Japanese black Wagyu cattle are renowned for producing some of the world's most highly valued and recognized beef with exceptional marbling. Therefore, the primary focus of genetic selection for Wagyu cattle has historically been on meat quality, particularly achieving high marbling levels. However, even when the price of the final product is high, production costs also remain high, especially considering that most of the feed has to be imported. The objective of this study was to evaluate phenotypic relationships between feed efficiency, specifically residual feed intake, as the most utilized efficiency index in cattle, and various meat quality parameters in Japanese black cattle in order to determine if a common phenotypic selection for these parameters could be feasible. For this, a total of 39 Wagyu cattle were evaluated for feed efficiency over their entire fattening period (900 days), with a focus on RFI as a key indicator. Animals were fed high-starch diets with vitamin A deprivation to achieve the desired marbling. Results revealed positive correlations between feed efficiency and meat quality in Wagyu cattle. Specifically, animals with higher feed efficiency exhibited superior meat quality traits, including firmness, marbling, and overall meat rating. When comparing the 20 most extreme RFI individuals (10 most and 10 least efficient), we observed that efficient RFI animals showed increased marbling levels (+13.2%, P=0.05) and ranking quality (+12%, P=0.06) of the meat. In conclusion, this research contributes to understanding the interplay between feed efficiency and meat quality in Japanese black Wagyu cattle. Phenotypic correlations observed suggest the possibility of incorporating RFI criteria into genetic selection programs without compromising the prized meat quality traits of Wagyu beef.

中文翻译：

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日本黑毛和牛肉质参数与剩余采食量之间的表型关系


日本黑和牛因生产一些世界上最有价值和最受认可的具有特殊大理石花纹的牛肉而闻名。因此，历史上，和牛遗传选择的主要焦点一直是肉质，特别是实现高大理石花纹水平。然而，即使最终产品的价格很高，生产成本也仍然很高，特别是考虑到大部分饲料必须进口。本研究的目的是评估饲料效率（特别是作为牛中最常用的效率指数的剩余采食量）与日本黑牛的各种肉质参数之间的表型关系，以确定这些参数的共同表型选择是否可以是可行的。为此，对总共 39 头和牛在整个育肥期（900 天）的饲料效率进行了评估，其中 RFI 是一项关键指标。给动物喂食高淀粉饮食，但缺乏维生素 A，以获得所需的大理石花纹。结果显示，和牛的饲料效率与肉质呈正相关。具体来说，饲料效率较高的动物表现出优异的肉质特征，包括硬度、大理石花纹和整体肉类评级。当比较 20 个最极端的 RFI 个体（10 个效率最高和 10 个效率最低）时，我们观察到高效的 RFI 动物表现出更高的大理石花纹水平（+13.2%，P=0.05）和排名质量（+12%，P=0.06）。肉。总之，这项研究有助于了解日本黑和牛饲料效率和肉质之间的相互作用。 观察到的表型相关性表明，可以将 RFI 标准纳入遗传选择计划，而不会影响和牛珍贵的肉质特性。