The season of feasting and merrymaking is upon us, so what better time to explore some of the reasons determining the tastiness of pork and bacon. Taste is subjective and the acceptability of pork products and their taste goes into cultural beliefs. But there are some key factors that influence meat quality and its nutritional benefits. Breeding is one, but pig nutrition also plays a major role.
Canadian work published in the Journal of Animal Science this summer showed that carcase characteristics were highly genetically heritable. It also pointed out that meat colour, shear force, drip loss and marbling fat can also be selected for when breeding.
What we feed the animal can also have a profound impact on the acceptability of the meat, and we’re constantly under pressure from processors to meet the backfat requirements for their markets. However, studies from the mid-1990s showed that feeding protein-deficient diets in the month before slaughter improves intra-muscular fat (marbling fat) – something known to improve meat quality, but at the cost of increased backfat.
Spanish research presented earlier this year by Dr Enric Estevez suggested that using the fat conjugated linoleic acid or the amino acid leucine also improves intramuscular fat. The results were variable, however, and he stated that Pietrain genetics actually blocked the effect of this intervention. Therefore, this approach could rule out a large proportion of UK herds.
Fats and oils used in rations also have a profound impact on the quality of the meat. Using high levels of polyunsaturated fats, such as soya oil and rape oil, leads to “soft fats” in the meat, making processing more difficult. As an energy source, these oils would be favoured in diets from a least-cost basis when cereal prices are high. Solid fats such as palm fat, as well as endogenously produced fats from starch conversion, give a white, easy-cutting carcase fat that has improved appearance characteristics.
Magnesium is an interesting element in pig rations. It’s being used to reduce behavioural vices by reducing plasma cortisol, norepinephrine, epinephrine and dopamine concentrations in the body. But there are also many studies that show its positive impact on improving meat quality. Magnesium appears to reduce drip loss and improve colour characteristics – basically reduce PSE (pale, soft and exudative) meat, improving colour and juiciness characteristics.
Drip loss can also be reduced with elevated levels of antioxidants used in the feed such as vitamin E, flavenoids and selenium. These can be particularly important to the retailer as they increase longevity of storage in the final cuts.
That’s just a few of the dietary interventions we can impose to improve the eating quality of pigmeat, but this branch of science is still active and continuing to make progress.
The product will get better, but to my mind there’s no substitute for purchasing good-quality British pork and cooking it correctly.
Born in Essex, schooled in Suffolk and a graduate of Reading University, Dr Phil Baynes has spent his career in pig welfare and nutrition. Now based in Cheshire, he runs Baynes Nutrition and is a consultant nutritionist to Provimi