The partial and total replacement of wheat and soybean meal by pollard in a wheat-soybean meal grower-pig ration

Abstract

This experiment was designed to investigate the effect of high levels of pollard in the ration on the growth and carcase quality of growing pigs. Twenty-four gilts and twenty-four male castrate weaner pigs of mean liveweight 23.4 kg were each fed one of four rations in a wet form in individual stalls twice daily until they were slaughtered at a mean liveweight of 86.5 kg. The control ration was 81.9 per cent wheat and 15.0 per cent soybean meal, with added minerals and vitamins. In the other three rations, the wheat and soybean meal portion was replaced by 48.4, 67.8, and 96.9 per cent pollard. Feed allowance was adjusted to give a similar intake of digestible energy for all rations. There was no significant difference between treatments in rate of liveweight gain or in efficiency of utilization of digestible energy. Efficiency of utilization of air-dry feed decreased as level of pollard in the ration increased. These differences were significant except for the difference between the rations containing 48.4 and 67.8 per cent pollard. There was a significant decrease in dressing percentage with each increase in the level of pollard in the ration. Backfat thickness was significantly less in pigs fed rations containing 67.8 and 96.9 per cent pollard than in pigs fed the other two rations. Gilts grew more rapidly, utilized feed and digestible energy more efficiently and produced carcases with greater eye muscle indices and higher appraisal scores than the male castrates. There were no digestive disturbances on any of the rations and all were readily eaten. The results indicate that the relationship between protein quality k d net energy in pollard is of an order normally occurring in well-balanced rations.