Phytate in pig and poultry nutrition

Abstract

SummaryPhosphorus (P) is primarily stored in the form of phytates in plant seeds, thus being poorly available for monogastric livestock, such as pigs and poultry. As phytate is a polyanionic molecule, it has the capacity to chelate positively charged cations, especially calcium, iron and zinc. Furthermore, it probably compromises the utilization of other dietary nutrients, including protein, starch and lipids. Reduced efficiency of utilization implies both higher levels of supplementation and increased discharge of the undigested nutrients to the environment. The enzyme phytase catalyses the stepwise hydrolysis of phytate. In respect to livestock nutrition, there are four possible sources of this enzyme available for the animals: endogenous mucosal phytase, gut microfloral phytase, plant phytase and exogenous microbial phytase. As the endogenous mucosal phytase in monogastric organisms appears incapable of hydrolysing sufficient amounts of phytate-bound P, supplementation of exogenous microbial phytase in diets is a common method to increase mineral and nutrient absorption. Plant phytase activity varies greatly among species of plants, resulting in differing gastrointestinal phytate hydrolysis in monogastric animals. Besides the supplementation of microbial phytase, processing techniques are alternative approaches to reduce phytate contents. Thus, techniques such as germination, soaking and fermentation enable activation of naturally occurring plant phytase among others. However, further research is needed to tap the potential of these technologies. The main focus herein is to review the available literature on the role of phytate in pig and poultry nutrition, its degradation throughout the gut and opportunities to enhance the utilization of P as well as other minerals and nutrients which might be complexed by phytates.

A comparative meta‐analysis on the relationship of faecal calcium and phosphorus excretion in mammals

“…These findings are similar to what Humer et al. () interpreted from findings of Hurwitz and Bar () in chicken. Further investigations concerning the identification of proposed Ca/P complexes and their molecular structure are needed to prove this hypothesis.…”

“…One hypothesis is that the regression equation of faecal Ca and P excretion reflects the intestinal formation of insoluble Ca/P complexes. In chickens, a constant ratio of intestinal Ca/P has been found (Hurwitz & Bar, ) and interpreted as the formation of insoluble Ca 3 (PO 4 ) 2 (Humer, Schwarz, & Schedle, ). The atomic weight ratio of Ca to P in this complex is 2 to 1, which should be represented in the regression equation of faecal Ca and P excretion if the complex actually is a major determinant of mineral excretion.…”

The algal chloroplast as a synthetic biology platform for production of therapeutic proteins

“…In addition, phytate also chelates important dietary minerals and essential amino acids. Therefore, dietary supplementation with bioavailable phosphate and exogenous phytases are required to achieve optimal animal growth [53]. Two separate studies have produced recombinant phytases in C. reinhardtii [54,55], with the earlier study demonstrating that dried algal biomass fed to broiler chicks significantly reduced phytate excretion, and the latter study calculating that the costs of production in microalgae are comparable to those for commercial supplies of phytase.…”

The effect of 25‐hydroxyvitamin D3 and phytase inclusion on pig performance, bone parameters and pork quality in finisher pigs

“…Cereal‐based pig diets require supplementation of inorganic phosphorus (P), as almost two‐thirds of the total P is present in the form of phytate, which is poorly utilised by monogastric animals due to low phytase activity in the digestive tract (Brady, Callan, Cowan, Mcgrane, & O'Doherty, ; Humer, Schwarz, & Schedle, ). The inclusion of phytase enzymes in low P pig diets can reduce the antinutritional effect of phytate and improve the digestibility of minerals and nutrients and reduce the negative impact of inorganic P excretion to the environment (Shim, Chae, & Lee, ; Singh & Satyanarayana, ).…”