Ensiling grass and strain mixtures: effect of an enzyme additive and urea on chemical composition and nutritive value for sheep

Extract

Straw mixed with grass before ensiling absorbs excess water and reduces effluent, but dilutes nutrients like crude protein and water soluble carbohydrates, and increases cell wall constituents of the mixture. Earlier studies by the authers showed that treating straw with urea before ensiling with grass increased the digestibility of grass+straw silages. A cellulase enzyme preparation had small but positive effects on fermentation and digestibility. The present paper describes the effect of treating straw with urea and a cellulase enzyme preparation on chemical composition and nutritive value of Silages.

Shredded barley straw was treated with urea (60 kg/t of straw dry matter) and a cellulase enzyme preparation (FS01, Forum Feeds Finland; 2 1/t of straw), just before mixing with the precision chopped perennial ryegrass in the ratio of 40:60 on a DM basis, in a 2 X 2 factorial experiment. All the four premixes were ensiled in polythene silos ( 1 t capacity). Eight male sheep were fed four silages in a 4 X 4 latin square design. Each feeding period consisted of a 4-day adjustment period, a 10-day preliminary feeding period and a 7-day period for measurement of digestibility.