Feed intake and daily gain increased as feeder openings increased, but feed efficiency improved the most at the middle feeder adjustment setting in recent Kansas State University (KSU) grow-finish studies.

KSU researchers set out to determine the effect of different feeder settings on growth performance and whether diet type influenced the optimal feeder setting. Two experiments were conducted in a double curtain-sided, deep-pit commercial swine facility with a totally slotted floor.

Each pen was equipped with a stainless steel Staco dry self-feeder and one cup waterer. Each five-hole, single-sided feeder had a feed pan dimension of 60 in. long × 7 in. wide × 5.75 in. high.

The feeder settings were based on the factory-cut holes in the side of the feeder. Moving a dial from one hole to the next adjusted the feeder gate. Feeder setting 1 was the most open setting, while setting 5 was the most closed feeder setting.

Researchers measured feeder gap openings so the data collected could be applied to other types/brands of dry feeders. The distance between the feeder trough and the top of the feed plate was measured on both the left and right sides of the feeder in both trials. The width of the feed plate was subtracted from the height measurement to determine gap opening.

The feed gate was designed to have some “give” or “play” to allow for feed agitation. Thus, the gap opening had a low and high position, which was measured when the feed plate was in the lowest and highest positions possible.

Gap opening measurements on the left and right sides of the feeder were obtained and averaged for each respective position, low or high, for each feeder. The high gap opening measurements and percentage of pan coverage were plotted and the resulting graph was used to develop a regression equation. This regression equation makes it possible to estimate the pan coverage at any feeder gap opening.

The first experiment, a 70-day study, took place in the late spring and early summer of 2007. A total of 1,170 barrows and gilts were randomly assigned among five treatments, with nine replications per treatment. Each pen contained 23-28 pigs with an equal distribution of barrows and gilts.

Pigs were fed a corn-soybean meal-based experimental diet in meal form. The feeder settings were set at 1, 2, 3, 4 or 5 for the five experimental treatments. Feeders were left at their respective settings for the duration of the trial.

Pigs and feeders were weighed on the first day of the experiment, then again on Days 15, 30, 42, 55 and 69 to determine ADG, ADFI and F/G.

Photos were taken of each feed pan during Weeks 2 and 6 and pictures were individually scored for pan coverage. Gap openings were measured according to the same procedures used in the first experiment.

From Day 0-30 and Day 30-69, pigs fed from feeders with increasing feeder openings had increased ADG and ADFI (Table 4). Overall, there were no interactions between feeder setting and diet type for growth performance in Experiment 2. Diet type did not affect growth performance (Table 5).

As feeder openings increased, ADG and ADFI increased. Pigs on feeder setting 1 grew fastest. When the setting was increased from 3 to 5 (the most closed setting), there was a large decrease in ADG. Optimal F/G occurred when feeders were on setting 3.

As the feeder setting increased, low gap opening and high gap opening decreased (Table 6). As feeder setting increased (decreasing gap opening), the percentage of the feeder pan covered with feed decreased for Weeks 2 and 6 (Table 7). Feed pan coverage at each gap opening was similar to coverage in the first experiment. Approximately 50% of the feed pan was covered with the high gap opening of 1.15 in. (Figure 1 and Figure 2).

KSU researchers concluded that feeder setting 3 was optimal. The average gap opening at that setting — from the feed trough to the bottom of the feed plate — was approximately 1.15 in. when the feed plate was in the high position. The amount of feed covering the bottom surface of the feeder pan averaged 61% at setting 3. However, the range for individual feeders on setting 3 was large — ranging from 14 to 93%.

On the basis of this data, KSU researchers recommend feeders be adjusted to allow feed to cover slightly more than half of the feed pan without feed accumulating in the corners.

Researchers: Alan Duttlinger; Steve Dritz, DVM; Mike Tokach; Joel DeRouchey; Jim Nelssen; and Robert Goodband, Kansas State University. Contact Duttlinger at (785) 532-1270, or email advtt@ksu.edu.