Source: DuPont Animal Nutrition via Feedinfo News Service
6 August 2019 – Shortly after the 2019 Poultry Science Association (PSA) Annual Meeting, held in July in Montreal, Quebec, Dr. Janet Remus, Technical Services Director North America, DuPont Animal Nutrition discussed the company’s ‘nutribiosis’ concept with Feedinfo News Service.
In today’s PERSPECTIVES, we resume the discussion with Dr. Abiodun Bello, Poultry Scientist at DuPont Animal Nutrition, and look at the company’s latest research with regard to Axtra® PHY phytase supplementation and how it fits into the overall nutribiosis approach.
[Feedinfo News Service] Dr. Janet Remus, Technical Services Director North America, recently discussed ‘nutribiosis’. What roles can phytase play, especially when it comes to US and Latin American poultry producer challenges?
[Abiodun Bello] Phytase has a very important role in nutribiosis, the interaction between nutrition, the microbiome, and the gut and immune function. The availability of phosphorus (P) and protein are vital for various cellular activities and the growth of microbiota in the gut. Axtra® PHY, a Buttiauxella sp. phytase, increases availability of P and calcium (Ca) along with metabolisable energy (ME), amino acids (AA), and sodium (Na), to allow for reduction in the dietary levels of energy and the nutrients. Optimizing phytase application helps to reduce levels of undigested and unabsorbed P and protein reaching the ileum and caeca. This minimises hind-gut fermentation of undigested nutrients and potential excretion of P and nitrogen compounds (N), contributing to a favourable nutribiotic state.
It is well known that phytate binds protein in the upper gastrointestinal tract, making it unavailable to the animal and resulting in increased acid and pepsin production. As the stomach empties, this increased acidity can damage the gut absorptive surface and requires more buffering through the release of sodium bicarbonate. The increased demand for sodium depletes sodium levels in cells, reducing the functionality of the sodium pumps required for absorption of key nutrients, such as glucose and amino acids. The use of phytase as part of a nutribiosis approach can significantly reduce feed costs while maintaining a broiler’s growth performance.
[Feedinfo News Service] Which latest company scientific findings about phytase performance were presented at PSA 2019?
[Abiodun Bello] DuPont continues to invest in phytase research and presented three abstracts on phytase this year. The first of these is entitled ‘Buttiauxella phytase at 3,000 FTU/kg improved growth performance and carcass yield of heavy broilers under mild-challenged condition’. This study found that at this level the phytase added to NC diets with reduced dietary ME, digestible AA, P, Ca, and Na outperformed the nutrient-adequate PC and reduced feed cost per kg BWG by 3.7%. This may be related to the extra-phosphoric effect and the favourable nutribiotic state.
Our second abstract entitled ‘Buttiauxella phytase supplementation in a nutrient-reduced diet increases the apparent ileal digestibility of amino acids in broiler starters’. This study found that a negative control diet supplemented with phytase at 500 and 1,000 FTU/kg increased the average of overall AA apparent digestibility by 4.8 and 6.1%, respectively, clearly demonstrating the extra-phosphoric effects of Buttiauxella phytase to degrade phytate and reduce protein-phytate complex. The data also support applying a digestible AA matrix in broilers diets when using the Buttiauxella phytase.
The third abstract looks at the ‘Impact of phytate concentration from corn in the diet on Ca and P digestibility in the presence or absence of phytase’. Our study found that digestible P improvement was 2.1g/kg with 1,000 FTU/kg feed, indicating a greater phytase dose is needed when increasing dietary PP levels to 0.29% and 0.34% to maximise the phytate degradation rate.
[Feedinfo News Service] What differences in performance have you observed between Buttiauxella phytase and other types of phytase?
[Abiodun Bello] We see Buttiauxella phytase, Axtra® PHY as the fastest-acting phytase with the highest phytate degrading efficacy on the market. But what also makes this phytase stand out is its highly potent extra-phosphoric ability. Literature studies showed inconsistent response on digestible AA improvement with commercial phytases. The gross effect of phytase to increase the digestibility of amino acids was recently reviewed by meta-analysis of data collected from 24 different broiler studies carried out between 1996 and 2015. The analysis showed that use of phytase at 500 to 2,000 FTU/kg can increase apparent digestibility of overall amino acids by 4.1% on average. Our study found that the use of Axtra® PHY in broiler diets at 500 and 1,000 FTU/kg increases apparent digestibility of overall amino acids by 4.8% and 6.1%, respectively, while the 1,000 FTU/kg dose increases apparent digestibility of Lys, Met, Cys, and Thr by 4.3%, 3.4%, 9.5%, and 7.0% respectively. The data from this study and the new publication from Dersjant-Li and Kwakernaak (2019) demonstrated that Axtra® PHY provides greater extra-phosphoric effects relative to other commercially available phytases.
[Feedinfo News Service] Are you seeing additional interactions between Buttiauxella phytase with phytate and other nutrients? What new discoveries occurred between PSA 2018 and PSA 2019?
[Abiodun Bello] Yes, a good example is dietary phytate P, which can vary from 0.20% in a pure corn-soybean meal diet to as high as 0.34% in a mixed diet rich in phytate-dense co-products such as canola meal and rice bran. A high level of phytate P in the diet results in considerably high chelation of Ca, AA, starch, and other cations even with dietary supplementation of phytase. This was made clear in one of our recent studies, which showed that an increase in dietary phytate P linearly decreases standardised ileal digestibility of Ca and P. An efficient remedy to alleviating the adverse effect of high dietary phytate P is by using an increased dose of a fast-acting phytase. Ensuring an increased rate of reaction in the upper gastrointestinal tract with a higher dose of Buttiauxella phytase, based on the dietary phytate P level, is vital for optimal P liberation and availability for absorption from the duodenum.
[Feedinfo News Service] Is there still room for phytase inclusion level growth in markets such as the US and Latin America?
[Abiodun Bello] Avian diets in the US and Latin American are traditionally based on corn and soybean meal. However, with prices of both commodities trending up, nutritionists are looking at opportunities to manage feed cost by use of higher by product inclusion and/or by adopting phytase addition tailored toward maximum phytate breakdown and maximum nutrient capture via phytase matrix
Phytase is currently supplemented at 500-2000 FTU/kg, depending on the composition of the ingredients, phytate levels, limestone Ca solubility and age of the broilers. As demonstrated by the study described in our third abstract, to maximise phytate destruction a phytase inclusion level of above 1,000 is needed to increase ileal digestibility P (eg to 80%) when phytate levels increase to 0.29% and 0.34%.
In addition, we found that increasing Axtra® PHY inclusion to 3,000 FTU/kg (applying dig AA, P, Ca and ME reductions) provides production benefits under mild challenge that mimic commercial production settings. It also helps to replace inorganic P completely, leading to both production and environmental benefits. We therefore expect to see higher phytase inclusion rates in the future.
[Feedinfo News Service] How do you currently supply the Americas with Buttiauxella phytase? Can we expect production expansions soon?
[Abiodun Bello] Every diet needs to be evaluated for optimum phytase inclusion levels, so we have to find the dosing level that works for each situation, in order to provide the best enzyme and substrate ratio and to optimise phytase utilisation. We supply Axtra® PHY to the Americas with specific recommendations linked to the dietary composition, phytate levels, limestone Ca solubility and specific customer needs. We also advise our customers to use the optimal dose and apply full digestible P, Ca ME and AA matrix values to maximise production benefits. DuPont is a market leader with Axtra® PHY. There are no constraints on how much phytase we can produce and, unlike inorganic feed phosphates, there is no practical limit either.
Published in association with DuPont Animal Nutrition