"You can't manage something you can't measure."
At the recent Tri-State Dairy Nutrition Conference, Perdue AgriBusiness' Normand St. Pierre one-upped this old saying.
"A number is meaningless unless you have quantified its error," the former Ohio State researcher explained.
Monitoring forage variation is an important tool for managing rations. However, St. Pierre reminded the audience that sometimes the day-to-day or sample-to-sample variation is simply noise.
What is noise? In the case of feeding, it's sample variation.
Similar to noise-canceling headphones that improved sound quality by eliminating background noises, feeding a ration that avoids sampling error improves ration quality.
St. Pierre discussed three types of variation: true forage variation, sampling variation, and analytical (lab) variation. In a study St. Pierre conducted with Bill Weiss of The Ohio State University, analytical variation played the smallest role in corn and hay crop silage variations for all nutrients. Meanwhile, on-farm sampling was the greatest source of variation for all nutrients other than dry matter.
What are St. Pierre's recommendations?
When sampling on farm, take more than one independent sample, being mindful to repeat the entire sampling process at least a second time. When discussing modifying rations to account for dry matter variation, he suggests adjusting the diet 50 percent of the difference between the formulation and the measurement. This will eliminate the noise caused by variation.
Sampling and forage analysis is one of the most powerful tools in our feeding toolboxes, but it must be done carefully and its results used properly.
(c) Hoard's Dairyman Intel 2016
May 16, 2016
