TY - JOUR N2 - This study investigated changes in the real-time measured levels of milk β-hydroxybutyrate according milk yield, lactation number and status of reproduction in dairy cows. A total of 378 cows were selected. According to their reproductive status the cows were classified as belonging to the following groups: Fresh (1 – 44 days after calving. n=43). Open (45 – 65 days after calving. n=78), Inseminated (1 – 35 days after insemination. n=133). Pregnant (35 – 60 days after insemination and pregnant (relatively pregnant) (n=124). The cows were milked with DeLaval milking robot (DeLaval Inc., Tumba, Sweden) in combination with a Herd Navigator (Lattec I/S. Hillerød. Denmark) analyser. We observed that milk β-hydroxybutyrate (BHB) had a tendency of increasing with an increase of lactation number. The average BHB in multiparous cows was 11.111% higher in comparison with primiparous cows (p<0.001). We found higher BHB concentration in the multiparous cows in all reproduction status groups (p<0.001). A strong positive statistically significant (p<0.001) relationship has been found between BHB and the average milk yield within all groups of primiparous cows although we found a statistically unreliable coefficient of correlation (from -0.202 to 0.057) between highest milk yield and BHB in primiparous and multiparous cows. L1 - http://www.czasopisma.pan.pl/Content/109581/PDF/14.pdf L2 - http://www.czasopisma.pan.pl/Content/109581 PY - 2018 IS - No 4 EP - 768 DO - 10.24425/pjvs.2018.125589 KW - cow KW - BHB KW - production KW - reproduction KW - herd navigator A1 - Antanaitis, R. A1 - Juozaitienė, V. A1 - Televičius, M. A1 - Malašauskienė, D. PB - Polish Academy of Sciences Committee of Veterinary Sciences PB - University of Warmia and Mazury in Olsztyn VL - vol. 21 DA - 2018.12.20 T1 - Changes in the real-time registration of milk β-hydroxybutyrate according to stage and lactation number, milk yield, and status of reproduction in dairy cows SP - 763 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/109581 T2 - Polish Journal of Veterinary Sciences ER -