9 commentslast update:May 6, 2009

Replacing plasma - how?

Dr Ioannis Mavromichalis
Following my last blog on the use of immunoglobulins from hyper-immunised eggs as a means of controlling diarrheas and replacing animal plasma, I have received many emails asking me how animal plasma works and on what grounds egg immunologlobulins can replace it. I think we should take time this week to discuss this issue!

First, let me say this before anything else. There is no 100% precise explanation on how animal plasma actually works. There are many theories and different data supporting each theory. Then, there is personal experience and common sense. I am offering here my interpretation of scientific literature.

So, to begin with, let's dispel the myth about animal plasma having a 'taste' effect. First, data to such an effect are very ambiguous, in that they are open to more than one interpretation due to unclear experimental designs. Common sense also tells that had plasma had any 'taste' effect, this response would be dependent on ingredient composition of the formula plasma was used in. In truth, plasma response depends on base animal growth performance and similar effects are seen with 'bad' and 'good' formulas!

Amino acids
Second, there is a notion that animal plasma's effect is due to its highly digestible amino acids. True, plasma protein is very digestible, but so is the protein of many other animal and even some vegetable proteins, all of which do not offer an effect comparable to that of animal plasma. Only in extremely poor formulas would animal plasma's high quality protein be of real benefit, but at what an extremely expensive price! So, when replacing animal plasma a high quality protein source is needed to cover the difference in amino acids.

Third, some have hinted, without even data, that it is the minerals and even the salt in plasma that enhance feed intake. True again, minerals are needed and piglets like their feed salty (check the work done by D. Mahan at The Ohio State University). But, responses to minerals are never so dramatic as those from plasma!

So, what is left?

Immunoglobulins and especially IgG. Plasma contains up to 15% IgG and this is quite unique among most if not all ingredients used in piglet nutrition. How immunoglobulin's work? Very simple...yet, very effective is their mode of action. They neutralize pathogens so that they cannot attach themselves to the intestinal mucosa to exert their harmful properties.

Therefore, the closer the match between IgG and the pathogen (here the lock and key analogy fits very well), the better the effect. And, it is the generic nature of IgG in plasma that prevents it from being effective against pathogenic diarrhoeas. As plasma contains low levels of a wide plethora of most generic IgG for a great range of pathogens, when piglets are truly hit with an E. coli infection, plasma derived IgG are not enough to overwhelm the invading pathogens.

Here is where egg-derived immunoglobulins from hens immunised against specific piglet pathogens are at their strongest controlling diarrhoea. Have a look at the table below where infected piglets (challenged with K88) animals receiving different levels of egg antibodies experienced less days of diarrhoea and higher survival rates compared to negative control (adapted from Infection and Immunity, 1992, Vol (60):998). And, following that, a couple photos showing the dramatic effect of enterotoxemic E.coli infection and the protection offered by egg antibodies.

Negative egg IgG

A study conducted many years ago (3 identical trials), but never got much publicity, at the Iowa State University by R. Gatnau at Dr. D.Zimmerman's laboratory clearly demonstrated that the heavy-molecular-weight fraction of plasma (the one containing IgG) is responsible for its beneficial effects. Other fractions were of without any consequence (see graph, adapted from Journal of Animal Science, 1995, Vol 73(1):82).

In addition to this report, I have seen at least four more to the exact same effect all pointing to the fact that IgG are the active component in animal plasma. Looking at the data again while writing this blog, I now notice that pure immunoglobulins almost invariably give numerically superior performance to that of plasma across all trials. This was something that puzzled me in my own trials but I dismissed it as biological 'noise'. Is there something in pure immunoglobulins making them even more effective than plasma... More research is needed for sure!




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    Hi I have use just plain old egg and mixed it with a little milk powder. This well eventually gives rise to a non scoury piglet. As a matter of fact when first brought home if they have not had their colostrum you take 1 egg, a teaspoon of olive oil, 1.2 teaspoon sugar Mix together, add a dash of cream and feed this to your piglets. The egg is also full of protein and this gets them started and then on to milk in the next day or so. This idea has also been used for lambs when in difficulty. Just a thought, that I have tried with good success.

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    Horacio Baldovino

    What your opinion about the precense in plasma of high of glutamine and glutamic acid?

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    Xavier Córdoba

    Dear Ioannis

    How are you ?

    I think that something it's losed in in this explanation.

    Phisiologicaly Ig G arent't designed to resist any intestinal digestion, in fact just could be absorved in piglets during the first 48 h of live as maximum, in other hand Ig A that are the natural immunoglobulins of any mucosa and are present in milk and in some dairy products doesn't show the same efficience than "porcine" plasma.

    We are losing something in the theory of plasma action ... perhaps plasma has some natural or "non natural" methabolites presents in the blood that have any antibacteria or growth promotion effect ¿?

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    Ioannis Mavromichalis

    Blonde, many thanks for sharing this technique. Very interesting!

    Horacio, indeed, glutamine has been suggested as an additive to improve piglet digestive health and performance. Plasma contains about 10% glutamine in its protein, so at 70% protein and at an inclusion level of 5% we have a level of 0.35% added glutamine. This could be significant enough to justify it's response. I have not seen any trial where glutamine was tested against plasma. Quite interesting! Thanks...

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    Ioannis Mavromichalis

    Xavier, you're right in anticipating immunoglobulins, like all proteins, to be susceptible to intestinal digestion. Nevertheless, research conducted with human infants has clearly and repeatedly demonstrated that immunoglobulins are extremely resistant to luminal digestion, with the majority of them appearing in fecal material. Some of these studies were also conducted using piglets fed human milk.

    So, unless clear evidence indicates otherwise, I am comfortable accepting current research demonstrating immunoglobulins being responsible for the effects of plasma. What gives further support to this notion is the fact that egg-derived immunoglobulins produce the same, if not stronger, effect in piglets. I have seen this in my own research and also under practical conditions!

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    Maybe plasma protein showed good results in replacement for other protein sources but what is your perspective in the issue of contamination of animal protein sources including fishmeal,meat meal,intestinal peptides and even egg powder? Like for example animal plasma, majority of plasma producers sourced out from bovine origin if not porcine. We all know that there is a "mad cow" disease scare before. And also the salmonella contamination which is normally seen from animal protein sources.

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    I forgot to add, one of the most important properties of plasma is immunoglobulin right? You think the immunoglobulin level in plasma, as based on the recoomended inclusion of the supplier, is already sufficient for the animal's requirement? Because there are some who formulate with lower levels of plasma and/or combining it with blood meal to compromise the desired protein/amino acid level. If that so, then immunoglobulin required will not be met. Am I right?

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    Ioannis Mavromichalis

    Clarisa: Yes, you're right. Unfortunately, nobody knows the exact concentration of IgG required in piglet feed. Even then, it is not the amount that matters most. It is the type and potency of those IgG! For example, a very low amount of piglet-specific IgG from egg antibodies can replace a very large concentration of pig plasma generci IgG...

  • Fernando Santos

    Hi Ioannis. I have never seen any good scientific pub that supports your claim 'For example, a very low amount of piglet-specific IgG from egg antibodies can replace a very large concentration of pig plasma generci IgG...'.

    Even more I have never been hable to replace plasma despite many intents. Plasma seems to work also for some other proteins rather than only Ig. The mode of action is not very well explained but I do not believe egg can do the job.

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