Lin C, Bolsen K K, Brent B E, Hart R A, Dickerson J T, Feyerherm A M, Aimutis W R
Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-0201.
J Dairy Sci. 1992 Sep;75(9):2484-93. doi: 10.3168/jds.S0022-0302(92)78010-2.
Epiphytic microflora were identified and counted on four cuttings of alfalfa, each harvested at three stages of maturity, and on three whole-plant corn hybrids. Enterobacteriaceae were predominant on both crops. Yeasts and molds also were major epiphytic microorganisms on whole-plant corn. The group--including lactobacilli, pediococci, and leuconostocs, which are genera that produce lactic acid and thus are instrumental in silage preservation--constituted only a small proportion of the total population (less than .5%) on both crops. Lactate-fermenting clostridial spores were not detected on standing alfalfa, and occurrences of these spores on standing corn plants were due to soil contamination from rainfall prior to harvest. The numbers of epiphytic microorganisms, except for the lactobacilli, pediococci, and leuconostocs group, were higher on standing corn than on alfalfa. The epiphytic microflora on alfalfa increased with increasing temperature during the growing season. However, neither cutting number nor maturity affected the epiphytic microflora on standing alfalfa, and wilting following mowing had little effect on most populations. Higher temperatures during wilting increased yeast and mold counts but had no effect on other microbial counts. The chopping process tended to increase the epiphytic microflora populations compared with those on the standing crops, and the group containing lactobacilli, pediococci, and leuconostocs was most enhanced. Only yeast and mold counts on the chopped alfalfa increased with greater DM content and buffering capacity.
对四个不同成熟阶段收获的苜蓿插条以及三个全株玉米杂交品种上的附生微生物区系进行了鉴定和计数。肠杆菌科在这两种作物上均占主导地位。酵母和霉菌也是全株玉米上的主要附生微生物。包括乳酸杆菌、片球菌和明串珠菌在内的菌群，这些属会产生乳酸，因此对青贮饲料保存有重要作用，但在这两种作物上，它们仅占微生物总数的一小部分（不到0.5%）。在直立苜蓿上未检测到乳酸发酵梭菌孢子，直立玉米植株上这些孢子的出现是由于收获前降雨造成的土壤污染。除乳酸杆菌、片球菌和明串珠菌菌群外，直立玉米上的附生微生物数量高于苜蓿。苜蓿上的附生微生物区系在生长季节随温度升高而增加。然而，刈割次数和成熟度对直立苜蓿上的附生微生物区系均无影响，刈割后的萎蔫对大多数微生物数量影响不大。萎蔫期间较高的温度会增加酵母和霉菌数量，但对其他微生物数量没有影响。与直立作物相比，切碎过程往往会增加附生微生物区系数量，其中含有乳酸杆菌、片球菌和明串珠菌的菌群增加最为明显。切碎苜蓿上只有酵母和霉菌数量会随着干物质含量和缓冲能力的增加而增加。
