Ultrasonographic image of fatty infiltration of the liver correlates with selected biochemical parameters and back fat thickness of periparturient Holstein-Friesian cows.

During the transition period, the cow's body activates adaptive mechanisms aimed at adjusting to the changing demand for energy and nutrients, which are necessary for the growing fetus and the subsequent start of milk production. This time is also associated with an increased risk of metabolic diseases and reproductive disorders. Our study aimed to identify prepartum and postpartum biochemical markers and weight loss patterns that could differentiate cows that would exhibit ultrasonographic signs of liver fatty infiltration during the latter half of the transition period. The study was performed in a single herd of Holstein-Friesian cows and the animals were divided into two groups: CON (n=13) - cows without ultrasonographic signs of fatty liver, and FL (n=16) - cows with ultrasonographic signs of fatty liver. Backfat thickness and specific biochemical parameters were measured weekly from one week before parturition to 9 weeks postpartum. Our study highlights the importance of using a combination of monitoring methods to assess the metabolic status of transition dairy cattle. The results showed that ultrasound measurements of backfat thickness, blood NEFA levels, glucose concentration, and AST activity were all different (p<0.05) between the control and FL groups, indicating the usefulness of these parameters in monitoring the health status of transition cows. Additionally, the results suggest that high prepartum glucose levels (4.99 mmol/l) could serve as a potential marker for future FL, while the elevated NEFA levels (0.51 mmol/l) and decreased AST activity (80.56 u/l) in FL animals indicate their potential as indicators of lipid mobilization and liver structural damage, respectively.