Effects of the Inclusion of Vitamin B2 By-Product on Growth Performance, Blood Profiles and Meat Quality in Growing-Finishing Pigs

High prices of traditional feed ingredients such as corn and soybean meal results in increasing demand for alternative ingredients to enhance economic sustainability of resource utilization and swine industry to decrease the cost of production. The vitamin B2 by-product (VBP) which contained 26.50% CP and 12.14% ether extract (as-fed basis), may serve as a cost-effective alternative resource to partly replace corn and soybean meal, and may serve as a cheaper form to provide an extra vitamin B2. This study was conducted to evaluate the effects of VBP on growth performance, nutrient digestibility, blood profiles and meat quality. A total of 140 crossbred [(Landrace × Yorkshire) × Duroc] pigs with an average initial body weight (BW) of 26.05 ± 1.32 kg were used in this 16-week feeding trial. The pigs were randomly allotted to 1 of 4 dietary treatments (5 pigs/pen and 7 replicates/treatment) with sex (2 gilts and 3 barrows) and different levels (0, 1, 2 and 3% as CON, VBP1, VBP2 and VBP3 dietary groups, respectively) of vitamin by-product in a 3 phase feeding program (0 to 4, 4 to 8, 8 to 13 week). All data were statistically analyzed using the GLM procedure of the SAS program (SAS Inst. Inc., Cary, NC, USA). Orthogonal comparisons were conducted using polynomial regression to determine linear and quadratic effects of increasing VBP levels on all measurements. With the supplementation of increasing levels of VBP, the results showed that there were no significant differences on growth performance and nutrient digestibility among treatments over the entire experimental period (P>0.05). During the phase 2 experimental period, there was a linear decrease (P=0.011; Quadratic, P=0.003, respectively) in blood norepinephrine concentration (1040.83, 983.68, 762.10, and 958.77) associated with the inclusion of VBP in the diets. At the end of phase 3, a linear decrease (P=0.043) was observed in sensory evaluation of meat color (3.29, 3.44, 3.57, and 3.47). The lean meat percentage (57.49%, 57.97%, 58.27%, and 58.16%) were linearly increased (P=0.016) by the increasing levels of VBP supplementation. In conclusion, dietary supplementation with increasing levels of vitamin B2 by-product can concomitantly decrease negative stress effects without adverse impact on growth performance, improve the lean meat percentage; indicating the potential of this by-product as a cost-effective substitute for partly replacing corn and soybean meal.