Effect of citron by-product fermented with beneficial bacteria as a functional feed additive for Korean native steers

This study was conducted to develop a functional feed additive, citron (Citrus junos Sieb. ex Tanaka) probiotics (CPB) for beef cattle, using citrus junos by-product (CJ) with probiotics. A two-step fermentation process was developed for the production of CPB and the effects of CPB on growth performance, immune status, carcass characteristics and fatty acid profile in Korean native (Hanwoo) steers were investigated. Twenty (20) Hanwoo steers (22 months old; 619.00±10 kg BW) were randomly assigned to two dietary treatments in a completely randomized design: control (basal diet) and 1.0% CPB (basal diet + CPB 1.0% DM basis). At the end of the trial, steers were slaughtered and carcasses were evaluated. Dietary CPB supplementation significantly increased the average daily gain (ADG) and feed efficiency (kg gain/kg DMI) of Hanwoo steers as compared to the control (P 0.05) was observed in muscle composition while cholesterol concentration reduced in CPB supplementation group (P < 0.05). Overall, the concentrations of n-3 fatty acids were increased, while the ratio of n-6/n-3 decreased in the CPB dietary group (P < 0.05). In conclusion, dietary CPB improved growth, immunity and carcass weight of Hanwoo steers while reducing muscle cholesterol concentration with an elevated n-3 fatty acids concentration, indicating that CPB can be used as a functional feed additive for beef cattle.