An international study indicates margins of error need to be built into net energy calculations when formulating rations for swine.
The Prairie Swine Centre conducted research in collaboration with the Universities of Illinois and Missouri to look at net energy systems used to calculate the energy content of feed ingredients when formulating swine rations. The goal was determine whether genetic or environmental factors would influence the calculations.
Dr. Denise Beaulieu, research scientist nutrition with the Prairie Swine Centre, says research techniques were carefully duplicated to ensure accurate comparisons.
“The maintenance, the requirement to maintain the animals was different between research centres. Whether this is due to genetics or environment, we’re not exactly sure but this certainly confounds our ability to estimate the energy retained in a feed.
“We did find also that the net energy was affected by growth so it was affected both by where the animal was, the environment, perhaps the genetics but also the stage of growth of the animal.
“So even if a producer is using, for example, the digestible energy system they may have to use different numbers depending upon the stage of growth of the animal that they’re feeding.
We’ve known about that for some time, that we may not be able to use a single number for each feed.”
In conclusion Dr. Beaulieu says, because the numbers are not precise, a margin of error is acceptable when formulating rations. However she suggests, with the current economics, producers may be willing to use lower cost ingredients, estimate the energy content of those ingredients and accept slightly lower performance.