Animal Performance at Risk with Poorly Derived Phytase Matrices25 March 2013
UK - 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 phosphorus can be removed from the diet, says AB Vista.
AB Vista stresses the need for feed producers to be aware of the safety margins placed on phytase matrices to ensure animal performance and profitability is not compromised and to make true efficacy comparisons between the different phytase products.
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 phosphorus is the second most expensive nutrient in the diet, even small adjustments to the phosphorus 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 phosphorus 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 phosphorus matrix of the phytase and the phosphorus requirements of the animal are now under intense scrutiny. As a result, safety margins in dietary phosphorus 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 phosphorus 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 per cent confidence limit. Quantum Blue matrix for available phosphorus is calculated based on a 90 per cent confidence value, assuring customers that in 90 per cent of the time Quantum Blue is included in the feed, it will release a phosphorus level equivalent to or higher than the recommended value.
ThePoultrySite News Desk