Nutritional skewing of conceptus sex in sheep: effects of a maternal diet enriched in rumen-protected polyunsaturated fatty acids (PUFA)
Nutritional skewing of conceptus sex in sheep: effects of a maternal diet enriched in rumen-protected polyunsaturated fatty acids (PUFA)
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DOI：
10.1186/1477-7827-6-21
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发表时间：
2008-06-09
影响因子：
4.4
通讯作者：
Roberts, R. Michael
中科院分区：
文献类型：
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作者：
Green, Mark P.;Spate, Lee D.;Roberts, R. Michael
工作背景：进化理论认为，在一夫多妻制的哺乳动物物种中，身体状况较好的雌性应该生更多的儿子而不是女儿。然而，很少有对照研究验证了这一假设，关于身体状况评分或母体饮食是否是后代性别的决定因素存在争议。在这里，我们研究了母体饮食，特别是增加n-6多不饱和脂肪酸（PUFA）的摄入量，母羊在怀孕期间的身体状况评分恒定是否会影响性别比。方法：在整个研究中保持相似身体状况的母羊（n = 44）被分配对照（C）饮食或富含瘤胃保护的PUFA的饮食（F），但在其他方面基本上等同，从配种前四周至发情后d13。在第13天，回收、测量、培养孕体以评估其产生干扰素-tau（IFNT）的能力并确定其性别。重复该实验，所有母羊被喂食F饮食，以消除任何影响的奇偶顺序的性别比。母体身体状况评分（BCS），血浆激素和代谢物浓度也进行了评估，在整个研究和相关的饮食。饲喂F日粮的母羊产生的雄性孕体显著多于雌性孕体（雄性比例= 0.69;偏离预期比例0.5，P < 0.001）。胎鼠IFNT的产生不受饲料的影响（P > 0.1），但与母体状况评分呈正相关（P < 0.05），培养4 h后雌性胎鼠的IFNT产生量高于雄性胎鼠（P < 0.05）。产妇血浆激素和代谢物的浓度，特别是孕酮和脂肪酸，也调制diet.Conclusion：这些结果提供了证据表明，产妇的饮食，在增加量的瘤胃保护的多不饱和脂肪酸喂养周围的概念，而不是产妇的身体状况，可以歪斜的性别比对男性。这些观察结果可能对畜牧业和动物管理政策产生影响，因为一种性别的后代可能比另一种更受欢迎。
Background: Evolutionary theory suggests that in polygynous mammalian species females in better body condition should produce more sons than daughters. Few controlled studies have however tested this hypothesis and controversy exists as to whether body condition score or maternal diet is in fact the determining factor of offspring sex. Here, we examined whether maternal diet, specifically increased n-6 polyunsaturated fatty acid (PUFA) intake, of ewes with a constant body condition score around the time of conception influenced sex ratio.Methods: Ewes (n = 44) maintained in similar body condition throughout the study were assigned either a control ( C) diet or one ( F) enriched in rumen-protected PUFA, but otherwise essentially equivalent, from four weeks prior to breeding until d13 post-estrus. On d13, conceptuses were recovered, measured, cultured to assess their capacity for interferon-tau (IFNT) production and their sex determined. The experiment was repeated with all ewes being fed the F diet to remove any effects of parity order on sex ratio. Maternal body condition score (BCS), plasma hormone and metabolite concentrations were also assessed throughout the study and related to diet.Results: In total 129 conceptuses were recovered. Ewes on the F diet produced significantly more male than female conceptuses ( proportion male = 0.69; deviation from expected ratio of 0.5, P < 0.001). Conceptus IFNT production was unaffected by diet ( P > 0.1), but positively correlated with maternal body condition score ( P < 0.05), and was higher ( P < 0.05) in female than male conceptuses after 4 h culture. Maternal plasma hormone and metabolite concentrations, especially progesterone and fatty acid, were also modulated by diet.Conclusion: These results provide evidence that maternal diet, in the form of increased amounts of rumen-protected PUFA fed around conception, rather than maternal body condition, can skew the sex ratio towards males. These observations may have implications to the livestock industry and animal management policies when offspring of one sex may be preferred over the other.