Abstract In the present study we estimated the genetic parameters of enteric methane emissions (EME) traits predicted from milk fatty acid profile (FA) and those of their predictors in 1,091 Brown Swiss cows reared on 85 farms in order to assess the potential of using EME-related phenotypes in selective breeding. Univariate and bivariate genetic models were fitted in a Bayesian framework. The means of the marginal posterior distribution of intra-herd heritability ranged from 0.12 for estimated methane production (g/d/cow) to 0.24 for estimated methane yield (g/kg dry matter intake [DMI]), with intermediate values for estimated methane intensity, increasingly higher when expressed per kg of corrected milk (0.13), fresh cheese (0.16), or cheese solids (0.20). Regarding the correlations, the milk quality traits and percentage cheese yields were generally moderately correlated with the estimated EME traits, and were variable in terms of sign. Daily milk and cheese yield traits were, as expected, all highly positively correlated with estimated daily methane production. In contrast, they were negatively correlated with estimated methane yield and intensity, the estimates being large in the case of phenotypic and herd correlations, and low in the case of additive genetic and residual correlations. With the exception of the negative correlations with daily methane production, EME traits exhibited trivial correlations with body size and BCS of cows, which, in turn, were negatively correlated with milk yield. Although the results should be validated on a larger population and different breeds, our study demonstrate the presence of additive genetic variation of EME traits, which could be exploited in breeding programmes for the improvement in both milk production and the ecological footprint of dairy farming. Highlights Enteric methane emissions (EME) of dairy cows can be estimated on the basis of milk fatty acid profile. EME exhibited exploitable genetic variation. Genetic selection could be preferentially based on predicted methane intensity per kg of milk, or per kg of cheese in countries where milk production is used mainly for cheese-making.

中文翻译：

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从脂肪酸谱预测的肠道甲烷排放的遗传力估计，以及它们与牛奶成分、奶酪产量、体型和状况的关系

摘要 在本研究中，我们估计了从牛奶脂肪酸谱 (FA) 预测的肠道甲烷排放 (EME) 性状的遗传参数及其在 85 个农场饲养的 1,091 头棕色瑞士奶牛的预测因子，以评估使用 EME 的潜力。选择性育种中的相关表型。在贝叶斯框架中拟合单变量和双变量遗传模型。群内遗传力的边际后验分布的平均值范围从估计甲烷产量 (g/d/cow) 的 0.12 到估计甲烷产量 (g/kg 干物质摄入量 [DMI]) 的 0.24，估计甲烷的中间值强度，每公斤校正牛奶 (0.13)、新鲜奶酪 (0.16) 或奶酪固体 (0.20) 表示时越来越高。关于相关性，牛奶质量性状和奶酪产量百分比通常与估计的 EME 性状中度相关，并且在符号方面是可变的。正如预期的那样，每日牛奶和奶酪产量性状都与估计的每日甲烷产量高度正相关。相比之下，它们与估计的甲烷产量和强度呈负相关，在表型和群相关的情况下估计值很大，而在加性遗传和残余相关性的情况下估计值很低。除了与每日甲烷产量呈负相关外，EME 特征与奶牛的体型和 BCS 表现出微不足道的相关性，而后者又与产奶量呈负相关。虽然结果应该在更大的人群和不同的品种上得到验证，我们的研究表明存在 EME 性状的附加遗传变异，可在育种计划中加以利用，以改善牛奶产量和奶牛养殖的生态足迹。亮点 奶牛的肠道甲烷排放量 (EME) 可以根据乳脂肪酸谱进行估算。EME 表现出可利用的遗传变异。在牛奶生产主要用于奶酪制作的国家，遗传选择可以优先基于每公斤牛奶或每公斤奶酪的预测甲烷强度。EME 表现出可利用的遗传变异。在牛奶生产主要用于奶酪制作的国家，遗传选择可以优先基于每公斤牛奶或每公斤奶酪的预测甲烷强度。EME 表现出可利用的遗传变异。在牛奶生产主要用于奶酪制作的国家，遗传选择可以优先基于每公斤牛奶或每公斤奶酪的预测甲烷强度。