The effects of feeder adjustment and trough space on growth performance of finishing pigs

Two studies were conducted to determine the effects of feeder adjustment and trough space on growth performance of finishing pigs. In Exp. 1, 234 pigs (initial BW 41.5 kg) were used in an 89-d trial. Pigs were randomly allotted to 1 of 3 treatments with 9 replications of 8 pigs/pen and 1 replicate with 6 pigs/pen. Treatments consisted of a minimum feeder gap setting of 1.27, 1.91, or 2.54 cm. Feeders were adjusted to a minimum gap setting, but the agitation plate could be moved upward to a maximum opening of 1.91, 2.54, or 3.18 cm, respectively. Feeder adjustments of 1.27, 1.91, and 2.54 cm averaged 28, 58, and 75% pan coverage, respectively. From d 0 to 58, increasing feeder gap improved (linear; P ≤ 0.04) ADG and ADFI, but decreased (linear; P < 0.05) G:F. Although the response was linear for ADG, no increase occurred (quadratic; P = 0.15) beyond the 1.91-cm feeder gap setting. From d 58 to 89, increasing feeder gap setting tended (linear; P = 0.08) to worsen G:F. Overall (d 0 to 89), pigs fed with increasing feeder gap had decreased (linear; P <0.03) G:F due to increased (linear; P <0.02) ADFI. In Exp. 2, 288 pigs (initial BW 41.3 kg) were used in a 91-d study to evaluate the effects of feeder trough space (4.45 vs. 8.9 cm/pig) and minimum feeder gap opening of 1.27 cm (narrow) vs. 2.54 cm (wide). The treatments were arranged in a 2 × 2 factorial with 6 replications per treatment. Feeder trough space was altered by having pens of either 8 to 16 pigs per pen with all pigs provided 0.74 m(2) floor space per pig. From d 0 to 56 and 56 to 91, no adjustment × space interactions or effects of trough space were observed. From d 0 to 56, pigs with the wide feeder gap setting had decreased (P < 0.02) G:F compared with those that had the narrow feeder gap setting. From d 56 to 91, pigs with the wider feeder gap setting had increased (P < 0.001) ADFI, but consequently had decreased (P < 0.01) G:F. Overall (d 0 to 91), no trough space × feeder adjustment interactions were observed. However, ADG tended to increase (P = 0.08) as feeder trough space increased from 4.45 to 8.9 cm/pig. Pigs fed with the wide feeder gap setting had increased (P < 0.01) feed disappearance and decreased (P < 0.01) G:F compared with pigs with the narrow feeder gap setting. These data indicate that pigs from 41 to 68 kg need approximately 58% pan coverage, whereas pigs greater than 68 kg should have approximately 28% pan coverage to optimize growth and reduce feed wastage.