Physiological adaptability of livestock to heat stress: an updated review

Abstract

Climate change associated heat stress was established to be the crucial factor, which negatively influences animal production. The animals possess several adaptive mechanisms which are helpful for their survival in harsh environmental conditions, but while doing so their productive performances are compromised. Among the various mechanisms, which helps to maintain homeostasis in animals, Physiological adaptability was considered one of the primary response mechanisms by which the heat stressed animals survive the heat stress. This review is therefore an attempt to provide the audience an updated review on the subject to signify the importance of physiological responses in animals and their role in surviving the stressful environment. Respiration rate (RR), pulse rate (PR), rectal temperature (RT), sweating rate (SR) and skin temperature (ST) are the cardinal physiological variables which helps to maintain the heat balance and homeostasis in the stressed animals. Among the various physiological variables, RR, RT and ST were established to be ideal indicators for quantifying heat stress in several farm animals. Therefore, these variables can be effectively used to assess the severity of heat stress in livestock. Although these variables are considered significant in establishing the heat stress impact in animals, a wide genetic variation was also established in these response mechanisms. Further, variations in physiological adaptability were also established between indigenous, cross bred and pure bred animals. The indigenous livestock breeds were tipped to be exhibiting less physiological variability as compared to their counterparts. These discussions vividly indicate the importance of studying in detail the physiological adaptive mechanisms in different farm animals and these efforts can help the farming community to identify the suitable agroclimatic zone specific livestock breeds which can go in long way to help to ensure climate resilient livestock production.

Genetic Parameters for Growth and Kid Survival of Indigenous Goat under Smallholding System of Burundi

“…Goats play a key multifunctional role in food security and poverty alleviation of smallholder farmers in many less developed countries such as Burundi. Native goats, the most important breed, were considered the most suitable species for harsh environments [1] but they are not productive enough to ensure food security and the well-being of goat farmers [2]. One reason is that native breeds have been naturally selected to be adapted to their marginal environment, but not to increase their level of performance [3].…”

Characteristics of smallholders’ goat production systems and effect of Boer crossbreeding on body measurements of goats in Burundi

“…Considering the other effects included in the fixed models, we would mention the lower weights and linear measures for goats raised in highlands (CHL and CNC) than in lowlands (DNE, IMB, MUM). An explanation for this may be that coldness and high relative humidity in highlands may affect production performances and compromise the immune system, which makes the animals prone to diseases (Melissa et al 2017;Rashamol et al 2018). The last observation in this section is that mean weight (22.3 kg) of indigenous goats was within the range expected for Small Eastern African goats of 20 to 30 kg in Kenya (Mbuku et al 2015).…”

Systems Biology under heat stress in Indian Cattle

“…It was observed that Ongole cattle rely on the respiration rate to maintain thermal balance, while, Bali cattle rely on rectal temperature [9]. In Brazil, Sindhi and Girolando breeds showed better physiological response to thermal stress than Gir cattle [10]. Increase in respiration rate was reported in Nellore breed when exposed to heat load [11].…”