The Effect of Fiber Addition to Diets Formulated to Contain Different Levels of Energy and Protein on Growth and Carcass Quality of Swine

The influence of dietary crude fiber, and of the methods used in formulating high fiber diets, on the performance and carcass composition of swine was studied in an experiment in which 72 pigs were fed four diets. Diet 1, the control, contained 14.1 MJ digestible energy (DE) per kilogram, 17.1% crude protein (CP) and 4.1 crude fiber (CF). Diets 2, 3 and 4 each contained 22% oat hulls, 9.8, 9.6, and 10.2% CF, respectively, and had energy contents of 12.2, 12.5 and 14.9 MJ DE/kg and 17.0, 14.4 and 17.3% CP, respectively. Diets were provided ad libitum. While pigs fed high fiber diets had significantly lower average daily gain (ADG) than control animals in the growing (22–63 kg) period, no significant treatment differences in ADG were observed in the finishing period (63–92 kg). However, differences in energy and protein levels, in diets with equal CF levels, were shown to affect CF intake, feed intake and feed/gain significantly in both periods. The inclusion of 22% oat hulls in diets 2, 3 and 4 had no significant influence on backfat depth. The present results indicate that changes in protein and energy associated with fiber addition to swine diets and the physiological age or adaptation of the animal to the dietary fiber may significantly influence the parameters measured and the conclusions drawn.