The fermentation changes in herbage inoculated with selected strains of lactobacilli were studied in two experiments. In the first, LolLum nzulti$orurn containing 16.2% of soluble carbohydrates was used in four silos, the treatments being : control, inoculated, molassed, inoculated-molassed. All silages were well preserved (pH 3.9 4.1). the gaseous losses being the lowest in the molassed herbages.In the second experiment, Dactylrs glonzerata of low soluble carbohydrate content (4.3 %) was used and the treatments were : control, inoculated, bruised, inoculated -bruised.The material which had been inoculated and bruised was well preserved (pH 4.2) while the non-bruised herbages were badly preserved (pH 4.9) and had higher gaseous losses. The bruised silage without inoculation had pH 4 3 .The results suggest that there may be no advantage in inoculating herbage rich in soluble carbohydrates, but that herbage of low sugar content may benefit from such treatment.
IntroductionIn silage making, it is generally assumed that herbage is adequately supplied with the lactic acid bacteria which ferment the soluble carbohydrates of plants. Recent studies, however, have shown that the number of these bacteria on fresh herbage may sometimes be extremely l~w . l -~ Nevertheless, if conditions in the silo are suitable for the development of the organisms, sufficient acid may be produced to preserve the silage at a pH level within the range 3.5 to 4.2. There is some evidence, however, that the longer the period of development before a satisfactory low pH is attained, the higher will be the loss of dry matter due to the activity of plant and bacterial enzymes. Various workers have added lactic acid bacteria to herbage in an attempt to secure rapid acidification but a beneficial effect has not always been noted.*The purpose of the present investigation was to study the effect of an inoculum of selected strains of lactobacilli on the chemical and bacterial changes occurring in grass ensiled in small tower silos.
Experiment a1 ProcedureThe silo unit used in this investigation has been described in detail in an earlier publication5 and consists of four metal silos, each having a maximum capacity of 1000 kg. of fresh herbage, and each being suspended from a weighing device which enables direct measurements of weight changes to be recorded. Preliminary tests showed that the four silos, filled under identical conditions with Loliunz multiJEorum (Italian ryegrass), yielded similar results.6 In the experiments reported in this paper conditions of filling and consolidation were similar to those described in earlier 7 Consolidation was achieved by covering the ensiled herbage with polythene sheeting, wooden compression discs and stone blocks corresponding to a surface pressure of 37 g./sq. cm.Temperature measurements were recorded from thermocouples (nine per silo) buried at different levels throughout the ensiled herbage. Effluents were collected daily, or when they appeared, and analysed for dry matter, sugars, total nitrogen and ash. Techni...
