The effect of inoculants and cellulase on the fermentation and microbiological composition of grass silage: II Microbiological changes in the silages

Authors

• Aino Rauramaa Valio Co-operative Dairies’ Association, Research and Development Department P.O. Box 176, SF-00181 Helsinki, Finland
• Jouko Setälä Valio Co-operative Dairies’ Association, Research and Development Department P.O. Box 176, SF-00181 Helsinki, Finland
• Tauno Moisio Valio Co-operative Dairies’ Association, Research and Development Department P.O. Box 176, SF-00181 Helsinki, Finland
• Seppo Sivelä Valio Co-operative Dairies’ Association, Research and Development Department P.O. Box 176, SF-00181 Helsinki, Finland
• Terttu Heikkilä Agricultural Research Centre, Department of Animal Husbandry 31600 Jokioinen, Finland
• Martti Lampila Agricultural Research Centre, Department of Animal Husbandry 31600 Jokioinen, Finland

DOI: https://doi.org/10.23986/afsci.72270

Abstract

Four experimental silages were made into bunker silos by adding lactic acid bacteria and cellulase enzyme. The control silages were made without any additives and with AIV II solution (80 % formic acid, 2% orthophosphoric acid). The microbial compositions of the experimental silages were studied in five microbial groups; (1) total count of bacteria, (2) lactic acid bacteria, (3) Clostridia, (4) coliform bacteria and (5) fungi (yeasts and moulds). At the beginning of the fermentations enteric bacteria and lactic acid bacteria were increasing. Inoculation of the silage decreased the growth of enterobacteria compared with silages made with cellulase or without additives. This effect was further increased by using AIV II solution. Heterolactic fermentations started in the silages made with cellulase, inoculants and no additives, when initial reducing sugars, primarily glucose and fructose, were fermented. In good ensiling conditions only a few butyric acid forming Clostridia and small amounts of moulds and yests were found. Yeasts existed mostly in silages made with cellulase and with inoculation.