PECTIN FERMENTATION AND UTILIZATION BY NATURAL MICROFLORA DURING RYEGRASS ENSILAGE

The ability of natural silage microflora to degrade and utilize indigenous and extraneous pectic materials during the ensilage of ryegrass was assessed in 2 liter laboratory glass silos. The treatments consisted of ryegrass wilted to 24% (R) and 32% (W) dry matter (DM) and three pectic treatments applied to (R) at approximately 10% of the total DM (R + pectin, R + polygalacturonic acid and R + galacturonic acid). All silages were of a good quality, as judged from visual and analytical evaluation. Pectin, either indigenous or extraneous, was not degraded, or was hardly degraded, by the natural silage microflora. Free galacturonic acid was markedly degraded and utilized, but its fermentation did not result in a higher concentration of preserving acids.