Effects of feed processing and feeding methods on growth and carcass traits for growing-finishing pigs

The present experiment was conducted to evaluate the effects of feed processing and feeding methods on growth performance and carcass characteristics of growing-finishing pigs. A total of 72 pigs (LYD, 22.24 kg BW) were employed for a 90-d feeding trial. Treatments were 1) mash dry feeding (MD), 2) mash wet feeding (MW), 3) pellet dry feeding (PD), and 4) extruded pellet dry feeding (EPD). Corn, soybean meal and wheat bran in the basal diets were extruded before mixing and pelleting for EPD diet production. Ileal or fecal digestibility and carcass traits including lean meat percentage and weights of stomach, small and large intestines, and the degree of stomach ulcer were also examined. During the growing period, pigs fed PD showed improved (p < 0.05) average daily gain (ADG) and feed conversion (F/G) over those fed MD, whereas no significant differences in average daily feed intake (ADFI) were found among dietary treatments. Finisher pigs fed MD showed lower, but not significant, ADG and F/G than those fed MW, PD or EPD. For the overall period, pigs fed PD grew faster (p < 0.05) than those fed MD or EPD. Feed intake was different between the two feeding methods (MD vs MW), and between the two processed feeds (PD vs EPD). The digestibility of crude fat was higher (p < 0.05) in pigs fed EPD than in pigs fed mash feeds. NFE digestibility of EPD treatment was also higher (p < 0.05) than that of PD. Back fat (10th rib area) was thicker (p < 0.05) in pigs fed MD than in pigs fed EPD. Other carcass traits including incidence of esophagogastric ulcers were not different among treatments. In conclusion, pelleting appeared to be the desirable processing methods and wet feeding could also be recommended for growing-finishing pigs.