Archivos de medicina veterinaria
versión impresa ISSN 0301-732X
CONTRERAS, P. A.; CEBALLOS, A.; MATAMOROS, R. y WITTWER, F.. Iodine concentration in forages from dairy farms in the IXth and Xth Regions of Chile. Arch. med. vet. [online]. 2003, vol.35, n.1, pp. 75-79. ISSN 0301-732X. http://dx.doi.org/10.4067/S0301-732X2003000100007.
Iodine (I) content of rations is a factor associated with the blood concentration of thyroxine (T4) and triiodothyronine (T3) in cattle. In herds from southern Chile, low blood concentrations of T4 in grazing dairy cows have been reported. The objective was to obtain information about the I content in forage samples from dairy farms in the IXth and Xth Regions of Chile. During 1999 forage samples were taken from 25 dairy farms located in both Regions. The I concentration was analysed by a kinetic-colorimetric method. Mean, standard deviation and ranges and the frequency of samples with values below 0.4 ppm on a dry matter basis (normal value) were obtained. The average of I concentration in the forage samples was 0.20±0.08 ppm. Forage with normal concentrations were not found. These results suggest an I deficiency in forage from southern Chile, and may be associated with low blood concentrations of T4 in grazing dairy cows
Palabras clave : dairy cattle; minerals; forage; iodine.