Effects of restricted feed intake on finishing pigs weighing between 68 and 114 kilograms fed twice or 6 times daily

摘要

In a previous study with limit-fed gestating gilts, we observed that gilts fed 6 times/d had greater ADG than those fed the same amount over 2 feedings. To confirm these earlier responses, we used finishing pigs as a model in two 42-d trials and two 28-d trials to evaluate the effects of restricted feed intake and feeding frequency (2 vs. 6 times/d, floor fed) on pig performance between 68 and 114 kg. In all experiments, pigs (10/pen) were housed in 1.8 x 3.1 m pens with a half-solid, half-slatted concrete floor. Pigs were fed a corn-and soybean meal-based diet formulated to 1.15% standardized ileal digestible Lys and 3,294 kcal of ME/kg. In Exp. 1 to 3, energy and Lys were supplied to pigs according to NRC (1998) calculations to target an ADG of 0.80 kg. In Exp. 4, the diet was supplied to pigs to target an ADG of 0.80 kg (low feed intake) or 0.95 kg (high feed intake) to determine if the amount of energy above the maintenance requirement and feeding frequency affected pig performance. Pigs were fed by dropping similar amounts of feed onto the solid concrete floor either 2 (0700 or 1400 h) or 6 times (3 meals within 2 h at the morning and afternoon feedings) per day with an Accu-Drop Feed Dispenser (AP Systems, Assumption, IL). In Exp. 1 and 2, pigs fed 6 times daily had increased (P < 0.02) ADG and G: F compared with pigs fed 2 times per day. Greater feeding frequency increased (P < 0.05) the duration of time spent feeding and standing and reduced the lying time. In Exp. 3, a third treatment was included to determine whether the improvements in performance were due to decreased feed wastage. This treatment was designed to minimize feed wastage by dropping feed closer to the floor for pigs fed 2 times per day. Pigs fed 6 times daily had improved (P < 0.05) ADG and G: F compared with pigs in either treatment fed 2 times per day. No difference (P > 0.05) in performance was observed between pigs fed 2 times per day when feed was dropped from the feed drop or by the modified method. In Exp. 4, increasing the feeding frequency from 2 to 6 times per day improved (P < 0.01) ADG and G: F for pigs fed the low feed intake and tended to increase (P < 0.06) ADG and improved (P < 0.05) G: F for pigs fed the high feed intake. In limit-feeding situations, increasing the frequency of feeding from 2 to 6 times per day improved pig performance, which confirmed our earlier findings in gestating gilts.