Nutrients such as iron, selenium and vitamins A, B12 and folic acid are either not present in plant-derived food or have poor availability, he told the British Society of Animal Science conference in York. In addition meat as a protein-rich and carbohydrate 'low' product, contributes to low glycaemic index.
"Taken altogether, meat is an important nutrient for human health and development. Meat ensures an adequate delivery of essential micronutrients and amino acids and contributes to regulation of energy metabolism," said Professor Biesalski.
Beneficial fatty acids from meat
Work at Reading University looked at the sources of EPA [eicosapentaenoic acid] and DHA [docosahexaenoic acid], considered beneficial fatty acids. Fish oils are promoted as being a rich source of these nutrients.
The study concluded that the population is not eating enough of it but says consumption could be increased if livestock were fed diets with suitable PU-FAs [polyunsaturated fatty acids] helping meat to contribute to the demand for healthier diets.
Most consumers [73%] eat no oily fish.
Changing the diet of livestock and using protected fats that did not change to harmful SFA [saturated fatty acids] by ruminating cattle and sheep was put forward by Hugh Sinclair of the Human Nutrition Group at Reading University.
He described the challenge for meat producers to reduce SFAs and other 'bad' fats including TFA [trans fatty acids] and increase the percentage of PUFAs. While meat has been considered a source of 'negative' fats, research now shows how to produce meat with a better fatty acid profile, he said. For every 1% reduction in SFA in the diet there is a 3% decrease in developing heart disease.
Meat and meat products contribute 23% of the total fat in adults' diets and 20% for children.
Better sheep fat and muscle depth
Scientists at the Roslin Institute in Edinburgh and Bristol University have been looking at Scottish Blackface lambs to see whether they can detect QTL [Quantitative Traits Loci] related to fatty acids. The research team has been successful ?nding QTLs on a number of chromosomes.
This breakthrough could be the start of genetically altering breeding flocks to raise the level of better fatty acid content of sheep meat. Another group at Roslin is checking QTLs for muscle depth in Texel, Charollais and Suffolk sheep, enabling these to be used in the selection of breeding stock for better meat yield and quality.
Most low birth weight piglets do not catch up during rearing and end up with the lowest lean meat percentage at slaughter. Moreover the muscle ?bres tend to be large leading to low quality meat. These were some of the ?ndings of scientists at the Dummerstorf research institute in Germany.
The development of muscle fibre is controlled by various genes. However, environmental factors such as better diet for the pregnant sow or growth hormones could improve the situation, particularly for runts. Pig breeders could select stock on the basis of its ability to pass on good quality lean meat as heritability of this factor is fairly high.
Stopping the feeding of pigs just before slaughter is the most practical way of reducing wet pork or PSE [Pale Soft Exudative], says Dr Mike Ellis from Illinois University, USA. This also helps reduce deaths on the lorry, keeps the gut fill down and fewer intestines are punc-tured during emptying of the gut cavity.
Other methods of reducing wet pork have negative side effects such as feeding the animal vitamin D3 which helps but reduces growth rate on the farm. The use of high fat diets in the latter stage of finishing shows some promise but more work is needed to avoid negative effects on production costs.
What happens in the slaughterhouse has more effect on meat tenderness than breed or diets, say scientists from Bristol University. They say slow chilling, electrical stimulation and hanging sides from the pelvis are techniques to make meat tender. Hanging by the pelvis as carcases enter rigor mor-tis tenderises the loin muscles and others outside the hip.
'Cold shortening' and toughness due to rapid chilling is particularly important for lambs. Slower cooling and elec-trical stimulation immediately after slaughter can tenderise meat without the need for hanging. However traditional hanging of meat at 1°C is still an important method of tenderising.
The University recommends 4-10 days for pork; 7-14 days for lamb; 10-21 days for beef. More work is needed to prove whether hanging carcases [dry ageing] is better than cuts in vacuum packs [wet ageing].