https://phaidra.vetmeduni.ac.at/o:5401 Evaluation of Hyperketonemia in the Transition Period of Dairy Simmental Cows and Association with Liver Activity, Uterine and Oviductal Health, and Reproductive Performance Pothmann, Harald Harald Pothmann 0000-0002-2361-721X University of Veterinary Medicine Vienna. Clinical Centre for Ruminants, Camelids and Herd Health Management Mitterer, Michael Michael Mitterer Flicker, Florian Florian Flicker Sahebi, Maryam Maryam Sahebi Havlicek, Vitezslav Vitezslav Havlicek 0009-0008-8271-0001 University of Veterinary Medicine Vienna. Centre of Biological Sciences Besenfelder, Urban Urban Besenfelder University of Veterinary Medicine Vienna. Centre of Biological Sciences Tichy, Alexander Alexander Tichy 0000-0001-8668-3858 University of Veterinary Medicine Vienna. Shared Facility Bioinformatics and Biostatistics Drillich, Marc Marc Drillich 0000-0002-2824-8185 University of Veterinary Medicine Vienna. Clinical Centre for Ruminants, Camelids and Herd Health Management MDPI journal article open access eng Hyperketonemia (HYK), defined by blood beta-hydroxybutyrate (BHB) ≥ 1.2 mmol/L, is described as a significant risk factor for cows developing postpartum (pp) diseases and impaired reproductive performance. The goal of the present study was to observe metabolic challenges in transition cows and to identify systemic markers reflecting HYK associated with lessened reproductivity. Fifty-four Simmental cows were monitored, revealing approximately 30% prevalence of HYK at the early pp period on 7, 14, or 28 days in milk (DIM). We assessed the dry matter intake, rumination time (RT), serum liver activity index, non-esterified fatty acids (NEFAs), acute phase proteins, and uterine and oviductal health. Elevated NEFA and reduced RT 14 days antepartum were a good predictor for HYK at 7 DIM. Hyperketonemia at 14 DIM resulted in higher milk yield compared with controls. We could neither detect differences in uterine health nor in reproductive key performance parameters between hyperketonemic and control cows, whereby the proportion of polymorphonuclear neutrophils in oviductal epithelia was significantly lower in hyperketonemic cows 14 DIM. We conclude that elevated concentrations of BHB in HYK 7, 14, or 28 DIM indicated energy supply to support physiological metabolic adaptations and lactation and that, in the absence of excessive inflammation during the transition period, HYK was not a risk factor for impaired fertility. Transition Period Beta-hydroxybutyrate Non-esterified Fatty Acids Acute Phase Proteins Subclinical Ketosis Immune Activation http://creativecommons.org/licenses/by/4.0/ https://phaidra.vetmeduni.ac.at/api/object/o:5401/download 10.3390/dairy7010002 https://phaidra.vetmeduni.ac.at/o:605 application/pdf Dairy issn:2624-862X VoR Dairy 7 1 435.40 kB 2025