Background and methodology
Limited data are available on the nutritive value of the ‘natural’, ‘bio’, or ‘organic’ foods as compared to the traditionally produced ones. The natural keeping of pigs without growth-stimulating hormones and antibiotics made it necessary to breed a new pig genotype more resistant than those so far available. The chemical composition in some major cuts of the new pig genotype when kept in natural circumstances was compared with that of those pigs held traditionally under large-scale farming circumstances. Feed and supplements were free of antibiotics, sulfonamides and yield-increasing hormones. Green-forage, beetroots and turnips originated from an environment free from chemicals.
In most cases, protein, zinc and copper levels and in some cases, iron levels were significantly higher in some major cuts (neck-end, loin, ham) of the ‘free-range’ pigs. There was on average, 15% less cholesterol in the muscles and 30% less cholesterol in the liver and less linoleic acid in all tissues of ‘free-range’ pigs. There was less fat, but the amount of thiamin and riboflavin in the liver of the naturally kept pigs was twice that in the controls. In respect of TBA-reactive compounds, there were no significant differences between the two groups, but superoxide dismutase (SOD) showed significantly higher activities in all cuts from pigs kept in a large scale farming system.
Dworschák, E., Barna, É., Gergely, P., Czuczy, P., Hóvári, J., Kontraszti, M., Gaál, Ö., Radnóti, L. & Biró, G. (1995). Meat Science 39:79-86.