Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK, Canada.
J Anim Physiol Anim Nutr (Berl). 2020 May;104(3):847-866. doi: 10.1111/jpn.13256. Epub 2019 Dec 18.
Indigestible dietary protein fermentation products have been suggested to negatively influence broiler performance due to their impact on health and digestive tract morphology. This study evaluated the digestive tract morphology and caecal protein fermentation metabolites of broiler fed 3 dietary protein levels (24%, 26% and 28%) with low or high indigestible protein (LIP, HIP). Two completely randomized 3 × 2 factorial trials were conducted with protein level (PL) and indigestible protein (IDP) as the main factors. In both trials, birds received six diets (24-LIP, 24-HIP, 26-LIP, 26-HIP, 28-LIP and 28 HIP) formulated with no medication. On day 5, trial 1 birds were vaccinated with Coccivac-B52, while trial 2 received no vaccine. Tissue and caecal samples were collected and caecal contents analysed for fermentation metabolites. Differences were considered significant when p ≤ .05. The LIP treatment caecal content in trial 1 at 14 days had greater histamine, agmatine and cadaverine levels, while HIP diets resulted in increased serotonin, tryptamine and spermidine. Histamine, serotonin and tryptamine at day 28 were not affected by IDP, and ammonia was not affected by treatments at day 14 or day 28. At day 14, HIP birds had lower total short-chain fatty acids, higher caecal pH and heavier pancreas, proventriculus, gizzard, jejunum and ileum weights. The same effects of IDP found in trial 1 were observed for histamine, agmatine, cadaverine, serotonin, tryptamine and spermidine at day 21 in trial 2. Trial 2 had a PL-by-IDP interaction influencing tyramine, spermidine (28-LIP > 24-LIP) and spermine with values increasing with PL for LIP diets and remaining constant for HIP diets. An interaction between PL and IDP was found for ammonia level and was similar to interactions for biogenic amines. In conclusion, dietary PL and IDP influence broiler caecal protein fermentation metabolites and those effects varied with coccidiosis vaccination and rearing environment.
不可消化的日粮蛋白发酵产物被认为会对肉鸡的生产性能产生负面影响，这是因为它们会影响动物的健康和消化道形态。本研究评估了低蛋白（LIP）和高蛋白（HIP）日粮条件下，3 种不同蛋白水平（24%、26%和 28%）对肉鸡消化道形态和盲肠蛋白发酵代谢物的影响。本研究采用完全随机 3×2 因子设计，以蛋白水平（PL）和不可消化蛋白（IDP）为主效因子。在这两个试验中，所有试验鸡均接受 6 种日粮（24-LIP、24-HIP、26-LIP、26-HIP、28-LIP 和 28-HIP）的处理，日粮中不添加任何药物。在试验 1 的第 5 天，试验鸡接种 Coccivac-B52 疫苗，而试验 2 不接种疫苗。在第 14 天和第 28 天，采集组织和盲肠样本，分析盲肠内容物中的发酵代谢物。当 p 值≤0.05 时，认为差异显著。在试验 1 的第 14 天，LIP 处理的盲肠内容物中组胺、胍丁胺和尸胺的水平较高，而 HIP 日粮导致血清素、色胺和亚精胺的水平增加。第 28 天，IDP 对组胺、血清素和色胺没有影响，而氨在第 14 天和第 28 天都不受处理的影响。在第 14 天，HIP 组的短链脂肪酸总量较低，盲肠 pH 值较高，胰腺、腺胃、肌胃、空肠和回肠的重量较重。在试验 2 的第 21 天，发现了与试验 1 中相同的 IDP 影响，包括组胺、胍丁胺、尸胺、血清素、色胺和亚精胺。试验 2 还发现了 PL 与 IDP 的互作，影响了酪胺、亚精胺（28-LIP＞24-LIP）和精胺，对于 LIP 日粮，PL 增加时这些物质的含量增加，而对于 HIP 日粮，这些物质的含量保持不变。PL 和 IDP 之间还存在氨水平的互作，这种互作与生物胺的互作相似。总之，日粮 PL 和 IDP 影响肉鸡盲肠蛋白发酵代谢物，这些影响因球虫病疫苗接种和饲养环境而异。
