Ability of milk pH to predict subclinical mastitis and intramammary infection in quarters from lactating dairy cattle.

Autor:	Kandeel SA; Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois at Urbana-Champaign 61802; Department of Animal Medicine, Faculty of Veterinary Medicine, Benha University, Kalyobiya, 13637, Egypt., Megahed AA; Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois at Urbana-Champaign 61802; Department of Animal Medicine, Faculty of Veterinary Medicine, Benha University, Kalyobiya, 13637, Egypt., Ebeid MH; Department of Animal Medicine, Faculty of Veterinary Medicine, Benha University, Kalyobiya, 13637, Egypt., Constable PD; Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois at Urbana-Champaign 61802. Electronic address: constabl@illinois.edu.
Jazyk:	angličtina
Zdroj:	Journal of dairy science [J Dairy Sci] 2019 Feb; Vol. 102 (2), pp. 1417-1427. Date of Electronic Publication: 2018 Oct 19.
DOI:	10.3168/jds.2018-14993
Abstrakt:	Milk pH is increased in lactating dairy cattle with subclinical mastitis (SCM) and intramammary infection (IMI). We hypothesized that milk pH testing provides an accurate, low-cost, and practical on-farm method for diagnosing SCM and IMI. The main objective was to evaluate the clinical utility of measuring milk pH using 3 tests of increasing pH resolution: Multistix 10 SG Reagent Strips for Urinalysis (Multistix strips, Bayer HealthCare Inc., Elkhart, IN), pH Hydrion paper (Microessential Laboratory, Brooklyn, NY), and Piccolo plus pH meter (Hanna Instruments, Woonsocket, RI), for diagnosing SCM and IMI in dairy cattle. Quarter foremilk samples were collected from 115 dairy cows at dry off and 92 fresh cows within 4 to 7 d postcalving. Quarter somatic cell count (SCC) was measured using a DeLaval cell counter (DeLaval, Tumba, Sweden), with SCM defined as SCC >200,000 cells/mL and IMI defined as SCC >100,000 cells/mL and the presence of microorganisms at ≥10 cfu/mL of milk. Milk pH was measured at 37°C using the 3 test methods. The Hydrion pH paper performed poorly in diagnosing SCM and IMI. Receiver operating curve analysis provided optimal pH cutpoints for diagnosing SCM for the pH meter (dry off, ≥6.67; freshening, ≥6.52) and Multistix strips (dry off and freshening, ≥7.0). Test performance of the pH meter and Multistix strips was poor to fair based on area under the receiver operating curve, sensitivity, specificity, positive likelihood ratio, and kappa coefficient. The pH meter and Multistix strips performed poorly in diagnosing IMI at dry off and freshening. We concluded that milk pH does not provide a clinically useful method for diagnosing SCM or IMI in dairy cattle. (© American Dairy Science Association®, 2019.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu