Source: Michael Fielding, MEATINGPLACE, 4/3/15


Phase feeding sows may lead to greater productivity for both the mother and her piglets, according to researchers at South Dakota State University.

A sow's protein requirement in late pregnancy is substantially higher than in early pregnancy, and the bulk of piglet growth takes place in the final trimester.

Although the National Research Council in 2012 developed nutritional models for gestating and lactating sows, "those models are based on very little data,” said assistant professor Crystal Levesque in a news release.

Phase feeding is used to meet the changing nutritional requirements of nursery and growing pigs, but gestation barns are not designed for feeding multiple diets. Consequently, the solution thus far has been simply to increase or bump up the sow's feed ration.

However, the question remains whether phase feeding a diet formulated especially to meet a sow's changing gestational needs would produce a better outcome.

"The hierarchy of nutrient demand shifts during late gestation," Levesque said. "The developing fetuses become the primary target for dietary nutrients and the sow takes what's left over."

Diet changes may improve survivability
Once the piglets are born, milk production in the first week or so requires more feed than the sow can consume. That means that a sow that goes into lactation at a low body condition will become even more nutritionally deficient. A young sow also needs to be able to develop her own body as well as support growing fetuses and then nursing piglets.

In a 30-sow pilot study comparing bump feeding and stage feeding, Levesque has found "fairly clear preliminary evidence that we're impacting at least piglet survivability in the first week post-weaning."

As the number of pigs per litter increases, the variability of birth weight gets higher, resulting in more lightweight piglets. Altering the diet is good for the sow, but "ultimately what we get paid for is the piglet she produces. Can we develop a stronger, more vigorous piglet that is more likely to survive?" according to Levesque.

According to 2014 National Pork Board statistics, the average pre-weaning mortality rate is 17.3 percent. If bump feeding results in saving even one piglet per sow each year, the producer stands to gain $200 per animal, depending on the market price, without changing herd size or genetics.

Next up: Proof-of-principle trials
"This could be huge," Levesque said. However, the economic benefit must justify the cost of retrofitting the barn.

To determine whether phase feeding is cost-effective, research trials using at least 100 animals of equal age per treatment are necessary. Since conducting that type of research at commercial facilities is expensive, proof-of-principle data must be gathered to justify moving to large-scale industry trials.

The SDSU Swine Education and Research Facility, which is expected to be completed by 2016, will allow Levesque to expand this research and to determine repeatability.

"It's about having access to a lot more animals which allows us to do much stronger proof-of principle trials that will help the industry decide whether there is potential economic benefit in moving to phase feeding,” she explained.

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