It's costing you more to raise those extended weight finishing hogs.

Many producers have moved to marketing hogs at heavier weights. Some have moved in this direction because their packer pays for larger carcasses. Others market heavier because they have the finishing space to allow it.

Whatever the reason, here are some considerations when finishing at heavier weights.

Throughput To market at heavier weights, the pigs must either grow faster or be in the buildings longer. In most cases, this can only be done by extending the finishing period. By extending the length of the building turn, a unit will get fewer pigs through the finisher per year.

This in effect increases the facility cost/pig. Turning a finisher in 18 weeks rather than 16 weeks decreases the turns from 3.25 to 2.89/year. This will increase yardage in a contract finisher at $36/pig space from $11.07 to $12.48/ pig finished.

Unless you have one of the few hog units with extra finishing space, you will spend more on contract fees or facility costs to market at heavier weights.

Feed Efficiency As pigs become heavier, they become less efficient at utilizing feed. This is true early in the feeding period as well as late. The genetics of your pigs determines how severe the dip in efficiency will be in your unit. Genetic variation in backfat, and thus, feed efficiency after 200 lb., is much greater than before 200 lb.

When we look at market weights going from 240 to 280 lb., some farms' feed conversions will go up 0.2 lb., while others will increase by as much as 0.6 lb. of feed/lb. of gain. With current feed at approximately $.05-.06/lb. of feed, each 0.1 in feed conversion costs about $1-1.20/head.

This of course does not include the additional feed required to get from 240 to 280 lb. of market weight. To calculate that, multiply the additional weight gain times the feed conversion and the feed cost/pound of feed.

There is also a common misconception in regards to average daily gain (ADG). Pigs do not continue to increase in growth rate as they get bigger. After about 200 lb., the growth rate actually decreases to 1.4 to 1.6 lb./ day. This is down from a peak of 2.0-plus lb./day from 140 to 200 lb. The growth curves vary across genetics but the trend is still there.

Space The desired square footage requirements for a finishing pig have been debated for many years. As we take pigs to heavier market weights, it makes sense that they require more room. If we give more square footage per pig, we also decrease throughput. We see pigs finished from 6.8 to 8.0 sq. ft. The ideal area is somewhat dependent on the system.

If the pigs are crowded, there will be more tail-end pigs, slower growth rate, etc. If the pigs are given more than adequate room, the yardage fees will be excessive. Each 0.1 sq. ft. increase in area allowance per pig will cost approximately $.50/pig space in contract situations. If the room is marketed on one day or "topped out," it will affect the square footage needs. If the biggest pigs are sold as they reach market weights, the square footage needs may not actually increase.

Equipment Most equipment can be used with various sizes of finishing hogs. We are beginning to push both ends of the growing period by putting weaned pigs into finishers and then taking out finishers from 260 to 300 lb.

There is a lot of difference between 240 and 280 lb. pigs when it comes to repairs in most finishing systems. Primary concerns are feeders, gating and previously unreachable objects. The feeders take a beating from the physical abuse of the pig. Welds and the metal itself become fatigued with repeated bumping. The gating repairs revolve around the welds, gate feet and latching mechanisms.

Be sure that your feeders allow for good nose, head and shoulder access for comfortable eating. The other concern we have with gating is the height. It becomes easier for the pigs to get over the top and into another pen as they get bigger. It is also easier for the pigs to climb over the gates if a barn has horizontal gate dividers.

We recommend 40-in. gating for heavier market weights. As pigs get taller, they have the ability to reach things that used to be safe like feeder tubes, environmental monitors, curtains, bird netting, etc.

Since ventilation requirements are based on pounds of pork, the requirements will need to be increased if the pounds of pork/room are increased. If you decrease pigs/room while increasing finishing weights, ventilation stays the same.

Health Although we expect a group of pigs to have an established health status by the time they are in late finishing, there are still some concerns. We expect to see death rates increase with longer stays in the finisher. Hemorrhagic Bowel Syndrome is a condition that we see in rapidly growing swine. Acute ileitis and acute erysipelas can strike at any time in the late finishing period. Hemorrhagic bowel and acute ileitis both cause a hemorrhage into the small intestine. All three of these conditions can occur without warning.