Aggression in pigs can be prevented with Devi-Jex

22nd November 2023

Aggressive behaviour in pigs can be caused by many factors, and when they go to a new place, new conditions and new groups are created, stimuli accumulate that trigger unfavourable reactions in animals.

Such a problem appeared a year ago in the piggeries of Gospodarstwo Rolne Józefowo Sp. z o. o. managed by the brothers Jakub and Mateusz, supported by their father Marian Biały. It is located in Józefów in the Złotów district in the north of the Greater Poland Voivodeship. Plant and animal production is carried out there. Animal production is based on weaners purchased in Denmark. Plant production consists of approximately 100 ha of corn, 50 ha of potatoes, 50 ha of peas and 20 ha of other cereals. This year, only peas and oats were intended for own feed needs. Field production provides approximately 10% of the demand for feed, which is produced by a mobile mixing plant, the rest of the raw materials are purchased. The range includes three types of feed.

A problem has occurred, what next?

Fattening takes place in three piggeries: two with 650 animals each and one with 500 animals. The buildings from the 1970s, repeatedly renovated and modernized, ensure welfare, but when they were inhabited with castrated animals for the first time at the end of October last year (2022), a problem with aggression appeared. At that time, castrated males were slightly cheaper, and the purchase was made at a time when there were problems with obtaining the weaners.

Initially, it looked very good, and during the first week there were no complications. Although the animals were hyperactive and anxious, there was no aggression. It appeared after about 2-3 weeks and increased until the pigs gained approximately 100 kg of body weight. Undesirable behaviour did not occur immediately in the entire building, only in some pens. Removing the most aggressive individuals, even just a few, did not help. In the first batches, the deterioration of results was not yet drastic - mortality from 3% increased to 7%, feed consumption per kg of growth increased from 2.85 to 3.20 kg. So far, pigs weighing on average 132 kg have been sold. The fattening houses were populated with weaners weighing 26 kg, the fattening period lasted an average of 100 days.

The pigs came from the proven Danbred line. When the rooms were populated with new castrated males, it turned out that the farmers had more work, they had to put more effort into handling these animals, and yet the mortality in the critical period increased to 11 and even 15%, and feed consumption to 3.7-3.8 kg.

Jakub Biały (right) took advantage of the advice of Marek Wróbel, a representative of A-ONE Feeds, part of the Devenish Group, who proposed a solution to aggression problems

Feed composition and other factors under the microscope

First, the feed was tested. The recipes were changed many times to reach what seemed to be the optimal composition at the time. Feed companies cooperating with the farm constantly modelled the doses to obtain the desired effect - sometimes the fibre level was too low, sometimes too high. Similarly with protein - it was difficult to determine its appropriate share says Jakub Biały. Various additives were tested to alleviate aggression, but to no avail.

The list of feed components was getting longer, but there was no improvement, only the costs were increasing. Additionally, veterinary expenses caused by wound treatment increased. They began to look for other reasons that could cause such behaviour in pigs. Castrated males (F1 cross of pure breeds of Yorkshire × Landrace or Landrace × Yorkshire) are very sensitive to factors that may cause stress - access to feed, access to water, ventilation, lighting, temperature, stocking density - all these parameters have been checked and their influence has been excluded.

To provide the animals with as much peace as possible, one person was assigned to handle them in each facility. No one else was allowed into the buildings so as not to disturb the pigs. Due to the growing problem, a decision was made to sell lighter fattening pigs so as not to generate greater losses.

However, the solution came through the digestive system

When the cause of the problems was still unresolved, the managers of the farm in Józefów used the contact provided by employees of the company transporting animals. At the beginning of March, they met with Marek Wróbel, a representative of A-ONE, and decided to implement the solution he proposed, first in one building.

The new batch received feed with the addition of Devi-Jex. In the remaining buildings, fattening was completed using the previously used feed, because giving other feed to pigs that had already "tasted" aggression would probably not change much. In the new batch, however, the preventive effect of the Devi-Jex supplement was revealed and cases of aggression occurred incidentally. Mortality decreased from 12% to 4.1% and feed consumption decreased from 3.25 to 2.96 kg.

What has been achieved?

From the start of using feed containing Devi-Jex to mid-September, two batches of fattening pigs have left the pig farms in Józefów. Jakub Biały estimates that for him, as a producer, the most important factor is mortality - which mainly determines losses or profits - he says.

In one building, reducing mortality from 12 to 4% resulted in 50 more fattening pigs. Counting further, it is 95 kg of carcass weight per head at PLN 11/kg (£2.19/kg), i.e. PLN 1,045 (£208) per pig. Applying Devi-Jex to one pig for the entire fattening period costs PLN 12-15 (£2.40-3.00). The reduction in feed consumption after its use was 0.3 kg, i.e. the feed savings per one fattened pig reached almost 28 kg. Assuming the average price of feed is PLN 1.200 (£239), it can be calculated that the value of saved feed on one fattened pig was PLN 33 (£6.57).

After using Devi-Jex, the problem of aggression was virtually eliminated.


Devi-Jex is manufactured by Devenish Nutrition in Ireland. It is a mixture of active ingredients that have a calming effect on pigs. The product prevents cannibalism as well as the formation of gastric ulcers. It includes essential amino acids, peptides, minerals and vitamins - substrates for key neurotransmitters and neuropeptides related to the regulation of animals' behaviour and response to stress. The next ingredient is table salt, traditionally used for problems related to cannibalism.

The preparation also contains minerals in a bioavailable form, which cover their potential deficiencies. Its formula uses red algae extracts, which have a buffering effect and reduce the level of stress in animals. This component is also a rich source of microelements that have a relaxing and calming effect on animals. An important feature of the preparation is the addition of carefully selected, slowly degrading fibre that facilitates the diversification of the intestinal biome and improves the digestion process.

The recommended dosage is 2 to 5 kg per tonne of feed. In Józefów, a dose of 4 and 5 kg/t was used, depending on the severity of the problem, and for simplicity, Devi-Jex is already in the premix.

Original article in Trzoda-Chlewna magazine and available in Polish from

Back to Press Releases