Further studies on the fattening value of grass silage and on the effect of the dry-matter percentage of the diet on dry-matter intake in ruminants

Abstract

1. A feeding trial is described including four groups of cattle fed on silage only, two mixtures of silage and roots, and roots, straw, hay and oats.2. The live-weight gains made are recorded together with the rate of dry-matter intake.3. The efficiency of the dry matter of the diets was calculated.4. Silage fed alone produced a significantly greater rate of fattening than the other three diets.5. Cattle receiving roots in the morning and silage at night consumed 10·78% more dry matter and made greater live-weight gains than cattle fed on silage in the morning and roots at night.6. Calculation of the starch values of the roots and silage showed that these are higher when fed together than when silage is fed alone or when roots are fed with straw, hay and oats.7. An experiment is described designed to determine the effect of the dry-matter percentage of the diet on dry-matter intake in ruminants and of sudden changes in dry-matter content on digestibility.8. Sheep receiving 19·46% dry-matter silage consumed 16·7% more dry matter and 19·8% more starch equivalent than sheep eating 15·85% dry-matter silage.9. When the dry-matter percentage of the silage fell from 19·46 to 15·77 the digestibility of the dry matter fell by over 10%.10. The starch equivalent of the silage when fed alone was determined from the results of a digestibility trial and according to the performance of the cattle in the feeding trial. The values found were 65·88 and 66·15% respectively.11. The losses suffered in silage-making in twentyfive silos are recorded and discussed. The loss of dry matter and crude protein both average approximately 40% of that ensiled. The need for finding methods of reducing these losses is again stressed.