乳酸菌和纤维素酶对不同含水量紫花苜蓿青贮品质的影响

本试验旨在探讨含水量和添加剂对紫花苜蓿青贮品质的影响,以期解决苜蓿青贮困难的问题,提高其青贮品质。采用双因素(含水量×添加剂)完全随机设计,含水量分别为70%和60%;添加剂分4个组,对照组不含添加剂,其余各组均含3个水平,分别为乳酸菌组(LA组,3、6、9 mg/kg)、纤维素酶组(CE组,25、50、100 mg/kg)以及乳酸菌和纤维素酶混合组(LA×CE组,3×25、6×50、9×100 mg/kg),每个组3个重复,共20个组。青贮90 d后,测定其粗蛋白质(CP)、粗纤维(CF)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、可溶性糖(WSC)含量及pH、氨态氮/总氮(AN/TN)。结果表明:与对照组相比,各LA组均显著提高了青贮料的WSC含量(P0.05),显著降低了青贮料pH(P0.05);且6 mg/kg LA组青贮料的CP和WSC含量高于3和9mg/kg LA组,pH低于3和9 mg/kg LA组。与对照组相比,各CE组均显著降低了青贮料的ADF含量和pH(P0.05),且50 mg/kg CE组青贮料的ADF含量和pH低于25和100 mg/kg CE组。各LA×CE组青贮料的CF、ADF含量和pH大部分低于各LA和CE组,WSC含量均高于各LA组和CE组,且6×50 mg/kg LA×CE组青贮料的CF、ADF、WSC含量和pH与各LA和CE组差异显著(P0.05)。除9 mg/kg LA组和100 mg/kg CE组外,相同添加剂下70%含水量青贮料的CP含量显著低于60%含水量(P0.05);相同添加剂下70%含水量青贮料的CF和ADF含量显著高于60%含水量(P0.05)。由此可见,乳酸菌和纤维素酶及两者复合添加均对苜蓿的青贮品质有明显的改善作用,并以添加6×50 mg/kg乳酸菌和纤维素酶效果最好,且60%含水量下的青贮效果更优。

Effects of Lactic Acid Bacteria and Cellulase on Alfalfa Silage Quality with Different Moisture

To solve the difficulty of alfalfa silage and improve the quality of silage, the study was conducted to investigate effects of moisture and additive on alfalfa silage quality. Used the two factor (moisture×additive) completely random design, the moisture was 70% and 60%, respectively; the additive divided into 4 groups, control group without additives, and the other three group contained three levels which were the lactic acid bac?teria group ( LA group;3, 6 and 9 mg/kg) , cellulase group ( CE group, 25, 50 and 100 mg/kg) and mix?ture of lactic acid bacteria and cellulose group (LA×CE group;3×25, 6×50 and 9×100 mg/kg), each group contained 3 replicates, altogether 20 groups. After silage for 90 days, the content of crude protein ( CP ) , crude fiber ( CF) , neutral detergent fiber ( NDF) , acid detergent fiber ( ADF) and water soluble carbohydrate (WSC) and pH, ammonia nitrogen/total nitrogen (AN/TN) were determined. The results showed as fol?lows: compared with the control group, the silage WSC content in all LA groups was significantly increased ( P<0.05) , and the silage pH was significantly decreased ( P<0.05);the content of CP and WSC of silage in 6 mg/kg LA group was higher than that in 3 and 9 mg/kg LA groups, and the pH was lower than that in 3 and 9 mg/kg LA groups. Compared with the control group, the ADF content and pH of silage in all CE groups was significantly decreased ( P<0.05) , and the ADF content and pH of silage in 50 mg/kg CE group was lower than those in 25 and 100 mg/kg CE groups. The CF and ADF content and pH of silage in all LA×CE groups most lower than those in all LA and CE groups, and the WSC content was higher than that in all LA and CE groups, the CF, ADF and WSC content and pH of silage in 6×50 mg/kg LA×CE group had significant differ?ence compared with all LA and CE groups ( P<0.05) . The silage CP content in 70% moisture under the same additive were significant lower than that in 60% moisture except 9 mg/kg LA group and 100 mg/kg CE group (P<0.05); the silage CF and ADF content in 70% moisture under the same additive were significant lower than those in 60% moisture ( P<0.05) . In conclusion, lactic acid bacteria, cellulase and their mixture can ap?parently improve the quality of alfalfa silage, and the supplementation of 6×50 mg/kg lactic acid bacteria and cellulase has the best effects, meanwhile, the silage effect of 60% moisture is superior to 70% moisture.