不同青贮添加剂对全株玉米青贮营养价值、发酵品质和瘤胃降解率的影响

Effects of Different Silage Additives on Nutritional Value,Fermentation Quality and Rumen Degradability of Whole Corn Silage

本试验旨在研究不同青贮添加剂对全株玉米青贮营养价值、发酵品质和瘤胃降解率的影响。全株玉米青贮时分别添加不同青贮添加剂,试验共设5个组,分别为对照组(不添加任何青贮添加剂)、乳酸菌组(添加5×10^5CFU/g乳酸菌制剂)、有机酸组(甲酸、乙酸和丙酸按照7∶1∶2的体积比进行混合,添加量为4 mL/kg)、有机酸盐组(苯甲酸钠和山梨酸钾按照1∶1的质量比进行混合,添加量为2 g/kg)和纤维素酶组(添加50 mg/kg纤维素酶),每组4个重复。青贮45 d后,测定全株玉米青贮的营养成分、发酵品质和瘤胃降解率。结果表明:1)有机酸组的粗蛋白质含量显著高于其他各组(P<0.05),有机酸盐组和纤维素酶组的中性洗涤纤维含量显著低于对照组(P<0.05),有机酸盐组和纤维素酶组的相对饲喂价值和非中性洗涤纤维性碳水化合物含量显著高于对照组(P<0.05),乳酸菌组、有机酸组、有机酸盐组和纤维素酶组的有机酸和可溶性糖含量均显著高于对照组(P<0.05)。2)乳酸菌组和有机酸组的总可消化养分含量、消化能、代谢能、维持净能和增重净能显著高于对照组、有机酸盐组和纤维素酶组(P<0.05)。3)乳酸菌组、有机酸盐组和纤维素酶组的pH显著低于对照组(P<0.05),乳酸菌组、有机酸组、有机酸盐组和纤维素酶的乳酸含量显著高于对照组(P<0.05),有机酸组和有机酸盐组的氨态氮/总氮(NH3-N/TN)显著低于对照组(P<0.05),有机酸组和纤维素酶组的发酵系数、费氏评分、24 h干物质降解率和24 h中性洗涤纤维降解率显著高于对照组(P<0.05)。由此可见,乳酸菌、有机酸、有机酸盐和纤维素酶对全株玉米青贮的营养成分含量、发酵品质和瘤胃降解率均有不同程度的提升作用。综合以上各项指标进行评价,各组全株玉米青贮的综合营养价值从高到低依次为:纤维素酶组>有机酸盐组>有机酸组>乳酸菌组>对照组。

This experiment was conducted to evaluate effects of different silage additives on nutritional value,fermentation quality and rumen degradability of whole corn silage.When whole corn ensiling,different silage additives were added,there were 5 groups in the experiment,which were control group(without any silage additives),Lactobacillus group(supplemented 5×105 CFU/g Lactobacillus preparation),organic acid group(formic acid,acetic acid and propionic acid were mixed in a volume ratio of 7∶1∶2,the additive amount was 4 mL/kg),organic acid salt group(sodium benzoate and potassium sorbate were mixed in a weight ratio of 1∶1,he additive amount was 2 g/kg)and cellulose group(supplemented 50 mg/kg cellulose),each group contained 4 replicates.After 45 days of fermentation,the nutrient content,fermentation quality and rumen de⁃gradability of whole corn silage were measured.The results showed as follows:1)the crude protein content of organic acid group was significantly higher than that of other groups(P<0.05),the neutral detergent fiber content of organic acid salt group and cellulase group was significantly lower than that of the control group(P<0.05),the relative feeding value and non⁃neutral detergent fiber content of organic acid salt group and cellulase group were significantly higher than those of the control group(P<0.05),and the contents of organic acids and soluble sugars of Lactobacillus group,organic acid group,organic acid salt group and cellulase group were significantly higher than those of the control group(P<0.05).2)The total digestible nutrient contents,diges⁃tive energy,metabolic energy,maintenance net energy and weight gain net energy of Lactobacillus group and organic acid group were significantly higher than those of control group,organic acid salt group and cellulase group(P<0.05).3)The pH of Lactobacillus group,organic acid salt group and cellulase group was signifi⁃cantly lower than that of the control group(P<0.05),the lactic acid content of Lactobacillus group,organic acid group,organic acid salt group and cellulase group was significantly higher than that of the control group(P<0.05),the ammonia nitrogen/total nitrogen of organic acid group and organic acid salt group was signifi⁃cantly lower than that of the control group(P<0.05),and the fermentation coefficient,Fleig score,24 h dry matter degradability and 24 h neutral detergent fiber degradability of organic acid group and cellulase group were significantly higher than those of the control group(P<0.05).In conclusion,Lactobacillus,organic acid,organic acid salt and cellulose had varying degrees of promote effects on nutrient content,fermentation quality and rumen degradability of whole corn silage.Comprehensive evaluation of the above indicators,the comprehensive nutritional value of whole corn silage in each group from high to low is:cellulase group>organ⁃ic acid salt group>organic acid group>Lactobacillus group>control group.