发酵棉籽粕对黄颡鱼生长性能、表观消化率和肠道健康的影响

Effects of fermented cottonseed meal on growth performance, apparent digestibility and intestinal health of yellow catfish (Pelteobagrus fulvidraco)

摘要:

目的 探究发酵棉籽粕对黄颡鱼生长性能、饲料表观消化率及肠道健康的影响。方法 实验设计3组饲料：第一组饲料为基础饲料，以鱼粉、豆粕等为主要蛋白源，第二、三组饲料以70%基础饲料+30%未发酵棉籽粕/发酵棉籽粕组成，饲料中添加三氧化二钇，以便测定营养物质和能量的消化率。饲料配好后，投喂初始体重为(6.20 ± 0.2) g的黄颡鱼，实验持续7周。测定指标包括黄颡鱼生长性能、营养物质（包括能量）消化率、肠道组织学、抗氧化酶活性和基因表达，以及炎症因子和紧密连接相关基因表达等。结果 发酵棉籽粕组的黄颡鱼WGR（167.35%）、SGR（2.01）相比于未发酵棉籽粕组（148.76%和1.86）显著上升。此外，固态发酵后，黄颡鱼对棉籽粕干物质消化率由35.64%提升至82.10%，粗蛋白消化率由77.31%提升至90.04%，粗脂肪消化率由68.53%提升至88.03%，能量消化率由48.43%提升至86.24%。相较于未发酵棉籽粕，发酵棉籽粕显著提升肠道组织的肠绒毛高度以及宽度，显著降低促炎因子 (il6、il8)的mRNA表达，显著升高抗炎因子 (tgf-β)的mRNA表达水平，显著升高抗氧化相关基因 (cat、sod1、sod2、gpx1、keap1)的mRNA表达，降低nrf2的mRNA表达，显著提升总抗氧化能力 (T-AOC)、CAT以及T-SOD酶活，降低MDA含量，显著升高紧密连接相关基因 (zo1、zo2、claudin1、claudin3、claudin4、occludin)的mRNA表达水平。此外，显著降低凋亡诱导相关基因 (caspase3、caspase9、p53)的mRNA表达，显著升高抗凋亡基因bcl2的mRNA表达，显著降低Caspase3、Caspase9的酶活性。结论 固态发酵棉籽粕能显著提高黄颡鱼的生长性能以及对棉籽粕的营养物质消化率，显著缓解棉籽粕对黄颡鱼肠道健康的负面影响。

Abstract:

To investigated the effects of fermented cottonseed meal on the apparent digestibility of diets and intestinal health in yellow catfish (Pelteobagrus fulvidraco), three dietary groups were designed. The first group consisted of a basic diet, with fish meal and soybean meal as the primary protein sources. The second and third groups were composed of 70% basic diet supplemented with 30% unfermented or fermented cottonseed meal, respectively. The weight gain rate (WGR) and specific growth rate (SGR) of P. fulvidraco fed the fermented cottonseed meal diet were significantly higher than those of fish fed the unfermented cottonseed meal diet. Solid-state fermentation of cottonseed meal significantly enhanced its digestibility in P. fulvidraco, with dry matter digestibility increasing from 35.64% to 82.10%, crude protein digestibility from 77.31% to 90.04%, crude fat digestibility from 68.53% to 88.03%, and energy digestibility from 48.43% to 86.24%. Compared with unfermented cottonseed meal, the fermented meal significantly increased intestinal villus height and width, decreased mRNA expression of pro-inflammatory factors (il6 and il8), and increased mRNA expression of anti-inflammatory factor tgf-β. Additionally, the fermented meal significantly increased mRNA expression of antioxidant-related genes (cat, sod1, sod2, gpx1, and keap1), while decreasing nrf2 mRNA expression. Total antioxidant capacity (T-AOC), catalase (CAT), and total superoxide dismutase (T-SOD) activities were significantly elevated, and malondialdehyde (MDA) content was reduced. The mRNA expression levels of tight junction-related genes (zo1, zo2, claudin1, claudin3, claudin4, and occludin) were also significantly increased. Furthermore, mRNA expression of apoptosis-related genes (caspase3, caspase9, and p53) was significantly decreased, while the mRNA expression of the anti-apoptosis protein bcl2 was significantly elevated, and enzyme activities of Caspase3 and Caspase9 were significantly reduced. In conclusion, solid-state fermentation of cottonseed meal can significantly improve growth performance and nutrient digestibility in P. fulvidraco and mitigate the adverse effects of cottonseed meal on intestinal health.