Phytate for Poultry and Swine

Thank you for this information about phytate antinutrient for poultry.

Do you advise to use always phytase in our rations formulation to avoid such a problem?

Hello from Spain. Congratulations for your article Mr. Santos. After reading your paper some questions come to my mind and I would like to share two of them with you. As far as I do understand, animal endogenous phytase - in the small intestine - is induced by phytate presence in the lumen, but at the same time I believe its production can be reduced by inorganic P presence (released from phytate or inorganic added in diet); would you expect some similar effect - the negative feedback - to occur with an exogenous phytase, even more if added on high doses as you suggest?. Is that not a risk you might have?.
My next question would be how do you foresee the effect of carbohydrase and phytsase together; is there a synergetic effect, additive effect or other, always referred to P release?. Many thanks for your answers.

A good informative article, use of Phytate enzyme is justified even it is not economical to reduce the feed cost.

Hello Dr. Ahmad,

Yes, we believe it’s possible to avoid such problem by including high levels of phytase in diets, what would increase phytate hydrolysis and reduce such problems. When doing so, just be careful not to overestimate the P release.

Hello Rafa,

You have 2 good questions here!

1) Endogenous phytase activity isn’t related only to the intact molecule of phytate (IP6) but it is also active against phytate with less phosphorus binds (IP4, IP3,..., IP1). Considering this, the result may even be the opposite as you rationally suggested as breaking IP6 in more soluble and susceptible IP4, IP3... molecules may even increase activity of these endogenous phytase. Another point to remember is that all phytases presents in the market need to follow toxicity trials when phytase in included in levels even 100 times higher than regularly recommended levels and if any negative effect was observed products wouldn’t be allowed to go to the market.

2) Carbohydrase and phytase: Carbohydrase (and here I’m talking about NSP enzymes like xylanase, but not necessarily other carbohydrases like amylase) have it effect in the animal by, between other factors, opening cell walls and making nutrients more available to digestion and absorption. On doing so, xylanases will make phytate in the feed more available for phytase hydrolysis and possibly getting a synergetic effect. In other hand if phytase used has small effectiveness on phytate hydrolysis or low activity, making phytate more available can have the opposite effect by exacerbating the anti-nutritional effects of phytate.