Effects of rice feeding on growth performance and protein (amino acids) metabolism in weanling piglets.

We investigated the effects of rice feeding on growth performance and protein (amino acids) metabolism of weanling piglets. In all, 16 weanling piglets with an average initial weight of 7.5 kg were divided into two groups. One group was fed a corn-soybean meal-based diet, and the other was fed a rice-soybean meal diet, containing around 46% of corn or rice, respectively. A two-week growth trial was conducted. The average daily gain (p = .025) and feed efficiency (p = .011) in rice-fed piglets were significantly higher than those in corn-fed piglets. Liver lysine-ketoglutarate reductase activity tended to be lower (p = .073) in rice-fed piglets than in corn-fed piglets. Plasma urea nitrogen concentration in rice-fed piglets was significantly lower than that in corn-fed piglets. Plasma glucose and insulin concentrations were significantly higher in rice-fed piglets than in corn-fed piglets. Plasma-free valine, isoleucine, and tryptophan concentrations were significantly higher in rice-fed piglets than in corn-fed piglets. In contrast, plasma histidine concentration was significantly lower in rice-fed piglets than in corn-fed piglets. Overall, these results show that rice feeding improves the growth performance and affects the protein (amino acids) metabolism in weanling piglets.