When the pork checkoff’s Sow Lifetime Productivity (SLP) project kicked off in the mid-2000s, the effort admittedly languished for a few years until it was given solid direction in 2010.
“When staff reviewed the research programs, it was decided that there should be a research project that reached across all disciplines within science and technology,” says Chris Hostetler, director of animal science for the National Pork Board.
The focus was set on the two driving factors that define SLP:
• How long the sow stays in the herd
• How many pigs she weans during that time
If the sow fails to meet certain productivity standards, it is expected that she will be culled from the herd, Hostetler explains.
Back in 2010, the SLP project was seen as sort of an umbrella project due to its multifactorial makeup. Factors affecting sow longevity range from welfare, housing conditions and swine health to genetics, nutrition and reproduction.
“When I came on board in 2011, I was charged with getting the effort up and going. So one of the first things we did was to clearly define sow lifetime productivity as the total number of quality pigs that a sow weans from the time she becomes breeding eligible until the time she leaves the herd,” Hostetler explains.
The goal to improve SLP was set at 30% in seven years, arguably a “pretty ambitious” endeavor, he admits. “There are really only two ways you can do that — keep the sow in the herd longer and wean more pigs per litter.”
Taking that definition of SLP and the pork checkoff’s mandate to improve SLP, Hostetler organized an oversight committee including producers, academics and representatives of genetics and nutrition companies, and tasked the group to help outline research needed to achieve the goal of 30% improvement in seven years.
The first project assigned was nutrition during gilt development. The scientific oversight working group acknowledged that the nutritional program the gilt undergoes affects not only that period of growth, but also that there are also downstream effects as to how long she stays in the herd, and the number and quality of the pigs that she weans.
To carry out the actual research, a second group was organized as an SLP research consortium to focus on a key element that affects how good a pig is when it is weaned: the amount and composition of the milk that it has consumed.
Hostetler says the first project was to determine the effect of diet on body composition. In it, approximately 1,000 females were identified at birth, and placed on one of six dietary treatments (as described) at 100 days of age, and then those gilts were followed through puberty. The results of this project will be used to determine the three dietary treatments to be used in the follow-up study.
In the second study, there will be approximately 3,000 females fed one of three dietary treatments during gilt development. Again, these females will be identified at birth, fed the experimental diets beginning at 100 days of age and then followed through three parities to determine the effect of body composition on sow lifetime productivity. Those trials will be conducted at the Murphy-Brown research facility near Milford, UT.
“We are interested in how those dietary treatments affect either fat or lean composition, and how we can use that preliminary study to narrow down our dietary treatments for the longer study, where we take the females out to third parity,” Hostetler observes.
Once that preliminary project is completed early this year, the primary study will begin, which will again involve identifying females at birth and narrowing the dietary treatments down to three.
The complete three-year project is being sponsored by the National Pork Board in collaboration with Murphy-Brown.
The plan to improve sow lifetime productivity must overcome some major deficiencies in sow productivity.
“The sad fact is that roughly 40% of females that are bred for the first time have less than nine pigs, and so 40% of the females that get bred get culled after their first parity,” Hostetler laments. “Then there is another 20% that get culled at second parity, so you are up to about 60% of the females that never have a third parity.”
The pork industry is currently producing an average of about 35 pigs in a sow’s lifetime, meaning that a 30% improvement would boost that figure up to about 42-43 pigs per sow lifetime, he says.
Failure to reproduce is the No. 1 reason for culling, much of which is underscored by issues with lameness.
“Most producers will just check off that the sow failed to reproduce, and won’t specify that it was a lameness issue,” Hostetler says.
“One of the things that this project will do is it will track our reasons for culling, and tell us specifically if the reason she was culled was because she was lame or because she was reproductively incompetent.”
Current projects take SLP through early 2015. A parallel project developed by the research consortium, which kicks in sometime this year, is the brainchild of University of Alberta research scientist George Foxcroft, professor emeritus. It looks at the effects of litter of origin.
“This is a term that producers may not understand. The litter that a sow is born in has great implications for how productive she is as a sow,” Hostetler says. Work by Billy Flowers at North Carolina State University has found that gilt litters raised in litters of eight stayed in the herd longer, weaned more pigs and had higher lifetime productivity than did gilts that were raised in a litter of 12.
The other part of the Foxcroft project will look at such things as whether the ratio of boars to gilts in a litter affects how females perform as sows in the herd, and how the amount of colostrum that a female consumes as a baby pig on day 1 affects her performance as a sow. This project, including data collection and analysis of females at birth, will be conducted at Holden Farms of Northfield, MN.
This project will also evaluate litter birth weight, which is a repeatable phenotype. “If a sow has a light birth weight litter the first time she has a litter, there is a very good chance that her subsequent litters will be low birth weight as well,” Hostetler says.
“Then we may be able to identify those females early and see if there are management practices that we can do that will increase the weaning weights of those pigs — more attention to nursing, or split suckling,” he adds.
All of these research projects should return DNA data (blood and tissue) that should be able to be mined for years, Hostetler says.
Over the seven-year life of this research effort, the $3 million contribution for the projects being made by the National Pork Board will serve as an investment that will buttress the pork industry and the future of the U.S. sow herd, he affirms.
In the end, the knowledge gained will provide some sort of a standard operating manual for how pork producers need to raise their females to ensure the highest likelihood that they will become sixth-parity sows.
“Ultimately, for each individual farm, whatever pieces of this ‘manual’ producers can use, the greater the potential that their sows will be in the herd for six parities,” Hostetler says.
As it stands, if sows stay in the herd until third parity, 90% of the time they will stay in the herd through their sixth parity, he says. “That’s why we only do trials that take sows out to third parity. It is a milestone to reach third parity.”
Preliminary results on sow lifetime productivity projects at the National Pork Board should be available for discussion at World Pork Expo, set for June 4-6, 2014 at the Iowa State Fairgrounds in Des Moines, IA.
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