7 commentslast update:Jan 10, 2011

Iron for piglets: injection or oral?

general general
Piglets need iron supplements as they have a low deposit at birth, have a high grow rate and normally not have the ability to get the iron from soil. Sow milk only covers 10% of the iron need: this comes down to an iron deficit of approximately 155 mg per piglet. An iron injection is the most common method of filling this gap, but oral supplementation is a good alternative with some positive side effects.

By Emmy Koeleman

The iron (Fe) may be given as an injection or be based on voluntary consumption. While early conventional iron injection is a safe way of securing sufficient iron to all the suckling piglets, there is some evidence that early iron injection as opposed to voluntary oral Fe intake may increase the risk of joint infections and generalized infectious diseases in the piglets.

A study by Holmgren from 1996 revealed that about 10 percent of the piglets get polyarthritis if injected with iron on the first day of life. If piglets were first injected with iron in their fifth day of life, the incidence of polyarthritis was significantly reduced (p <0.01), and if they instead of iron injection received iron orally via an iron-enriched rooting material, the incidence of polyarthritis was further reduced (p <0.001). A similar study by Rantzer et al presented at IPVS this summer showed a similar picture with regard to arthritis and iron injection. An early injection (day 1-4) leads to more polyathritis (17.5 pecent) A later injection reduced the prevalence of joint infection, but the growth was reduced. With oral iron the polyarthritis incidence was low and growth was high.

Iron regulation
Of course we don't want more joint problems in piglets, but just want them to be strong and healthy with the extra iron shot. According to some experts, oral iron powder is a better alternative to the needle because it mimics the natural iron uptake and regulates natural regulatory iron mechanisms in the intestines. This means that it helps the piglet in fighting diseases. When a piglet gets infected with a pathogen, different mechanisms are triggered in the body: an immune response, fever but also the iron uptake is regulated. The iron balance plays an important role in fighting pathogens. Bacteria need iron to grow and hepcidin - a small peptide synthesized in the liver - makes iron unavailable for this bacterial growth by blocking the iron transporter in the intestinal cell (ferroportin). Ferroportin is also inhibited by hepcidin when iron levels in the body are sufficient.

What is better?
Both iron injection as oral administration work in terms of getting the iron in the piglet, but which administration method is better or more efficient? With injection you know for sure that the piglet received a certain dosage. Oral supplementation depends on the amount of food or water the piglet consumes - or does not consume - and therefore carries a risk of the piglet receiving either too little or too much iron. However, the same can happen with injection, small piglets receive too much iron, and the big piglets too little. Too much iron in turn can increase the risk of bacterial infection (e.g. polyarthritis in young piglets) according to some studies. On the other hand, dietary iron uptake is regulated in the duodenum, triggered by oral administration of iron. Injected iron cannot be regulated this way. In terms of animal welfare, the oral supplementation wins, less injections is less pain and stress in the piglets. It also seems the most natural way of getting the iron to the piglet. In terms of the differences in efficiency, costs and labour between both ways of iron supplementation I am not aware of any studies done in this field. Maybe some readers have experiences with this?

On the picture: Haemoglobin levels are tested for iron anaemia. It is generally accepted that Haemoglobin levels in piglets should be above 80-90 g/1000 ml blood.


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    Ioannis Mavromichalis

    Emmy, great analysis...The easiest way to provide iron without injections is by the use of an oral paste. This ensures uniform intake by all piglets. It only takes some training in doing it right, otherwise it is as easy and efficient as injections. Costs may vary depending on quality of product used!

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    Tore Framstad, Dipl ECPHM

    Treating piglet anaemia

    First, iron deficiency anaemia happens to day, but the piglets are usually not very anaemic. Haemoglobin concentrations below 70 g/L give clinical visible anaemia but values below 90 g/L are shown to give reduced weight gain. Piglets with haemoglobin concentration between 70 and 90 are not easy to pick up clinically; you need to take blood samples. Fast growing piglets will develop anaemia shortly after birth unless iron is supplemented. The main reason for this is that that the iron body reserves in piglets are only 6 � 7 mg, not about 50 mg as said in different textbooks. Most of the iron in the piglet at birth (50 mg) is already bound as haemoglobin and therefore not a reserve for additional synthesis. This was already found by Venn & al for more than 60 years ago and confirmed by Thoren-Tolling in the 70�ies and Egeli in the late 90�ies. Egeli found in her Thesis that the reserves of iron in the piglet are emptied already on day 3. Some (very few) piglets showed a haematological blood picture similar to iron deficiency anaemia already at birth.

    We have calculated the amount of iron needed to prevent anaemia and cover iron in myoglobin and enzyme-systems. If the piglets have available 40 mg iron/kg weight gain, the haemoglobin concentration will be good. Therefore, if the piglets have weights of about 6 - 6.5 kg (4.5 - 5 kg weight gain) in 21 days, 200 mg (with 95% utilisation) of iron given as an injection will cover this. HOWEVER, the bioavailability of iron given into the mouth is, at best, perhaps only 50%. 200 mg iron given in mouth by birth, even as iron dextran, will not cover the iron demand in those piglets. The absorption of iron dextran will go down very soon after the piglets start to suckle and you should therefore give this compound within 24 hours.

    Therefore, fast-growing piglets need iron early in life. When they are kept indoors, you need to give them a start-dose iron �by force�. This start-dose �by force� can be oral. With only voluntary intake, the piglet will develop some degree of anaemia, because the piglets grow very rapid from sow�s milk before they consume enough iron voluntary. Nevertheless, after a start-dose, the supplementation can be voluntary uptake. We have tried iron in peat, iron in water solutions, iron in powder and iron in �iron-pellet�. When the supplementation is administered freely available or daily, these methods will cover the iron supplementation. Iron injection (200 mg) alone can cover the iron demand for maximum about 21 days. However, with that amount, very fast-growing piglets (very high milk production/consumption) will also be in shortage of iron from about day 18 and haemoglobin concentration will go downwards. This could be detrimental at weaning.

    Broken needles in ham or neck are not the only problem with injections at these places. It is also a question about animal welfare. Try to inject 1 ml of a solution in your neck/ham and the same amount subcutaneously and decide what you prefer! With some training, it is no problem to inject subcutaneously in front of the knee. From animal welfare reasons, injections should be done subcutaneously instead of intramuscularly whenever possible!

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    Henk Lecluyse

    A study from Maarten Steyaert at the university of Ghent revealed that less labour is needed to provide the piglets with oral iron. The cost of the products (inj and oral) are about the same. Oral iron would be a bit cheaper

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    Professor Peter Brooks

    Why does the sow only provide 10% of the piglet's iron needs in her milk? We does she lock that up in lactoferrin? This is undoubtedly an evolutionary adaptation to help prevent piglets from enteropathogens. Enteropathogens need iron for their growth. If the iron is locked up in a form thay cannot access, this helps protect the piglet from scours. Unless oral iron can be supplied in a form that can be absorbed by the piglet, but is demonstrably unavailable to enteropathogens, injections will always be preferable.

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    Randall Ellis

    Great article! My question, at what age do you give oral iron? We, here in rural Thailand, will give oral directly to each piglet.

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    Emmy Koeleman

    Dear Randall, haemoglobin levels in the piglets drop to approximately 50-60g/l when the piglets are two weeks of age. It is recommended however to start using the oral iron powder from day 2-4 after farrowing.

    Use the powder over 3 administrations (3-4 days interval)at a rate of 40 grams per litter. 3-4 days after the last administration (when the piglets are 10-12 days old), the supplementation of a starter feed can begin.

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    KC Siow

    Dear Randall, haemoglobin levels in the piglets drop to approximately 50-60g/l when the piglets are two weeks of age. It is recommended however to start using the oral iron powder from day 2-4 after farrowing.

    Use the powder over 3 administrations (3-4 days interval)at a rate of 40 grams per litter. 3-4 days after the last administration (when the piglets are 10-12 days old), the supplementation of a starter feed can begin.
    Emmy Koeleman at 12-01-2011 14:49

    Dear Emmy

    Could you elaborate the use of oral iron powder? Very keen to get more details from you.

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