An Iowa veterinarian reports increasing weaning age can trim costs without adding to the cost of production, while a Kansas State University Extension swine specialist cautions producers to find the best program for their system.

Cutting sow herd numbers, increasing farrowing crate utilization and weaning a little later can combine to reduce costs and improve production at virtually no out-of-pocket expense to the producer, says swine veterinarian Daryl Olsen, Audubon-Manning Veterinary Clinic (AMVC), Audubon, IA.

That three-tiered process can work in some cases, agrees Mike Tokach of Kansas State University (KSU). But whenever possible, weaning later by adding farrowing crates affords the best means to producing high-quality weaned pigs with quick payback, he says.

Move to Later Weaning

Recent data suggests that increasing weaning age can dramatically reduce the cost of production through finishing, reports Olsen.

About two years ago, KSU conducted a series of trials documenting the value of later weaning. (See “Later Weaning: The Quiet Revolution” and related stories, Feb. 15, 2004 issue of National Hog Farmer.)

“Although the data overwhelmingly supports increasing the age of weaning, some farms struggle with finding additional farrowing spaces or are restricted by permit requirements from adding farrowing spaces,” explains Olsen.

For those producers, Olsen suggests there are two viable options: reducing the number of sows on the farm and utilizing the crates they have more efficiently.

At a 2,400-sow, farrow-to-finish operation for which Olsen consults, sow numbers were reduced by 116 head from 2001 to 2004 (Table 1). Currently, the sow herd stands at 2,240 head. Meanwhile, weaning age was increased slightly from 16.4 to 17.8 days. Weaning weights increased from 10.9 lb./pig in 2001 to 12.04 lb./pig in 2004. Bigger, older pigs resulted in higher-quality pigs available for finishing.

Extending lactation and maximizing weaning age also have been shown to enhance subsequent sow performance, he says. For example, Figure 1 shows previous lactation period ranges from 14 to 24 days for all the sows in the AMVC database, and the impact those changes have on future total pigs born and live born.

Adding farrowing crates is a very simple way to increase weaning age, but it does come with some caveats, says Olsen.

The cost of construction has gone up significantly in the past year, boosting the cost for adding farrowing spaces from about $1,500/crate to about $2,500/crate. Estimated one-year payback still provides an excellent benefit for adding another week's worth of farrowing, he points out.

“There is tremendous payback in adding farrowing crates. But cutting sow numbers slightly and going to later weaning is a change which we can make within sow farms without spending a lot of money,” declares Olsen.

A comparison of a five-month period in 2001 (before the change to later weaning) to a five-month period in 2004 (after the change), reveals the number of pigs produced was nearly identical (Table 1).

Poor Performance Plagued System

In 2001, gilts were brought in at a young age, litters were weaned at a young age and gilts were bred back aggressively, recalls Olsen. As this practice was repeated, problems snowballed. Gilts were bred increasingly younger, and owners were forced to increasingly retain subpar breeding stock.

All that changed when the operation switched to later weaning and sow numbers were reduced, stresses Olsen. With less breeding pressure, gilts are introduced with more care. The goal is to ensure that gilts are handled properly, given good boar exposure, and provided adequate time to come into heat and become acclimated to the herd before breeding.

A gilt doesn't enter the herd unless she shows heat by 190 days of age, he says. And instead of breeding gilts at 195-210 days of age, now they must be at least 230 days old, he explains.

The extra space in gestation created by the sow herd reductions allowed the addition of 100 gilts to the gilt pool. The breeding herd counts gilts when they are selected as Isoweans.

With less sows, focus is also on utilizing farrowing crates better, notes Olsen. The goal of most operations should be an 85-90% utilization rate.

The goal for the one-site operation is to farrow 112 sows/week using 360 farrowing crates.

The status of each crate is closely watched. “The staff does one heck of a job making sure there are sows farrowing in those crates, and that they are not using them to gestate sows in the farrowing facilities,” says Olsen. “Their goal is to wean nothing but pigs at 17 days of age or older.”

To increase crate utilization, and keep weaning age intact, litters are weaned three times a week. It spreads out the use of labor more efficiently. Transportation costs are controlled by the use of an on-site “holding” nursery to limit shipment of weaned pigs to once or twice a week, he explains.

For optimum utilization, farrowing rooms are washed in the morning, soon after weaning, and left to dry. Rooms are refilled that same afternoon before staff leaves for the day.

Despite reduced sow numbers, Olsen calculates that better breeding performance, the switch to later weaning and improved farrowing throughput still yielded a total savings of $3/pig to the farm.

“This is a win-win situation. The producer has got a bigger pig for less money, and from a welfare standpoint, sow death loss is way down and gilts are performing better,” he says.

“The $3 in savings doesn't look like a lot right now because we are in an industry that you could call the ‘perfect storm,’ with pork demand and hog prices (high), but it might not last. This savings could have a huge impact as we get back to lower prices,” says Olsen.

He says adding both farrowing crates and increasing weaning age, boosts the payback to $4-5/pig.

Concerns from Kansas State

KSU's Tokach says a few Kansas producers he works with have managed to achieve similar production results from trimming sows and extending weaning age.

But in Kansas, where operations are generally smaller (1,500 sows or less), producers can't afford to transport pigs to nursery sites multiple times per week, because the numbers are smaller and sites are farther apart.

These producers have moved to later weaning ages and added enough farrowing crates for another half a week's worth of farrowings, says Tokach. This allows them to maintain production as before, and still only wean once a week.

Adding crates still reduces your costs over time “because every pig is heavier, older pigs need less expensive nursery diets and piglet mortality is lower,” he points out.

“So, for example, if you have to pay for an extra 30 crates, say you've got 600 pigs a week, you're spreading the cost over a much larger group of pigs, instead of just the pigs weaned out of those 30 crates,” Tokach suggests.

With the extra value of later-weaned pigs, and the reduced cost for each pig, the payback for buying more farrowing crates ranges from nine to 18 months, based on KSU data, he says.

“The benefit of increased farrowing crate utilization or adding farrowing crates is that you produce the same number of pigs, and they are all worth more because they are heavier.

Table 1. Pig Production Before and After Changes in Sow Herd Numbers and Weaning Age
Item 2001 2004
Population (Female inventory) 3,109 2,993
Farrowing rate 82% 85.1%
No. born alive 11.1 11.4
Pigs weaned/sow 9.7 10.2
Avg. weaning age, days 16.4 17.8
Weaning weight, lb. 10.9 12.0
Total pigs weaned 23,325 23,339

“If you reduce (sow) numbers, unless you push the system hard, you may end up with a lower-cost pig, but you have less of them, so you have less profit potential,” warns Tokach.

A small bump in weaning age can improve farrowing crate utilization without a big change in sow numbers, but it can take extra effort.

“Improving crate utilization is sometimes a lot easier to talk about than it is to do,” he continues. “Workers must be of a mindset that they are going to make moving to multiple weanings per week, or moving the sows to the farrowing room later, work.”

Weaning at 17 days of age (as in Olsen's example), a day's cleanup and four days in the crate before farrowing produces only a 77% utilization rate (17-day lactation divided by 22 days of crate time/litter).

To get above that 85% farrowing utilization rate on a 17-day weaning schedule, downtime before the next group of sows farrows must be cut back to two days. “The problem is that gestation lengths vary on sows, so if you only have two days for sows to farrow, some will end up farrowing in gestation crates,” he says.

Another way to improve farrowing crate utilization is by moving to an older weaning age, comments Tokach. At a 21-day weaning age and four days of downtime, farrowing crate utilization goes to 84% (21 days of lactation divided by 25 total days of crate time per litter).

“What you really want to do is figure out what weaning age is going to be optimal for your system and then optimize crate utilization within those constraints,” he says.

According to KSU research, the best range for later weaning remains at 19-21 days of age.

Research has not yet determined the benefits beyond that point, though a number of U.S. producers have moved to 30-day weaning, similar to their peers in Europe, Tokach says.