Supplementation of algae to the diet of pigs: a new possibility to improve the iodine content in the meat

Meat products with a higher iodine content can be produced through feeding animals with a diet supplemented with inorganic iodine salts or with algae containing high iodine. This may help to improve daily iodine intake and to control iodine deficiency disorders (IDD) in man. In the present study a total of 40 crossbred pigs (Deutsche Landrasse × Piétrain) with an average body weight of 17 kg were allotted to either a control group, to two groups receiving potassium iodide (KI) at different concentrations (5 or 8 mg iodine per kg of feed) or to two groups receiving the algae Laminaria digitata containing the same amount of iodine. After pigs were fed with iodine-supplemented diets for 3 months, it was found that compared to the control group the iodine content increased by up to 45% in fresh muscle, by 213% in adipose tissue, by 124% in the heart, by 207% in the liver and by 127% in the kidneys. There was a significant (p < 0.01) higher concentration of serum thyroxine (T₄) and a lower concentration of serum triiodothyronine (T₃) in those iodine-supplemented groups. The iodine content of urine from all iodine-supplemented groups was also greatly increased. Furthermore, it was shown that the supplementation of algae into feed could increase daily body weight gain by 10% (p > 0.05). It is suggested that the carry-over of iodine through feeding pigs with an algae-supplemented feed could be beneficial to both the control of IDD and the improvement of pig production.