As pork producers keep a closer eye on feed costs, sow body condition will be scrutinized more closely. In doing so, the feed drops (box or cylinder) used to feed gestating and lactating sows are good candidates for a closer look.

In a series of trials conducted at Kansas State University (KSU) a few years ago, researchers set out to determine whether the angle of the drop boxes affected the actual amount of feed delivered to the sows.

Generally, feed drops are mounted perpendicular to the feed line. Constant vibration of the feed lines through daily use, installation of other equipment and the natural wear and tear of the feed delivery components can cause the mounting angle of the feed drops to change.

To test how angle affects accuracy, researchers set the box-type feed drops at three different angles — 60, 75 and 90 degrees (Figure 1). Each of the feed drops was set to deliver 2, 4, 6, 8 or 10 lb. of a corn-soybean meal-based gestation diet (Figure 2).


“The (gestation) feed drops are filled from the top of the feed line in a volumetric delivery,” explains Mike Tokach, KSU swine nutritionist. “The pounds dropped increase linearly as the volumetric setting on the drop (box) increases.”

Interestingly, when the boxes were set at 90°, the amount of feed dropped actually exceeded the box setting. Of equal concern was when the boxes were twisted to 75° or 60°, sows received less feed than the box setting indicated. Clearly, inaccurate feed delivery makes it more difficult to ensure that sows are fed to their ideal body condition and get maximum value from the diets fed.

If all of the boxes were set at the same angle, the amount of feed dropped could be weighed by the producer and adjusted for consistency. However, if boxes are setting at different angles throughout the barn, the amount of feed dropped will be inconsistent.

Further, researchers found the cylindrical feed drops were less prone to inconsistencies. Although slightly more expensive, these newer styles could not only save feed but also ensure sows are fed to their optimum body condition.

See related story, "Refining Feed and Water Delivery."