Disease resistance in chickens one step closer

As well as giving an insight into possible mechanisms of these natural antibodies in general disease resistance, especially towards bacteria, it brings closer selection of chickens with an increased disease resistance.

This in turn has the potential to cut the use of antibiotics, leading to greater well-being in the birds, say researchers from Wageningen University.

The study concentrated on getting better insight in the general protection of natural antibodies. Layer chickens, supplied by Hendrix Genetics, were selected for high or low natural antibody levels for two generations.

The layer hens of the second generation were vaccinated with one of three different vaccines.

Immune responses

Lead researcher Tom Berghof said: “We used vaccines that cause different immune responses: one immune response is directed against bacteria, one immune response is directed against viruses and one immune response was specific for our selection on natural antibodies.”

Animals with high natural antibody levels had, compared to animals with low levels, a higher antibody response against the bacterial vaccine, but not to the other two vaccines.

“This suggests that animals with higher natural antibodies might have a better protection against bacterial diseases,” he added.

The study offers a hopeful perspective to breed chickens on natural antibody levels to improve general disease resistance, especially towards bacteria.

“But first we want to know more about the selection on natural antibodies, so we will continue the selection for a couple more generations.

“In addition, we will investigate if the lines also respond differently to real bacterial pathogens, and if they differ in other forms of protection against, for example, viruses.”

Eventually, the research could lead to animals with improved general disease resistance, lower antibiotic use, lower economic losses for poultry farmers and higher welfare for the birds.

The study was published in the March edition of the journal Vaccine. The research, financed by the Netherlands Organisation for Scientific Research, is part of the “Divergent selection for natural antibodies in poultry” research programme.