The present study investigated the impact of dietary protease supplementation on the growth performance and intestinal function of weaned piglets when fed a diet comprising high levels of low digestible protein sources, in comparison with a standard commercially representative piglet diet. A total of 180 weaned piglets, 21 d old, of Duroc × Large White × Landrace crossbreeds, with an initial body weight (BW) of 6.27 ± 0.45 kg, were randomly assigned to three dietary treatments: 1) a standard commercial positive control (PC) diet comprising 22.2% soy protein, 5% whey protein, and 3% fish meal, 2) a negative control (NC) diet comprising 30.1% soy protein without whey protein and fish meal, and 3) a NC diet supplemented with 0.02% protease (NC + PROT). The diets were formulated to be iso-nitrogenous and iso-caloric and were pelleted at conditions of 0.4 MPa and 75°C. The experimental design employed a completely randomized design with 6 replicate pens per treatment, each pen containing 10 piglets. Statistical analysis was conducted using one-way ANOVA, with differences between means assessed using Duncan’s Multiple Range Test (P < 0.05). In terms of piglet performance, feeding the NC diet, containing high levels of low digestible protein sources, resulted in a significant decrease (P < 0.05) in final BW, average daily gain (ADG), and average daily feed intake (ADFI) by 3.1%, 8.2%, and 5.2%, respectively, compared with piglets fed the PC diet. Conversely, the NC diet significantly increased (P < 0.05) the feed-to-gain ratio and incidence of diarrhea by 3.4% and 88.3%, respectively, relative to PC. However, the supplementation of protease in the NC + PROT diet restored final BW, feed-to-gain ratio, and incidence of diarrhea to the same level as PC, while ADG and ADFI were increased (P < 0.05) by 4.6% and 4.3%, respectively. Regarding intestinal function, relative to PC, piglets fed the NC diet exhibited significantly less (P < 0.05) duodenal villus height, crude protein digestibility, and gene expressions of duodenal peptide transporter PepT1 and jejunal amino acid transporter b0,+AT, while blood urea nitrogen and diamine oxidase concentrations were greater (P < 0.05). However, the addition of protease in the NC diet reinstated measures of intestinal function, as NC + PROT-fed piglets showed similar duodenal villus height, crude protein digestibility, gene expressions of duodenal peptide transporter PepT1 and jejunal amino acid transporter b0,+AT, as well as blood urea nitrogen and diamine oxidase concentrations to PC. In conclusion, dietary supplementation of protease in weaned piglets fed higher levels of lower digestible protein sources mitigated losses in growth performance and intestinal functionality by enhancing intestinal development, protein digestibility, nutrient transport efficiency, and overall health status of piglets.

中文翻译：

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375 补充蛋白酶对断奶仔猪生产性能和肠道功能的影响饲喂了大量的低消化性蛋白质来源


本研究调查了日粮蛋白酶补充剂对断奶仔猪生长性能和肠道功能的影响，与标准的商业代表性仔猪日粮相比，饲喂含有高水平低消化蛋白来源的日粮。将 180 头杜洛克×大白×长白杂交种 21 d 龄断奶仔猪随机分配到三种日粮处理中，初始体重 （BW） 为 6.27 ± 0.45 kg，随机分配到三种日粮处理中：1） 标准商业阳性对照 （PC） 日粮，包括 22.2% 大豆蛋白、5% 乳清蛋白和 3% 鱼粉，2） 阴性对照 （NC） 日粮，包括 30.1% 大豆蛋白，不含乳清蛋白和鱼粉， 3） 补充 0.02% 蛋白酶 （NC + PROT） 的 NC 饮食。日粮被配制成异氮和等热量，并在 0.4 MPa 和 75°C 的条件下沉淀。 实验设计采用完全随机设计，每个处理 6 个重复猪栏，每个猪栏包含 10 头仔猪。使用单因素方差分析进行统计分析，使用 Duncan 多范围检验评估均值之间的差异 （P < 0.05）。在仔猪生产性能方面，饲喂含有高水平低消化蛋白来源的 NC 日粮导致最终体重、平均日增重 （ADG） 和平均日采食量 （ADFI） 显著降低 （P < 0.05） 分别降低 3.1%、8.2% 和 5.2%，与饲喂 PC 日粮的仔猪相比。相反，相对于 PC，NC 饮食显着增加了 （P < 0.05） 饲料增重比和腹泻发生率分别增加了 3.4% 和 88.3%。 然而，在 NC + PROT 日粮中添加蛋白酶使最终体重、采食增重比和腹泻发生率恢复到与 PC 相同的水平，而 ADG 和 ADFI 分别增加 4.6% 和 4.3% （P < 0.05）。在肠道功能方面，相对于 PC，饲喂 NC 日粮的仔猪表现出显著较低的十二指肠绒毛高度、粗蛋白消化率以及十二指肠肽转运蛋白 PepT1 和空肠氨基酸转运蛋白 b0，+AT 的基因表达，而血尿素氮和二胺氧化酶浓度较高 （P < 0.05）。然而，在 NC 日粮中添加蛋白酶恢复了肠道功能的测量，因为 NC + PROT 喂养的仔猪显示出相似的十二指肠绒毛高度、粗蛋白消化率、十二指肠肽转运蛋白 PepT1 和空肠氨基酸转运蛋白 b0，+AT 的基因表达，以及血尿素氮和二胺氧化酶浓度到 PC。总之，在饲喂较高水平的低消化蛋白质来源的断奶仔猪中，日粮中添加蛋白酶通过增强肠道发育、蛋白质消化率、营养物质运输效率和仔猪的整体健康状况来减轻生长性能和肠道功能的损失。