Effect of feeding cyanidin 3-glucoside (C3G) high black rice bran on nutrient digestibility, blood measurements, growth performance and pork quality of pigs

Abstract

Two experiments were conducted to investigate the effect of feeding cyanidin 3-glucoside (C3G) high black rice bran on nutrient digestibility, blood measurements, growth performance and pork quality of pigs. In Exp. 1, a total of fifteen pigs (19.91 +/- 1.80 kg, average initial body Weight) were used in assay of nutrient digestibility and blood measurements. All pigs were allotted to 5 treatments with 3 replicates according to a completely randomized design (CRD) in an individual metabolic crate. Treatments included 1) CON: basal diet, 2) BRB-2: basal+brown rice bran 2%, 3) BRB-4: basal+brown rice bran 4%, 4) CRB-2: basal+C3G high black rice bran 2% and 5) CRB-4: basal+C3G high black rice bran 4%. The digestibility of dry matter (DM), crude protein (CP), crude fat (CF), crude ash (CA) and crude fiber (CF) was not affected by dietary treatments. Serum triglyceride (TG) and high density lipoprotein (HDL) cholesterol concentrations were not affected by addition of C3G high black rice bran. However, at the end of experiment, pigs fed rice bran showed decreased tendency in total cholesterol concentration. Especially pigs fed C3G high black rice bran showed significantly lower total cholesterol concentration compared to pigs fed brown rice bran (p < 0.03). There was numerically lower total cholesterol concentration with increasing levels of black rice bran in the diet. In terms of serum glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT), there were no significant differences among treatments, even though pigs fed CRB-4 showed the lowest GOT concentration compared to other pigs. In Exp. II, sixteen finishing pigs (average initial body weight 89.96 +/- 0.35 kg) were divided into 4 treatments to investigate the effect of feeding C3G high black rice bran on growth performance and pork quality. There were no significant differences in average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR) among the treatments. Pigs fed C3G high black rice bran showed numerical decrease in ADG and increase in FCR while not effecting feed intake. There was no significant difference in live weight, carcass weight, carcass rate, backfat thickness and carcass grade. However, pigs fed C3G high black rice bran tended to show lower backfat thickness than pigs fed basal diet. Pigs fed C3G high black rice bran showed a tendency of decreased TBA value than pigs fed basal diet, although there was no overall significant difference among treatments. In conclusion, nutrient digestibility, blood measurements, growth performance and pork quality were not significantly affected by feeding C3G high black rice bran to pigs. However, C3G high black rice bran might have an effect on lowering serum total cholesterol and decrease the TBA value in pork compared to control group and these effects might be due to high concentration of antioxidative compounds in C3G high black rice bran.