Why is iron supplementation in piglets a weighty issue?

Anaemia in newborn piglets is not uncommon. The condition develops when there aren’t enough haemoglobin and red blood cells to deliver oxygen throughout the body, which is often due to a lack of iron.

Piglets are born with low stores of iron and they’re unable to get the level they need from their mother’s milk to keep pace with their fast growth rates.

That’s why iron supplementation is so vital for newborn piglets; helping them to grow healthily, building their immunity and enabling them to thrive.

And without it?

“The main effect of [iron deficiency] anaemia is reduced growth rate. It is very significant. It can mean several kilos of bodyweight lost at weaning,” explains Dr Jens Peter Nielsen, professor of porcine health and director of the Department of Large Animal Sciences, at the University of Copenhagen.1

More severe symptoms include fatigue, pale skin, and shortness of breath. Because clinical signs are so subjective and sometimes there are no outward signs at all, the condition can easily go undetected.

Anaemia can be diagnosed by measuring the amount of haemoglobin in the blood, which can be carried out in specialised laboratory or on farm, using recently developed hand-held devices.

Yet, while farmers are highly aware of the importance of giving piglets iron, the question of the optimal quantity needed remains. Blanket iron supplementation, often given as one single 200mg dose in the third to fifth day of life, may not be optimal.


weaning weight of pigs

Iron supplementation versus small and large piglets

Dr Nielsen highlights that producers can achieve better growth rates by adapting the iron dose to the piglet’s bodyweight. He explains: “You can imagine that if one piglet is under one kilo, and another one is two kilos, then it is a very different dose per body weight.”

Piglet birthweight varies considerably from 700g to 2.6kg and small piglets will react differently to the standard dose than larger piglets.

“There is an issue of toxicity if the piglets are very small. The effect actually shows up as reduced growth rate,” says Dr Nielsen.

Meanwhile, producers need to pay attention to their larger, fast-growing piglets. These animals are in fact at a greater risk of developing anaemia because they require more iron to fuel their development.

Day three for optimal iron supplementation

Just as the dose, the timing of iron supplementation is very important too. “Newborn piglets actually need iron very early on,” says Dr Nielsen, “because some of them are almost born with anaemia.” But swine producers need to be careful of toxicity in small piglets, which becomes even more pronounced in newborns.

“We have to make a compromise between early intervention and toxicity. If we were to pin down the most appropriate timing – the ‘golden date’ so to say – it is day three of life,” Dr Nielsen advises. “This is when it’s still early enough but the piglets are stronger.”

Yet there are still cases in which piglets injected with iron could still be at risk of anaemia because farmers may not realise they are injecting piglets incorrectly. “Piglets are very often stained by the iron, which shows you that it's leaking out from the injection site,” he says. “Farmers have to be careful about their injection technique.”

The research shows that iron may be even more important in rearing robust piglets than previously understood. If producers can take the time to optimise iron supplementation across the herd, they could quickly see the pay off in production.


Prof Dr Jens Peter Nielsen has worked on diagnosis and prevention of diseases in pigs for 30 years. He will be discussing modern challenges in iron supplementation at the Bayer European Swine Symposium 2019 on September 17.


Learn more about Bayer's latest innovation to prevent iron deficiency anaemia while improving swine well-being and farm management.


Egeli, A.K., Framstad, T., 1999. An evaluation of iron-dextran supplementation in piglets administered by injection on the first, third or fourth day after birth. Res Vet Sci, 66, 179-184