Canada - PSC Recomends Feeding Strategies that will Reduce Phosphorus Levels in Swine Manure
Published:March 16, 2005
Source :Manitoba Pork Council/Sask Pork
Scientists at the Prairie Swine Centre are recommending a combination of feeding strategies designed to help reduce the levels of excess phosphorus excreted by pigs into the environment.
Because the phosphorus contained in grain is largely tied up in the form of phytate phosphorus and is unavailable to the animal, producers have traditionally supplemented diets with inorganic forms of phosphorus.
Research Assistant Dr. Denise Beaulieu says the overformulation of phosphorus in diets not only adds to feeding costs but it also results in excess phosphorus being applied to the soil in the manure.
"One strategy that we can use is feed more closely to our requirements, so formulate rations on the basis of available phosphorus.
We know the proportion of phosphorus in grains that is available but it's very small. Add inorganic phosphorus but don't add these huge safety margins that people have been historically using. I say historically because, just to be on the safe side we add a little bit more.
We can do things like, for example, phase feeding where we decrease the phosphorus percentage of the diet as an animal grows to more closely match its requirements. Split sex feedings, we know that gilts require a little bit more phosphorus than boars so feed them separate diets.
Of the phosphorus that's tied up in the feed that the animal is unable to use, and this would be the phosphorus in grains, there's an enzyme called phytase.
Supplementing the diet with phytase makes that phosphorus available to the animal. We did some economic analysis based upon allowing phytase to come into a diet on a least cost basis and we showed savings at current prices of about 33 cents a pig with the use of phytase."
Dr. Beaulieu says, by reducing phosphorus in the diet and making more of the phosphorus in grains available to the animal, producers can benefit both their bottom lines and the environment.
