Comparison of Electrical Conductivity of Milk with Other Indirect Methods for Detection of Subclinical Mastitis

Abstract

Efficacy of detecting subclinical mastitis by electrical conductivity of milk was compared with that of other indirect methods including chloride, sodium, potassium, lactose, bovine serum albumin, and somatic cell count of milk. Quarter samples of foremilk, strippings, and bucket milk were obtained from 75 cows at the afternoon milking over 8 wk. Infection of quarters was ascertained by bacteriological analysis. Electrical conductivity, chloride, and sodium content of milk were more accurate for predicting infection status of quarters than were other variables. Most variables were more accurate in predicting infection when measures were in strippings rather than in foremilk or bucket milk. For measures in strippings, misclassifications by electrical conductivity were 11.2 and 15.5% for false positives and false negatives. The accuracy of the electrical conductivity of milk for detection of subclinical mastitis compared favorably with all indirect methods. Accuracy of detection and adaptability to both manual and automatic cow-side mastitis detection systems indicate that the method has considerable potential as a screening test for subclinical mastitis.

Apical electrolyte concentration modulates barrier function and tight junction protein localization in bovine mammary epithelium

“…Thus, one can infer from these results that changes in the paracellular pathway that are caused by the modified apical medium are sufficient to allow for the permeation of albumin into the milk. Both the appearance of albumin and the elevation in electrolytes have been used as clinical measures of mastitis (9,18,23). The fact that milk conductivity is used as an early indicator of mastitis suggests, but does not demonstrate, that changes in milk electrolyte composition precede changes in the epithelial barrier integrity.…”

“…When the barrier function of this secretory epithelium is compromised, permanent damage to the gland can occur. Change in milk electrical conductivity, related to ionic composition, is one of the earliest indicators of pathological changes in epithelial function in the bovine mammary gland (9,31). The mammary epithelial barrier breaks down during gland inflammation, milk production is reduced, and the lack of separation of the milk compartment from the blood compartment is associated with a cascade of events that can cause permanent damage to the gland (16,17,24).…”

A feasibility study of the use of a SIRE biosensor in the monitoring of H2O2 added to milk samples. A possible new technology for early detection of mastitis?

“…Methods for in-line monitoring of milk from individual cows described in the literature are based on the change in yield, temperature, and electrical conductivity (Fernando, Spahr, & Jaster, 1985;Maatje, Huijsmans, Rossing, & Hogewerf, 1992;van Asseldonk, Huirne, Dijkuizen, & Beulens, 1999). However, no general and reliable quick method is currently available for the direct indication of mastitis for use by the farmer to separate poor quality milk before the milk stream is allowed access to the bulk tank.…”

Effect of restricted suckling on milk yield, composition and flow, udder health, and postpartum anoestrus in grazing Holstein cows

“…Milk flow rate and milk electrical conductivity (MEC), an indirect index of udder health (Fernando et al, 1985), were recorded daily in both milkings by the milking machine (Westfalia, Elk Grove Village, IL, USA), with software (Dairyplan C21) equipped with a Metatron 21 Premium recording system based on near infrared technology. Milk flow rate was recorded every 5 s and was averaged for each milking.…”