Using Phytase Matrix Value with the LCF

In practical formulation, nutritionists usually consider P & Ca as per the recommendation of 'phytase company', keeping the rest of the nutrients escaped to provide benefit, if any, to birds. As for as terminology of 'P' is concerned, it's being used as 'non-phytate' and 'digestible'. The value of both is different for different sources (e.g.) MCP has 100% non-phytate P whereas its digestible value is 55% (as per the latest work of Ravindran). Why 'Ca' is taken as the total is, obviously, its low price. However, Anwar (2017) recently found out the digestible Ca value of different ingredients which range from 28-30%, for example, for canola meal.

Hello. Any nutrient defined as digestible is, in principle, potentially of use to the animal. Total has much less meaning vs digestible from the nutritive stand point.

Dear Rami Unfortunately still many of the nutrients in feed specification for poultry is crude, like CP , CF , EE and of course Ca. Ca is usually over supplied to the poultry diet from many sources like: Drinking water (as a rule of thumb poultry take water twice the feed intake) , Carrier in premix , concentrate , pro-prebiotics also as anti-caking agent in SBM. For example when you add 1 kg of probiotic to the diet, practically you added 1 kg of CaCo3 that need to be taken under consideration. Also, consider that excess Ca has negative impact of Phytaze activity via complexing with Phytic acid in the small intestine and forming an insoluble complex via binding to the active site of phytase enzyme. Then my understanding about matrix value is as below: 1) Any source of Ca coming to the poultry diet (water, additives and so on) 2) Adjustment on the matrix value of Phytaze, as matrix values of enzymes are based on the average substrate content in the raw materials. Substrate is not fixed therefore matrix value should not be fixed also. 3) Considering both Ca and Av.P matrix in phytas Phytase matrix value Although each phytase product has its own matrix value that published by the manufacturing company, these matrices are not derived in the same way. The matrix involves values for Av. phosphorus, calcium, protein/amino acids, energy, and sodium. Research results and field experiences revealed that there should not be a fixed matrix value for phytase in all feed formulations. Poultry nutritionists can have their own matrix values that can be more reserved and have more safety margin than the values published by the manufacturing companies. The most important characteristics influencing phytase efficacy include activity in the upper digestive tract, affinity to phytate, and resistance to degradation. 1) pH : pH of 2.5 to 5.5 is the optimum range at which maximum benefits are obtained from phytase. Research studies revealed that bacterial phytase is more effective than fungal phytase at the above mentioned pH range. 2) Resistance to endogenous protease : Phytase enzyme is a proteinaceous compound, so, it can be susceptible to hydrolysis by pepsin enzyme in the GIT. Bacterial phytases revealed higher resistant against hydrolysis than fungal phytases. 3) Resistance to temperature : Due to its protein nature, phytase enzyme can be inactivated if exposed to a high temperature (above 70-75 ° C) as that occurs during feed conditioning and pelletizing. If the temperature exceeds 80 ° C as that occur during feed pelletizing, phytase enzyme should be protected either by coating or by providing it in an intrinsically thermostable form. Unprotected phytases can be utilized in pelletized feed in liquid form via spraying on the feed post pelleting. 4) Effect of NSP enzymes : a) elimination of the nutrient encapsulating effect of cell walls b) reduction of digesta viscosity (Kim et al., 2005) c) NSP enzymes may also increase the efficacy of phytase by eliminating the phytate chelating effects of NSP (Kim et al., 2005).is because NSP have the capacity to bind multivalent cations (Debon and Tester, 2001), which associate with phytate in both feedstuffs and in digesta. 5) Dosing and mixing errors ( mixing and dosing errors are almost every where ) 6) Availability and variation of the substrates 7) Dietary Factors a) Mineral content Although doubted in some literature, high level of dietary calcium has been reported to adversely affect phytase efficacy either via complexing with phytic acid in the small intestine and forming an insoluble complex or via binding to the active site of phytase enzyme. Similarly, higher levels of iron or zinc make insoluble complex with phytate and subsequently decrease the phosphorus releasing efficacy of phytase. Recently, high dietary sodium has been revealed to decrease phytase activity. Inspection of the mineral content of farm drinking water should be conducted at least once per year as most water of desert areas contains very high level of some minerals that could hinder phytase activity. Phytases that efficiently hydrolyze phytate in the proximal gut (crop and proventriculus) will counteract the adverse effect of high dietary minerals. b) Dietary phytate level Although phytase activity (phytate hydrolysis) is increased in diets containing low level of phytic acid, the absolute amount of liberated phosphorus is high in diets containing high level of phytic acid compared to those with low phytic acid. The degree of phytate hydrolysis and phosphorus release was at its highest level in rice polish followed by rice bran, wheat bran, sunflower meal, wheat middling, canola meal, soybean meal, corn gluten meal, full fat soy, wheat, corn, barley, sorghum, and corn DDGS respectively. c) Feed acidification As the acidic pH is the optimum pH for phytase activity, adding organic acids in the feed such as citric acid has been reported to increase phytase activity. 8) Feed conditioning and pelleting ( heat damage ) : Enzyme coating, granulation or post-pelleting applications have been proposed to counteract such effects 9) Granulation size I hope this can help

Yes

If we don't use a "digestible calcium" value for the ingredients I think Rami is right saying that we should put a 0% value for calcium in the phytase matrix because the enzyme does not provide calcium by itself.

Dear Ali Afsar Very good nice presentation covering all possible aspect to be care for for getting maximum from a phytase enzyme.Direct and indirect effect of different minerals and other enzyme regarding it enhancing efficacy of Phytase enzyme.Hope more detailed work on points highlighted will improve use of enzyme and performance of feeds.keep sharing more.

Hello again. Respecting all opinions, from my experience, I would certainly use a tot Ca value as a matrix - the phytase has an sparing effect of Ca by avoiding its chelation to the phytate-, but then for the rest of the ingredients I would add to the existing tot Ca, a new value - identical to the total Ca-, called "label", "analytical"..., you name it. After the LCF exercise, you´ll get the solution with: i) tot Ca - including the value provided by the phytase matrix - and; ii) label Ca, lower than the tot Ca, but this will be the one to reflect in the label, since it should match in reality with the Ca coming from all other ingredients but the phytase. If still not clear, then I will accept my educational skills are poor. Have a great day you all, Rafa, from Colmenar Viejo, Spain.

Yes, I like.

Sir, Its knowledge giving Article regarding use of phytase Enzyme, Matrix value of phytase , Activity at acidic pH , Most important things is that it is proteinaceous enzyme which can not be blend with Protease like enzymes while making cocktail enzymes. Enzyme making company having cocktail enzymes containing both Protease as well as Phytase . from This Article this is sure that phytase should not be mixed with Protease . Bacterial phytase is more resistant than fungal this point also a learning one. Phytase activity is depends upon Phytic acid contain to releases the phosphorus. Very good information I got from this Article its great Article thanks

yaghobfar@yahoo.com