Sorting and mixing pigs not beneficial.

• Position: Animal Husbandry

For pork producers, nothing boats spending less time in the barn, unless it's making a little mom money at market time. University of Nebraska, Lincoln, research shows that leaving pigs in the same pen instead of sorting and mixing lightweight ones in a wean-to-finish barn is better for pigs, can save producers time, and may help their pocketbooks, too.

Pork producers know that variations in pig weight can increase the time needed to get pens of the animals to market weight. Variation also can hurt sales prices, notes animal scientist Mike Brumm. To combat this problem, many producers overstock pens at weaning time and then remove the lightest pigs from a pen about three weeks later and remix them with other lightweight pigs in hopes of enhancing performance. His research shows it's best to just leave the pigs in the same pens. Brumm discovered that, contrary to this popular swine industry management practice, removing and mixing lightweight pigs doesn't improve performance.

"Once pigs have established their home in a wean-to-finish facility, don't mess with it," Brumm stresses. "There is an inherent growth variation. Even if we start with uniform pigs, they will create variation. If we move pigs in an attempt to change variation...