Published online by Cambridge University Press: 27 March 2009
1. Ammoniated sugar-beet pulp has been compared with decorticated ground-nut meal, when added to a control diet low in protein, in feeding trials with seventy-five cows on three farms and in a balance experiment with four cows.
2. In the feeding trial the cows receiving decorticated ground-nut meal gave 8·4 lb. more milk weekly than cows receiving the control diet. Cows given the diet in which the molassed sugar beet pulp in the control diet was replaced by ammoniated sugar beet pulp gave 7·9 lb. more milk weekly than the control group. The milk-fat percentage was not affected by the treatments. Slight increases in solids-not-fat percentage resulted in an increased yield of solids-not-fat with both high-nitrogen treatments. The increases in milk yield approached statistical significance and the increases in solidsnot-fat were significant.
3. It was concluded that the feeding trial showed that the nitrogen added to sugar-beet pulp during ammoniation could be utilized by milking cows, but the experiment did not permit an estimate of the efficiency of utilization.
4. In the nitrogen balance experiment the utilization of nitrogen was measured as the sum of milk nitrogen and the nitrogen balance. It was concluded that 29·5 g. of nitrogen from 0·8 lb. decorticated ground-nut cake increased the daily utilization of nitrogen by 12·9 g., whereas 55·7 g. nitrogen from 8 lb. ammoniated sugar-beet pulp increased the utilization by only 6·0 g. In this experiment the efficiency of utilization of the nitrogen from groundnut meal was 44% and of the ammonia nitrogen from ammoniated sugar-beet pulp only 11%.
5. Ammoniation raised the crude protein content of molassed beet pulp from 10 to 20%. If for the computation of rations the content of digestible crude protein in sugar-beet pulp is taken as 5·0%, that in the ammoniated pulp should be approximately 7·5%.
6. If given in sufficient amounts the ammonia nitrogen had as great an effect as the nitrogen of ground-nut meal in correcting the effects of a diet low in protein.