Identification and removal of barriers preventing the use of entire males for Canadian pork production

Why is this project important?

Castration of male pigs is a growing animal welfare concern that also negatively affects the environment and returns to producers due to the associated reduction in animal feed efficiency. However, this is currently the most effective strategy for preventing boar taint in all animals. Boar taint is an objectionable odour or flavour that is often present in heated pork products from entire male pigs, due to the accumulation of two compounds, known as androstenone and skatole, in the fat.

Over the past five years, advancements in boar taint research have made it possible to raise entire (uncastrated) males with undetectable levels of taint. However, Canadian swine producers still rely on surgical castration to prevent boar taint, as many existing solutions have not yet been validated in commercial herds. There are also concerns that raising entire males will lead to increased aggressive behaviour and mounting, and will negatively impact meat quality due to the inability to detect tainted animals at slaughter. Therefore, the main objective of this project is to develop solutions to the barriers that prevent the use of entire male pigs for swine production.

What will researchers do?

• Validate their panel of genetic markers in commercial herds to allow for the control of boar taint with genetic selection. Researchers have established a panel of over 1000 genetic markers (single nucleotide polymorphisms or SNPs) for boar taint that has been used to identify boars with low levels of boar taint, and these SNPs are included on a commercial 60K genotyping panel available to Canadian breeders.

• Develop behavioural and nutritional management strategies in animals selected for low levels of boar taint on commercial farms. Scientists are currently generating behavioural and nutritional management strategies for boar taint that could be used to raise entire males for pork production with existing genetics. These strategies will allow for the use of entire males while selection for low boar taint is being implemented in breeding programs.

  
  
  
  

• Develop a simple, accurate, and inexpensive rapid test for the detection of boar taint at slaughter plants. This rapid, on-site test would be used as a quality assurance tool in slaughter plants to ensure that tainted carcasses do not enter the food chain.

What will be the benefit of this research?

By removing barriers to using entire males for pork production, this project will enhance animal care and the use of emerging technologies. The validation of the marker set in commercial swine herds will allow for the genetic selection of animals with undetectable levels of boar taint.

This innovative approach will ultimately allow producers to raise entire males without the need for surgical castration, which will significantly improve animal welfare and health. This will also lead to greater efficiencies in the pork value chain, as entire males have better feed efficiency and reach market weight faster than surgical castrates, which will have significant economic benefits. This also decreases the effect of pork production on the environment and climate change.

As well, the testing of different behavioural and nutritional management strategies for boar taint will further address animal care and health by establishing management protocols to reduce the negative behaviours associated with raising entire males. This project allows researchers to relate the treatment outcome of simple nutrition strategies to the genotype of the animal, which will provide an opportunity to treat groups of animals based on their genetic potential to respond favorably.

What has been done so far?

Scientists have started to collect data on boar taint phenotypes (the set of observable characteristics of an animal or person) on three breeds and crossbred pigs and we have started genotyping animals. Genotyping is the

process of determining differences in the genetic make-up (genotype) of an individual by examining their DNA sequence and comparing it with another individual's sequence.

Researchers have also begun analyzing data from 3-way cross boars to validate markers. They conducted direct behaviour experiments according to the protocols, and data analysis from these trials is complete. As well, they prepared special feed for the first feeding trial, which is now complete.

Project status: Currently in progress. Results expected in 2028.

Collaborators:

Renee Bergeron, University of Guelph

Lee-Anne Huber, University of Guelph

Flavio Schenkel, University of Guelph

Maria DeRosa, ,Carleton University

Christine Bone, University of Guelph

Mohsen Jafarikia,  Canadian Centre for Swine Improvement