本试验以前期筛选获得的具有潜在抑菌和脱毒活性的副干酪乳杆菌LS2(Lactobacillus paracasei LS2)、植物乳杆菌 S6-2(Lactiplantibacillus plantarum S6-2)和干酪乳杆菌 GD2-1(Lac-tobacillus casei GD2-1)3株乳酸菌为研究对象,探讨其对全株玉米青贮饲料有氧稳定性和霉菌毒素的影响.试验将田间遭受霉菌侵染(FI组)和霉菌未侵染(NFI组)全株玉米分别进行以下接种剂处理:1)未接种乳酸菌对照(CON处理);2)接种副干酪乳杆菌LS2(LS2处理);3)接种植物乳杆菌S6-2(S6-2处理);4)接种干酪乳杆菌GD2-1(GD2-1处理).青贮180 d后开窖,将各组青贮饲料暴露于空气中4 d,期间动态取样分析全株玉米青贮饲料的发酵参数、化学组分、微生物数量和霉菌毒素含量.结果表明:1)无论是否遭受霉菌侵染,LS2处理有氧暴露4 d后全株玉米青贮饲料pH最低;NFI组中LS2处理乳酸和乙酸含量最高.2)NFI组S6-2和GD2-1处理酵母菌和霉菌数量在有氧暴露第2天时快速上升,之后GD2-1处理保持稳定,而S6-2处理略有下降;FI组各处理酵母菌和霉菌数量在有氧暴露期间整体呈现上升趋势.3)田间霉菌侵染显著提高了全株玉米青贮饲料黄曲霉毒素B1(AFB1)含量(P＜0.05),各乳酸菌接种剂处理显著降低了 AFB1含量(P＜0.05),GD2-1处理降低了玉米赤霉烯酮含量(P＜0.05),而GD2-1处理显著降低了呕吐毒素含量(P＜0.05).4)无论是否遭受霉菌侵染,LS2处理均维持了最长的有氧稳定时间,有氧稳定性显著高于其他处理(P＜0.05).综上所述,青贮饲料有氧暴露后,田间霉菌侵染使全株玉米青贮饲料品质进一步下降并导致有氧腐败提前;无论是否遭受霉菌侵染,接种副干酪乳杆菌LS2的全株玉米青贮饲料在有氧暴露期间始终保持着较高的乳酸和乙酸含量,并维持了最高的有氧稳定性.
Effects of Inoculation with Lactic Acid Bacteria on Aerobic Stability and Mycotoxin Contents in Whole-Plant Corn Silages
This experiment focused on the potential antibacterial and detoxifying activities of three strains of lactic acid bacteria as Lactobacillus paracasei LS2,Lactiplantibacillus plantarum S6-2 and Lactobacillus casei GD2-1,which were screened in the preliminary stage,and aimed to investigate their effects on the aerobic sta-bility and mycotoxin contents in whole-plant corn silages.The experimental whole-plant corns from fields either infected(FI group)or not infected(NFI group)with fungi were ensiled with the following inoculant treat-ments:1)no lactic acid bacteria inoculation control(CON treatment);2)inoculation with Lactobacillus pa-racasei LS2(LS2 treatment);3)inoculation with Lactiplantibacillus plantarum S6-2(S6-2 treatment);4)inoculation with Lactobacillus casei GD2-1(GD2-1 treatment),respectively.After 180 days of silage fermen-tation,the silage pits were opened,and the samples from each group were exposed to air for 4 days to analyze of fermentation parameters,chemical composition,microbial counts and mycotoxin contents in whole-plant corn silages.The results showed as follows:1)regardless of fungal infection,LS2 treatment displayed the lowest pH in whole-plant corn silages after 4-day of aerobic exposure;and LS2 treatment in NFI group showed the highest lactic acid and acetic acid contents.2)In NFI group,the numbers of yeasts and molds in S6-2 and GD2-1 treatments increased rapidly on the second day of aerobic exposure,after which GD2-1 treatment re-mained stable,while S6-2 treatment decreased slightly.In FI group,the numbers of yeasts and molds in each treatment showed an overall increasing trend during aerobic exposure.3)Field fungal infection significantly in-creased the aflatoxin B1(AFB1)content in whole-plant corn silages(P＜0.05),all lactic acid bacteria inocu-lant treatments significantly decreased the AFB,content(P＜0.05),GD2-1 treatment significantly decreased the zearalenone content(P＜0.05),and GD2-1 treatment significantly decreased the deoxynivalenol content(P＜0.05).4)Regardless of fungal infection,LS2 treatment maintained the longest aerobic stability time,and the aerobic stability was significantly higher than that in the other treatments(P＜0.05).In conclusion,after aerobic exposure,the field fungal infection further degrades the quality of whole-plant corn silages and leads to premature aerobic spoilage.Regardless of fungal infection,the inoculation with Lactobacillus paracasei LS2 can maintain higher contents of lactic acid and acetic acid in whole-plant corn silages during aerobic exposure,and exhibit the highest aerobic stability.[Chinese Journal of Animal Nutrition,2024,36(11):7383-7393]
万方数据
维普
