含水率和发酵时间对以全株玉米为基础的发酵全混合日粮养分的影响

Effects of Moisture Ratio and Fermentation Time on Nutrients of Fermented Total Mixed Ration Based on Whole Plant Corn

本试验研究了含水率和发酵时间对全株玉米发酵全混合日粮(FTMR)发酵品质及养分含量的影响,旨在为FTMR的生产提供参考。试验选用腊熟期全株玉米为主要原料,在保持饲粮精粗比例约为3∶7(干物质基础)的前提下,与干花生秧、混合精料等饲料充分混合配制成含水率为35%的全混合日粮(TMR),然后加水调整TMR含水率分别为40%、45%、50%和55%,将这5种含水率的TMR快速装入塑料密封袋内,压实并抽去空气后密封保存制备FTMR。分别在发酵后的第0、10、20、30、40、50、60、70和80天,测定常规养分含量、发酵指标及霉菌毒素含量。结果表明:5种含水率的TMR在发酵至第80天时感官指标良好,均无发霉现象;发酵初期各组均有涨袋现象,随着发酵时间的增加,涨袋现象逐渐消失;含水率对FTMR常规养分含量影响较小;发酵前20天,pH随含水率的升高而升高,此后随含水率的升高而下降; 45%、50%和55%组具有较高的乳酸含量;乙酸、丙酸含量随发酵时间增加而增加,只在发酵的第10、20、30天检出微量的丁酸;各组均未检出玉米赤霉烯酮、呕吐毒素及黄曲霉毒素B1。综合分析认为,本试验条件下,全株玉米FTMR的含水率以45%和50%为宜,发酵时间不少于40 d。

In this experiment,the effects of moisture ratio and fermentation time on fermentation quality and nutrient content of whole plant corn fermented total mixed ration(FTMR)were studied in order to provide references for FTMR production.The whole plant corn in the dough stage were selected as main material.On the premise of keeping the ratio of concentrate to roughage of diet at about 3∶7(dry matter basis),total mixed ration(TMR)with 35%moisture ratio was prepared by mixing with dried peanut vines and mixed concentrate,and then adding water to adjust the moisture ratio of TMR were 40%,45%,50%and 55%,respectively.TMR were quickly loaded into plastic sealed bags,compacted and removed air,sealed and preserved to prepare FTMR.At days 0,10,20,30,40,50,60,70 and 80 of fermentation,the contents of conventional nutrients contents,fermentation indexes and mycotoxins content were determined.The results showed that the TMR of 5 kinds of moisture ratios showed good sensory indexes when fermented to day 80,and there was no moldy phenomenon;in the early stage of fermentation,bags expansion appeared in each group.With the increase of fermentation time,the expansion phenomenon gradually disappeared;the different moisture ratios had a small effect on the conventional nutrients of FTMR;at day 20 before fermentation,the pH increased with the increase of moisture ratio,since then,it decreased with the increase of moisture ratio;the 45%,50%and 55%groups had higher contents of lactic acid;the contents of acetic acid and propionic acid increased correspondingly with the increase of fermentation time,the content of butyric acid was detected only at days 10,20 and 30 of fermentation;none of the treatments showed zearalenone,vomit toxin and aflatoxin B 1.According to the comprehensive analysis,under the experimental conditions,the optimal moisture ratio of whole plant corn FTMR are 45%and 50%,and the fermentation days are not less than 40 d.