Report on an experiment to compare the fattening values, for beef cattle, of silages made from grass cut at different stages of growth

Abstract

1. The method adopted for making three different grades of silage, from grass cut at different stages of maturity, is described.2. A feeding trial is described including four groups of cattle fed on grades I–III silages and on swedes and straw respectively.3. The live-weight gains made are recorded together with the rate of dry-matter intake.4. A digestibility trial was carried out on the three grades of silage. The digestibility coefficients found are recorded.5. It is shown that cattle fed solely on silage build up a bigger ‘gut fill’, to the extent of 40 lb. (± 11), than similar cattle fed on swedes and straw.6. When an allowance had been made for a 40 lb. greater ‘gut fill’ in silage-fed cattle it was found that grades I and II silages produced a significantly greater rate of fattening than grade III silage and than swedes and straw.7. It was found that the rate of total daily drymatter intake rose to a peak at the eighth week and then fell; it did not continue to rise beyond that point but the cattle continued to gain in live weight.8. The efficiency of utilization of the dry matter of the rations fed increased during the latter part of the trial.9. It is suggested that the increase in efficiency of utilization of the dry matter consumed may be attributed to an adaptation in the rumen microflora of the cattle which proceeded for up to 8 weeks after the cattle were put on to the experimental diets.