In recent years, the use of antibiotics in Danish livestock production has been a controversial issue – and with good reason. A high antibiotic consumption on Danish farms may result in problems with resistance, which can reduce the possibilities of effectively treating infections in both animals and humans. 

The Danish Parliament therefore adopted the Veterinary Settlement III that has a strong focus on reducing antibiotic consumption in Danish pig production.

As part of the settlement, targeted research efforts have been initiated in collaboration between Aarhus University, University of Copenhagen and Statens Serum Institut (SSI) in order to procure knowledge and tools to reduce antibiotic consumption with due consideration to animal welfare and economic sustainability. Part of Aarhus University’s contribution takes place within the framework of the university’s agreement with the Ministry of Environment and Food of Denmark on the provision of research-based policy advice.

Focus on weaner pigs 

At the Department of Animal Science, Aarhus University, three projects have been initiated that focus on reducing antibiotic consumption in weaner pigs. Weaners are pigs from weaning at the age of 3-5 weeks (conventional production systems) or older (organic production systems) until they weigh 30 kg at the age of approximately 12 weeks. During this period, a conventional Danish weaner pig receives antibiotic treatments five times on average, primarily because of diarrhoea. 

In one of the projects, the researchers aim to improve the pigs’ resilience and disease resistance in the suckling period. Professor Charlotte Lauridsen, Department of Animal Science, and head of the project, explains:

- We do not know yet why some pigs manage better than others during the weaning period. Therefore, we will examine whether pig size is important to their ability to access the udder, and if the time of birth is important in relation to their competition for access to the colostrum. 

Just like breastmilk, the sow’s colostrum is rich in various substances that are important to healthy development of the gastrointestinal tract and a strong immune system. If there are many piglets in a litter, it is necessary to supplement the sow’s milk with milk and feed in the suckling period. 

-  There is a significant difference in the pigs’ inclination to eat anything else than sow milk, and we will study this behaviour in more detail to clarify how old the pigs should be in order to reduce the risk of developing diarrhoea at weaning. We will also examine the connection between this and the robustness of the intestine and immunity. This will be examined in relation to two different ages at weaning, says Charlotte Lauridsen.

Feeding strategies to improve intestinal health in piglets

Within the framework of another project, the researchers will develop feeding strategies expected to stimulate feed intake in piglets as early as the suckling period. Increased feed intake during the suckling period may entail increased feed intake after weaning. This is very important in order to maintain intestinal health and productivity, and it further helps reduce the risk of diarrhoea.

In a series of infection experiments, weaner pigs will be fed fermented wet feed, which is a softer transition from milk than dry feed. Senior Researcher Nuria Canibe explains:

- When fermenting wet feed, you achieve a very strong growth of lactic acid bacteria, a high concentration of lactic acid and a low pH value, which will kill pathogenic bacteria such as E. coli and salmonella in the feed as well as in the intestine.  Fermented wet feed thus protects the piglet against these bacteria. 

Subsequently, the researchers will study the effect of this strategy on intestinal health, immune system, productivity, and specifically the effect in relation to weaning diarrhoea.

Increased weight at weaning and reduced antibiotic consumption

A third project focuses on increasing pig weight; partially by weaning at an older age, and partly by keeping the piglets in stable litters together with the sow during the suckling period. Several studies and practical experience indicate that bigger and more robust pigs at weaning may reduce the occurrence of infections requiring treatment and thus the need for antibiotics. This project is being carried out in four large Danish sow herds under production conditions. 

- Today, the sow will typically have larger litters than she can take care of, and therefore many piglets are moved to another sow who will take care of them until weaning. We want to study the effect of keeping the litter together from birth to weaning, meaning that the sow will only have her own piglets to take care of, says Professor Jan Tind Sørensen. He further explains that the researchers will study the piglets at two different ages at weaning.

- Subsequently, we will follow the piglets as weaners in the weaning barn and examine the prevalence of diseases and antibiotic treatments. 

The three projects described will run until 2021. Results are expected to be available together with those from the other collaboration projects in 2021.

Further information

The research activities, that include new projects at Aarhus University, are a collaboration between Aarhus University, the University of Copenhagen and Statens Serum Institut.

Read more about the Veterinary Settlement III here (in Danish)

For further information please contact

Professor Jan Tind Sørensen

Department of Animal Science, Aarhus University

E-mail: jantind.sorensen@anis.au.dk
Tel.: 8715 7923
Mobile: 2078 3343

Professor Charlotte Lauridsen

Department of Animal Science, Aarhus University
E-mail: charlotte.lauridsen@anis.au.dk
Tel.: 8715 8019

Senior Researcher Nuria Canibe

Department of Animal Science, Aarhus University
E-mail: nuria.canibe@anis.au.dk
Tel.: 8715 8058