Short communication: Cow- and herd-level prevalence of hypoglycemia in hyperketonemic postpartum dairy cows

The objective of this study was to quantify the prevalence of hypoglycemia in hyperketonemic dairy cows during the early postpartum period. A prospective observational study was conducted in 100 dairy herds selected by convenience. Within all participating herds, 40 cows (or the entire herd if smaller than 40 cows) were enrolled in the study (total of 3,776 enrolled cows). Herds were visited every 2 wk by an animal health technician. Cows were bled from their coccygeal vessels once between 1 and 14 d in milk, and cow-side testing was performed for ketonemia and glycemia using a device validated in cattle (Precision Xtra, Abbott, Mississauga, ON, Canada). Hyperketonemia was defined as β-hydroxybutyrate ≥1.4 mmol/L, and hypoglycemia was defined as glucose ≤2.2 mmol/L. Descriptive statistics were computed at the cow and herd levels. The cow-level prevalence of hyperketonemia, hypoglycemia, and simultaneous hypoglycemia and hyperketonemia was 20.0% (757/3,776), 13.8% (642/3,776), and 6.2% (235/3,776), respectively. Within the subset of hyperketonemic cows only, the prevalence of hypoglycemia was 31.0% (235/757). At the herd level, the median prevalence was 17.5% (minimum: 5.0%, first quartile: 10.0%, third quartile: 22.5%, maximum: 77.5%) for hyperketonemia, 15.0% (minimum: 5.0%, first quartile: 12.5%, third quartile: 20.0%, maximum: 47.5%) for hypoglycemia, and 7.5% (minimum: 2.5%, first quartile: 5.0%, third quartile: 12.5%, maximum: 17.5%) for simultaneous hypoglycemia and hyperketonemia. The herd-level median prevalence of hypoglycemia within the subset of hyperketonemic cows only was 30.6% (minimum: 2.5%, first quartile: 20.0%, third quartile: 39.1%, maximum: 63.0%). The results from this study show that the prevalence of simultaneous hyperketonemia and hypoglycemia is relatively low in the overall early postpartum cow population but also that approximately one-third of hyperketonemic cows are hypoglycemic, which might represent an opportunity to improve their management on the farm.