Animal Science, Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
Department of Animal Science and Aquaculture, Dalhousie University, Halifax, Nova Scotia, Canada.
Am J Physiol Gastrointest Liver Physiol. 2024 Dec 1;327(6):G818-G831. doi: 10.1152/ajpgi.00146.2024. Epub 2024 Oct 15.
The postweaning period in pigs is a critical window where nutritional interventions are implemented to prevent postweaning diarrhea (PWD) and antibiotic use. One common strategy is feeding low-protein diets immediately following weaning. This intervention may reduce protein fermentation and pathogen proliferation, therefore decreasing the incidence of postweaning diarrhea. These effects may also be mitigated by providing dietary fiber. However, studies examining the role of protein and fiber on gastrointestinal microbiota and metabolism are complicated by the presence of other substrates, including polyphenols and antinutritional factors in complex ingredients. In this study, semipurified diets formulated to meet nutrient requirements were fed to 40 weaned pigs ( = 10/diet) to examine the effects of high protein (HP), high fiber (HF), or both (HFHP) compared with a control (CON) diet with industry-standard crude protein and fiber content. Critical alterations in host metabolism and cecal transcriptome were identified in response to the CON diet. Diets with lower protein levels (CON and HF) induced alteration in transcripts from the serine synthesis pathways and integrated stress response in cecal tissue alongside systemic increases in metabolic pathways related to lysine degradation. High protein diets did not induce increases in gastrointestinal pathogen abundance. These results challenge the practice of feeding low-protein diets postweaning, by demonstrating a detrimental effect on intestinal cell function and muscle accretion. This suggests that with careful ingredient selection, increased dietary protein postweaning could improve pig health and growth compared with a standard diet. Although low-protein diets are commonly used for weaned pigs and are thought to decrease diarrhea incidence, this study showed that low-protein diets may induce muscle catabolism and intestinal epithelial stress response. Eventhough high-protein diets increased protein fermentation by gut microbes, no increase in diarrhea was detected. Protein fermentation was mitigated by fiber while still supporting growth and intestinal epithelial cell function, suggesting new strategies for feeding weaned pigs with careful ingredient selection.
仔猪断奶后是一个关键时期，在此期间采取营养干预措施来预防断奶后腹泻（PWD）和抗生素的使用。一种常见的策略是在断奶后立即喂养低蛋白日粮。这种干预措施可以减少蛋白质发酵和病原体增殖，从而降低断奶后腹泻的发生率。通过提供膳食纤维，这些效果可能会得到缓解。然而，研究蛋白质和纤维对胃肠道微生物群和代谢的作用时，由于复杂成分中存在多酚和抗营养因子等其他底物，研究变得复杂。在这项研究中，使用满足营养需求的半纯化日粮来喂养 40 头断奶仔猪（= 10/日粮），以研究与具有行业标准粗蛋白和纤维含量的对照（CON）日粮相比，高蛋白（HP）、高纤维（HF）或两者（HFHP）日粮的影响。CON 日粮会导致宿主代谢和盲肠转录组发生关键变化。低蛋白水平日粮（CON 和 HF）会引起盲肠组织中丝氨酸合成途径和整体应激反应的转录本发生变化，同时与赖氨酸降解相关的代谢途径在全身增加。高蛋白日粮不会增加胃肠道病原体的丰度。这些结果挑战了断奶后喂养低蛋白日粮的做法，表明低蛋白日粮对肠道细胞功能和肌肉积累有不利影响。这表明，通过仔细选择成分，与标准日粮相比，增加断奶后日粮中的蛋白质可以改善猪的健康和生长。尽管低蛋白日粮常用于断奶仔猪，并且被认为可以降低腹泻的发生率，但本研究表明，低蛋白日粮可能会引起肌肉分解代谢和肠道上皮应激反应。尽管高蛋白日粮增加了肠道微生物的蛋白质发酵，但未检测到腹泻增加。膳食纤维可以缓解蛋白质发酵，同时仍支持生长和肠道上皮细胞功能，这表明通过仔细选择成分来喂养断奶仔猪的新策略。
