Still no Evidence to Justify Use of Multi-Enzymes to Tackle Monogastric Diets
Published:January 20, 2014
Source :AB Vista
According to AB Vista’s Research Manager, Dr Helen Masey O’Neill, until a definitive study is published to show that all components within a multi-enzyme product are necessary for optimum benefit, there is no evidence to justify their use over an optimised single-component non-starch polysaccharide (NSP) enzyme.
The statement was made in a paper recently published in the Asian-Australasian Journal of Animal Science (AJAS) reviewing the mechanisms by which fibre-degrading feed enzymes can improve animal performance when added to monogastric diets. The problems associated with the fibrous NSPs in plant-based feed ingredients – increased digesta viscosity, wet litter, reduced nutrient utilisation – are widely known, but the optimum strategy for tackling them is less well understood.
“The challenge is that the literature advocating multi-enzyme dosing is based on studies which are incomplete, inadequately designed to support the conclusions made, or both,” Dr Masey O’Neill states. “In products claiming multiple activities, it is impossible to assign results to a particular enzyme or enzyme combination unless a complete analysis of each individual component is carried out separately, and all the various permutations of two or more enzymes are also assessed.
“Practically, this is difficult to achieve, yet without it there is no clear evidence that the extra activities are producing any additional benefit beyond that achieved by an optimised dose of an appropriately targeted single enzyme.”
In one published evaluation, a purified xylanase extracted from the multi-enzyme product being studied was less than 30% stable at the pH found in the gut, compared to 70% stability for the crude product. Failing to compare ‘like-with-like’ means any performance difference cannot be attributed to the additional enzyme activities present, highlights Dr Masey O’Neill.
“Caution needs to be applied when interpreting such data. There is currently no robust evidence showing whether additional activities are beneficial, superfluous or even detrimental, and in the many comparisons carried out to date, it is not usually the enzyme product with the greatest number of activities that results in the best performance.”
Hello there. To my dearest ABVista friends, just tell you that the statement you gave, lack of evidence...., is not shared by me at all. It might be that you did not manage to show it, but we have enzymes containing more than 2 activities (is this considered multienzyme?)from which we have showed benefits derived from each one. Needless to say: i) we combine these activities in a well guaranteed manner so that all enyzmes are found in the feed, ii) we select the activities we think are really needed to cope with the substrates/nutrients found in the feed and iii) I don´t see why a combined product should not have a positive effect when the feed offers various substrates of different nature which can be targeted by the enzymes mixed, just like it happens in nature within the gut and the endogenous enzymes. All the best. Cheers from Israel.
Before I write let me clarify, enzymes are not nutrients. As we are aware enzymes in general act as catalyst in chemical reaction.They react with substrate, form a product and work till the substrate is available or environment is suitable and finally disappear.Enzymes improve digestibility of nutrients present in feed by overcomming antinutritional factors present in feed.
The efficacy of enzyme depends on type and concentration of substrate which is decided by composition of diet,age of the bird ,pH in digestive tract and concentration of enzyme in feed.Over and above inherant qualities of feed ingredient plays a very important role.
Evolution of phytase enzyme for poultry feed is greatest achievement as far as biotechnology is concern.It is possible due to most favourable condition for enzyme to act i.e.availability of substrate(phytate phoshorous),favourable pH and the retention time in GI tract and that too the substrate is well defined.
In case of nonstarch polysasccharides,there is multiple substrate like xylans,mannans,glucans which are present at diffrent concentrations in diffrent raw material.Amongst these NSP's xylans are abundant in feed ingredient.So the major focus is to breakdown xylans using xylanase enzyme in non viscous ingredient and glucanase in viscous cereals.There are plenty of research papers favoring the use of enzymes.Secondly market forecast of enzyme is very strong suggesting strong inclination of farmers towards their use.
Although the feed pelleting technology has improved the performance of the broilers,the enzyme technology can help to alleviate the increasing pelleting cost .
Thank you for a detailed review of the current technologies of multi-enzyme compositions or lack thereof. I am sure it will serve a solid basis for AB Vista to develop the next generation solution, more effective than the current products from Alltech, Kemin and Canadian Biosystems.
Some side notes:
1. Enzyme efficacy strongly depends on the grain variety used in the diet. For example, it is almost impossible to demonstrate the benefit of Phytase on low-phytate maize. There are simply no targets for the enzyme to attack. High-wheat poultry diets in Italy will require very low dosages of Xylanase, its further addition will not show benefit. French-grown maize will benefit from Xylanase addition, while US-imported will not, since it is low in NSP.
2. There is a big difference in enzyme performance between poultry and pig diets, though both types of animals are monogastrics. Pigs have more efficient digestive system, with higher residence times and more exogenous enzymes secreted. For instance, their amylase will almost always be sufficient. As a result, the typical compositions for pigs, such as Avizymes, will contain 3 - 5 times higher enzyme dosages compared to these for poultry: small increments of exogenous enzymes will remain unnoticeable on the background of powerful endogenous enzyme system.
3. Not every Xylanase can become an animal feed Xylanase. Same is for BG and protease. Apart from possible instability during pelletizing and in the gut, there are enzyme-substrate limitations. A Xylanase may be released by the enzyme producer, standardized on birch glucurono-xylan. There is no guarantee that the enzyme will work on wheat arabino-xylan. With beta-glucanase we might have a bacterial enzyme released on lichenan (1,3-beta-glucan), but intended to work on a structurally distant 1,3/1,4-beta-glucan of barley. Protease will be released on casein or hemoglobin, while intended for plant, not animal, protein degradation. Therefore, I would define an Animal Feed Xylanase as an enzyme delivering benefit as shown in feeding trials on diets with elevated grain Xylan content. Same with BG, Protease and Phytase. This will automatically take care of complaints such as "This type of enzymes does not work in animal feed".
4. I think we do not need to be overly pessimistic about the benefit of enzyme cocktails versus "straight" enzyme concentrates from the enzyme producers, such as Novozymes, Genencor, Iogen and Dyadic (more power to them otherwise!). If the enzymes in cocktail go after significantly different targets in the diet, there should be at least arithmetical addition of benefits. E.g. Xylanase removes viscosity and uplifts energy by 3%, while protease uplifts protein by 3% (whether the animals do need these additional 3% would be another matter and depends on the art of diet formulation). However in most cases I would expect a synergetic effect (i.e. super-addition) between different types of enzymes in cocktails, well pronounced already in the current generation of multi-enzyme compositions. I realize that the topic of your article is limited to compositions containing only carbohydrases, such as Xylanase, BG, Mannanase and amylase (however, the papers reviewed also discuss use of Phytase and Protease). In the case of solely carbohydrases, it would be of course more difficult to defend the "cocktail" strategy, especially if a non-GMO enzyme concentrate is available, naturally containing substantial amounts of side activities. On the other hand, is it really important to discuss the design of carbohydrase-only enzyme cocktails? Wouldn't it be more productive to focus on more comprehensive enzyme compositions, incorporating Carbohydrases + Protease + possibly Phytase, even Lipase?
More scientific information is now essential to understand how multi-enzyme or any enzyme inclusion in feed formulation would support digestive process in gut over and above the quantity of normal enzyme or enzymes released in the gut during different times and locations of gut and there by support absorption through the intestinal wall.
2-Is there good data available to say that the losses of nutrients is reduced significantly after inclusion of certain enzymes in the diet in mono gastric digestive process?It seems it is very complex to emphatically say on this issue and all enzymes feedings are made with close scientific thoughts.Say on Phytase of different strengths we feel ok by adding 0.1% and reducing use of MCP or DCP for economical formulations. But all doubts are not yet answerable although phytase is manufactured through bacterial base or fungal base with expectation of bio-availability.Similarly for improving all nutrient digestibility in the gut for more expected release of energy,CP,EE,P etc is projected through multi-enzyme uses in poultry ration. But do we have any expected and achieved comparison data along with nil enzyme used feeds in poultry when balanced target rations are fed? I don't say the enzyme use is wrong but i am searching the scientific logic/clarification at my level.
3-Further do we need to include organic enzymes derived from different sources would hold good when we do not know/quantify the exact amount of normal enzymatic release in the gut in-response to the feed and feed type as a genetic response? My point is if X gm feed is feed with enzyme Y micrograms and Z micrograms released in the gut at normal biological function according to genetic response. Then is it possible to know that Y+Z as the bird's requirement for digesting X gms of feed?
4-Is there any data available to prove that the performance is only due to inclusion of enzyme ? some more thoughts are essential at RnD levels to confirm so that there will be uniform view to make the feed more economical by utilizing the non-starch polysaccharides and high fiber diets to mono-gastric birds and animals. For ruminants some more thought has to be made to make the enzyme encapsulated so as to get benefits at abomesum and small intestine levels.
Thank you sir, it is a view only although i use some enzyme and searching answer to my own question only. dr m rath.
dear author, I am happy to see your statement when many multienzyme products are sold for showing better performance in terms of economic traits and economical use of nutritional formulations in support of such products. Really such advantages for getting better performance at least cost may not be a good positive thinking for both mono and poly gastric digestive system. Trading products with hypothesis and field trail without explanation to the pathway of each input is just a waste of time and money. But yes more digestibility in gut for any animal is only possible if the input is predigested or processed for high digestibility then only there is expected results in right directions. This will add to cost and it is possible to think how to prepare new type pellets with more definite return for sustaining commercial nutritional husbandry practices. Thank you. dr m rath