March 19, 2013

AB Vista warns feed producers on the use of phytase matrices

In order to ensure animal performance and profitability is not compromised and to make true efficacy comparisons between the different phytase products, AB Vista stresses the need for feed producers to be aware of the safety margins placed on phytase matrices.

Inorganic phosphorus is often the second most expensive nutrient in a diet, and consequently there is pressure to minimise dietary phosphorus safety margins. Most producers use a phytase enzyme and rely on the manufacturer's recommended matrix value to determine how much added phosphorous can be removed from the diet.

With many phytase matrices derived from amalgamations of growth performance and/or digestibility trials, there is growing concern among nutritionists that the matrix values applied to a given phytase do not accurately represent the results seen in the field. Given that the inorganic P is the second most expensive nutrient in the diet, even small adjustments to the P matrix can result in significant cost savings when using a phytase.

Field results with Quantum Blue consistently show that the matrix is achieved in the vast majority of cases where it is employed.  As market economics continue to put pressure on P levels in diets, the robustness of claimed phytase matrices will be tested more than ever before, and as a result such conservative approaches to matrix derivation become more and more warranted.

Mike Bedford, Research Director, AB Vista said, "With rising costs, decisions made on the P matrix of the phytase and the P requirements of the animal are now under intense scrutiny.  As a result, safety margins in dietary P are under pressure, challenging the matrices of all phytases to a greater extent. Factors such as mineral levels in the diet and intrinsic animal metabolism will affect enzyme activity and consequently P release.  At AB Vista we strongly recommend feed producers consider how the matrices are derived, taking into account the safety margins applied, in order to evaluate product efficacy."

Not all phytases matrices are derived in the same way and some use a 50% confidence limit.  Quantum Blue matrix for available phosphorus is calculated based on a 90% confidence value, assuring customers that in 90% of the time Quantum Blue is included in the feed, it will release a P level equivalent to or higher than the recommended value.