When formulating diets for swine it's important to ensure the animal receives adequate amounts of key nutrients however the levels of some nutrients can vary considerably from grain sample to grain sample.

Canadian International Grains Institute director of feed Dr. Rex Newkirk notes, in the past, producers have compensated for this variability by providing extra amounts of some nutrients as a safety margin but that is changing.

Dr. Rex Newkirk-Canadian International Grain Institute

We always put a fairly large safety margin on phosphorus in that we were putting in more than enough phosphorus just to make sure we were meeting their needs.

It was a relatively expensive ingredient so we didn't put a huge margin on but now we need to really narrow down and look at what are the specific requirements of that animal at that point and what's the availability of those nutrients from the plant source you're using and so now we can be much tighter but we still have to have a safety margin in there to make sure we meet those needs.

The other thing we need to consider is nitrogen.

One of the disadvantages of using something like a distillers grain which is a good source of protein but the protein's not balanced.

It's short on things like lysine and so what happens is if you use too much of a particular ingredient you can get excess nitrogen excretion because not all of that nitrogen is needed by the animal and if you put in too much nitrogen or too much protein in a diet they're going to excrete it out and you'll have excess nitrogen in your manure.

Both phosphorus and nitrogen are the environmental considerations.

Dr. Newkirk notes there are tools available to better manage these nutrients, including grains with higher levels of available phosphorus

and supplements that help the animal better utilize phosphorus.

He adds excess nitrogen can be managed by formulating according to exactly what the animal needs, using synthetic amino acids to get closer to the required amino acid balance and reduce nitrogen excretion.