TY - JOUR A2 - Tonacchera, Massimo AU - Šamanc, Horea AU - Stojić, Velibor AU - Kirovski, Danijela AU - Jovanović, Milijan AU - Cernescu, Horia AU - Vujanac, Ivan PY - 2010 DA - 2010/02/10 TI - Thyroid Hormones Concentrations during the Mid-Dry Period: An Early Indicator of Fatty Liver in Holstein-Friesian Dairy Cows SP - 897602 VL - 2010 AB - Relationship between postpartal fatty liver and thyroid gland activity during the peripartal and mid dry periods was studied. Twenty one dry cows were chosen. Blood samples were obtained on days −30, −2, and +12 related to calving and analized for thyroxine (T4) and triiodothyronine (T3). A T3/T4 ratio was calculated. Liver tissue samples were taken 12 d after calving and tested for the lipid content. Cows were divided into three groups: mild (<20% fat), moderate (20 to 30%), or severe fatty liver (>30%). Cows, that were affected with severe fatty liver, were hypothyroid prior to development of the condition due to lower T4 concentrations, and had significantly lower concentration of T3 and higher T3/T4 ratios than cows with mild and moderate fatty liver. Thus, hypothyroid state during mid-dry period may be an early indicator of postpartal fatty liver and may provoke T3/T4 ratio increase in this group of cows. SN - 2090-8067 UR - https://doi.org/10.4061/2010/897602 DO - 10.4061/2010/897602 JF - Journal of Thyroid Research PB - SAGE-Hindawi Access to Research KW - ER -