AHEAD IN ANIMAL HEALTH
Testing dry cows for risk of postpartum diseases: two-year results from a routine laboratory S. van der Drift1, S. Carp – van Dijken1 1 Royal GD, PO Box 9, 7400 AA Deventer, The Netherlands
Aim of the study To present results from two years of testing close-up dry cows in the Netherlands based on serum samples sent to the laboratory of GD from July 2016 to July 2018. GD dry cow test panel • Since July 2016, dairy farmers can send serum samples of a set of 4 to 10 dry cows between 21 and 2 days before calving to the laboratory of GD in the Netherlands for a dry cow test panel. • Samples are analyzed for NEFA, BHBA, urea, haptoglobin, and magnesium and the (herd-level) test result can be used to evaluate dry cow management. Magnesium analysis was part of the test panel only from April 2018. • The following criteria are used for individual cow results: - NEFA ≥0.40 mmol/L and/or BHBA ≥0.80 mmol/L: increased risk for postpartum disease due to negative energy balance. - Urea ≤3.3 and ≥6.6 mmol/L: increased risk for a suboptimal protein supply. - Haptoglobin ≥0.30 g/L: increased risk for postpartum disease. - Magnesium ≤0.78 mmol/L: increased risk for hypocalcaemia.
Analysis
> 50% cows at risk
25% - 50% cows at risk
≤ 25% cows at risk 0%
10%
20%
30%
40%
50%
60%
70%
% of farms Figure 1 Percentage of farms with ≤ 25% cows at an increased risk, 25% - 50% cows at an increased risk, or > 50% cows at an increased risk for postpartum health problems based on NEFA and BHBA concentrations (energy balance; blue bars) or urea concentrations (protein supply; green bars) from 3228 serum samples sent to the GD routine laboratory for the dry cow test panel.
• Results from serum samples sent to the GD routine Table 1 Descriptive statistics for concentrations of NEFA, BHBA, urea, haptoglobin, and magnesium in serum of 3228 cows sent to the laboratory for the specific dry cow test panel between GD routine laboratory from July 2016 to July 2018 for the dry cow test panel. July 2016 and July 2018 with complete results for all parameters were included in the analysis (3228 samples; Indicator Mean (± SD) Median Min - Max 25th – 75th Cut-off value % of cows above/ 655 sets of 4 to 10 samples). percentile below cut-off • The advice of GD is to sample cows between 21 and 2 days NEFA (mmol/L) 0.25 (± 0.20) 0.19 0.05 – 2.03 0.14 – 0.28 ≥ 0.40 13% before parturition, but results may occasionally originate BHBA (mmol/L) 0.6 (± 0.2) 0.6 0.1 – 5.2 0.5 – 0.7 ≥ 0.80 23% from cows sampled outside this interval. Urea (mmol/L) 4.3 (± 1.3) 4.2 2.0 – 20.4 3.5 – 5.1 ≤ 3.3 and ≥ 6.6 22% and 5%
Results • Descriptive statistics for concentrations of trace elements in serum of dry cows are shown in Table 1. • The percentage of farms in the different categories of proportions of cows at risk are shown in Figure 1.
Haptoglobin (g/L) Magnesium* (mmol/L)
0.13 (± 0.23) 0.99 (± 0.10)
0.07 0.98
0.03 – 2.90 0.64 – 1.36
0.06 – 0.10 0.93 – 1.05
≥ 0.30 ≤ 0.78
6% 3%
*Results for magnesium are based on samples of 461 cows (added to the test panel from April 2018)
Conclusions • Testing cows for metabolic indicators in the dry period can be helpful for farmers and their (veterinary) advisors to evaluate dry cow management and indicate cows at risk for postpartum diseases. • Over 40% of farms participating in the dry cow test had >25% of cows at an increased risk for postpartum diseases.
s.v.d.drift@gdanimalhealth.com www.gdanimalhealth.com
GD1964/06-19