For those of you who did not make it to Eurotier this year, I am providing below the summary of my presentation there on the topic of 'Immunoglobulins in Piglet Nutrition'. A PDF file of the slides is also available in my website at www.ariston-nutrition.com/downloads. As you might have guessed, I am really excited about the topic of in-feed immunoglobulins in piglet nutrition. More developments are on the way!
For now, it remains to share with you the summary as promised.
Natural globular proteins
Immunoglobulins are natural globular proteins produced by all animals as part of their immune system. They are the last and most powerful line of defense against invading pathogens. Their production is quite taxing for the organism and as such they are only produced when the pathogens are not cleared by the firstline systems of defense.
When immunoglobulins are produced, they are created specifically to target in a lockkey model the particular invading pathogen, virtually 'tagging' it for destruction or clearance.
We have been providing piglets with immunoglobulins since we first started feeding them with dairy products, and specifically with whey powder-based diets. A good quality whey contains about 3-4% immunoglobulins, which although are of a weak 'potency' still make their presence felt when whey is added at 10 to 20% of a piglet feed. Yet, a stronger and more potent source of immunoglobulins has recently surfaced in the form of animal plasma. This ingredient contains 8 to 15% immunoglobulins and its presence in piglet feed at levels of up to 5-7% has been shown to dramatically increase piglet performance, especially during the first couple weeks post-weaning.
The fact that animal plasma exerts its beneficial effect through its immunoglobulin concentration is evidenced by two facts. First, research first pioneered at the University of Iowa has clearly demonstrated that when plasma is fractioned into parts according to the molecular weight of its proteins, it is only the heavy fraction (containing all immunoglobulins) that enhances piglet performance. This was verified later in many other studies by different research groups and has been well published in scientific journals.
Second, research and empirical evidence has indicated that healthy piglets do not benefit from animal plasma. A more sophisticated source of immunoglobulins exists in the market, in the form of egg immunoglobulins. These are derived from eggs produced by hens hyper-immunised with specific piglet pathogens. As such, their eggs are extremely rich in immunoglobulins with a high specificity (both avidity and affinity) for piglet pathogens such as E.coli.
Early research has demonstrated that piglets infected with various pathogens and then fed with egg immunoglobulins recover faster and with less loss of performance than unsupplemented piglets. More importantly, mortality due to disease is reduced drastically compared to the unsupplemented controls, with huge economical significance under practical conditions. More recently, research and empirical evidence has provided compelling evidence that egg immunoglobulins are also effective in replacing animal plasma completely.
It has been advocated that immunoglobulins should be labelled as the new nutrient in piglet diets. We still do not know the exact levels required and the exact form that we need to supply them in piglet formulas.
Nevertheless, immunoglobulins appear to be the most exciting ingredient/nutrient in piglet diets, about which a lot is going to be said in the coming years.
In the next issue of Pig Progress (vol 26, issue 10) a background article on immunoglobulins will be published by Dr Mavromichalis.