Detection of subclinical milk fever and ketosis in fresh dairy cows using rumination time, lying time, reticulorumen temperature, and neck activity

Abstract Text: The objective of this study, conducted at the University of Kentucky Coldstream Dairy, was to evaluate changes in rumination time (RU), lying time (LT), reticulorumen temperature (RT), and neck activity (NA) around subclinical hypocalcemia (SHC) and ketosis (SKET) events.  Fresh cows (90 Holstein, 19 crossbred, and 11 Jersey cows) were assigned HR Tags (SCR Engineers Ltd., Netanya, Israel), IceQubes (IceRobotics, Edinburgh, Scotland), and DVM boluses (DVM Systems, LLC., Boulder, CO) ≥ 14 days pre-partum.  The Milpro P4C (Milkline, Gariga di Podenzano, Italy) system measured milk yield (MY). Blood calcium was measured on 3, 7, and 14 DIM to determine SHC (≤ 1.8 mmol/L). Milk KetoTest (Elanco, Greenfield, IN) and blood Precision Xtra (Abbott Laboratories, Abbott Park, IL) beta-hydroxybuterate tests were analyzed on 3, 7, and 14 DIM to determine SKET (both tests ≥ 1.2 mmol/L). Mean RU, LT, RT, NA, and MY were recorded and summarized for each cow day for the first 7 DIM. The GLM Procedure of SAS (Cary, NC) was used to evaluate the relationship between SKET or SHC presence and RU, LT, RT, NA, and MY. LSMeans NA was less in cows with SHC than cows without SHC (210.30 ± 6.40 and 253.81 ± 3.93, respectively, P < 0.01). LSMeans RT was less for cows with SHC than cows without SHC (38.58 ± 0.05 and 39.01 ± 0.03 °C, respectively, P < 0.01). No difference was observed for RU (316.99 ± 8.35 and 299.90 ± 5.12 min/d for SHC and non- SHC cows respectively, P = 0.08), MY (48.57 ± 1.64 and 50.83 ± 1.14 kg/d for SHC and non- SHC cows respectively, P = 0.26), or LT (10.66 and 9.97 h/d for SHC and non-SHC cows, respectively, P = 0.03). LSMeans LT was greater for cows with SKET than cows without SKET (10.26 and 9.58 h/d, respectively, P = 0.04). LSMeans NA was greater for cows without SKET compared with cows with SKET (258.86 and 236.73, respectively, P < 0.01). No difference was observed for RT  (38.91 ± 0.04 and 38.93 ± 0.04 °C, for SKET and non-SKET cows respectively, P = 0.72), RU (307.11 ± 4.88 and 295.84 ± 8.14 min/d, for SKET and non-SKET cows respectively, P = 0.24), or MY (51.64 ± 1.09 and 49.03 ± 1.65 kg/d for SKET and non-SKET cows respectively, P= 0.19). These parameters may be useful for identifying fresh cow diseases.

Keywords: ketosis, hypocalcemia, fresh cow