Characterisation of Goats’ Response to Heat Stress: Tools to Improve Heat Tolerance

Abstract

This chapter aims to review present knowledge about the effects of heat stress on goats, summarising what is known about its measurement, its impact on the performances of the animals, mainly milk traits, the physiological and genetic bases of the animals' response and the improvement of resilience through selection. A short historic review of the climatic indexes used to measure heat stress, with special emphasis on the temperature humidity indexes, and the main consequences on milk yield and composition are followed by a description of the results of experiments carried out to study the physiological and metabolic consequences of heat stress. The results of the quantitative analyses of the genetic bases of heat stress using norm of reaction models and of the application of omic techniques, particularly transcriptomic and genomic, to understand the complexity of the genetic background of animal's reaction to thermal stress, constitute the next points. The chapter ends treating the possible ways and difficulties of applying selection to increase resilience to heat stress.

Use of Principal Component Analysis to Combine Genetic Merit for Heat Stress and for Fat and Protein Yield in Spanish Autochthonous Dairy Goat Breeds

“…Our results in Table 5 show a positive correlation between a o for the three breeds, meaning that if the selection process favored these components the genetic level of the animal increases along the scales of DIM and THI, but at the same time the correlated response is negative due to an antagonist correlation between a o and a s. As a consequence, the results suggest more productive animals but with less adaptation to change in THI, which is an expression of Ige in line with the same general conclusions presented by Misztal [ 10 ]. The results of the genetic correlations between the fpy at different levels of THI or DIM trajectories found in this study ( Figure 3 and Figure 4 ) agree with previous studies showing the same decreasing pattern for dairy traits in goats [ 26 ]; sheep [ 5 , 19 ] and dairy cattle [ 9 , 27 ] and cannot be considered as the same traits across both scales.…”

Floods, Hurricanes, and Other Catastrophes: A Challenge for the Immune System of Livestock and Other Animals

“…Other studies in cattle and chicken identified genes involved in different mechanisms such as immune response (interleukins and cluster differentiation markers), metabolism (NADH), remodeling of mammary gland and central nervous system functions confirmed the complexity of heat shock response in animals (43,44). All these studies evidence that the resistance to high temperature negatively correlate to the production level of the animals (45).…”

Application of a Protocol to Assess Camel Welfare: Scoring System of Collected Measures, Aggregated Assessment Indices, and Criteria to Classify a Pen

“…Other measures, such as environmental parameters, the demographic data of caretakers or the volume of rubbish, need instead further analysis to evaluate their influence on camel welfare. Unlike other livestock species [ 49 , 50 ], for example, there are no studies evaluating the effect of Temperature Humidity Index on the level of heat stress of the camel.…”