Cutting stress levels is route to tastier pork

Do you ever think about what happens to your pigs after they’ve been sent to the slaughterhouse?

Producers may believe their job is done the moment animals leave the farm, but weeks of hard work could be compromised in the run-up to slaughter.

To secure the future of the pig industry, pork quality needs to consistently meet customer expectations so they keep coming back, says JSR meat scientist Caroline Mitchell.

And this means that all farmers – even those that are paid as soon as an animal enters the abattoir – should be thinking about the final eating product.

“Producers may be focusing on using top genetics, but when animals are handled poorly, the end product can be ruined,” she says.

Chronic stress at farm level can result in dark, firm and dry meat (DFD), with short-term stress just prior to slaughter resulting in pale, soft or exudative meat (PSE), where meat is wet and spongy.

A number of controllable factors can influence eating quality:

Growth rates

• Faster growth rates produce better eating quality

• Pigs that experience interrupted growth rates have the worst meat quality

Feed composition

• High energy, low protein diets increase intramuscular fat and add flavour

• Over feeding protein can lead to less tasty meat

• Adding vitamin E to the diet can increase meat shelf life

• Selenium supplementation can improve meat colour and water-holding capacity which means less yield loss for the processor

Group mixing

• Group mixing should be avoided as it activates the stress process

• Mixing within a week of slaughter is undesirable

• The number of group swaps from the lorry to lairage should also be limited

Lairage

• Avoid extended lairage time

• 2-3 hours is ideal to give animals enough time to recover from the journey

• More than nine hours will illicit stress as stock will become hungry and fight

• Pigs should be transported on an empty stomach – full stomachs are not only undesirable at the abattoir, but also cause stress through travel sickness. Withdraw feed up to 8-12 hours before transport

• Loading ramps should be less than 20°.

Meat testing post-slaughter can help producers identify if stress is an issue and where the problem may be originating from.

“When selling under your own umbrellas or as part of a co-op as a branded product, pH monitoring can highlight management areas which have been overlooked,” says Ms Mitchell.

The pH and temperature analysis is carried out 45 minutes post-mortem and again 24 hours after slaughter.

“When pH is more than six 24 hours after slaughter, it suggests an animal has been stressed for a long time, creating a DFD meat.”

Such information can be used to address management issues on farm. Equally, when PSE is identified, it may make farmers look more closely at the slaughter process.

• JSR Genetics has set up a taste panel to help develop and improve the eating quality of their products.The panel will be made up of about 12-16 members of the public which will have undergone a strict selection process.

They will be tested on their ability to assess colour, recognise flavours and intensity, assess scents and textures and describe what they perceive.

The chosen panel will taste sets of products produced by the company’s farms as well as some of their good customer’s products, says Ms Mitchell.

“This will highlight where we have a good product and enable us to present our findings to the retailer. We can also demonstrate how a product scores in comparison to other product lines.”

Applications for the taste panel have been received through the company’s cookery school. Some of the applicants will be good enough to enter the trained taste panel, where as others will join the consumer panel.

“We want to create a test bed for meat quality and use what we learn to improve quality. The taste panel is a toolbox we can use to tweak products where necessary,” explains Ms Mitchell.

For example, if the panel identified a specific product did not have enough flavour, pig rations may be altered to modify meat fat content. Feedback will also allow focused improvements to the company’s breeding programme.