Urine pH as predictor of blood acid-base status in dairy cattle fed acidogenic diets.
Vet J
; 306: 106187, 2024 Aug.
Article
in En
| MEDLINE
| ID: mdl-38942283
ABSTRACT
We determined the association between urine pH and blood acid-base indicators and assessed a urine pH cut-off value to predict severe metabolic acidosis under field conditions in cows fed acidogenic diets. Eighty-six cows were sampled for urine and blood. Urine pH was evaluated immediately after collection, and blood acid-base status was evaluated within 2â¯hours of collection using a portable blood analyzer. Twenty-five cows were classified as having severe metabolic acidosis (blood pH ≤ 7.4; bicarbonate < 24â¯mmol/L, base excess ≤ -0.5; PCO2 low to normal concentrations and urine pH between 4.88 and 5.71. There was a positive linear association between urine pH and blood pH (r = 0.46), and between urine pH and base excess (r = 0.74). The area under the ROC curve was 0.91 (CI 95â¯%= 0.84-0.96; good-excellent test). The optimal cut-off value for urine pH to categorize a cow with severe metabolic acidosis was 5.5 (94â¯% specificity and 72â¯% sensitivity). For each 0.1 unit of decrease in urine pH below 5.5, cows were 1.6 times (95â¯% CI= 1.3-2.1) more likely to exhibit a severe metabolic acidosis. We conclude that a urine pH of 5.5 or less is indicative of more life-threatening metabolic acidosis in dairy cows.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Acid-Base Equilibrium
/
Acidosis
/
Cattle Diseases
/
Diet
/
Animal Feed
Limits:
Animals
Language:
En
Journal:
Vet J
Journal subject:
MEDICINA VETERINARIA
Year:
2024
Document type:
Article