Replacing Inorganic Phosphate in Swine Diets a Viable Possibility with New Phytase, Says Danisco – INDUSTRY PERSPECTIVES

28 June 2022 – Phosphorus makes up a large part of the cost of swine feed formulations. But with the recent sharp increases in the price of inorganic feed phosphates (IFPs), and supply chain difficulties making it harder to secure sources, further reducing its inclusion in formulas has moved up higher on the industry’s agenda.

And there is also pressure from outside the industry driven by environmental concerns over phosphorus waste, and the fact that that rock phosphate, from which IFPs are produced, is a finite resource and vital to agricultural crop fertilizers.

Phytases have been instrumental in helping the swine industry reduce its use of IFPs by helping with the improved degradation of phytate in feed raw materials, making more plant-based phosphorus available to the animal. And now, according to Danisco Animal Nutrition and Health’s Global Segment Manager for Swine, Dr. Arno de Kreij, PhD, they can potentially be employed to replace IFPs in swine diets.

And it is all thanks to the company’s new Axtra® PHY GOLD phytase, which it claims is “the most bio-efficacious phytase enzyme currently available on the market”. So, for this Industry Perspectives, Feedinfo sat down with Dr. de Kreij to talk through some of the studies backing up this claim and the product’s “potential to nullify the need for inorganic phosphorus additives”.    

[Feedinfo] Dr. de Kreij, to kick off, how common does the use of inorganic phosphate remain in animal nutrition?

Dr. Arno de Kreij
Global Segment Manager for Swine
Danisco Animal Nutrition & Health (IFF)

[Arno de Kreij] Producers have traditionally used inorganic phosphate supplementation to avoid phosphorous deficiencies in animals, which would otherwise lead to problems with growth, bone development and nerve function. We now know, however, that this causes excess phosphorous to be excreted in the form of manure, seeping into soil and ground water, with negative environmental consequences. As global awareness of this issue grows, along with the roughly fourfold price increase of inorganic phosphate prices in the past year, producers are increasingly looking for ways to revise feed formulations in a way that reduces their reliance on inorganic phosphate, while still ensuring the animals get all of the nutrients they need.

Until now, phosphate supplementation couldn’t be eliminated from commercial feed formulations – particularly in the early life phase. With the use of inorganic phosphorous together with a bio-efficient phytase enzyme now seen as a highly effective – and science backed – feed strategy, we fully anticipate a more widespread and rapid shift away from inorganic phosphate.


[Feedinfo] By reducing inorganic phosphate use, how can this impact the feed industry’s CO2 emissions? What is the connection here?

[Arno de Kreij] The animal nutrition industry currently uses 7 million tons of inorganic phosphate in animal feed annually. We first need to consider the impact that the mining and production of inorganic phosphate has on the environment. To this we add the transport and use of inorganic phosphate in feed. All of these factors combined result in a total of 5 million tons of CO2 emissions every year. This is a major sustainability problem. That’s why we are focusing on driving the science towards more sustainable protein production by helping producers reduce and remove inorganic phosphate in animal diets.


[Feedinfo] What data can you share with us on the efficacy of your Axtra® PHY GOLD phytase in reducing the need for inorganic phosphorous in swine diets? How were you able to prove this?

[Arno de Kreij] Every year, we carry out a large number of animal studies to evaluate the safety of our products, as well as their economic and environmental impact – and Axtra® PHY GOLD is no exception. For this product we have done research at various institutes, for example at IRTA (Institute of Agrifood Research & Technology), to demonstrate the viability of inorganic phosphate-free diets under semi-commercial scale and conditions.  

For the first time, the total replacement of inorganic phosphate in all-vegetable diets has been shown to be a viable possibility. With its excellent bio-efficacy, Axtra® PHY GOLD has the potential to nullify the need for inorganic phosphorus additives.

As such, it offers the very real possibility of reducing phosphorous safety margins in commercial diet formulation and freeing diets from the burden – and cost – of inorganic phosphate supplementation. All of which places Axtra® PHY GOLD at the front of the race towards more sustainable swine production.

[Feedinfo] So how is Axtra® PHY GOLD able to deliver these results?

[Arno de Kreij] Independent research has shown that there are more positive effects on mineral and protein digestibility when phytate is broken down early in the stomach. Therefore, a phytase should be fast acting at low pH and degrade phytate as completely as possible. This requires a phytase enzyme that is highly active at the low pH in the animal’s upper digestive tract. Axtra® PHY GOLD has been developed with this in mind. Its unique pH profile means that unit for unit, Axtra® PHY GOLD works twice as fast as any other competitor phytase currently available in the market.

Of course, animal studies are crucial to validate and confirm performance improvements and develop reliable matrix values. At this year’s Digestive Physiology in Pigs conference, we presented two abstracts on Axtra® PHY GOLD matrix values and the impact of limestone solubility. This is part of the work we have done to develop matrix values that are species, life stage and diet specific.

I always recommend customers look at head-to-head comparisons in properly designed trials. A pH profile should include relevant competitors across the entire pH range. For efficacy trials, there should be a positive control without safety margins and a negative control with a full matrix downspec. Looked at in this context, Axtra® PHY GOLD is well supported with over 60 animal studies – with more in progress – to prove its consistently superior performance.


[Feedinfo] With more alternative and local raw materials now making their way into diets, does this present a problem for producers looking to reduce their IFP reliance? 

[Arno de Kreij] From a feed producer’s point of view, a higher inclusion of these cheaper raw materials is a logical choice to keep rising feed prices under control. However, they are often harder for the animals to digest due to higher indigestible fibre content and greater nutrient complexity. Usually, alternative raw materials also contain higher levels of phytate. We have been working on a number of solutions to address these challenges, and feed enzymes are a key part of this strategy. Using alternative raw materials with a suitable phytase dose, for example, helps the animals get all the nutrients they need from the diet and benefits producers by reducing feed costs and contributing to sustainability goals through inorganic phosphate-free diets. Axtra® PHY GOLD can support these efforts by helping with the relaxing of constraints on the inclusion of phytate rich ingredients in diets.


[Feedinfo] Of course, no two operations are the same. How have you committed yourself to ensuring that you can provide customers with optimal dose recommendations?

[Arno de Kreij] We continuously invest in research and development to help livestock producers solve their challenges. Every year, we carry out extensive studies on our products and use this data to provide customers with tailor-made recommendations according to their operational objectives, diet composition, species and age of the animal, and so on. In terms of Axtra® PHY GOLD, for example, we continue to focus on developing and improving phytase applications – and customer collaboration is an essential part of this journey. Our latest effort is a collaboration with Single Spark on a free feed formulation app for Android, aimed at small and medium-sized farmers and feed mills in Africa. This Feed Calculator app together with our redesigned Optimize Feed™ online tool enable our customers to quickly check different approaches and apply this practical information to their dietary feed formulations.

Our collaborative approach has led to a number of successful outcomes, such as the introduction of nutribiosis which takes a holistic view of the impact and possibilities of our products, both in terms of animal performance and health. These underlying principles have further helped to inform our phytase research, which now not only encompasses phosphorous, but amino acids, energy and the role of calcium too. 

[Feedinfo] How have you been able to ensure the accuracy of your recommendations?

[Arno de Kreij] We have focused on providing scientifically robust data, method transparency and flexibility to adapt to different formulation approaches. 

In terms of the phosphorous matrix, we carried out 12 studies in both broilers and pigs that covered globally representative diets, breed, as well as a wide range of phytate levels and limestone solubility. The resulting data means we are now able to provide tailor-made matrix values according to phytate level, limestone solubility, and feeding phases across the entire dose range; from 250 to 4,000 FTU/kg of feed.

Given that phytase is usually used in combination with other non-phytase enzymes, such as xylanase or protease, we also provide matrix values for combinations of feed additives – and continually evaluate and validate these recommendations. In addition, our application and technical service lab can deliver sophisticated solutions to individual market conditions and customer needs.

This detailed approach, together with our investment in ongoing research and animal trials, generates the necessary knowledge to support more customised and accurate recommendations for phytase application.



Published in association with Danisco Animal Nutrition & Health (IFF)