Prognostic Value of Plasma L-Lactate Concentration Measured Cow-Side with a Portable Clinical Analyzer in Holstein Dairy Cattle with Abomasal Disorders

Background: L-Lactate has been used as a prognostic indicator for ill humans and animals. A portable analyzer that measures L-lactate could help veterinarians decide to proceed with correction of a displaced abomasum. Hypotheses: The likelihood of a dairy cow with a displaced abomasum remaining in the herd can be predicted by lactate concentration and other variables. Animals: Thirty-four healthy early-lactation dairy cows, and 131 cows with abomasal displacements (DA) presented to Cornell University, Ithaca, NY. Methods: Plasma L-lactate was measured using a commercial analyzer (i-STAT). A cow had a positive outcome (PO) if she remained in the herd 30 days after surgical correction of the displaced abomasum and a negative outcome (NO) if she was culled or died in that time. A multivariable model with physical examination and clinicopathologic variables for predicting NO for cows with right-sided abomasal displacements was constructed. Results: The median plasma L-lactate was 0.54 mM/L (interquartile range, 0.42-0.74) in healthy lactating Holstein cows. In cows with right-sided displaced abomasa, median plasma L-lactate concentrations were higher in cows with NO (5.88 mM/L) versus PO (3.23 mM/L) (P = .002). In a multivariable model, which identified chloride, heart rate, and L-lactate as the best fitting variables for cows with right-sided displacements, the probability of NO increased as L-lactate increased. Conclusions and Clinical Importance: Plasma L-lactate concentration might be a useful predictor of productive outcomes in cows with right-sided abomasal disorders.