“Feed mills worldwide from America to Asia are using egg powder as a regular feed ingredient in different lines of products and milk replacers, from basic to top end lines. It’s the real world corroborating what science has shown over years and years of research,” Dr Fellipe Barbosa, product manager – Globigen, with the German feed supplement manufacturer, told FeedNavigator.
Immunoglobulins or antibodies are natural protein compounds found in all animals as part of their immune system. They identify and neutralise foreign substances – mainly harmful pathogens such as bacteria and viruses.
According to some scientific papers the IgY (Immunoglobulins from the Yolk) produced by laying hens are more effective at neutralising pathogens than cow-derived immunoglobulins. Another advantage of using IgY is the high concentration of IgY in the yolk, explained by the fact that the hens produce and transfer the full load of antibodies to the egg at once in order to support their chicks during the first days of life. Those eggs can be used to produce egg powders such as Globigen, a feed ingredient that is promoted as supporting the immature immune systems of piglets and calves.
Mind the immunity gap
Right after birth, young animals receive passive immunity from their mother via colostrum. However, the concentration of antibodies in the colostrum decreases rapidly after 12 hours, and this is one of the critical phases during their lives that egg powders can act as external support to the undeveloped immune system, according to Dr Barbosa.
“The active immune system will be developed over a longer period of time after birth. During these critical phases, the animals face a ‘gap of immunity’ that has to be filled somehow. Egg antibodies have an important role, attaching to the antigens in the intestine where the pathogens causing diarrhea proliferate and colonise,” he explained.
Egg powder origins
According to Dr Barbosa, the idea of using egg powder in animal feed dates back to observations that eggs from hens that were raised together with pigs could be used to reduce diarrhea in piglets, giving local immune support in the gastro-intestinal tract of those animals.
“As we know from the nature of laying hens, they will produce IgY related to the pathogenic challenges they are confronted with. Based on this knowledge, a modern production process was developed and is used to produce egg powders,” explained Dr Barbosa.
Tackling new pathogens
He cited several scientific papers that had shown that IgY can bind to bacteria, virus and protozoa like Clostridium perfringens, E. coli, Salmonella typhimurium, Rotavirus and Cryptosporidium, thereby reducing the incidence of diarrhea in young animals such as calves and piglets.
With the pathogens responsible for diseases in calves and piglets constantly changing, Dr Barbosa said research was continuously being updated to prove the ability of IgY to neutralise ‘new’ harmful pathogens.
An egg-xcellent alternative
Egg powder is not the only commercially available source of immunoglobulins; other sources such as bovine colostrum, whey protein concentrate/isolate and spray dried animal plasma are also available.
However, according to Dr Barbosa, these products tend not to be standardised in terms of antibody levels. Furthermore, whilst it has been proven that immunoglobulins from other products “are useful”, they can also be “less effective than IgY, depending on the pathogens the animals have been confronted with”.