Abstract:
Proc. Aust. Soc. Anim. Prod. Vol. 18 EFFECT OF DEGREE OF WILTING ON STORAGE LOSSES OF SILAGE STORED IN BUNKERS AND NUTRITIVE VALUE FOR MILK PRODUCTION A. HADERO-ERTIRO*, P.J. MOATE*, I.B. ROBINSON* and G.L. ROGERS* Wilting pasture prior to ensiling improves the nutritive value of silage for milk production (G. Rogers, Unpublished data). This practice is widely adopted The effect of the degree of wilting on and crops are often heavily wilted. This is important nutritive value and storage losses is not well understood. because heavily wilted crops require more drying time and/or additional turning of the swath. Perennial ryegrass/white clover pasture was cut with a rotary mower in mid November and alternate windrows were either left in place or immediately tedded to speed drying. After wilting for 24 hours both treatments were harvested with a New Holland 718 precision chop forage harvester and ensiled in bunkers sealed with polythene. The composition (g/kg DM) of the pasture at cutting and of the moderately and heavily wilted pasture at ensiling were : digestible dry matter (DDM) 680, 670, 680; crude protein (CP) 163, 156, 156 and water soluble carbohydrate (WSC) 100, 45, 69. In March, two groups of twenty cows grazing restricted pasture were offered one of each of the silages at a level of 10 kg/DM/cow/day. The compositions (g/kg) of the moderately and heavily wilted silages were : DDM 664, 664; CP 156, 175; Pasture ensiled and silage fed were weighed and WSC 15,20 and NH,N 0.7, 0.5. sampled for composition. Storage losses and milk composition are shown in Table 1. Table 1 Effect of degree of wilting on storage loss and milk production of pasture silage stored in bunkers There was no apparent spoilage in either stack but fermentation losses of DM were substantial. The highest losses occurred with the heavily wilted silage. Although, on a daily basis, cows produced more milk (P<O.O5) when fed the heavily wilted silage, the greater storage losses reduced the total silage fed Heavy wilting resulted in a silage of superior and total milk production. nutritive value for milk production, but this benefit was negated by the greater storage losses encountered when pasture was ensiled in pits. * Dep t Agriculture and Rural Ellinbank, Vic. 3820. Affairs, Dairy Research Institute, 483