Department of Animal Science, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
University of Brasilia, Darcy Ribeiro University Campus, Brasília, Distrito Federal, Brazil.
J Anim Sci. 2020 Sep 1;98(9). doi: 10.1093/jas/skaa294.
This systematic review and meta-analysis aim to summarize the effects of maternal undernutrition or overnutrition during pregnancy on fetal weight and morphometric measurements during pregnancy, at birth, and postnatal period in sheep. After completing the search, selection, and data extraction steps, the measure of effect was generated by the individual comparison of each indicator with the average of the control and treated group (undernutrition or overnutrition) using the DerSimonian and Laird method for random effects. Subgroup analyses were also performed for lambing order, litter size, sex, as well as level, timing, and duration of the intervention. Fetal weight during the first third of pregnancy was not affected by maternal undernutrition or overnutrition. On the other hand, undernutrition in the second and last third of gestation reduces the weight of the lamb both during pregnancy, at birth, and during the postnatal period, requiring at least 120 postnatal days to achieve the same weight as its contemporaries in the control treatment. However, this reduction in weight is not accompanied by reductions in morphometric measurements, demonstrating that the animals were lighter, but of equal size. In overnutrition, there is an increase in fetal weight in the second third of gestation. However, in the last third of the gestational period, there are no differences in fetal weight for the multiparous subgroup, but it was reduced in primiparous ewes. There are no effects of overnutrition on birth weight; however, this result is highly heterogeneous. Thus, maternal nutrition of ewe during pregnancy has effects on fetal and postnatal weight, but not on size. Furthermore, the effects of undernutrition are more homogeneous while overnutrition showed heterogeneous responses.
本系统评价和荟萃分析旨在总结妊娠期间母体营养不良或营养过剩对绵羊胎儿体重和妊娠期间、出生时和出生后形态测量的影响。在完成搜索、选择和数据提取步骤后，使用 DerSimonian 和 Laird 方法对随机效应，通过个体比较每个指标与对照组和处理组（营养不良或营养过剩）的平均值来生成效应量。还对产羔顺序、产羔数、性别以及干预的水平、时间和持续时间进行了亚组分析。妊娠前 1/3 期胎儿体重不受母体营养不良或营养过剩的影响。另一方面，妊娠中、晚期的营养不良会降低羔羊在妊娠期间、出生时和出生后的体重，需要至少 120 天的产后时间才能达到与对照组中同期羔羊相同的体重。然而，体重的减轻并没有伴随着形态测量的减少，这表明动物较轻，但大小相同。在营养过剩的情况下，妊娠中 2/3 期胎儿体重增加。然而，在妊娠晚期，多产亚组的胎儿体重没有差异，但初产母羊的胎儿体重减轻。营养过剩对出生体重没有影响；然而，这个结果具有高度异质性。因此，妊娠期间母羊的营养对胎儿和产后体重有影响，但对大小没有影响。此外，营养不良的影响更具有同质性，而营养过剩则表现出异质性反应。
