Newly weaned pigs often have problems with diarrhoea and low growth rates, but zinc can reduce the problems. Why zinc has this – for pigs at least – beneficial effect is not precisely known, but will be studied by a scientist from Aarhus University.

This is the question that postdoc Karoline Blaabjerg from the Department of Animal Science at Aarhus will try to unravel how zinc benefits newly weaned pigs in her project.

Newly weaned pigs often have problems with diarrhoea and low growth rates, but zinc can reduce the problems. Why zinc has this – for pigs at least – beneficial effect is not precisely known, but will be studied by a scientist from Aarhus University.

Today, newly weaned pigs are given a zinc supplement in their diet. By increasing the level from the recommended 100mg zinc per kg in the diet to 2,500mg zinc per kg, however, the piglets’ weight gain is increased considerably, and the incidence of diarrhoea - which is common among piglets - is reduced by up to 50 per cent.

Karoline Blaabjerg’s research project, 'Do piglets have a specifically high zinc requirement at weaning?', has received DKK3.9 million from The Danish Council for Independent Research Technology and Production, and Ms Blaabjerg will be looking closer at the reason why zinc has the effect that it has.

"The idea behind the project is that the proteins that transport zinc across the intestine are not fully developed in the newly weaned pigs, and they are therefore not able to absorb sufficient zinc to meet the demand when the zinc concentration in the feed is 100mg per kg feed," she explained.

Zinc transporters are not understood in pigs, but zinc absorption in humans and rodents has been found to be tightly regulated by different zinc transporters in the intestinal cells. It is also known that the physiological mechanisms controlling the development of these transporters are dependent on the zinc intake, and there are indications that ontogenesis (the development of the individual with age) also plays a role.

In her project, Ms Blaabjerg will initially identify the presence of different zinc transporters in the pigs' intestinal cells. She will subsequently look at how the mechanisms that control the development of these transporters depend on zinc intake. The same mechanisms will also be examined in relation to the ontogenetic development.

New insights into the mechanisms controlling zinc uptake in newly weaned pigs can be crucial in determining the needs of the newly weaned pigs during the critical 14 day post-weaning, thus ensuring the pigs' health, welfare and growth.