No abstract

Summary ― On the basis of our studies which demonstrated that Tg is a natural milk-borne component of cow mammary secretions, this study investigated the influence of T 3 (and thyroxine, T 4 ) on the serum lg level (used here as an indicator of intestinal absorption). Forty healthy calves were given a single dose of either T 3 or T 4 with the first colostrum meal 6 h following birth. Blood samples were taken before and 42-50 h after hormone administration. The T 4 treatment resulted in metabolic changes that were reflected by an increase in blood glucose, triglycerides (TG), non-esterified fatty acids (NEFA), and a decrease in total serum proteins (TP). lg levels were reduced from 27.5 gll (controls) to 20.6 g/I. The