Utilization of low crude protein diets and probiotics to support gut health and function in weaned piglets

仔猪断奶后腹泻会降低生长性能，从而造成养猪业的经济损失。传统上，养猪业通过使用含有高度可消化和特殊成分的起始日粮来减轻这些损失，例如喷雾干燥猪血浆和亚治疗性水平的抗生素作为生长促进剂。然而，公众施加了巨大压力，要求停止在猪饲料中使用动物产品和抗生素，因为担心这些产品对人类健康构成风险。因此，养猪业热衷于寻找有效、安全和环境友好的营养干预措施，以取代饲料中抗生素的使用。现有证据表明，低粗蛋白-氨基酸添加日粮(LCP-AA)可以作为整体策略的一部分，以调节断奶仔猪的肠道发育、微生物群落和免疫反应。然而，至关重要的是，这样的饮食要仔细制定，以避免氨基酸缺乏。此外，LCP-AA日粮与其他添加剂(如益生菌)之间可能存在协同效应。因此，将进行研究，以确定可能限制饲喂LCP-AA日粮的猪的氨基酸需要量。将研究LCP-AA和益生菌之间协同作用的可能性，以确定预防仔猪腹泻的有效治疗方法的组合。免疫挑战模型将被用来有效地测试这些干预措施支持仔猪肠道健康和功能的潜力。该项目的结果将有助于为断奶仔猪开发可持续的营养管理选择，从而帮助加拿大养猪业适应饲料中抗生素使用的新限制，以保持在国际市场上的竞争力。

Post-weaning diarrhea in piglets reduces growth performance and therefore causes economic losses in the swine industry. Traditionally, the swine industry has mitigated these losses by utilizing starter diets containing highly digestible and specialized ingredients such as spray dried porcine plasma and sub-therapeutic levels of antibiotics as growth promoters. However, there is intense public pressure to discontinue the use of animal products and antibiotics in pig diets for fear that these products pose a risk to human health. Thus, the swine industry is keenly interested in identifying effective, safe and environmentally friendly nutritional interventions that could replace the use of in-feed antibiotics. Existing evidence suggests that low crude protein-amino acid supplemented diets (LCP-AA) could be used as part of the overall strategy to modulate intestinal development, microbial communities, and immune response in weaned piglets. However, it is critical that such diets are carefully formulated to avoid amino acid deficiencies. Also, there may be synergistic effects between LCP-AA diets and other additives such as probiotics. Therefore, research will be conducted to determine requirements of amino acids that are likely to limit performance of pigs fed LCP-AA diets. The potential for synergistic interactions between LCP-AA and probiotics will be studied with a view of identifying a combination of effective therapies for prevention of piglet diarrhea. Immune challenge models will be used to effectively test the potential of these interventions to support gut health and function in piglets. Results of the project will be useful in developing sustainable nutritional management options for weaned pigs thus helping the Canadian swine industry to adapt to new restrictions regarding in-feed antibiotic usage so as to remain competitive at the international market place.