RAPESEED MEAL AS A PROTEIN SOURCE IN THE STARTER CONCENTRATE FOR REPLACEMENT CALVES

Abstract

Two trials were carried out to assess the extent to which commercial, prepressed, solvent-extracted rapeseed meal could be substituted for soybean meal in starter concentrates for replacement calves. In trial I, rapeseed meal comprised 0, 8, 16, and 24% of the mixes, but still did not replace all of the soybean meal. When offered from 10 days of age, along with a "limited" milk feeding program and dry hay, there were no significant differences (P < 0.05) in feed consumption or average daily gain (ADG) to a final body weight of 114 kg. In trial II, rapeseed meal was used at three levels of replacement for protein from soybean meal: 0, 50, and 100%. This represented actual levels of rapeseed meal in the starter of 0, 14.5, and 29.8%. In addition, half the calves were fed a low-fat milk replacer and half a high-fat milk replacer. There was no significant interaction between milk replacers and the starter diets, nor did the milk replacers have any significant effect on feed intake or ADG over the whole trial to the final body weight of 114 kg. Replacement of all the soybean meal in the starter did result in a significant decrease in ADG because of lower feed intake per day. It is concluded that if a calf starter is to be pelletted it is possible to include up to 20% of rapeseed meal.