不同发酵温度对液体发酵饲料营养成分、挥发性脂肪酸和活菌数的影响

Effects of different fermentation temperatures on nutrient composition,volatile fatty acids and viable bacterial count of liquid fermented feed

文章旨在研究不同发酵温度对液体发酵饲料营养成分、挥发性脂肪酸和活菌数的影响。试验分别设定20、25、30℃三个发酵温度,每个发酵温度设置6个重复,厌氧发酵24?h。试验结果表明,随着发酵温度的升高,饲料中粗蛋白质含量显著提高(P <0.05),粗纤维含量无显著变化(P> 0.05),但总能显著降低(P <0.05);25和30℃发酵时,液体饲料中乳酸含量显著高于20℃组(P <0.05),但25和30℃之间差异不显著(P> 0.05);而挥发性脂肪酸方面,25和30℃发酵时,饲料中乙酸和丙酸含量显著高于20℃发酵组(P <0.05),而25和30℃之间的丙酸含量差异不显著(P> 0.05),乙酸含量25℃发酵组高于30℃发酵组(P <0.05)。丁酸含量则随发酵温度升高而显著降低(P <0.05);液体饲料中的乳酸菌和酵母菌活菌数显著升高(P <0.05),其中25和30℃发酵组酵母菌活菌数无显著差异(P> 0.05);液体饲料中均未检出沙门氏菌和大肠杆菌。

The effects of fermentation temperature on nutrient composition,volatile fatty acids and viable bacteria of liquid fermented feed were studied. Three fermentation temperatures(20,25,30 ℃)were set,and six replicates were set for each fermentation temperature. The results showed that the crude protein content increased significantly(P < 0.05),the crude fiber content did not change significantly(P > 0.05),but the total energy decreased significantly(P < 0.05)with the increase of fermentation temperature,the content of lactic acid in liquid feed was significantly higher than that in 20 ℃(P < 0.05),but there was no significant difference between 25 and 30℃(P > 0.05),the contents of acetic acid and propionic acid in feed were significantly higher than those in 20℃ fermentation group(P < 0.05),but the contents of propionic acid between 25 and 30℃had no significant difference(P > 0.05),the content of acetic acid in 25 ℃ fermentation group was higher than that in 30 ℃fermentation group(P < 0.05). The content of butyric acid decreased significantly with the increase of fermentation temperature(P < 0.05),and the number of lactobacillus and yeast in liquid feed increased significantly(P < 0.05),there was no significant difference in the number of viable yeasts between 25 and 30℃ groups(P > 0.05),and no salmonella and Escherichia coli were detected in the liquid feed.