News article, 28. September 2023

Entire male pigs in Danish pig production

The past half year, it has been possible to increase production of entire male pigs as more slaughterhouses enable producers to take out entire male contracts.

Photo: Danish Agriculture & Food Council

Slaughterhouses have increased their intake of entire male pigs on contract. This is to be welcomed as there are a number of benefits to avoiding castration and producing entire male pigs. Farms that take out an entire male pig contract with a slaughterhouse can supply entire male pigs, which means that a sow unit or piglet supplier can stop castrating piglets. All in all, this means a higher welfare standard and improved production.

"Entire male production is a good option compared to castrate production. Welfare is improved for the non-castrated piglets and finisher productivity is enhanced. Also, it is beneficial for the climate because entire males need less feed. So, if you have a reasonably low rejection rate caused by boar taint, the bottom line is healthier,” says Hanne Maribo, Chief Scientist, SEGES Innovation.

Risk when slaughtering entire males
There are, however, risk factors associated with entire male pig production. Boar taint may mean that entire males are rejected with the result that the carcass has less value. Boar taint is primarily caused by two substances: skatole and androstenone. Skatol is produced in the pig’s intestine from the amino acid, tryptophan. Skatol and androstenone are metabolised and can partly be broken down via the liver.

“Androstenone is produced in the pig’s testicles and is actually a scent hormone. This is the substance you can smell if you walk past a boar pen. Androstenone is primarily linked to sex hormones and therefore depends on whether the pig is sexually mature and its age and weight,” says Hanne Maribo.

Reducing boar taint
With immunocastration and the vaccine, Improvac, antibodies are formed against the pig’s sex hormones. Pigs must be vaccinated twice, first at approx. 30 kg and a second time at 4-6 weeks prior to slaughter. In general, pigs that are fully vaccinated have significantly less boar taint and fight less during their growth period. Figures from 2019 show that Improvac is mainly used by three countries – Brazil, Australia and Belgium.

DanBred is examining the possibilities of sorting Duroc boars according to boar taint. By selecting boars with a lower odour, tests have shown that boar taint in entire males can be reduced. In general, however, this will require a change of attitude in export markets for the production of entire males to continue its positive trend.