Some producers complain that their meat or egg type chickens suffer from problems in bone or egg shell quality when they include phytase in the diet as a partial substitute for the inorganic phosphorus sources (MCP; DCP; bone meal) according to the matrix value provided by the manufacturing company. Under field conditions, phytase activity is controlled by several pa...
Excellent article,covering in quite simply way all aspects of phytates /phytase /phosphorus.
I like it very much. Just some additional words.
1.phytase unit: there is more than one unit name and value.The registration conditions (eg.pH 5,5, temp 37C, 1 min....) are same but other factors (the buffer, colorant, etc in lab conditions) are different. Eg.one unit FTU (Du Pont) is not equall to FYT (DSM). All companies/producers have own system/method to describe 1 unit.
2.The hydrolysis of IP6,IP5, IP4 depend on the speed; we (birds) have short time in low pH (proximal gut) to work efficiently and hydrolyse as much as possible higher esters (IP6,IP5,IP4). Adding more proper phytase (higher dose per t feed) we influence the speed and the final result. Lower esters (IP3,IP2, IP1) are not as bad (as antinutrients) as the higher ones (as you wrote above) and could be hydrolysed by internal enzymes. Finally we got pure myoinositol- a "factor" improving weight gain and FCR. The "speed" of degradation the higher esters is different for various phytases.
3.the matrix: should be different for various species, age, dose (response is not linear). Good/serious companies based the matrix values on many scientific trials and research,but we see sometimes a matrix values taken "from the roof". Then we could meet problems on a farm- deficiency in macrominerals and ME (as the main values saving fed cost).
The conclusion- I like yours.
Thanks Mahmoud.
Dear Sir,
Please elaborate whether age of the bird affect phytase activity to relase phytate Phosphorous.
can layer chicks in 0-8 wks of age , 8-12 wks of age utilizes phytase as same way that utilized by laying phase bird ?. Is phytase activity same in grower broiler bird as like in finisher broiler bird to utilize phytase phosphorous ?
Regards,
Dr Narsing Pawale
Apart from the above points you can also add that simple human errors during feed mixing can influence the expected content of phytase. Too much confidence in the mixing equipment may also cause unexpected phytase levels in the final feed.
Incorrect storage of the phytase product may also lower the expected phytase activity in the final feed.
The phytase products´ particle size and particle size distribution may influence the homogeneity of the distribution of phytase in the final feed.
when we talk about enzyme work actually we talk about enzyme stability during both feed processing and in animal digestive system.
when we use any kind of enzyme we should know that either substrate is also available or not, in absence of substrate using enzyme is waste of money.if substrate is available then enzyme must be able to breakdown the target substrate within a short window of time, enzyme must withstand a broad range of PH, an enzyme with a narrow PH range has limited sections of the digestive tract where activity can occur. a PH range 3-7 is optimal.
during enzyme selection we should know can it cope with endogenous proteolysis within GIT.
during enzyme selection we should know about its structure, either it is intrinsically thermostable(thermostability encoded by amino acid sequence in molecular structure) or coated?
thermostability does matter especially in Pakistan where 4-6 months of the year are very hot, pelleting temperatures shoots automatically above 90C in order to alleviate the production costs.
intrinsically thermostable enzymes are considered by many enzyme manufacturers to be the optimum solution, as they claim the activity levels of these enzymes is not lost due to high pelleting and conditioning temperatures, they also say that the enzyme with protective coating may not fully dissolve in the upper digestive tract of the animal. at the end the GIT of chicken is a tough envirom, it limits the enzyme 's ability to catalyze substrate as quickly as it can in Lab, conditions are quite different in vivo. so keep in mind so many factors involved in enzyme selection.
Just reacting to the original question (do phytases always work in poultry nutrition). Clearly this depends on how you define 'work' i.e. what the expectations you have of the phytase. It would be possible, for example, to manufacture a situation where the efficacy of the added phytase looked very poor e.g. if the diet to which you add the phytase has a high concentration of digestible phosphorus (above the animals requirement), or a very low concentration of phytic acid, or has a digestible SAA limit or where the phytase has been added inappropriately (perhaps a heat labile product was added pre-pelleting and the conditioner temperature, steam pressure and residence time were high) etc. However, when high quality phytase products (gastric stable, appropriate pH range, stable product form, good particle size and distribution through the feed etc) are added with the appropriate adjustments to diet composition (including Ca and P in particular) I think we can safely say that yes, phytases always work in poultry nutrition. In fact, phytases save the global feed industry in the region of $5-6bn per annum through reducing nutritional input costs, not to mention the added benefits on animal performance and environmental sustainability.
The effect of phytase in poultry nutrition will depend on the amount of available phosphorus in the diet of the poultry. Phytase is meant to break down the phytate into phosphorus and myoinnositol. The efficacy of phytase in poultry nutrition will depend on the presence of phytate in the feed. Several experiments have shown the efficacy of phytase in reducing the amount of feacal phytate as well as improving the digestibility of other nutrients like protein and carbohydrate. This is possible because phytate is known to also chellate with these nutrients (protein and carbohydrate). So a breakdown of phytate by phytase will not only release phosphorus and other minerals but also lead to the release of these nutrients and make them available to their respective digestive enzymes. Some phytase enzymes are also known to contain other enzyme activities . This is due to the type of substrate and type of organism used in their manufacturing (innoculation). I think from several points of view (nutritional, financial, environmental), it still worth it to include phytase in the diet of poultry.
The phytases work in an excellent way in poultry nutrition. We need to remember the balance of the phosphates and calcium to increase the absorption of the nutrients in any formulation. I use the phytases in the formulas and I can see serious changes in the performance of the birds. Remember the live period of the birds and the genetics, we need to have all this aspects in mind, and give the best quality feed and reduce the stress to our bird, don't expect to have big results with a poor formulation.
The phytase normally works very well.
The problem had experience for some products required to use 750 ftu per gram (not 500 ftu/g like some products) and cannot use double dose. Some problems from the stability of products and the coating technique should be concerned.
Ken Ken
To use the optimal dose need to measure phytic P content of the feed to understand whether it is enough to apply the matrix relevant to the specific inclusion rate of certain phytase product.
Is you have enough substrate in the feed and animal requirements for available P allow, you can use not only 500 and 750 but even 1000FTU/kg
Ang Lee Fhytase 10000 has activity 2 times more, than fhytase 5000. If you need 1000 FTU/t of feed, you must use 100 g/t of feed fhytase 10000, or 200 g/t of feed fhytase 5000. The result will be equal.
If phytase is intrinsically heat stable, then there is no question that it wouldn't work, however question is that what is maximum threshold of this temperature for each of fungal or bacterial phytase???
Moreover, what is digestibility coefficient of each of the ingredient against such phytases, is it same or different???
At the end sometimes it is speculated if only phytase is the reason of lameness in Broilers???? Means AvP from the ingredients isn't sufficient to protect birds from lameness at least???? OR birds use AvP to protect themselves from lameness only......
Respected Aaron Cowieson,
You have mentioned about particle size of Phytase among other features. Could you please briefly describe it and also advise what is ideal particle size of Phytase?
Zeeshan Ahmad Dr Slominski did a lot of work on the particle size of phytase. Smaller the particle size, more the chances of the presence of phytase in each pellet.
Really very informative data shared. I would like to add some points about Ideal Phytase Based on PPS P-pH profile Important to be highly effective in low pH. Important to be effective at broad range of pH (1-5) range P-Pepsin Pepsin Resistant Important to be resistance to pepsin to avoid the loss of activity in vivo. S-Speed Important to have fast working phytase because feed passage time in proximal gut is very less, so to release more and more phytate with the high speed. Regards, Dr Sachin Patil,India M.V.Sc
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