Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia.
Department of Animal Science, University of Ghana, Legon, Ghana.
Int J Biometeorol. 2020 Sep;64(9):1613-1628. doi: 10.1007/s00484-020-01929-6. Epub 2020 May 6.
During the summer, high ambient temperature and humidity cause economic loss to the global livestock industry via reduced livestock productivity and increased mortality. The problem of heat stress (HS) is likely to be exacerbated by global warming and climate change. Recent research has shown that HS not only leads to physiological and metabolic perturbations in live animals but can also affect carcass and meat quality characteristics plausibly by altering the rate and extent of postmortem muscle glycolysis and resultant pH. However, these impacts of HS are not consistent across species. Higher incidence of pale soft and exudative (PSE) meat has been reported in poultry. On the contrary, higher incidence of high ultimate pH and dark firm and dry (DFD) meat or no impacts of HS have been reported in sheep and cattle. With the limited data on HS impacts on meat quality of ruminants, it is difficult to explain the exact mechanisms driving these variable impacts. However, it is hypothesized that the severity and duration of HS may lead to variable impacts due to lack of opportunity to adapdate to acute heat exposure. Longer HS exposure may allow ruminants to adapdate to heat and may not record any negative impacts on meat quality. This paper reviews the recent research on impacts of HS on meat quality characteristics and identify the key areas of further research required to better understand these negative impacts to develop strategies for amelioration. In addition, some mitigation strategies of HS have also been discussed which include both managemental and nutritional interventions.
在夏季，高环境温度和高湿度会通过降低牲畜生产力和增加死亡率给全球畜牧业造成经济损失。热应激（HS）问题可能会因全球变暖及气候变化而加剧。最近的研究表明，HS 不仅会导致活体动物的生理和代谢紊乱，而且还可能通过改变死后肌肉糖酵解的速度和程度以及由此产生的 pH 值，对胴体和肉质特性产生影响。然而，这些 HS 的影响在不同物种之间并不一致。在禽类中，报道了更高比例的苍白、松软和渗出（PSE）肉。相反，在绵羊和牛中，报道了更高比例的高最终 pH 值和暗、硬和干燥（DFD）肉，或者 HS 没有影响。由于有关 HS 对反刍动物肉质影响的数据有限，因此很难解释导致这些可变影响的确切机制。然而，据推测，HS 的严重程度和持续时间可能会由于缺乏适应急性热暴露的机会而导致可变的影响。较长时间的 HS 暴露可能会使反刍动物适应高温，并且不会对肉质产生任何负面影响。本文综述了最近关于 HS 对肉质特性影响的研究，并确定了进一步研究的关键领域，以更好地了解这些负面影响，从而制定改善策略。此外，还讨论了一些 HS 的缓解策略，包括管理和营养干预。
