Fat depots, daily activity and their correlation in dairy Holstein cows with different condition during the transition period

Background
Energy balance (EB) and fat metabolism during transition period and their connection to production, reproduction and health of dairy cows have been studied extensively in last decades (Roche et al., 2009, Roche et al., 2013, Gartner et al., 2019, Siachos et al., 2022). Most findings suggest that cows with higher body condition compared to cows with normal condition have higher odds to develop different metabolic diseases (i.e. milk fever, ketosis), metritis and lameness. Therefore, controlling the body condition several times during lactation would be of benefit to prevent these problems (Panne and Mansfeld, 2022).
Several methods can be used to determine the condition of dairy animals, such as body condition scoring (BCS) (Roche et al., 2004), ultrasonographic measurement of different fat depots (Staufenbiel et al., 2004, Raschka et al., 2016), as well as 3D-Sensor Systems (Panne and Mansfeld, 2022). However, these methods are labor-intensive, time-consuming and/or technical, requiring skilled personnel (Džermeikaitė et al., 2023).
Accelerometers are used extensively on dairy farms to record behavior of the animals (Richeson et al., 2018). Extensive research has been done using these sensors for detection of mastitis, estrus, and locomotion problems (Rutten et al., 2013). However, only few studies examined the behavior of cows with different body condition (Matthews et al., 2012, Lovarelli et al., 2020).
Aim
Our aim was to examine the fat depots, daily activity and their correlation in dairy Holstein cows with different condition during the transition period.
Materials and methods
Fifty-three pluriparous cows at the Friedrich-Loeffler-Institute (FLI), Braunschweig, Germany were used to determine the estimated depot mass (DM) of subcutaneous (SCAT) and abdominal (AAT) adipose depots by ultrasonography (US) on day (d)-42, 3, 42 and 100 relative to parturition. Cows were allocated into the LBC (n = 27) or HBC (n = 26) group according to the DM of SCAT on d-42. Average daily change (DC) of adipose mass was calculated for the dry period (DP; d-42 to d3), fresh cow period (FCP; d3 to d42) and early lactation period (ELP; d42 to d100). IceTag pedometers were used to record daily activity (lying time, number of lying bouts, lying time per bout and steps per day) of the animals around the time of US examinations.
Results
The HBC cows had greater depot masses, as well as greater changes in depot mass during the study period (p<0.02). No significant differences could be found in the daily activity of the groups (p>0,05). However, the HBC cows showed trend for higher number of steps per day (P=0.084). Some significant correlations between fat depots and daily activity were found, but these were not consistent.
Conclusions
Our results indicate that higher conditioned cows have a more pronounced change in adipose tissue metabolism and tend to be more active. However, no consistent correlations between these parameters could be found.