摘要
本试验旨在研究不同粒度苜蓿干草饲料对羔羊体外发酵特征和微生物数量的影响.采用单因子试验设计,将苜蓿干草制备为6种不同粒度,分别为1.00、2.36、3.35、4.75、8.00 mm和12.50 mm,苜蓿干草作为饲粮中纤维的唯一来源.根据不同粒度分为6个处理组,每个处理组4个重复,利用体外人工瘤胃Rusitec-s型模拟装置进行48 h发酵后,测定饲粮中营养物质降解率、体外发酵参数和发酵液中6种微生物的数量.结果显示:随着苜蓿干草粒度增加,体外干物质降解率(IVDMD)显著降低(P＜0.05),分别较1.00 mm组降低了 1.8％、3.85％、5.80％、15.01％和12.09％;与其他组相比,粒度为2.36 mm 组中性洗涤纤维降解率(IVNDFD)、丁酸摩尔比、异戊酸摩尔比、产琥珀酸丝状杆菌(F.succinogene)和甲烷杆菌(Methanobacteriale)数量显著提高(P＜0.05),瘤胃发酵液pH、NH3-N浓度及总产甲烷菌数量(Total methanogens)显著降低(P＜0.05),其他指标各组间均无显著差异(P＞0.05).综上所述,粒度为2.36 mm的苜蓿干草饲料对3月龄羔羊瘤胃体外发酵效果最佳.
Abstract
This experiment aimed to investigate the effects of different particle sizes of alfalfa hay on the in vitro fermentation characteristics and microbial population of lambs.Six different particle sizes(1.00,2.36,3.35,4.75,8.00 mm and 12.50 mm)of alfalfa hay were selected as the sole source of fiber in the experimental rations using a single factorial experimental design,and divided into six groups according to different particle sizes,with four replicates in each group.In vitro fermentation was carried out for 48 h using a Rusitec-s type artificial rumen simulator,and nutrients degradation rate,in vitro fermentation parameters and the copy number of six microflora in the fermentation broth were determined.The results showed that the in vitro dry matter degradation rate(IVDMD)decreased significantly as the particle size of alfalfa hay increased,compared with 1.00 mm group,they were decreased by 1.8％,3.85％,5.80％,15.01％and 12.09％(P＜0.05);the 2.36 mm group significantly increased the in vitro neutral detergent fiber degradability,molar ratio of butyric acid,molar ratio of isovaleric acid,and molar ratio,F.succinogene and Methanobacteriale(P＜0.05),and significantly decreased the pH,NH3-N concentration and the total methanogens in the rumen fermentation broth(P＜0.05),while there were no significant differences among the treatments for other indicators(P＞0.05).In conclusion that the alfalfa hay particle size of 2.36 mm was the best in vitro fermentation of the rumen of 3-month-old lambs.
基金项目
国家自然科学基金(32160803)
甘肃农业大学学科团队项目(GAU-XKTD-2022-20)
维普
万方数据