title: Effect of a combined iodine and selenium supplementation on I and Se status of cows and their calves.
abstract: Iodine (I) and selenium (Se) deficiencies are commonly reported in cattle, however, there are also studies regarding a very high iodine supply. The aim of the study was to determine the long-term effect of I and Se supplementation on non-pregnant cows, pregnant cows and their calves. The hypothalamus pituitary axis was investigated (TSH, T4, T3 assays) during a TRH challenge on non-pregnant cows. Twenty-four cows, half of them pregnant, were assigned into 2 diet-groups, one group with a low I (0.45 ppm) and Se (0.15 ppm) diet (LISe), the other with a high I (5.45 ppm) and Se (0.45 ppm) diet (HISe), for a period of 120 days. Nutritional (plasma iodide, urinary I, plasma Se, I content in colostrum and foetal fluids) and functional (thyrotropin, thyroid hormones, glutathione-peroxidase activity in erythrocytes) markers of I and Se status were assayed in dams at regular intervals for 120 days and in their calves at birth. A TRH challenge was performed on 8 non-pregnant cows at day 110 of the trial. At the end of the study, I and Se nutritional markers were higher in dams in the HISe group, compared to the LISe group, except for plasma Se. At birth, I nutritional markers in calves in the HISe group were higher compared to the LISe group. Reactivity of the pituitary-thyroid-axis was not influenced by I and Se supplementation. I and Se supplementation is efficient in improving newborn status.
authors.affiliation: University of Liege, Faculty of Veterinary Medicine, Clinic for Ruminants, Liege, Belgium. hugues.guyot@ulg.ac.be
authors.forename: Hugues
authors.initials: H
authors.lastname: Guyot
authors.forename: Laurent Alves
authors.initials: LA
authors.lastname: de Oliveira
authors.forename: Eve
authors.initials: E
authors.lastname: Ramery
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Beckers
authors.forename: Frederic
authors.initials: F
authors.lastname: Rollin
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002417:Cattle; D019587:Dietary Supplements; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007455:Iodine / Q000097:blood*; D009752:Nutritional Status; D011247:Pregnancy; D012643:Selenium / Q000008:administration & dosage* / Q000097:blood*; D013961:Thyroid Gland / Q000378:metabolism; D013963:Thyroid Hormones / Q000097:blood
chemical_list: D015415:Biomarkers; D013963:Thyroid Hormones; D007455:Iodine; D012643:Selenium