BROWN RICE IN PIG DIETS .2. EVALUATION OF GROWTH-PERFORMANCE AND CARCASS QUALITY CHARACTERISTICS OF GROWING-FINISHING PIGS

The effect of replacement of dietary corn by brown rice on pig performance, carcass quality characteristics. and fatty acid composition of backfat was examined. A total of 64 crossbred (Duroc X Landrace X Yorkshire) pigs, averaging 19.2 kg each, was randomly assigned to four treatment groups with replications based on sex and weight. The four treatments were : (1) a corn -soybean meal diet as control diet ; (2)33.3% replacement of the corn by brown rice ; (3)66.7% replacement of the corn by brown rice ; and (4)100% replacement of the corn by brown rice. The results showed that the feeding period, average daily gain, feed intake, and feed efficiency of pigs were not influenced (P > 0.05) by dietary treatments. Differences in the carcass dressing percentage, carcass length, mean backfat thickness, and loin eye area were not significant (P > 0.05) among treatments. The values of pH, color, and water holding capacity of longissimus were also similar among dietary treatments. The total unsaturated and saturated fatty acids of the outer layer of backfat were not significantly different (P > 0.05) among dietary treatments. As to the inner layer of backfat, the total unsaturated fatty acid decreased (P < 0.05) , but the total saturated fatty acids was increased (P < 0.05) as the dietary brown rice increased, It is concluded that dietary corn can be replaced by brown rice with satisfactory results based on growth performance, carcass characteristics, and meat appearance characteristics. Despite significant change in the fatty acid composition of backfat, there was no deteriorative effect on the texture of fat. It is certain that brown rice can be freely used in pig diets.