Neonatal levels of plasma thyroxine in male and female calves fed a colostrum or immunoglobulin diet or fasted for the first 28 hours of life.
The effect of diet on changes in plasma thyroxine levels was studied in 83 newborn Friesian X Holstein calves. Fifty-four received four copious meals of first-milking colostrum at 4, 10, 16 and 22 neonatal hours. At the same time, 24 animals received four meals of a solution of colostrum immunoglobulins containing little energy, and 5 calves were kept fasted. The last two treatments resulted in lower plasma thyroxine levels than those in colostrum-fed calves. At the same time, plasma thyroxine level was higher in females than in males during the first neonatal week.
D000818:Animals; D000831:Animals, Newborn; D002417:Cattle; D003126:Colostrum / Q000276:immunology; D004032:Diet; D005215:Fasting; D007136:Immunoglobulins / Q000008:administration & dosage*; D013974:Thyroxine / Q000097:blood*; D013997:Time Factors
D007136:Immunoglobulins; D013974:Thyroxine