苯甲酸钠对再水化高粱青贮饲料营养价值的影响

Effect of sodium benzoate on nutritional value of rehydrated sorghum silage

本研究旨在评价用苯甲酸钠处理的再水化高粱青贮饲料在奶牛饲料中的营养价值。试验选择1500 kg的干高粱,再水化后水分为350 g/kg,然后装在200 L的塑料桶里发酵。在青贮时,谷物以2 g/kg的速度用苯甲酸钠处理(处理组),或不做任何处理(对照组)。将12头泌乳期为(170±47)d的泌乳中期荷斯坦奶牛随机分为两组,前2周饲喂相同的对照组日粮,后4周分别饲喂对照组和处理组日粮。日粮组成:360 g/kg青贮玉米、48 g/kg梯牧草、120 g/kg棉粕、184 g/kg豆粕、27 g/kg复合多维多矿、258 g/kg再水化青贮高粱。每周测定干物质摄入量、产奶量和乳成分,而瘤胃发酵特性和采食行为则在试验期间的最后一周测定。结果:用苯甲酸钠处理的高粱青贮饲料可溶蛋白、氨氮、乙醇、丁二醇、乳酸乙酯、乙酸乙酯的浓度显著降低(P<0.05),苯甲酸钠组较对照组显著降低了乳酸菌、酵母菌数量(P<0.05),但处理组较对照组提高了好氧稳定性、降低了气体和干物质损失(P<0.05)。不同处理间的干物质摄取量、产奶量和乳成分无显著差异(P>0.05)。与饲喂对照青贮饲料奶牛相比,饲喂苯甲酸钠处理的再水化高粱青贮饲料奶牛的丙酸比例较低(P<0.05),乙酸与丙酸的比例较高(P<0.05)。结论:苯甲酸钠处理的青贮饲料提高了再水化高粱青贮饲料的好氧稳定性、瘤胃液中乙酸与丙酸的比例,但饲粮处理并没有改变泌乳奶牛的生产性能。

The purpose of this study was to evaluate the nutritional value of sodium benzoate treated sorghum silage in dairy cattle feed.In the experiment,1500 kg of dry sorghum was selected,and the water content after hydration was 350 g/kg,which was then fermented in 200 L plastic barrel.In silage,the grain was either treated with sodium benzoate at a rate of 2 g/kg(the treatment group)or without any treatment(the control group).Twelve Holstein cows with lactation period of 170±47 d were randomly divided into two groups.They were fed the same standard diet for the first 2 weeks and the control group and the treatment group for the second 4 weeks.Dietary composition:360 g/kg silage maize,48 g/kg hay,120 g/kg cotton meal,184 g/kg soybean meal,27 g/kg minerals and vitamins,258 g/kg rehydrated silage sorghum.Dry matter intake,milk production and milk composition were measured weekly,while rumen fermentation characteristics and feeding behavior were measured during the last week of the trial period.Results:treated with sodium benzoate sorghum silage of soluble protein,ammonia nitrogen,ethanol,butylene glycol,ethyl lactate,ethyl acetate concentration decreased significantly(P<0.05),sodium benzoate group than the control group significantly reduced the number of lactic acid bacteria and yeast(P<0.05),but the treatment group than the control group improved the aerobic stability,reduces the loss of gas and dry matter(P<0.05).There was no significant difference in dry matter intake,milk production and milk composition between different treatments(P>0.05).Compared with cows fed silage control,cows fed sodium benzoate treated sorghum silage had a lower proportion of propionic acid and a higher proportion of acetic acid and propionic acid(P<0.05).Conclusion:sodium benzoate treatment of silage improved the aerobic stability of rehydrated sorghum silage and the ratio of acetic acid to propionic acid in tummy juice,but the feeding treatment did not change the production performance of lactating cows.