Rice protein concentrate partially replaces dried whey in the diet for early-weaned piglets and improves their growth performance

BACKGROUND: Recently, rice protein concentrate (R-PC), a much cheaper source of dietary protein, has become commercially available for use in the feed industry. Importantly, dietary supplementation with RPC can increase feed intake by early-weaned pigs. The objective of this study was to determine whether RPC can replace milk protein in the diet for early-weaned pigs. RESULTS: Neither average daily gain (ADG), average daily feed intake (ADFI), nor the feed/gain ratio differed among the treatment groups in weeks 1 and 2. In week 3, the addition of S or 10% RPC to diets increased (P < 0.05) ADFI and ADG of pigs compared to those in the control group fed a 60% dried whey diet. During the entire 21-day trial, ADFI and ADG were greater (P < 0.05) in pigs fed the 5 and 10% RCP diets than in pigs fed the 60% dried whey and 15% RCP diets. There were no differences in the serum concentrations of growth hormone on days 14 and 21, serum concentrations of insulin growth factor-I (IGF-I) on day 14, or IGF-I gene expression in liver and skeletal muscle on days 14 and 21 among the dietary treatments. Serum concentrations of IGF-I in pigs fed the 5, 10 and 15% RPC diets were greater than those in pigs fed the 60% dried whey diet. CONCLUSION: Findings indicate that up to 10% RPC can be used to replace dried whey in the diet for 7- to 21-day-old weaned piglets and can improve their growth performance. (C) 2008 Society of Chemical Industry.