Center for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1Canada.
AbacusBio Limited, PO Box 5585, Dunedin, New Zealand.
Animal. 2020 Jan;14(1):171-179. doi: 10.1017/S175173111900154X. Epub 2019 Jul 22.
Feed represents a substantial proportion of production costs in the dairy industry and is a useful target for improving overall system efficiency and sustainability. The objective of this study was to develop methodology to estimate the economic value for a feed efficiency trait and the associated methane production relevant to Canada. The approach quantifies the level of economic savings achieved by selecting animals that convert consumed feed into product while minimizing the feed energy used for inefficient metabolism, maintenance and digestion. We define a selection criterion trait called Feed Performance (FP) as a 1 kg increase in more efficiently used feed in a first parity lactating cow. The impact of a change in this trait on the total lifetime value of more efficiently used feed via correlated selection responses in other life stages is then quantified. The resulting improved conversion of feed was also applied to determine the resulting reduction in output of emissions (and their relative value based on a national emissions value) under an assumption of constant methane yield, where methane yield is defined as kg methane/kg dry matter intake (DMI). Overall, increasing the FP estimated breeding value by one unit (i.e. 1 kg of more efficiently converted DMI during the cow's first lactation) translates to a total lifetime saving of 3.23 kg in DMI and 0.055 kg in methane with the economic values of CAD $0.82 and CAD $0.07, respectively. Therefore, the estimated total economic value for FP is CAD $0.89/unit. The proposed model is robust and could also be applied to determine the economic value for feed efficiency traits within a selection index in other production systems and countries.
饲料在奶制品行业的生产成本中占很大比例，是提高整个系统效率和可持续性的一个有用目标。本研究的目的是开发一种方法来估计饲料效率性状的经济价值和与加拿大相关的甲烷生产价值。该方法通过量化选择那些在最小化用于低效代谢、维持和消化的饲料能量的同时将消耗的饲料转化为产品的动物所带来的经济节约水平，来估算饲料效率性状的经济价值。我们定义了一个名为饲料表现（Feed Performance，FP）的选择标准性状，它是初产奶牛每增加 1 公斤更有效地利用饲料。然后，通过量化该性状在其他生命阶段的相关选择响应对更有效地利用饲料的终生总价值的影响，来估算其对总终生价值的影响。然后，将由此产生的饲料转化率的提高应用于确定在甲烷产量不变的假设下，排放物（以及基于国家排放价值的相对价值）减少的情况，其中甲烷产量定义为每公斤干物质摄入量（DMI）的甲烷产量。总体而言，将 FP 估计育种值提高一个单位（即奶牛第一次泌乳期间更有效地转化 1 公斤 DMI），可在终生范围内节省 3.23 公斤 DMI 和 0.055 公斤甲烷，其经济价值分别为 0.82 加元和 0.07 加元。因此，FP 的估计总经济价值为 0.89 加元/单位。该模型具有稳健性，也可应用于在其他生产系统和国家的选择指数中确定饲料效率性状的经济价值。
