Haja Kadarmideen – Københavns Universitet

6. december: Pig production and human eating behaviour

KU's Alumneforening har bedt forskere fra Københavns Universitet om at fortælle om et af deres aktuelle forskningsprojekter. Det er tilsammen blevet til de 24 låger i årets forskningsjulekalender, hvor du kan læse om alt fra strafferet til sorte huller.

I dagens låge fortæller professor Haja Kardamideen fra Det Sundhedsvidenskabelige Fakultet om sin forskning i svineproduktion.

Welfare and Efficiency in Pig production through Genomic Breeding and Systems biology

Every animal and human is different at the level of their genome (DNA) sequence and these differences contribute to observed differences in their phenotypes, e.g. performance, disease susceptibility/health status, and reproduction. However the genome is extremely long (a string of a few billion of nucleotides) and complex, and finding the right gene causing disease or change in performance are like finding a fish in the ocean. Using Quantitative Genetics, Genomics, and Systems Biology (QGSB) approaches we try to find those genes and their expression profiles and connect them to phenotypes through the underlying networks and biology.

30 million pigs

In my research group, we have many different research projects that are based on QGSB approaches, a few of which presented here address feed efficiency, product quality and welfare in pig production. A spin-off from this project was that we now know (more or less) why humans do overeat like pigs and get obese!

Feed costs are by far the largest cost of raising pigs and cattle for human food consumption which in turn affect the efficiency and cost of animal production. We have been finding genes and developing genomic predictions and selection strategies for genetic improvement of feed efficiency in pigs.

The results show that we can identify pigs that have a set of gene variants that make them very efficient in utilizing the feed given to them to achieve good growth and weight. This can save pig farmers substantial amount of money because a fully grown pig or a sow or a boar can eat anywhere between 700 kg and 1000 kg of feed each, reaching enormous amounts of feed in the pig industry, as every year 30 million pigs are produced in Denmark!

Welfare in pig production 

Animal welfare is a big issue in Denmark and world-wide. Boar taint is an offensive smell caused by the sex hormone androstenone (and another compound produced in hindgut – skatol), both finds its way into the meat. Currently, the only solution to avoid boar taint is surgical castration of 2-4 day-old young piglets which raises a huge animal welfare issue. Using selective breeding strategies, we try to find a painless and sustainable solution, by breeding pigs that have naturally less or no boar taint compounds. We have been very successful in doing this and a major 4-year project has also started. Thanks to a very good collaboration and support from the Pig Research Centre of the Danish Agriculture and Food Council (VSP-L&F) and the Danish Meat Research Institute (DMRI) and two largest international food companies, the Danish Crown and TICAN

Pigs and humans share obesity and eating behaviour genes, Humans and animals share hundreds of diseases, and consequently animals can act as excellent models for the study of human diseases. Pigs have specifically been used to study genetics and epigenetics of obesity (fatness) that can lead to metabolic syndrome and type 2 diabetes, because pigs develop these diseases in much the same way as humans do. In two on-going research projects, one called ‘BioChild’ and the other on eating behaviour in pigs; we used pigs as a proxy for human obesity and eating behaviour.

Why do some humans have a compulsive behaviour to overeat

Realizing it would be impossible to monitor the eating behaviour of thousands of humans every single hour of every day, we turned to Danish pigs to find out why humans “pig out”. We wanted to understand “Why do some humans have a compulsive behaviour to overeat, while others have control over their eating habits?” Is it behavioural, for example when we are stressed or happy or sad, or are we genetically programmed to seek more food than we need? We linked genomic profiles and eating behaviour observations of 1200 pigs to detect eating behaviour genes. We then translated these finding to human eating behaviour via comparative genomics methods. Our research shows that potentially we could come to understand and treat this ‘unhealthy eating behaviour’ as a disability issue. This “pigging out” story was picked-up locally, nationally and internationally and is compiled in a list here. We need more follow-up studies and resources to strengthen our findings that some people cannot stop “pigging out” as it is written in their DNA.

Mød også

I morgen kan du i KU's forskningsjulekalender 2014 møde Per Ambus, der blandt andet forsker i klimaændringernes påvirkning af plantesamfund.