利用体外胃蛋白酶-胰酶-盲肠液法评价驴不同粗饲料组合的营养物质降解率与组合效应  

Evaluation on Nutrient Degradation Rate and Combination Effects of Different Roughage Combinations of Donkey by in Vitro Pepsin⁃Trypsin⁃Cecal Fluid Method

作　　者：刘畅 赵艳丽[1] 郭晓宇[1] 郭咏梅[1] 郑亚光[1] 闫素梅[1] LIU Chang;ZHAO Yanli;GUO Xiaoyu;GUO Yongmei;ZHENG Yaguang;YAN Sumei(Inner Mongolia Key Laboratory of Animal Nutrition and Feed Science,College of Animal Science,Inner Mongolia Agricultural University,Hohhot 010018,China)

机构地区：[1]内蒙古农业大学动物科学学院,动物营养与饲料科学自治区高等学校重点实验室,呼和浩特010018

出　　处：《动物营养学报》2024年第5期3183-3191,共9页CHINESE JOURNAL OF ANIMAL NUTRITION

基　　金：内蒙古自治区科技重大专项(zdzx2018001);内蒙古自治区直属高校基本科研业务费(BR22-13-13)。

摘　　要：本试验利用体外三步法(胃蛋白酶-胰酶-盲肠液法),比较研究不同粗饲料组合的营养物质体外胃-小肠-盲肠降解率(GICD)与胃-小肠的体外降解贡献率;并以经胃与小肠降解后的残渣为底物研究其盲肠体外发酵参数,探究主要粗饲料的组合效应,为驴生产中粗饲料资源的科学搭配和利用效率的提高提供依据。试验选择成年健康德州驴作为盲肠液供体进行体外培养,采用单因素完全随机试验设计,分为4组,每组6个重复。将谷草与玉米秸秆的混合草(谷草∶玉米秸秆=6∶4)作为对照组(CON组),其余3组分别利用苜蓿草、全株玉米青贮和羊草等比例替代CON组中20%的谷草和玉米秸秆混合草,依次为Ⅰ组、Ⅱ组和Ⅲ组。结果表明:与CON组相比,Ⅱ组干物质(DM)和有机物(OM)的GICD与消化能(DE)及Ⅰ组粗蛋白质(CP)的GICD显著升高(P<0.05);Ⅰ组、Ⅱ组和Ⅲ组中性洗涤纤维的GICD及Ⅰ组和Ⅲ组酸性洗涤纤维的GICD显著升高(P<0.05),各组间半纤维素的GICD差异不显著(P>0.05)。Ⅰ组和Ⅱ组的DM和OM在胃-小肠(盲肠前)的体外降解贡献率及Ⅰ组、Ⅱ组和Ⅲ组的CP体外降解贡献率显著高于CON组(P<0.05)。体外盲肠发酵结果表明,各组间pH与氨态氮浓度的差异均不显著(P>0.05),CON组的菌体蛋白(P=0.091)与总挥发性脂肪酸浓度(P=0.075)有低于其他组的趋势。在3、24和48 h,CON组的产气量均有低于其他3组的趋势(P=0.061,P=0.096,P=0.080);在其余时间点,各组间产气量差异均不显著(P>0.05)。多项组合效应值(MFAEI)从高到低依次为Ⅱ组、Ⅰ组、Ⅲ组和CON组。综上可知,将苜蓿草、全株玉米青贮和羊草分别替代20%的谷草和玉米秸秆混合草,均产生正组合效应,提高了营养物质降解率和盲肠发酵功能,尤以苜蓿草和全株玉米青贮替代组的组合效应较好。In vitro three⁃step method(pepsin⁃trypsin⁃cecal fluid method)was used in this study,the in vitro nutrient degradation rate of gastro⁃intestinal⁃cecum(GICD)and the contribution rate of gastro⁃intestine nutrient degradation in different roughage combinations were compared.The fermentation parameters of cecum in vitro were determined by studying the residue after degradation through stomach and small intestine,to explore the combination effects of main roughage.It provides a basis for improving the scientific collocation and utilization efficiency of roughage resources in donkey production.Healthy adult Texas donkeys were selected as cecal fluid donors for culture in vitro.A single⁃factor completely randomized design was adopted,which was divided into 4 groups with 6 replicates per group.The millet straw was mixed with corn straw(millet straw∶corn straw=6∶4)as the control group(CON group).The other three groups(groupsⅠ,ⅡandⅢ)used alfalfa,whole corn silage and Leymus chinensis to replace 20%of the millet straw and corn straw in CON group,respective⁃ly.The results showed that compared with the CON group,GICD and digestive energy(DE)of dry matter(DM)and organic matter(OM)in groupⅡand the GICD of crude protein(CP)in group I were significant⁃ly increased(P<0.05).GICD of neutral detergent fiber in groupsⅠ,Ⅱ,Ⅲand the GICD of acid detergent fiber in groupsⅠandⅢwere significantly increased(P<0.05).There was no significant difference in GICD of hemicellulose among all groups(P>0.05).The in vitro degradation contribution rates of DM and OM in the stomach⁃small intestine(pre⁃cecum)and CP contribution rates in groupsⅠ,ⅡandⅢwere significantly higher than those in CON group(P<0.05).The results of cecum fermentation in vitro showed that there were no significant differences in pH and NH3⁃N concentration among all groups(P>0.05).The concentration of bacterial protein and total volatile fatty acid in CON group was lower than that in other groups(P=0.091,P=0.075).At 3,24 and 48 h tim

关 键 词：驴 体外胃-胰酶-盲肠液法 营养物质降解率 盲肠体外发酵 组合效应 

分 类 号：S822[农业科学—畜牧学]