Occurrence of Congenital Goiters in Calves in Fattening Farms

Abstract

From December 1992 to August 1993, 12 stillborn calves and 24 other calves were shown to have enlarged thyroids in two feedlot farms of the first-calving heifers. The thyroids of 3 still-born calves weighed. 250g, 360g and 420g, respectively. Histopathology revealed that the follicular epithelium was of tall columnar cells showing papillary growth and that the follicular lumen was filled with degenerated, and exforiated epithelium without colloid. The thylonine-T₃ level was higher in cows and lower in calves of the affected farms while serum lipids and thyloxine-T₄ were within the normal range. Average iodine content was significantly lower in the thiroid of still-born calves (5.9 ppm/DM) as well as several feeds examined (0.3ppm/DM) of its farms. The present cases of calf goiter might be due to iodine shortage.