Assessment of daily activity patterns and biomarkers of pain, inflammation, and stress in lactating dairy cows diagnosed with clinical metritis.

The objectives of the present case-control study were to assess (1) daily activity patterns (lying time, number of steps, number of lying bouts, and lying bout duration), and (2) circulating concentrations of biomarkers of pain (substance P), inflammation (haptoglobin), and stress (cortisol) in lactating dairy cows diagnosed with clinical metritis. Lactating dairy cows (n = 200) from 2 commercial dairy herds were enrolled in the present study. Cows diagnosed with clinical metritis (n = 100) at 7 ± 3 d in milk were matched according to lactation and days in milk to cows without clinical metritis (NO-CM; n = 100). On study d 1, clinical metritis was diagnosed (using a Metricheck device, Simcro Tech Ltd., Hamilton, New Zealand) by the presence of watery, reddish, or brownish foul-smelling vaginal discharge, and blood samples were collected for assessment of circulating concentration of substance P, haptoglobin, cortisol, total calcium, β-hydroxybutyrate, and blood cells. In addition, on study d 1 body condition of cows was visually assessed, and activity monitors were placed on the hind leg of a subset of cows (CM, n = 56; CON, n = 56) and were kept until study d 7. Cows showing any other signs of other diseases were not included in the study. Cows with clinical metritis tended to spend more time lying (CM = 628.92 min/d; NO-CM = 591.23 min/d) compared with NO-CM cows. Activity analysis by parity revealed that primiparous cows with clinical metritis spent more time lying compared with primiparous cows without clinical metritis. However, no differences in daily lying time were observed between multiparous cows with and without clinical metritis. Furthermore, cows in the CM group had a higher circulating concentration of substance P (CM = 47.15 pg/mL; NO-CM = 37.73 pg/mL) and haptoglobin (CM = 233.00 µg/mL; NO-CM = 99.98 µg/mL) when compared with NO-CM cows. Cows with clinical metritis had lower body condition score, and a greater proportion of cows in this group had hypocalcemia when compared with cows without clinical metritis. The circulating concentration of leukocytes and erythrocytes were decreased in cows with clinical metritis compared with cows without clinical metritis. Results from this study showed that concentrations of markers of inflammation, stress, pain, and activity were affected in cows diagnosed with clinical metritis; thus, strategies aimed to minimize the negative effects associated with clinical metritis may be required to improve the welfare of dairy cows.