As the pork industry strives to increase productivity in the form of more total pigs born, more attention must be focused on saving more quality pigs, emphasizes Tom Gillespie, DVM, Rensselaer (IN) Swine Services.
But as liveborn pig numbers increase, stillborn rates tend to follow, as do other pig loss issues that add to preweaning mortality rates, he says.
“It should be the goal of a high-producing farm to raise 85% of the total number of pigs born to weaning,” he stresses. “A farm's goal should be to strive for a combined loss of no more than 15%, which includes preweaning mortality, stillborns and mummies.”
Top Production Brings Challenges
More producers are striving and achieving 13-14 total liveborn pig/litter averages. But along with those double-digit farrowing numbers come double-digit pig preweaning losses.
While not easy, Gillespie demonstrates in Figure 1  how a select group of producers representing 8,000 sows managed to take total pigs born per litter from 11.5 to over 13 across a 15-year period. At the same time, average preweaning mortality was kept at or below a very respectable 7%, and just 5% for 2007 and 2008.
Gillespie says it's common to see stillbirth rates climb when liveborn numbers increase. For this group, the opposite proved true; the stillbirth rate shrunk significantly over the years.
And in a database of 65,000 sows owned by producers who represent the bulk of his clients (Table 1 ), total pigs born/litter averaged 12.5, with the best at 14.3. Preweaning mortality was 11.1% for the median ranking in the group and just 4.5% for the best producers.
This group, which ranged from very large farms to very small, is indicative of the advances that have been made in reproductive performance — 23.7 pigs/sow/year (p/s/y) for the average based on 86.1% farrowing rate to 29.1 p/s/y for the best herds with 94.5% farrowing rate.
Gillespie says when modern genetics and health are running on all cylinders, there are two major contributors to successful pig development — farm attitude (employee engagement) and detailed pig management.
“Farm attitude is something that runs from top to bottom in an operation. With team attitude, it can be amazing how well facilities are kept and top performance can be achieved,” he says.
In these types of operations, a mindset has been established that every job is important, from the owner to the person doing the power washing. And it fosters a high level of employee satisfaction and morale that is driven by farm leaders.
Detailed management starts with getting the pigs out alive.
Studying the gestation length of a 2,600-sow farm in his practice, Gillespie converted the farm from a program of not inducing sows to one in which sows were induced at 114-115 days of gestation (Figure 2 ). “I said I only wanted to induce sows on Day 114 and that's what they did. They were averaging 115.5 days at farrowing, and we dropped that just a hair under 115, and we didn't change that sow farm's vigor. That farm is now running about 8-8.5% preweaning mortality,” he says.
Watch sow card records to document key events that occurred during the farrowing process to look for warning signs, he continues. “If the sow has had stillborns or long gestation periods (117 days) in the past, then farm staff wants to make sure that she is induced and that somebody is present during the farrowing process.”
Don't scrimp on lactation sow feed. If feeders are licked clean, that probably means sows need to be fed more. “What we forget is that it is the pigs that will drive milk production, which drives sow appetite,” he reminds.
Breeding and gestating sows need to consume about 3-4 gal. of water a day. “I don't believe sows will drink an adequate amount of water unless we force them to,” Gillespie asserts. At one sow farm studied over three years, sows consumed an average 4-4.5 gal. of water a day. Today sows are averaging 5-5.5 gal. of water a day. To elevate water consumption, the farm installed bowl drinkers. The bowl is filled with some water and feed is then dropped into the bowl, which sinks to the bottom of the bowl. Sows have to consume a certain amount of water to get to the feed, so the system promotes water consumption.
Some farms add water on top of feed in farrowing to promote increased water consumption, and that has improved performance and milking ability and reduced health problems, he says.
Next Page: Pig Management 
Previous Page: Top Production Brings Challenges 
Pay attention to details to spot chilled pigs. “The number-one enemy in the farrowing house is chilling. People automatically think about that pig that is huddled and is obviously chilled. But all newborn pigs are coming out of a 100°F environment into a 70°F environment that is cold for them, and they have to quickly adjust to it before they can get colostrum,” he states.
Hot boxes and tubs can greatly assist those struggling newborns. Drying powders play a vital role in reducing the affects of chilling. “I had a farrowing house manager tell me the other day that she likes to put pigs in the hot box right away and lets them stay there until they wake up — so to speak. She gives them time in the boxes to dry off and by the time she takes them out to nurse, they are ready to go — and are not flopping around under the sow and getting laid on,” Gillespie notes.
The Indiana veterinarian used to promote the use of bump weaning/fostering before the advent of milk replacers, etc. Litters were equalized and the use of nurse sows for small pigs was maximized. It was a lot of work but there were a lot of farms doing it, he recalls.
Gillespie observes: “We were weaning very uniform pigs and we met our goal. But we didn't realize the negatives. One day I was on this farm walking through farrowing when I noticed all of the litters that had been bumped. I calculated by Day 10 that over 50% of the litters had been disrupted — and suddenly realized this can't all be good.”
Gillespie says a study patterned after some work in Denmark identified the problems — putting new litters on all those sows reduced sow appetite and their ability to milk.
Bump weaning is still practiced to a limited degree, but he is finding that larger pigs are being weaned without using this management tool.
Another farrowing tip is marking pigs that look like they are starting to fade. These pigs can be closely watched and treated before they become fallbacks.
Milk replacer systems can play a role in helping save pigs. “There are places for these milk systems, or you can build more farrowing crates, extend weaning age, and let the sows do the nursing,” he says.
Saving small pigs was the subject of another trial Gillespie conducted. Fifty piglets from one farm were raised normally, using nurse sows to boost performance. The piglets — weighing 1 lb. 13 oz. to 2 lb. 4 oz. — were raised and 76% of them survived. They weighed 9-12 lb. when they were weaned at 20 days of age.
“We answered the first question, and that was whether we could take these pigs and make them into almost average pigs, and we did that,” he says. In a second, similar study, compromised pigs were raised and weaned at 12 lb. vs. 13 lb. for the normal litters.
“Three years or so ago, we wouldn't have even tolerated those little pigs, but we didn't have the amount of those types of pigs that we are seeing now,” Gillespie says.
He clarifies that the pigs that can be saved are of normal appearance, just small in size, similar to human preemies that are born prematurely and turn out to be very normal people.
The ability to create more full-value pigs is also due, in part, to the trend to later weaning, which Gillespie believes will end up averaging 23-24 days of age.
By moving to later weaning, those current average 3-lb. or heavier birthweight pigs with a 13- to 14-lb. weaning weight will suddenly become nearly 16 lb., meaning that change could translate into fewer days to market.
The genesis for this article was a presentation by Gillespie at the March annual meeting of the American Association of Swine Veterinarians in Dallas, TX.
|Database of 65,000 sows|
|Average female inventory||Farrowing rate||Total born||Pre-weaning mortality||Average pigs weaned/litter||Pigs weaned/sow/year||Weaning to 1st service interval, days||Litters/mated female/year||Sow mortality||Replacement rate|
|Average by average female inventory|