Zhu Qingqing, Wang Yuxin, Liu Yanjie, Yu Bing, He Jun, Zheng Ping, Mao Xiangbing, Huang Zhiqing, Luo Junqiu, Luo Yuheng, Yan Hui, Yu Jie
Key Laboratory for Animal Disease-Resistance Nutrition of Sichuan Province, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China.
Jinan Bestzyme Bio-Engineering Co., Ltd., Jinan 250101, China.
Animals (Basel). 2022 Oct 17;12(20):2803. doi: 10.3390/ani12202803.
This experiment was conducted to evaluate the effects of different protease levels on performance, diarrhea rate, nutrient digestibility, blood metabolites, digestive enzyme activities, and intestinal health of weaned piglets. A total of 96 weaned piglets (Duroc × Landrace × Yorkshire, 28 d of age, initial average BW = 6.55 ± 0.17 kg) were divided into four groups (4 pigs/pen and 6 replicates/group) according to a completely random block design. Piglets were fed different levels of protease (0, 150, 300 or 600 mg/kg of diet) for 28 d. The results showed that the addition of protease had no significant effect on the growth performance of weaned piglets (p > 0.05), and the addition of 300 mg/kg protease significantly increased the apparent total intestinal digestibility (ATTD) of nutrients and the apparent ileal digestibility (AID) of amino acids in weaned piglets (p < 0.05), while the addition of 150 mg/kg and 600 mg/kg protease had no significant effect on the digestibility (p > 0.05). The nutrient digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and total energy (GE) showed a trend of increasing and then decreasing with increasing protease concentration (p < 0.05). Adding 300 and 600 mg/kg protease significantly decreased serum ALB/GLO levels (p < 0.05) and duodenal pH (p < 0.05) and increased duodenal villus height (p < 0.05). The addition of protease significantly increased jejunal trypsin and chymotrypsin activities (p < 0.01) and duodenal and jejunal mucosal tight junction proteins in piglets. The mRNA expression levels of ZO-1 and CLAUDIN-1 in the duodenum together with ZO-1 and OCCLUDIN in the jejunum of piglets in the 300 and 600 mg/kg protease supplementation groups were significantly higher than those in the control group (p < 0.05). The results showed that, compared with the control group, protease could promote nutrient absorption, improve small intestine morphology and enhance digestive enzyme activity in weaned piglets. The suitable addition amount was 150−300 mg/kg in the present study.
本试验旨在评估不同蛋白酶水平对断奶仔猪生产性能、腹泻率、养分消化率、血液代谢产物、消化酶活性及肠道健康的影响。选用96头断奶仔猪（杜洛克×长白×大白，28日龄，初始平均体重=6.55±0.17 kg），按完全随机区组设计分为四组（每栏4头猪，每组6个重复）。仔猪饲喂不同水平的蛋白酶（0、150、300或600 mg/kg日粮），为期28天。结果表明，添加蛋白酶对断奶仔猪的生长性能无显著影响（p>0.05），添加300 mg/kg蛋白酶显著提高了断奶仔猪养分的表观总肠道消化率（ATTD）和氨基酸的表观回肠消化率（AID）（p<0.05），而添加150 mg/kg和600 mg/kg蛋白酶对消化率无显著影响（p>0.05）。干物质（DM）、有机物（OM）、粗蛋白（CP）和总能（GE）的养分消化率随蛋白酶浓度的增加呈先升高后降低的趋势（p<0.05）。添加300和600 mg/kg蛋白酶显著降低了血清ALB/GLO水平（p<0.05）和十二指肠pH值（p<0.05），并增加了十二指肠绒毛高度（p<0.05）。添加蛋白酶显著提高了仔猪空肠胰蛋白酶和糜蛋白酶活性（p<0.01）以及十二指肠和空肠黏膜紧密连接蛋白。300和600 mg/kg蛋白酶添加组仔猪十二指肠中ZO-1和CLaudin-1以及空肠中ZO-1和Occludin的mRNA表达水平显著高于对照组（p<0.05）。结果表明，与对照组相比，蛋白酶可促进断奶仔猪养分吸收，改善小肠形态，增强消化酶活性。本研究中适宜的添加量为150−300 mg/kg。
