Research shows benefits of higher phytase levels in poultry feed

A worldwide phosphorus shortage is forcing up prices of feed phosphates. One way to avoid this extra expense is by greater use of feed enzymes, as Jason Sands explains

As the demand for phosphate fertilisers continues to rise to meet increases in global cereal demand, poultry producers face the challenge of sourcing sufficient quantities of feed phosphates to meet bird requirements.

Adding more phytase to feed offers poultry producers an opportunity to overcome these limited supplies of feed phosphates and also allows opportunities for feed cost savings at a time of escalating feed phosphate prices.

Standard rate

Research on new generation, bacterial phytases has shown them to be more effective at releasing plant-bound phytate phosphorus than traditional fungal phytases. At a standard inclusion rate of 500 FTU/kg feed, bacterial phytases (Phyzyme XP) can replace 7.7kg dicalcium phosphate (DCP) in broiler feed formulations – an additional 1.3 kg digestible crude protein compared with traditional fungal phytases.

To help poultry producers further maximise value from using phytase, Danisco carried out research investigating the effects of increasing phytase dose beyond the standard inclusion rate of 500 FTU/kg feed to allow broiler producers to replace more inorganic phosphate in the feed.

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Ten broiler trials conducted in universities and research institutes in various parts of the world examined the effect of increasing dose from 500 FTU/kg feed to 1000 FTU/kg feed on nutrient digestibility, bodyweight gain, feed conversion and tibia ash. Increasing levels of phytase were added to broiler diets reduced in calcium and phosphorus and the effects on nutrient digestibility and bird performance were assessed.

Results clearly showed that doubling the dose of phytase in broiler feed (500 to 1000 FTU/kg feed) allowed at least an additional 1.9 kg DCP to be removed from the formulation, without negatively affecting bird performance. In addition to allowing the replacement of inorganic phosphate, bacterial phytase also reduced the negative effects of phytate as an anti-nutrient in the diet, thereby increasing amino acid and energy availability to the bird.

Reducing costs

Traditionally 500 FTU/kg feed tended to be the standard phytase inclusion rate in broiler diets. However, with current DCP prices at about £700/t the economic optimum for phytase inclusion is currently about 1000 FTU/kg feed.

And this inclusion rate will currently reduce broiler feed costs by more than £6/t, resulting in an additional feed cost saving of about £1/t compared to the standard inclusion rate of 500 FTU/kg feed.

To fully embrace the greater potential of this new-generation phytase, poultry producers can not only make greater reductions in dietary inorganic phosphorus in their diets, but also consider reaping the benefits of energy and amino acid reductions in the diet, due to the product’s effects on phytate as an anti-nutrient. At current high grain, fat and protein meal prices these benefits can potentially be worth an extra £8-9/t broiler feed.

Project at a glance

The problem

  • As the demand for phosphate fertilisers continues to rise to meet increases in global crop production to feed developing nations and produce bioethanol, poultry nutritionists and producers face the twin challenges of sourcing sufficient quantities of feed phosphates and dealing with their escalating price

Key findings

  • Doubling the dose of bacterial phytase versus traditional levels (from 500 to 1000 FTU/kg feed) can reduce inorganic phosphate use by well over 50% compared to diets without phytase
  • Doubling the dose of bacterial phytase can reduce broiler feed costs by more than £6/t of feed when phosphorus and calcium benefits are considered, at current feed prices
  • Including the energy and amino acid benefits from bacterial phytase can increase net feed cost savings by a further £8/t of feed, at current feed prices

Jason Sands is a regional technical services manager with Danisco Animal Nutrition and before this position he was an R&D manager at Danisco. His PhD research at Purdue University, USA, focused on the mode-of-action and use of phytase in both poultry and pigs.