SILAGE AND MILK-PRODUCTION - COMPARISON BETWEEN SOYA, GROUNDNUT AND SINGLE-CELL PROTEIN AS SILAGE SUPPLEMENTS

Grass silage made in May from S24 perennial ryegrass was offered ad libitum to twelve Ayrshire cows in a 12‐week feeding experiment. The silage had a DM concentration of 217 g kg ‐1, contained 147 g crude protein per kg DM and had a D‐value of 64·6. In addition each cow consumed 1 kg hay per d plus concentrate supplements of dried sugar‐beet pulp with (A) soya bean meal, (B)‘Pruteen’, a single‐cell protein (C) groundnut cake. The three concentrate supplements each contained 250 g crude protein per kg DM and were offered at the rate of 2·9 kg per 10 kg milk. The daily intakes of silage DM were 8·38, 7·94 and 7·49 kg on treatments A, B and C, respectively, with the extreme values being significantly different. The mean daily yields of milk on treatments A and B were both 16·2 kg per cow, and were significantly higher than the yield of 15·2 kg per cow on treatment C. The fat and lactose contents of the milk on the three treatments were not significantly different, but the CP content on treatment C was significantly lower than that on the other treatments. It is concluded that soya bean meal and‘Pruteen’were superior to groundnut cake as a protein supplement in a silage‐based ration. Copyright © 1979, Wiley Blackwell. All rights reserved