Evaluation of Expanded Diet and Different Phase Feeding Programs in Growing-Finishing Pigs

Two experiments were conducted to determine the effects of expanded diets and phase feeding programs on growth performance, carcass traits, and meat quality in growing-finishing pigs. In Exp. 1, a total of 72 crossbred pigs (Duroc × [Landrace × Yorkshire]) with an initial body weight (BW) of 25.88 ± 1.34 kg were randomly allotted to 1 of 3 dietary treatments with 6 replicates and 4 pigs (2 gilts and 2 barrows) per pen. The dietary treatments were: 1) unexpanded corn-wheat-soybean meal (CWSBM)-based diets with two-phase feeding program; 2) expanded CWSBM-based diets with two-phase feeding program; 3) unexpanded CWSBM-based diets with three-phase feeding program. Pigs offered the expanded two-phase feeding program diets had better (P < 0.05) feed conversion ratio (FCR) compared with those fed unexpanded two-phase feeding program diets during 12 to 14 weeks (3.031 vs. 3.133) and 1 to 14 weeks (2.647 vs. 2.726). No differences in growth performance were observed between two- and three-phase feeding programs (P > 0.05). Expanded diets or phase feeding programs had no significant effects on carcass traits and meat quality (P > 0.05). In Exp. 2, one hundred and twenty growing pigs (Duroc × [Landrace × Yorkshire]; 20.51 ± 0.62 kg initial BW) were randomly assigned to 1 of 3 dietary treatments on the basis of their sex and BW (10 replicate pens with 2 gilts and 2 barrows per pen). Dietary treatments were as follows: 1) unexpanded corn-soybean meal (CSBM)-based diets with two-phase feeding program; 2) expanded CSBM-based diets with two-phase feeding program; 3) unexpanded CSBM-based diets with three-phase feeding program. Pigs fed expanded two-phase feeding program diets had increased (P < 0.05) daily gain and decreased (P < 0.05) FCR (2.964 vs. 3.073) compared with those fed unexpanded two-phase feeding program diets during 15 to 17 weeks. Additionally, meat firmness in sensory evaluation (2.88 vs. 2.55) was higher (P < 0.05) in pigs fed unexpanded two-phase feeding program diets than in pigs fed expanded two-phase feeding program diets. There were no significant differences on growth performance, carcass characteristics, and meat quality between two- and three-phase feeding programs. In conclusion, expanded CWSBM- or CSBM- based diets improved growth performance of growing-finishing pigs. Phase feeding programs did not affect growth performance, carcass characteristics and meat quality in growing-finishing pigs fed CWSBM- or CSBM- based diets.

Keywords: expanded diet; growing-finishing pigs; growth performance; meat quality; phase feeding program