Biological bases of grass silage and haylage making (review)

The current concept about regularities of microbiological processes at ensiling and haymaking depending on the kind of preserved grasses and a degree of wilting is represented in the review. On this base the rational methods for plant mass conservation have been proved. The conservation method should be selected with due regard to the crop peculiarities (gramineous or leguminous grass), sugars contents (per dry matter) and its changes under the grass wilting, a degree of plants drying, the pH and sugar-buffer ratio in forage mass, and the composition of epiphytic microflora to provide an improved fodders storage and increased quality. Besides, it is necessary to keep strictly the modes of preliminary mass processing and loading as well as silage storage and removing. The silage additives, based on the osmotically tolerant strains of lactic acid bacteria, is one of the important elements in the applied technology, providing inhibition of growth of the undesirable microorganisms, including butyric acid bacteria and the yeasts activity, that can lead to fodders contamination by the butyric acid. Most perennial grass varieties, as well as their mixtures with legumes, cultivated in Russia, are characterized by optimal sugar-buffer ratio (1.3-4.0) for the effective ensiling with above pointed bacterial inoculants. But some new perennial gramineous grass varieties have excessive sugar contents (sugar-buffer ratio is ≥ 4.0) and are included in the group of the hard-to-ensile crops. For solving the ensiling problems with such perennial grasses, it should be recommended to cultivate them in mixed sowings with crops, characterized by lack of sugar minimum.