AN EVALUATION OF AN INOCULANT ENZYME PREPARATION AS AN ADDITIVE FOR GRASS-SILAGE FOR DAIRY-CATTLE/

Herbage from the first regrowth of perennial ryegrass-based swards was directly ensiled after treatment with a bacterial inoculant/enzyme pr eparation (SIL-ALL, Alltech UK) at 3.0 1 t(-1), formic acid (850 g kg( -1)) at 2.59 1 t(-1) or no additive (Control). The mean dry matter (DM ) and water-soluble carbohydrate concentrations of the grass were 185 and 24.0 g kg(-1) (fresh basis) respectively. Lactic acid concentratio ns after ensiling increased at a lower rate in formic acid-treated her bage than with the other treatments. All silages were well preserved a nd formic acid-treated silage had a lower ultimate concentration of la ctic acid and higher concentration of water-soluble carbohydrate. Effl uent output was increased on a proportional basis by approximate to 0. 06 with formic treatment, whereas the inoculant reduced effluent outpu t by 0.05 in comparison with the mean effluent production of the contr ol silage. The in vivo digestibilities of the silages were determined using sheep. The digestibilities of DM, organic matter and energy were significantly higher with inoculant-treated silage than with formic a cid treatment, whereas values for the control silage were intermediate . The three silages were offered ad libitum to forty dairy cows with i ndividual recording of daily intakes for a 10-week period in a randomi zed block experiment with four treatments. Sixteen animals were offere d the control silage with half of these offered 3 kg concentrates per day (C3) and the other half offered 7 kg concentrates per day (C7). Tw elve animals were allocated to each of the additive-treated silages, w ith concentrates offered at 5 kg d(-1). Treatment effects on animal pe rformance were measured in weeks 7-10. To compare animal performance f or the treated silages with the control, an estimate of performance at 5 kg concentrates per day was obtained by regression using values obt ained at 3 and 7 kg concentrates. In comparison with estimated silage intake for the control silage with 5 kg d(-1) concentrates, inoculant and formic acid treatment of the silages increased dry matter intake b y 0.04 (P > 0.05) and 0.13 (P < 0.01) respectively. In comparison with estimated milk production and yield of fat plus protein for the contr ol treatment with 5 kg d(-1) concentrates, neither inoculant treatment nor formic acid treatment produced any significant differences.