Assesment of the SLICK phenotype for thermotolerance in cattle through HSP70 gene expression analysis

Climate change poses a significant challenge for agricultural production, especially livestock. As cattle are unable to adapt as fast as global temperatures are rising, heat stress has become of growing concern. Heat stress in cattle often causes a decrease in appetite and weight gain. In addition to underweight cattle, the adverse effects of heat stress also include a decreased reproduction rate, increased susceptibility to disease and poor-quality meat and dairy products. With the growing demand for high quality meat and dairy products, mitigating the effects of heat stress in cattle has become a priority. A promising solution to this problem is the introduction of the SLICK phenotype for cattle production, which has been associated with a shorter haircoat to enhance heat dissipation. This study aimed to evaluate the effectiveness of the SLICK phenotype in alleviating heat stress by comparing Heat Shock Protein 70 (HSP70) gene expression levels in Red Angus and Angus-Senepol hybrid (SLICK) cattle. In addition, haircoat properties, including length and diameter were compared to determine the difference in haircoat morphology between the two groups. RNA was extracted from hair follicles during different environmental conditions to generate cDNA for quantitative PCR (qPCR) analysis of HSP70 gene expression. Results confirmed that SLICK cattle exhibited significantly shorter haircoats than Red Angus cattle, suggesting an increased ability for thermoregulation. HSP70 gene expression analysis did not show significant differences between the two groups after experiencing a maximum temperature humidity index (THI) of 76.4. Although gene expression results were inconclusive, the findings from this study highlight the potential for selecting heat tolerant traits to improve heat stress resistance. This research supports the idea that the SLICK phenotype offers a promising strategy for enhancing the sustainability of cattle production in temperate climates.