Effects Of Different Lactic Acid Bacteria On Fermentation Quality And Feed Characteristics Of Yellow Corn Stalk At Low Temperature

The subjects of this study are how to improve availability of resources with non-grain feed in low temperature and screening for low temperature fermentation of LAB agent. We purpose to decrease feed costs and promote the development of aquaculture. This thesis includes three parts as follow.First part, the fermentation characteristics and the aerobic stability of corn stalks with low temperature were studied, and a randomized design with 2 × 4(temperature × days) factorial treatment structures was used. After sealing treatment, the corn stalks ferment with different temperature condition(room temperature、4 °C) and different fermentation condition(7、14、28、56、oxidized 28、oxidized 56 days).Second part, the fermentation characteristics and the aerobic stability of corn stalks with different LAB were studied by using a randomized design with 7 × 2 × 4(LAB × temperature ×days) factorial treatment structures. There are 7 treatment group in the experiment, includes additive free 、 LAB1(Lactobacillus plantarum Chikuso-1) 、 LAB2(Master-LP) 、 LAB3(Master-AC)、LAB1+LAB2、LAB1+LAB3、LAB2+LAB3. And we tested 3 times per group. The corn straw silage was stored at different temperature condition(room temperature、4 °C) and different fermentation condition for 7、14、28、56 days, and the silage for 28 and 56 days was oxidized. Microorganism, feed fermentation parameters of yellow corn stalk silage were determined.Third part, the effects of adding LAB on the in vitro dry matter(DM) digestibility and rumen fermentation characteristics of corn straw yellow storage were determined by using a randomized design with 7 × 2 × 2(LAB × temperature × days) factorial treatment structures.The corn stalk silages were stored at different temperature condition(room temperature or 4 °C for 28 or 56 days, respectively. After the silages were opened, in vitro DM digestibility、rumen fermentation and the content of methane generated in rumen were determined.The study shows as follow:1. The fermented 28 days yellow corn stalk silage’s CP(Crude Protein) and EE(Ether Extract)contents are more than 56 days with room temperature condition(P<0.05); The fermented 28 days and 56 days yellow corn stalk silage ’s CP and EE contents with 4 °C condition are less than the yellow corn stalk silage with room temperature condition(P<0.05). After 7、14、28、56 days fermented, the lactic acid bacteria content in the yellow corn stalk silage with room temperature condition is more than with 4 °C condition(P<0.05).2. After 28 、 56 days fermented and oxidized, the all group CP content is less than without oxidized in the yellow corn stalk silage, but the yeast and mold content is more than without oxidized. The p H of 28 days fermented and oxidized yellow corn stalk silage higher than 56 days(P<0.05).3. After 4 °C and 28 days fermented, the DM(Dry Matter) 、 OM(Organic Matter) and CP contents of the yellow corn stalk silage are increased with LAB2 are more than other groups(P<0.05); the DM and CP contents of the yellow corn stalk silage are increased sharply with LAB2+LAB3 in room temperature, and the NDF(Neutral Detergent Fiber) and coliform bacteria contents are decreased sharply(P<0.05). After 4 °C and 56 days fermented, the DM lost slowly with LAB2(P<0.05); in the 4 °C conditions, the p H of the yellow corn stalk silage with LAB1+LAB3 is decreased significantly, the lactic acid content is increased, the growth of coliform bacteria is suppressed(P<0.05); in the room temperature conditions and added LAB1,the DM 、OM and lactic acid bacteria contents are increased sharply, but the yeast content is decreased significantly(P<0.05).4. After 2 different oxidized days conditions, the yeast content in LAB1+LAB2、LAB1+LAB3and LAB2+LAB3 groups are lower than LAB1、LAB2 and LAB3 groups, and the DM、OM contents in LAB1+LAB2、LAB1+LAB3 and LAB2+LAB3 groups are higher than LAB1、LAB2and LAB3 groups. After 4 °C and 2 different oxidized days groups, the DM 、 OM and CP contents of the yellow corn stalk silage are increased with LAB1+LAB2 and LAB1+LAB3 are more than other groups(P<0.05), and the coliform bacteria、clostridium、yeast contents reduced in this two treatment processes(P<0.05); but with the room temperature condition, DM、OM、CP contents are high in the LAB2+LAB3 group, at the same time the bacilli bacteria、mold contents reduced significantly(P<0.05).5. After 4 °C and 28 days with room temperature fermented, the DM disappearing rate in rumen and VFA content are increased in LAB1 group(P<0.05), but with 4 °C condition, the yield ofmethane is decreased in LAB1 group; With 2 different temperature, the ammoniacal nitrogen content is high in LAB1 and LAB2+LAB3 groups(P<0.05). With 4 °C and 56 fermented days conditions, VFA(Volatile Fatty Acid) content is increased significantly in LAB1+LAB3 group(P<0.05). With 2 different temperature and 2 different fermented days conditions, the yield of methane is decreased significantly in LAB2 and LAB2+LAB3 groups(P<0.05).In low temperature fermentation condition, the yellow corn stalk silage had lower nutritional ingredient and fermentation quality than the yellow corn stalk silage under ambient temperature fermentation condition; In addition, compare to the ambient temperature fermentation condition,low temperature fermentation condition could decreased the aerobic stability. The yellow corn stalk silages with LAB improved the fermentation quality and effectively reduced the nutritional ingredient loss under the two temperature fermentation conditions; With 2 different temperature,added mix LAB into yellow corn stalk silages could increased the aerobic stability; In low temperature fermentation condition, and added mix LAB into yellow corn stalk silages could promoted the protein degradation in rumen; In ambient temperature condition, group with LAB could effectively increased DM digestibility and VFA concentrations, except for inhibited the production of rumen methane gas and promoted the protein degradation in rumen.