it does not reflect the physiological changes experienced by dairy cows undergoing heat stress. However, the simultaneous measurement of THI and physiological indexes (e.g., body temperature) would be very useful for improving dairy production. The successful development of automatic detection techniques makes it possible to combine THI with other physiological indexes (i.e., body temperature and activity), which could help us to comprehensively evaluate heat stress in dairy cows and provide important technical support to effectively prevent heat stress.

Glucose Metabolism and Dynamics of Facilitative Glucose Transporters (GLUTs) under the Influence of Heat Stress in Dairy Cattle

“…Temperature-Humidity Index (THI) is a widely accepted criterion of heat stress measurement, while generally cows experience heat stress at 25 • C. However, recently researchers are focusing THI calculation at the most ambient level, considering the actual micro-climates around cows. This approach of THI evaluation, combined with the physiological parameters of heat stress, is essential to depict the actual heat stress magnitude of cows [114]. By this way, managers can monitor heat stress events and design appropriate housing and husbandry to attain heat stress abatement through appropriate cooling, management, and nutrition support aids [110].…”

Review: Impact of Food and Climate Change on Pastoral Industries

“…Morignat et al (2015) reported that each degree temperature increase above a certain threshold is associated with a 5% increase in mortality risk. Heat stress adversely affects follicle development and reduces pregnancy rate in cattle (Liu et al, 2019). An increase in temperature-humidity index from 72 to 78 reduced pregnancy rate from 39.4 to 31.6% in dairy cows (Domínguez et al, 2005).…”

Circular RNAs Are Regulators of Diverse Animal Transcriptomes: One Health Perspective

“…Even though swine milk is not a primary product for human consumption, quality and yield of milk in lactating sows plays an important role for feeding viable offspring raised for meat. Several previous reports suggested a potential direct correlation between environmental temperature and milk yield (Black et al, 1993;West, 2003;Liu J. et al, 2019). Heat-stressed lactating sows reduce their feed intake and their declined milk production does negatively affect piglet growth and development during lactation.…”