Zhou Jia, Ding Ziyue, Pu Qijian, Xue Benchu, Yue Shuangming, Guan Shengtao, Wang Zhisheng, Wang Lizhi, Peng Quanhui, Xue Bai
Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China.
Chengdu Mytech Biotech Co., Ltd., Chengdu 611130, China.
Animals (Basel). 2022 Aug 18;12(16):2113. doi: 10.3390/ani12162113.
This study aimed to evaluate the effect of enzymatic hydrolysate of cottonseed protein (ECP) on the kinetic of gas production, rumen fermentation characteristics, and microbial diversity in continuous in vitro culture with a single factorial design of supplementation with various concentrations of ECP or yeast culture. Treatments were control (without supplementation, CON), supplementation with 10 g/kg Diamond-V XP yeast culture of substrate (XP), and supplementation with 6, 12 and 18 g/kg ECP of substrate (ECP1, ECP2, ECP3), each incubated with 30 mL of buffered incubation fluids and 200 mg of fermentation substrate in graduated glass syringes fitted with plungers for 48 h. Compared with the CON treatment, supplementation of XP yeast culture increased the cumulative gas production at 12 and 24 h, the concentration of ammonia nitrogen (NH3-N) concentration at 24 and 36 h, the concentration of microbial protein (MCP) concentration at 24 and 48 h, the molar butyrate proportion at 12, 24, and 48 h, the molar valerate proportion at 48 h, and the ratio of non-glucogenic to glucogenic acids (p < 0.05). Compared with the CON treatment, the concentration of MCP and the molar propionate proportion at 12 h were higher in the ECP1 treatment (p < 0.05); the cumulative gas production at 2, 4, and 12 h, the concentration of NH3-N at 36 h and the molar valerate proportion at 48 h were higher in the ECP2 treatment (p < 0.05); the cumulative gas production at 2, 12, and 48 h, the concentration of NH3-N at 12 and 36 h, the concentration of MCP at 12, 36, and 48 h, the molar butyrate proportion at 12 and 48 h, and the molar valerate proportion at 48 h were higher in the ECP3 treatment (p < 0.05). Compared with the CON treatment, supplementation with XP yeast culture significantly altered the relative abundance of the phyla Firmicutes, Kiritimatiellaeota, and Proteobacteria, while supplementation with ECP had minimal effect on bacterial diversity. The prediction of bacterial functions showed that the main gene functions of rumen bacteria are associated with carbohydrate metabolism, amino acid metabolism, and membrane transport. The findings of this study suggest that ECP can be used as a superior feed ingredient for ruminants, the suitable level of ECP was 18 g/kg in vitro experiment.
本研究旨在通过单因素设计，在连续体外培养中评估棉籽蛋白酶解物（ECP）对产气动力学、瘤胃发酵特性及微生物多样性的影响，该设计涉及添加不同浓度的ECP或酵母培养物。处理组包括对照组（不添加，CON）、添加10 g/kg底物的钻石-V XP酵母培养物（XP），以及添加6、12和18 g/kg底物的ECP（ECP1、ECP2、ECP3），每组在装有活塞的刻度玻璃注射器中，与30 mL缓冲培养液和200 mg发酵底物一起孵育48小时。与CON处理相比，添加XP酵母培养物可提高12和24小时的累积产气量、24和36小时的氨氮（NH3-N）浓度、24和48小时的微生物蛋白（MCP）浓度、12、24和48小时的丁酸摩尔比例、48小时的戊酸摩尔比例以及非生糖酸与生糖酸的比例（p < 0.05）。与CON处理相比，ECP1处理中12小时的MCP浓度和丙酸摩尔比例更高（p < 0.05）；ECP2处理中2、4和12小时的累积产气量、36小时的NH3-N浓度以及48小时的戊酸摩尔比例更高（p < 0.05）；ECP3处理中2、12和48小时的累积产气量、12和36小时的NH3-N浓度、12、36和48小时的MCP浓度、12和48小时的丁酸摩尔比例以及48小时的戊酸摩尔比例更高（p < 0.05）。与CON处理相比，添加XP酵母培养物显著改变了厚壁菌门、基里马蒂埃洛菌门和变形菌门的相对丰度，而添加ECP对细菌多样性的影响最小。细菌功能预测表明，瘤胃细菌的主要基因功能与碳水化合物代谢、氨基酸代谢和膜转运有关。本研究结果表明，ECP可作为反刍动物的优质饲料成分，在体外实验中ECP的适宜添加水平为18 g/kg。
