Department of Animal Science, University of Minnesota, St. Paul, MN 55018, USA.
West Central Research and Outreach Center, University of Minnesota, Morris, MN 56267, USA.
J Anim Sci. 2023 Jan 3;101. doi: 10.1093/jas/skad188.
Traditionally, swine diets have been formulated to meet nutrient requirements at the lowest cost with little regard toward minimizing environmental impacts. The overall objective of this study was to evaluate the relative differences among four grower-finisher feeding programs, using precision diet formulation practices, on growth performance, carcass composition, nitrogen utilization efficiency, and environmental impacts. In experiment 1, four 4-phase growing-finishing feeding programs consisting of diets containing corn and soybean meal (CSBM), low protein CSBM supplemented with crystalline amino acids (LP), CSBM with 30% distillers dried grains with solubles (DDGS), and DDGS supplemented with crystalline Ile, Val, and Trp (DDGS + IVT) were fed to 288 mixed sex pigs (initial body weight [BW] = 36.9 ± 4.2 kg) for 12 wk to determine effects on growth performance and carcass characteristics. Pigs fed with CSBM had greater (P < 0.05) final BW than those fed with LP and DDGS, and greater gain efficiency than pigs fed with LP. Pigs fed with DDGS + IVT tended to have greater (P = 0.06) backfat depth than pigs fed with DDGS, and less (P < 0.05) loin muscle area than pigs fed with CSBM. In experiment 2, nitrogen (N) and phosphorus (P) balance of barrows (n = 32; initial BW = 59.9 ± 5.1 kg) fed with each of the phase-2 diets from experiment 1 was determined in a 12-d metabolism study (7 d adaptation and 5 d collection). Pigs fed with CSBM had a greater (P < 0.05) amount of N retained than pigs fed with other diets, but also had a greater (P < 0.05) amount of urinary N excretion and blood urea N than pigs fed with LP and DDGS + IVT diets. Pigs fed with LP tended (P = 0.07) to have the greatest N utilization efficiency but the least (P < 0.05) P retained as a percentage of P intake among dietary treatments. Diet composition and data collected from experiments 1 and 2 were used to calculate life cycle assessment environmental impacts using Opteinics software (BASF, Lampertheim, Germany). The CSBM feeding program had the least impact on climate change, marine and freshwater eutrophication, and fossil resource use. The LP feeding program had the least impact on acidification, terrestrial eutrophication, and water use, while the DDGS feeding programs had the least impact on land use. These results indicate that feeding CSBM diets optimized growth performance and carcass composition while simultaneously reducing impacts on climate change, marine and freshwater eutrophication, and fossil resource use compared with the other feeding programs evaluated.
传统上，猪的饮食配方是在满足营养需求的最低成本下制定的，很少考虑到最小化环境影响。本研究的总体目标是评估四种生长-育肥喂养方案在生长性能、胴体组成、氮利用效率和环境影响方面的相对差异，这些方案使用了精确的饮食配方实践。在实验 1 中，使用四种 4 阶段生长-育肥喂养方案，方案中包含玉米和豆粕（CSBM）、低蛋白 CSBM 补充结晶氨基酸（LP）、含有 30%干酒糟及其可溶物（DDGS）的 CSBM 和补充结晶异亮氨酸、缬氨酸和色氨酸（DDGS+IVT）的 CSBM，喂养 288 头混合性别猪（初始体重[BW]为 36.9±4.2kg）12 周，以确定对生长性能和胴体特征的影响。与 LP 和 DDGS 相比，饲喂 CSBM 的猪的最终 BW 更大（P<0.05），与 LP 相比，饲喂 CSBM 的猪的增重效率更高。饲喂 DDGS+IVT 的猪的背膘深度有增加的趋势（P=0.06），与饲喂 DDGS 的猪相比，饲喂 DDGS+IVT 的猪的腰肉面积更小。在实验 2 中，在 12 天的代谢研究（7 天适应和 5 天收集）中，使用实验 1 中第 2 阶段的每种饮食来确定公猪（n=32；初始 BW=59.9±5.1kg）的氮（N）和磷（P）平衡。饲喂 CSBM 的猪比饲喂其他饮食的猪保留了更多的 N（P<0.05），但也排泄了更多的尿液 N（P<0.05）和血尿素 N。饲喂 LP 的猪有增加的趋势（P=0.07），表现出最高的 N 利用率，但作为饲料摄入的 P 保留的百分比最小（P<0.05）。实验 1 和 2 中收集的数据和饮食组成用于使用 Opteinics 软件（巴斯夫，兰珀特海姆，德国）计算生命周期评估环境影响。CSBM 喂养方案对气候变化、海洋和淡水富营养化以及化石资源的使用影响最小。LP 喂养方案对酸化、陆地富营养化和水的使用影响最小，而 DDGS 喂养方案对土地利用的影响最小。这些结果表明，与评估的其他喂养方案相比，饲喂 CSBM 饮食在优化生长性能和胴体组成的同时，还减少了对气候变化、海洋和淡水富营养化以及化石资源使用的影响。
