Source: Dr Francois Siebrits, SAPPO Weekly Update 14 May 2021, photo credit: South African Reserve Bank
The South African consumer can rest assured that everything possible is done by the industry to limit the incidence of boar taint and that our pork compares favourably with the best in the world, says Dr Francois Siebrits of SAPPO’s Research Committee. He explains why and discusses recent research in this regard.
Boar taint is mainly caused by a compound called androstenone, formed in the testes of some entire male pigs after puberty and which may end up in the fat of some individuals.
There are also two other compounds namely skatole and, to a lesser degree, indole which are formed by microbial action in the hind gut, which may also end up in the fat.
When fat with androstenone is heated, an unpleasant urine like odour is released, which can be smelled by 90% women and 50% men. Skatole and indole result in an offensive faecal like odour, which is volatile and fortunately lost during cooking.
Skatoles and indoles are excreted in the faeces and pigs lying in dirty pens with inadequate flooring and cleaning absorb these volatile compounds through their skins from where it is deposited in the subcutaneous fat tissues.
They can therefore be limited by good management practices such as modified nutrition and clean pens. “Boar taint” may in some cases also occur in females and castrates. Most of South Africa’s pig producers comply with Pork 360 standards, which, among others, require clean pens.
In the past, this problem was prevented by castration, but this practise was stopped internationally for animal welfare reasons. Also, castrated animals grow slower, need more feed, and become fatter than entire males.
All these factors encourage the producer to rather produce entire males. New technology where boars are immunised against androstenone production has been developed and is starting to be used. This requires two immunisations.
The incidence of boar taint is related to weight of the animal. Heavier (older) animals have reached puberty and therefore sex hormone production has started. There is also a genetic effect. Some breeds are more prone to produce boar taint.
Some of the international breeding companies have embarked on an active selection strategy against boar taint. Internationally figures of “about 4%” were mentioned but there are genetic differences.
There is also individual variation between animals in the concentration of odorous compounds. Certain breeding companies found incidences of only 2.3% in certain lines. This means that there is scope for further selection.
One of these lines was used in a recent study in South Africa where 175 heavy carcasses (106-118 kg warm carcass weight) slaughtered at 26 weeks age were tested for boar taint. Only one was slightly odorous.
The South African classification system stipulates that no carcass over 100 kg may be used in the fresh meat market. Such carcasses are classified as sausage pigs and sell at lower prices.
The South African consumer can rest assured that everything possible is done by the industry to limit the incidence of boar taint and that our pork compares favourably with the best in the world.