Changes in the oxidative - biochemical status in dairy cows during the transition period affecting reproductive and health parameters.

Negative energy balance (NEB) after calving leads tounique metabolic changes incows and itprovides important information onthe period when nutrient output prevails over nutrient intake associated with anumber ofphysiological changes inthe organism suitable for detection using biochemical blood analyses. The aim ofthis paper is to summarise current knowledge ofthe changes inblood parameters during the period ofNEB inrelation tonon-esterified fatty acids, ketone bodies, and immunologic and stress indicators. The impact ofthese changes onbovine reproduction and health isalso discussed inthe sequel. The period ofNEB isstill avery pertinent area ofresearch as it provides anew insight into connections between physiological systems, towit, ​​immunology, manifestation ofvarious stress indicators, including oxidative stress, and heat shock proteins inter alia. Understanding the physiological changes during NEB iscrucial for successful management ofthe transition period and subsequent overall good animal health and productivity.