There is a quiet revolution taking place in today's pork industry. Litter sizes are climbing with each uptick in the number of total born and born alive, providing tremendous potential to change farm throughput, according to Minnesota swine veterinarian Tim Loula.
“What we once thought was a big litter will become the herd average,” as operations reach 30 pigs per sow per year — and turn a dream into a reality, he reported at the 18th Annual Carthage Veterinary Service Swine Conference last fall in Macomb, Ill.
Loula, senior partner of the Swine Vet Center at St. Peter, Minn., says when producers hear about the trend to 30 pigs per sow per year, they raise two questions:
- What if I'm losing $20-30 per pig?
- What if I get a lot of small pigs that I have to sell light?
His answer comes with a review of pig history. Thirty years ago, the late Al Leman, DVM, returned from England saying the United States needed to get to 20 pigs per sow per year to compete with the Europeans, Loula recalls. At the time, U.S. herds were at 14 pigs per sow per year.
By the 1990s, almost all breeding herds were achieving 20 pigs per sow per year. Today, many systems are hitting 25 pigs per sow per year, and some are on the threshold of 30 pigs per sow per year, reaching that level for weeks, and individual sows are achieving 40 pigs per sow per year, he observes.
Sure, weaned pig, sow feed and liquid propane fuel costs have risen significantly. “But weaning more pigs/sow significantly decreases these costs/pig weaned,” Loula says.
For example, when sow feed costs $0.13 per lb., 1 ton of feed per sow per year = $260 per sow per year. Based on those prices, he calculates increased sow production lowers pig costs as follows:
22 pigs per sow per year = $11.82 per pig;
25 pigs per sow per year = $10.40 per pig; and
30 pigs per sow per year = $8.67 per pig.
Two years ago, sow feed costs were half of that, reducing the cost/pig proportionately, he adds.
Higher pigs per sow per year obviously drives costs lower on many other related inputs including buildings, insurance, taxes, labor, sow replacements, sow medication, vaccine and semen.
Loula has compiled a list of “big drivers” that will enhance efforts to raise pigs per sow per year.
First is total born/born alive. “The industry is making tremendous improvement in total born and born alive. This will be the key driver in more farms achieving 30 pigs per sow per year,” he emphasizes. “Fourteen total born is happening regularly. The carrot has moved. The old goal used to be 11 born alive; now it is 13.”
He adds: “We've seen the greatest increase in the last several years since the European white line hybrids replaced the U.S. genetic base of three-way cross (Duroc x Hampshire x Yorkshire) breeding programs in the late '70s and '80s.” The European white breeds essentially took over and replaced most U.S. female genetics, he says.
Loula insists that producers will need to achieve 12-13 pigs born alive to stay competitive, and he envisions 13-15 being achievable in the not-too-distant future with genetics leading the way.
Again, the Europeans led efforts to increase litter size, dating back 15 years, and it is really paying off. The top French farms are averaging 28.1 pigs per sow per year, with 14.1 total born, 13.1 born alive and 11.4 weaned per litter.
Increased U.S. reproductive efficiency will result in 90%-plus farrowing rates, increased total born, decreased wean-to-first service interval (5.5 days or less) and decreased non-productive sow days, he predicts.
The pig industry is moving to a later weaning age to improve nursery performance. Loula says there is linear evidence that shows longer lactation length (18-21 days) also plays a role in improved subsequent farrowing rate, total born and born alive. Some systems are actually moving to 21-23 days wean age.
Avoid overbreeding, he cautions, because it can result in early weaning, an increase in litters of less than seven pigs born alive and more fall-out pigs. Early weaning also has other effects on reproductive performance:
- Decreased total born;
- Prolonged wean-to-first service interval;
- Shortened estrous cycle; and
- Lowered farrowing rate.
Don't try to compensate for a short breeding group by early weaning some animals, because those females will breed at the same time they would have if they were allowed to lactate three to four more days,” he emphasizes.
To achieve high total born to reach 30 pigs per sow per year, producers must pay closer attention to their gilt development programs.
Manage gilt supply
Balance parity distribution to provide for adequate gilt supply. Too few gilts results in retaining old, less-productive sows, which will reduce farrowing rate, decrease total born, increase preweaning mortality and exacerbate sow death loss.
However, avoid adding marginal gilts to the breeding herd. “More herds have gotten into trouble because of inadequate gilt supply rather than the high cost associated with high replacement rates,” the Minnesota swine veterinarian suggests.
Adjust gilt matings based on actual results, seasonal estimates or by farm historical data. Summer breedings are important because they make the most profitable pigs (next summer's market hogs when the market is traditionally at its highest).
For years, producers have failed to manage gilts correctly, according to Loula. Gilt performance can be great. But if gilts are bred too young, too small or on the first heat, housed in pens and moved at the wrong times, then the results will be poor and gilt retention will often be low. Instead, breed gilts at 240 days of age, at 300 lb. or heavier, and on the second or third heat cycle.
Heat induction and heat checking while gilts are in isolation should be done seven days a week. Put a boar in each gilt pen for 10 minutes. Synchronize gilts with hormones (PG600 from Intervet). The goal should be 80%-plus of the gilts in recorded heat within four weeks in isolation.
Once gilts are identified in heat, they should be tagged by color and day of the week. Record if they are in standing heat; swollen, wet vulvas should be recorded as “swell.” The gilt may not stand while she's in the gilt development unit, but she's still going through a heat cycle, he says.
Breeding barn flow
To Loula, there is too much use of pens in breeding barns. Don't breed gilts in pens. If you have to use pens, relegate them to sow use after Day 30 of gestation, following a pregnancy check.
Use pens to house thin sows so they can exercise to gain back condition.
Breeding pens cause labor inefficiencies from jumping pens to check open animals, to moving open females to pens to check for heat.
“Breeding barn movement is a very big deal. Less is better,” Loula affirms. Develop a flow with the least moves that allows you to properly observe animals, provide boar exposure, check for heat and breed sows.
Prepare for breeding
“Crate break” or house all breeding-age gilts in crates for a minimum of 10 days (21 days is preferred), before breeding, says Loula.
To prepare gilts for breeding, full feed two to three times per day for at least two to three weeks.
Again, don't breed gilts in pens, and don't move gilts from breeding stalls from Day 5-30 postbreeding.
“Remember the gilt is the future of the herd. Have a plan for success and stick to it to achieve your targets,” Loula states.
Signs your gilt development program may need improvements include high replacement rates and high sow death loss.
Watch for low gilt reproductive performance, particularly a low percentage of gilts making Parity 3, Loula says.
When it comes to feeding lactating sows, Loula's simple philosophy is “the more they eat, the better they reproduce.”
Lactation intake drives reproduction. Females must be fed at least three times per day from Day 3, post-farrowing, to maximize feed intake. With automatic sow feeders, sows can be fed up to five times per day: 5:30 a.m., 9:30 a.m., 2:30 p.m., 5:30 p.m. and 9:30 p.m.
A big trend in recent years is the move to automatic lactation feeders, either the INTAK (ad-lib lactation feeding system from Automated Production Systems) or the straight tube feeder.
Feed all open females from weaning to breeding at least twice a day and preferably three times/day to achieve “full feed,” he says.
Provide sows maximum amounts of feed from weaning to breeding, and feed above maintenance levels from breeding to 30 days of gestation.
Don't allow animals to get fat.
Treat thin sows as an emergency. Lean genetics require much more feed to get back into normal weight ranges.
Provide sows with the same level of care that you would pigs in intensive nursery management.
Devote time to the job. Walk slowly. Look at each sow carefully. Be prepared to stop and check individuals. Focus on your task.
Establish a consistent daily schedule that makes breeding simple and uses a team breeding lineup to drop feed, walk the barn, provide feedback, clean, check semen, heat check and breed groups.
The old way of thinking is that “semen is semen,” and that there is no difference in quality between companies or studs, he comments.
In fact, bacterial contamination, acrosome integrity problems, different concentrations and poor standard deviation in counts can all lead to lower farrowing rates and total born.
Boar studs and farms that collect semen should monitor for these issues every collection day. Among the most common bacterial contaminations are pseudomonas, eptococcus and Cornebacterium staphylococcus.
To minimize bacterial contamination, sanitize lab floors and equipment daily.
Reducing stillborns is essential to the goal of achieving 7-8% preweaning mortality. Identify your problem areas, find out when pigs die and what can be done to make a difference.
“Stillborns are a big deal because they're usually big pigs,” Loula relates. This problem can be reduced through induced farrowings, attended farrowings, proper sow condition and parity management. Watch especially for sows with a history of stillborns.
Reduce constipation and provide adequate fresh air to farrowing sows.
Mark farrowing cards when the room is loaded as an easy visual check for sows with a history of stillborn problems.
Recognize early on when a sow is having farrowing difficulty to ease stillborn problems. Possible signs include:
- One or two dry pigs;
- Sows' eyes are red and bloodshot and may appear to bulge;
- Obvious straining and contractions with no results;
- No new pigs farrowed for 30 minutes; and
- Bloody discharge behind the sow with no pigs.
Old sows noticeably increase stillborn rates (Figure 1).
Most preweaning mortality occurs within the first 48 to 72 hours of farrowing, so the more attention paid to the 1- to 4-day-old pig, the less work needed later, Loula states.
From 75-90% of stillborns are caused by three factors: traumatic injuries including laid-ons and crushing deaths, low-viability pigs and starveouts.
Colostrum is critical
Energy management is a solution to saving challenged piglets. “The idea is to get more energy (colostrum) into the pig than what goes out by increasing the colostrum intake and decreasing chilling and other stresses,” he points out.
Along with split suckling and hot boxes to warm and dry off piglets, Loula advises the following colostrum management steps:
- Observe all pigs for colostrum intake;
- Make sure each piglet has found and suckled a teat; and
- Mark each pig once it has nursed.
Colostrum is made up of two components: antibodies and cells. Antibodies primarily protect against bacterial diseases such as E. coli, Clostridium Type A, Streptococcus suis and Haemophilus parasuis. Specialized white blood cells primarily protect against porcine reproductive and respiratory syndrome, swine influenza virus, porcine circovirus type 2 and other viruses.
Protective antibodies can be obtained from any sow; however, the cellular portion of colostrum only comes from the newborn's mother. That's why it is vital for pigs to suckle their mother before crossfostering, Loula reminds.
Piglets need to fill up with colostrum as soon as possible to overpower the germs in the environment.
Check pigs' bellies. If full, don't crossfoster pigs at all because it upsets the sows and the pigs. Every litter has a smallest pig. Recognize and treat fall-behinds quickly.
“Thirty pigs per sow per year is the new goal. It's in our sights — it's no longer a dream,” Loula concludes.