EFFECT OF FORAGE MATTING ON RATE OF GRASS DRYING, RATE OF SILAGE FERMENTATION, SILAGE INTAKE AND DIGESTIBILITY OF SILAGE BY SHEEP

The effects of forage matting on rate of grass drying and silage ferme ntation, digestibility, and intake were examined using perennial ryegr ass swards. Treatments compared were: forage mats, where grass was pro cessed through a laboratory scale macerator prior to matting and wilti ng to 228 g dry matter (DM) kg(-1) (FM treatment); unconditioned grass which was direct ensiled at 163 g DM kg(-1) (DE treatment); unconditi oned grass which was wilted for the same period as FM to 213 g DM kg(- 1) (UC treatment); unconditioned grass which was wilted to 234 g DM kg (-1) (UC25 treatment). All forages were dried on black plastic sheetin g. For each treatment a total of approximately 80 kg grass DM was ensi led in seven 290 1 plastic bins for 136 d prior to feeding to wether s heep. A further total of 14 kg grass DM from each treatment was ensile d in twenty-one plastic pipes (152 mm diameter, 762 mm long) to give a total of 84 pipes. Rate of silage fermentation was determined by dest ructively sampling pipes following 1, 2, 4, 6, 13, 20 and 50 d of ensi lage. Over the mean wilting period of 6.9 h, grass from the FM treatme nt dried significantly faster (P < 0.001) and required less solar ener gy per unit of moisture loss than unconditioned grass. The rate of gra ss drying was highly correlated with solar radiation. The FM treatment did not influence the rate or extent of silage fermentation. The inta kes and digestibilities of FM, UC and UC25 were not significantly (P < 0.05) different from each other but were higher than for the DE treat ment (P < 0.05 for digestibility and NS for intake). In Northern Irela nd it is unlikely that there will be sufficient solar radiation to all ow forage mats to be made, wilted to a level to prevent effluent produ ction and harvested within one working day. Further work is required t o optimize mat-making technology for more rapid drying and to determin e the effect of adverse weather on nutrient losses from mats.