EFFECTS OF A BACTERIAL MIX INOCULANT ON GRASS-LEGUME SILAGE FERMENTATION AND NUTRITION VALUE FOR THE DAIRY COWS

Two silages were prepared from the first cut grass-legume sward consisting of ryegrass, red clover and fescue and wilted for up to 10 h. The control silage had no additives and the experimental silage was prepared with a mix of bacterial inoculant. Both silages were stored in round-bales wrapped with 6 layers of stretch film for 82 days, and silage pH, organic acids, ammonia N and nutrient content were investigated. In control and inoculated silage pH were 4.6 and 4.2, amount of lactic acid 27.6 and 46.1 gkg -1 DM (P<0.05), acetic acid 12.3 and 13.7gkg -1 DM, and butyric acid 4.7 and 2.2 gkg -1 DM, respectively. DM losses were reduced (P<0.01) and DM metabolisable energy concentration was increased (P< 0.01) by the bacterial inoculation. The inoculated silage was more (P<0.05) aerobically stable than the control silage. Ten third lactation Lithuanian Black-and-White cows, in the fifth month of the lactation stage, were used to measure intake of silages and animal performance. Treatment of the silage with inoculant showed a trend towards increased silage dry matter intakes and an improvement in average milk yield of 1.2 kg/day, whereas these differences were not significant. Milk composition was not affected by inoculation, but the output of milk constituents (butterfat and protein) was improved. It is concluded that the increase in milk production with inoculant-treated forage is the result of improvements in both intake of the forage and increasing efficiency of utilisation.