Thyroid hormone profiles and TSH evaluation during early pregnancy and the transition period in dairy cows.

The thyroid hormone axis is one important endocrine system within a complex system of various factors and hormones necessary to establish and maintain pregnancy in cattle and in metabolic adaptations towards lactation. Pregnancy and lactation occur contemporaneously in dairy cows, and have major impacts on thyroid hormones as well as status of the hypothalamus-pituitary thyroid axis influences pregnancy and lactation. As especially the thyroid hormone axis with special focus to TSH is not well studies in the past, the aim of the study was to examine the thyroid hormone axis, especially in heifers during adaptation to the first lactation, to verify the association between lactation and thyroid hormones.

Increased Concentrations of Insulin-Like Growth Factor Binding Protein (IGFBP)-2, IGFBP-3, and IGFBP-4 Are Associated With Fetal Mortality in Pregnant Cows.

Insulin-like growth factors (IGFs) play a critical role in fetal growth, and components of the IGF system have been associated with fetal growth restriction in women. In human pregnancy, the proteolytic cleavage of insulin-like growth factor binding proteins (IGFBPs), particularly IGFBP-4, releases free IGF for respective action at the tissue level. The aim of the present study was to determine IGFBP-2, IGFBP-3, and IGFBP-4 concentrations by Western ligand blotting during pregnancy until day 100 in cows and to compare these concentrations with those of non-pregnant cows and cows undergoing embryonic/fetal mortality.