Enzyme Solutions for Poultry Diets

Thanks for this report Enzyme Solutions for Poultry Diets. I do agree with the conclusion...

Interesting article about Enzyme Solutions for Poultry Diets.
What might be useful is a table of potential enzyme activity for different feed raw materials. This would be particularly useful when trying to add on a new raw material to the feed ration

Congratulations Gwen. Good article about Enzyme Solutions for Poultry Diets. You cannot explain more, in such a clear way, with less words. Greetings. Rafa

The reality - in my view- is that results with other enzymes different than Phytases are VERY equivocal. It is so for many reasons including:

1. Lack of precise info on feed substrate for the enzyme
2. Poorly estimated energy values for ingredientes and formulas
3. Inter brand enzyme activities comparison today is close to impossible: units are completely different.
4. It is not certain if "purified" enzymes are better or not than multienzymatic complexes with all their side activities.
4. In may experiments the negative control diet with added enzymes already exceeds animal requirements and therefore results can be very misleading
5. Other criteria, different than whole animal on farm performance such as digestibility and ingesta viscosity reductions do not correlate well or clearly explain treatment effects. I speculate that overall cell wall structures (in case of carbohydrases) are so complex and recalcitrant that perhaps we need much more powerfull or complex enzume activities.

Enzymes are extremely powerful, are here to stay but i have the feeling - as i think many other do- that today we are only at the beginning of the their intellogent use and that somehow we do have more of a merchandising than a very precise scientific base use and that industry is partially responsible for the difficulties in their use. Time will tell and most probably this is one of those issues that we in the future may look backwards in time and be very surprised as how crude users we were.....

Good job; the value of feed enzyme as pro-nutrient feed additive is well, perhaps better quantified by growth perfromance and mechanisticaaly so by digestibility. The ability to find and evolve the next generation of feed enzymes will be driven by understanding of target substrates and the implications to the animal nutrition. However, the gut is populated with diverse assemblage of microbiota (billions of metabolically active cells) that plays a critical role not only for the overall well-being of the animal, but also for it’s nutrition, performance and quality of the products produced. In this context, there is greater need to integrate animal performance/digestibility & gut microbial profiling in feed enzyme research.

I have an questioned.
All enzyme manufacturer companies give the recommended dosage level 200g, 30g, 400g etc
But how we calculate the dosage of enzyme according to available Substrate in the feed.
Can we increase the or decrease the dosage of enzyme according to substrate.

Thanks

Reg# Rahat Mobeen

Dear Rahat, in case you'd like to know more about what you ask, then there is a need of a F2F meeting or a more detailed conversation. Are you by any means in the area of any DuPont office? At least I would say there is a clear relationship enzyme dosage substrate when it comes to the phytase. Cheers.

Yes I will like to know more about it.

in our many studies involving numerous phytase products, it seems like the term FTU is totally meaningless. supposedly 500 FTU from phytase A should be equal to 500 FTU from phytase b but seldom is.

Hello all,

From the point of view of enzyme activities, the standard measure is how many moles of the product (the result of the chemical reaction) is released by a specific amount of the enzyme during a specific time and pH conditions. Although I am a biotechnologist I have worked in the animal industry and know that information does not translate well with industrial enzyme users.
However, in the realm of purified laboratory grade enzymes (companies such as Megazyme Sigma Aldrich are pioneer of this) this is the way we classify enzymes. Now is important to consider that in animal feed (pigs/poultry) the substrates are very diverse, as an example you can have b-glucans from barley and xyloglucans from soybeans in a diet made with barley and soy, these substrates are different although their backbone is the same (a chain of glucose units very similar to cellulose). Now a glucanase (let's imagine is a purified glucanse) may have higher activity towards b-glucans from barley than xyloglucans from soy. It's possible to do this at laboratory level, to take a sample of the raw material, the commercial enzyme and compared to the activity of a laboratory grade enzyme, then you have a true comparison of the activity of the enzyme toward a substrate at standard conditions. That is what actually an FTU definition wanted to be, however, the fact that other companies can say that a certain amount of FTU´s are the same as other units is just a commercial play that end up confusing the final user in an already confusing subject (if you change the pH of the measurement then the activities are not equivalent). What the enzyme industry should give to the customer is the real activity of an enzyme connected to a specific substrate and raw material, let's say the activity of the phytase to release phosphorus from soybean will be different from the activity of the same phytase releasing phosphorus from rape seed meal or corn. Plus add the ionic strength or pH of the medium (for those around liking the calcium story), I would ask in this type of reports the conditions and ionic strength to see if the enzyme I am using will work on the raw material I am buying.
Just let's remember that enzymes are catalyzers that work on a substrate to release a product (and reduce antinutritional effects), is not energy or amino acids, therefore, the matrix values are not reliable numbers for comparison between enzymes.

I think Rahat Mobeen raised an interesting point that was only partially addressed by later participants. With phytases, besides the characterization of different efficiencies of different enzymes in the market (the meaning of FTU discussion), there's a great deal of knowledge and commercial application of the concept of using different dosages based, not only on the amount of substrate and type of ingredient, but also what to expect in each specific situation from the use of higher than typical historical doses (like 500 ftu/kg) and it's economical impact. With carbohydrases, we still face a general fixed recommendation that does not take into account (usually) more than the fact that the basic cereal is corn or wheat (or other winter cereal). The difficulty of analyzing the proper substrates might account in part for this situation but in my opinion, it also reflects a more conservative approach. It's not like using a product at the suggested dosage (let's say 100 g/t) works 100% and then at 80 g/ton it doesn't produce any result. There's always a dose:response curve that follows the law of diminishing returns and if we know it then we might decide for a more economical dose to be used. Looks to me we are far from it for carbohydrases.

Each phytase has an optimum pH with ftu’s conveying its relative activity under that specific condition. Phytases first act during storage in the crop with pH’s varying between 4-6 over varying durations. This ingests is conveyed into gizzard where pH’s decrease to 2-3 again over varying durations. Phytases of different pH optima continue to function through crop and gizzard only to varying extents. The Ftu units simply approximate expectations of action through highly variable terms of “gastric digestion.” Don’t be surprised with results varying with any defined ftu.

I think everyone in this discussion made good comments. It seems to me that all that is needed is an underlying theory to fit all the various pieces into. This is the same for phytase and all the other enzymes:
First, it should be accepted that responses to enzymes follow Michaelis-Menten kinetics. Enzymes do not give linear responses. This was very nicely illustrated by Shirley and Edwards, Jr. (Graded Levels of Phytase Past Industry Standards Improves Broiler Performance, 2003 Poultry Science 82:671–680). Ignoring this approach, animal nutritionists seem absolutely fixated with the linear programming least-cost paradigm of feed formulation. They have just got to find a single number for everything in their feed formulation problem. A good metaphor? Round pegs into square holes? They want to drive in screws, but their only tool is a hammer? Animal nutritionists tend to like biology much more than mathematics. Our brains like to work with straight lines in two dimensions. But the linear programming approach of finding one number to put in a matrix just doesn’t work in this case: “However, this approach is flawed from the economic perspective because it implicitly assumes that there is a single relative value of the sources, regardless of the cost of feed components and the price of live birds” (Vedenov & Pesti, An economic analysis of a methionine source comparison response model, 2010 Poultry Science 89:2514–2520).
Second, once it is accepted that the responses are not linear, it should be a simple matter of applying production economic theory to the curves to find economic optimums (Pesti & Vedenov, An economic comparison of several models fitted to nutritional response data. J. Anim. Sci. 2011, 89:3344–3349). Transforming complex equations into economic space is just not what nutritionists want to do. And with ingredient and meat and egg prices changing daily, economic optimums change daily. I am glad I don’t have to explain that relative values are changing daily to a purchasing agent, but such a discussion may prove prudent.
Third, to try to understand the economic implications of the technical problems observed in animal nutrition, my approach was to team up with a very good agricultural economist, in these cases, Dmitry Vedenov. It is not easy to get even agricultural economists to understand the finer points of animal nutrition, like FTU’s. And it is not easy to understand exactly what they mean when they start talking in terms of Greek symbols. But they are really good at solving non-linear problems. With large sums of money at stake in using the right products at the right levels, it may be worth considering involving a professional economist in the decision-making process.

For sure enzyme responses are non-linear but in the range, we test them in animal nutrition they occasionally appear linear. I think it is crucial to also examine available/reactive substrate concentration when interpreting enzyme response. Systems may be saturated with the substrate in which case enzyme responses may be exaggerated across a wide range of inclusion concentrations, or they may be saturated with enzyme (low substrate concentrations) in which case the enzyme effects may reach a plateau very quickly. Relative substrate/enzyme concentrations should be quantified as often as practically possible before concluding on optimum doses. The next moving part is the limiting nutrients in the diet and which biological response you want to measure as an indication of enzyme value e.g. FCR, uniformity, digestibility, bone ash, etc. In the enzyme domain we have not been as consistent as we should have been in measuring and reporting these points in a systematic way.

Over last decade enzymes have become more and more prominent from standard to super dosing to double dosing reasons could be two either the substrate is higher or efficacy of enzyme is lower. Current recommendations to first calculate all anti nutrition factors and make a cocktail enzyme mic to get synergistic effect. What is the ideal PH it is up to 6.5 and optimum temp? In areas where drinking water with 7.5 plus PH
in the upper track body will not be able to reduce the PH particularly in summer when water intake is about 3.5 times instead of 1.8 to 2.it definitely affect feed digestion and passing out of undigested feed to different extent is common, that phenomena will definitely affect the efficacy of enzyme. Technical comments in this regard will be greatly appreciated.
Thanks.