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Interpretive Summary: Temperature Fluctuations Modulate Molecular Mechanisms in Skeletal Muscle and Influence Growth Potential in Beef Steers

By: Zachary K Smith, Erika Eckhardt, Won Seob Kim, Ana Clara Baio Menezes, Warren C Rusche, Jongkyoo Kim

In this study, we investigated the effects of severe temperature fluctuations on beef cattle and their cellular and physiological responses. Our findings demonstrate that even moderate temperature swings can cause thermal stress in cattle, leading to observable behavioral signs such as extended tongue protrusion, reduced appetite, excessive salivation, and increased respiratory rate. We also observed a significant increase in the expression of heat shock proteins (HSPs), which protect cells from stress, indicating their importance as early responders to temperature fluctuations. Furthermore, we examined the signaling pathways involved in skeletal muscle growth and found that severe temperature fluctuations can stimulate the upregulation of myogenic regulatory factors and myosin heavy chains. These changes suggest an increased demand for muscle contractile properties and hyperplasia during temperature challenges. In addition, our study revealed alterations in transcription factors associated with adipogenesis, such as PPARγ and C/EBPα, indicating the potential for adipose tissue accumulation in response to temperature fluctuations.

Read the full article in the Journal of Animal Science.