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Reduction in pig medicine usage is plausible

Genetic differences between the content of certain compounds in pigs affects their disease resistance. If this knowledge is developed and included in breeding programmes it can have an impact on the usage of antibiotics in Danish pig production.

06.12.2010

Research can reduce the use of antibiotics on Danish pig farms via the development of a tool that can be used in breeding programmes. Photo: Janne Hansen

It is very possible that the usage of antibiotics on Danish pig farms can be reduced without negatively affecting pig welfare, farmer finances or consumer health. On the contrary, it would be beneficial for all three things.

 

A reduction in the use of antibiotics can take place through target-oriented breeding programmes. Scientists from the Faculty of Agricultural Sciences have actually already discovered a tool that can be used to this aim. All they need now is the opportunity to test how well the tool works in pigs.

 

The tool is mannose-binding lectin (MBL). New studies show that MBL is one of the key parameters in innate broad-spectrum disease resistance. Not only that, scientists from the Faculty of Agricultural Sciences have found that there is a marked variation in the content of the compound in pigs which gives reason to hope that selection against pigs with a low MBL content is feasible.

 

This is described in an article sent to the scientific journal ”Immunogenetics”.

 

Not all pigs are born equal

- Pigs have several types of MBL. We have developed antibodies against MBL-A which makes it possible to test specifically for MBL-A content in the blood, explains senior scientist Helle R. Juul-Madsen from the Department of Animal Health and Bioscience at the Faculty of Agricultural Sciences and leader of the research project.

 

The scientists investigated 3,000 pigs from Danish Pig Production’s test station, Bøgildgaard. The results show that among the Landrace pigs there were four clearly different groups of animals with regard to MBL-A blood serum content. The scientists thereafter investigated the DNA of the pigs in question and found that there were corresponding differences in the DNA profiles of the animals.

 

- The animals with a low level of MBL-A turned out to have a genetic defect. The defect causes an improper unfolding of the MBL-A molecule that therefore does not function properly. Instead it is broken down and never reaches the blood, explains Helle R. Juul-Madsen.

 

The interesting thing about MBL-A is that it probably has an effect on pig disease resistance. In similar studies in poultry Helle R. Juul-Madsen has found that robust chickens have a higher MBL content than average chickens. They have improved resistance against diseases caused by bacteria, viruses and parasites and it is not necessary to medicate or vaccinate them as much as average chickens.

 

Promising results should be followed up

- There is no reason to believe that the situation is not the same for pigs. In mice it has been shown that MBL-C plays a supporting role and in our studies we have shown that some of the pigs also have a defect in their MBL-C. It would be interesting to investigate this and to find out if this can be used in breeding programmes, says Helle R. Juul-Madsen who is chomping at the bit to try out her ideas in a follow-up study.

 

- It would have been obvious to investigate if we could relate the level of MBL in the pigs to their disease frequency or the frequency of treatment with antibiotics but it was not possible with the data from Bøgildgaard because on that farm the whole pen is medicated even if only one pig in the pen is sick, says Helle R. Juul-Madsen.

 

If she can acquire funds for a follow-up project, then she would like to carry out infection trials with pigs with a high and a low level of MBL, respectively, to see if the pigs with a low MBL content get sick more easily than pigs with a high MBL content. The results could be very important with regard to health and finances in Danish pig production and with regard to the prevalence of antibiotics resistance in Denmark.

 

The project was supported by the Centre for Animal Production and Health Management (CEPROS) and the Ministry of Food, Agriculture and Fisheries. Danish Pig Production via Danavl kindly supplied the animal material at Bøgildgaard.

 

For more information please contact: Senior scientist Helle R. Juul-Madsen, Department of Animal Health and Bioscience, telephone: +45 8999 1515, email: Helle.JuulMadsen@agrsci.dk

 

Text: Janne Hansen

 

 

 

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