Yun et al., 2005. Asian-Aust. J. Anim. Sci., 18 (3): 384-389

These experiments were conducted to evaluate the feeding value of rice protein concentrate (RPC) in weaning pigs. In experiment 1, a 5-week feeding trial was conducted with 126 pigs (L * Y * D; 21 d-old; 5.320.34 kg). Treatments were spray-dried plasma protein (SDPP; control), soya protein concentrate (SPC) and RPC (phase 1), and dried porcine soluble (DPS; control), SPC and RPC (phase 2). An ileal digestibility trial was also conducted to compare digestibility of amino acids in the tested protein sources. In experiment II, 160 weaning pigs (L * Y * D; 21 d-old; 5.650.35 kg) were used in a 5-week feeding trial to determine the optimal inclusion level of RPC in the diet. Treatments were control (9% SPC), and three levels of RPC instead of SPC in the diets (3, 6 and 9%). During phase 1, pigs fed SDPP showed better (P<0.05) average daily gain (ADG) and feed conversion ratio (FCR) compared with those fed SPC or RPC, while there was no difference in average daily feed intake (ADFI) among treatments. During phase 2, however, pigs fed DPS showed lower (P<0.05) ADG than those fed SPC or RPC. During the total period, there were no significant differences in ADG, ADFI and FCR among treatments. The apparent ileal digestibilities of his, lys, phe, thr and met were not different among the tested protein sources. The apparent ileal digestibilities of arg, ile, leu and val were lower (P<0.05) in RPC than SDPP. The true ileal digestibilities of arg and leu were lower (P<0.05) in RPC than SDPP and SPC. However, that of met was higher (P<0.05) in RPC than SDPP. In experiment II, there were no significant differences in ADG and FCR when SPC was substituted with RPC up to 9% during the total period. In conclusion, based on the results, RPC could replace SPC in the complex prestarter diet, which is somewhat cheaper than SPC.