http://www.anuragaja.staff.ipb.ac.id/files/2012/10/Selle_2007_AFST_Phytase-poultry-rev.pdf

Microbial phytase in poultry nutrition

Exogenous enzymes in monogastric nutrition - their current value and future benefits.

The excretion of large amounts of P in effluent from intensive pig and poultry units is indicative of the poor availability of phytate-bound P in plant-derived feed ingredients. This environmental problem prompted the development and acceptance of microbial phytase feed enzymes for single-stomached animals. Their introduction led to an increasing recognition that phytate may have adverse effects on protein utilisation in addition to P. Consequently, the nutritional relevance of protein-phytate interactions for pigs and poultry is considered in the present review. Since the current understanding of the effects of protein-phytate interactions comes mainly from responses obtained to added phytase, literature on the influence of microbial phytases on amino acid digestibility and utilisation is summarised, followed by a discussion of possible mechanisms contributing to the negative effects of phytate. However, the rationale for the protein responses to added phytase remains largely speculative, and several modes of action are probably involved. It may be that the release of protein from protein-phytate complexes occurring naturally in feed ingredients, the prevention of formation of binary and ternary protein-phytate complexes within the gut, the alleviation of the negative impact of phytate on digestive enzymes and the reduction in endogenous amino acid losses are all contributing factors. A better understanding of the mechanisms of protein-phytate interactions and the modes of action of exogenous phytase enzymes is clearly desirable. Studies are also needed to identify and quantify the factors that contribute to the variable amino acid responses to added phytase. It appears that the relative solubilities of phytate salts and proteins from different feed ingredients and their effects on the extent of protein-phytate complex formation, coupled with variations in the effectiveness of phytase in different dietary contexts, may be the major factors responsible.

/pdf/phytate-and-phytase-consequences-for-protein-utilisation-4012vcqxrl.pdf

Phytate and phytase: consequences for protein utilisation.

https://www.harvestplus.org/sites/default/files/tech08.pdf

An interactive 24-hour recall for assessing the adequacyof iron and zinc intakes in developing countries.

This review focuses on phytase functionality in the digestive tract of farmed non-ruminant animals and the factors influencing in vivo phytase enzyme activity. In pigs, feed phytase is mainly active in the stomach and upper part of the small intestine, and added phytase activity is not recovered in the ileum. In poultry, feed phytase activities are mainly found in the upper part of the digestive tract, including the crop, proventriculus and gizzard. For fish with a stomach, phytase activities are mainly in the stomach. Many factors can influence the efficiency of feed phytase in the gastrointestinal tract, and they can be divided into three main groups: (i) phytase related; (ii) dietary related and (iii) animal related. Phytase-related factors include type of phytase (e.g. 3- or 6-phytase; bacterial or fungal phytase origin), the pH optimum and the resistance of phytase to endogenous protease. Dietary-related factors are mainly associated with dietary phytate content, feed ingredient composition and feed processing, and total P, Ca and Na content. Animal-related factors include species, gender and age of animals. To eliminate the antinutritional effects of phytate (IP6), it needs to be hydrolyzed as quickly as possible by phytase in the upper part of the digestive tract. A phytase that works over a wide range of pH values and is active in the stomach and upper intestine (along with several other characteristics and in addition to being refractory to endogenous enzymes) would be ideal. © 2014 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/jsfa.6998

Phytase in non-ruminant animal nutrition: a critical review on phytase activities in the gastrointestinal tract and influencing factors.

http://directory.umm.ac.id/Data%20Elmu/jurnal/A/Animal%20Feed%20Science%20and%20Technology/Vol81.Issue3-4.Oct1999/10408.pdf

The effect of minerals and mineral chelators on the formation of phytase-resistant and phytase-susceptible forms of phytic acid in solution and in a slurry of canola meal

Rex W. Newkirk

Papers

The effect of minerals and mineral chelators on the formation of phytase-resistant and phytase-susceptible forms of phytic acid in solution and in a slurry of canola meal

The effects of toasting canola meal on body weight, feed conversion efficiency, and mortality in broiler chickens

In vitro hydrolysis of phytate in canola meal with purified and crude sources of phytase

Nutritional evaluation of low glucosinolate mustard meals (Brassica juncea) in broiler diets

The non-mineral nutritional impact of phytate in canola meal fed to broiler chicks