Impactos do aquecimento global na bovinocultura de leite e genes de resistência ao calor nos bovinos: revisão de literatura

Abstract

Climate forecasts indicate a rise in global average temperature, leading to environmental and climatic changes that will affect livestock, particularly dairy cattle. In this context, it is essential to select more heat-resistant animals, which requires a deeper understanding of the gene mechanisms associated with heat tolerance. This study aimed to review the literature on global warming, its economic and social impacts on dairy farming, and to identify genes related to heat stress (HS) and their action mechanisms in cattle, focusing on indicine and Holstein breeds. Studies have shown that the response to HS is complex, involving physiological and cellular mechanisms. Genes encoding heat shock proteins (HSP) and heat shock factors (HSF) are the primary genes associated with heat resistance found in the literature, including HSP70 and HSP90 for proteins, and HSF1, HSF2, HSF3, and HSF4 for transcription factors. However, studies have revealed the polygenic nature of thermophysiological traits, with additional genes being discovered, such as those associated with immune responses and oxidative stress involving reactive oxygen species (ROS), linked to HS sensitivity, and with great genetic potential for further exploration. Moreover, other genes were identified as being more highly expressed in indicine than in taurine cattle, which may explain indicine breeds' higher resistance to HS. The information compiled here is crucial for assessing the impact of global warming on dairy cattle and for understanding the genetic mechanisms already described about HS, guiding future research on these topics.