To meet growing worldwide demands for animal products, animal production will need to increase in capacity and efficiency. Every opportunity to improve animal protein yield should be considered and explored. Developmental programming is one such opportunity that has not yet been thoroughly investigated in farm animal production. While developmental programming can be advantageous for the survival of the offspring, it is often described in conjunction with negative consequences. The known and potential causes and mechanisms are numerous, often stemming from some sort of stress experienced during the prenatal or early postnatal period. One stressor that is particularly concerning for farm animal production is heat stress. Heat stress is known to elicit adaptations associated with developmental programming in several species, but has not been investigated in dairy cattle until recently. Multiple studies have shown that heat stress experienced during the periconceptional period is generally associated with reduced milk production of resulting offspring. This could be the result of adaptations within the pre-ovulatory oocyte or early developing embryo. Interestingly, in a few select comparisons, periconceptional heat stress was associated with greater milk production. This was only observed when dairy cattle calved in the spring, and would therefore be reaching peak milk production in late spring or early summer (in heat stress). This is consistent with the match/mismatch theory associated with developmental programming, where matched prenatal/postnatal environments confer advantageous adaptations and mismatched prenatal/postnatal environments are generally detrimental to the offspring. While these studies are important additions to our growing knowledge of heat stress impacts on dairy cow production, the broader implication of developmental programming requires further investigation.

中文翻译：

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围孕期热应激对荷斯坦奶牛初产和经产女儿的影响

为了满足全球对动物产品不断增长的需求，动物生产需要提高产能和效率。应考虑和探索每一个提高动物蛋白产量的机会。发展规划是一种尚未在农场动物生产中进行彻底调查的机会。虽然发育编程可能有利于后代的生存，但它通常与负面后果一起描述。已知和潜在的原因和机制很多，通常源于产前或产后早期经历的某种压力。对农场动物生产特别关注的一种压力因素是热应激。已知热应激会引起与几种物种的发育程序相关的适应，但直到最近才在奶牛中进行研究。多项研究表明，围孕期经历的热应激通常与后代产奶量减少有关。这可能是排卵前卵母细胞或早期发育胚胎内适应的结果。有趣的是，在一些选择的比较中，围孕期热应激与产奶量增加有关。这仅在奶牛在春季产犊时观察到，因此将在春末或夏初（在热应激下）达到产奶量峰值。这与与发展编程相关的匹配/不匹配理论一致，匹配的产前/产后环境赋予有利的适应性，而不匹配的产前/产后环境通常对后代有害。虽然这些研究是我们对热应激对奶牛生产影响的日益增长的知识的重要补充，但发育规划的更广泛含义需要进一步调查。