GenPhySE, Université de Toulouse, INRAE, F-31326, Castanet-Tolosan, France.
Animal. 2020 Dec;14(12):2598-2608. doi: 10.1017/S175173112000138X. Epub 2020 Jun 22.
To identify a proper strategy for future feed-efficient pig farming, it is required to evaluate the ongoing selection scenarios. Tools are lacking for the evaluation of pig selection scenarios in terms of environmental impacts to provide selection guidelines for a more sustainable pig production. Selection on residual feed intake (RFI) has been proposed to improve feed efficiency and potentially reduce the associated environmental impacts. The aim of this study was thus to develop a model to account for individual animal performance in life cycle assessment (LCA) methods to quantify the responses to selection. Experimental data were collected from the fifth generation of pig lines divergently selected for RFI (low line, more efficient pigs, LRFI; high line, less efficient pigs, HRFI). The average feed conversion ratio (FCR) and daily feed intake of LRFI pigs were 7% lower than the average of HRFI pigs (P < 0.0001). A parametric model was developed for LCA based on the dietary net energy fluxes in a pig system. A nutritional pig growth tool, InraPorc®, was included as a module in the model to embed flexibility for changes in feed composition, animal performance traits and housing conditions and to simulate individual pig performance. The comparative individual-based LCA showed that LRFI had an average of 7% lower environmental impacts per kilogram live pig at farm gate compared to HRFI (P < 0.0001) on climate change, acidification potential, freshwater eutrophication potential, land occupation and water depletion. High correlations between FCR and all environmental impact categories (>0.95) confirmed the importance of improvement in feed efficiency to reduce environmental impacts. Significant line differences in all impact categories and moderate correlations with impacts (>0.51) revealed that RFI is an effective measure to select for improved environmental impacts, despite lower correlations compared to FCR. Altogether more optimal criteria for efficient environment-friendly selection can then be expected through restructuring the selection indexes from an environmental point of view.
为了确定未来饲料效率高的养猪策略，需要评估当前的选择方案。缺乏用于评估猪选择方案对环境影响的工具，无法为更可持续的养猪生产提供选择指南。有人提出选择残余饲料摄入量（RFI）来提高饲料效率，并可能减少相关的环境影响。因此，本研究的目的是开发一种模型，以在生命周期评估（LCA）方法中考虑个体动物的性能，从而量化对选择的反应。从第五代 RFI （低线，更高效的猪，LRFI；高线，效率较低的猪，HRFI）差异选择的猪中收集了实验数据。LRFI 猪的平均饲料转化率（FCR）和日采食量比 HRFI 猪低 7%（P < 0.0001）。基于猪系统的膳食净能量通量，为 LCA 开发了一个参数模型。InraPorc®作为模型中的一个模块，包括了一个营养猪生长工具，以嵌入饲料成分、动物性能特征和饲养条件的变化灵活性，并模拟个体猪的性能。基于个体的比较性 LCA 表明，与 HRFI 相比，LRFI 每头活猪在农场门口的平均环境影响降低了 7%（P < 0.0001），这主要体现在气候变化、酸化潜力、淡水富营养化潜力、土地占用和水资源消耗方面。FCR 与所有环境影响类别之间的高度相关性（>0.95）证实了提高饲料效率对减少环境影响的重要性。所有影响类别中的显著线性差异以及与影响的中度相关性（>0.51）表明，尽管与 FCR 相比相关性较低，但 RFI 是选择改善环境影响的有效措施。通过从环境角度重新构建选择指数，可以期望选择出更高效、更环保的标准。
