The patterns of myoelectrical activity and reaction for teat stimulation recorded in highly productive dairy cows’ udders

Abstract

The aim of the study was to evaluate electrical properties of the mammary gland of dairy cow during manual and mechanical milking and to adapt the electrographic method for analysis of udder physiology. Udder myoelectrical activity was measured on 10 healthy highly productive dairy cows of Slovak Pied cattle breed. The electrical activity of four quarters of the udder was recorded simultaneously using four bipolar electrodes. The udder was stimulated by delicate twofinger massage, manual milking and mechanical milking. During the experiment the duration of the reaction for stimulation and the amplitude of spike dischargers were listed. The udder stimulation through palpational massage of the teat end, manual and mechanical milking caused immediate reaction. The udder responded to stimulation with an increase in myoelectrical activity: increase in discharge frequency to 2.33 ± 0.6 per min and an increase in discharge amplitude with the average of 457 ± 147 µV. The average count of spike discharges was 3.86 ± 0.97, the average duration of the action potential was 8.12 ± 1.68 s and the average myoelectrical index was 31 ± 4%. Manual milking caused the highest increase in the udder myoelectrical activity. Evaluation of the mammary gland myoelectrical activity may provide an alternative method to study milk ejection disorders and to diagnose mastitis. Myoelectrical activity, udder health, two-finger massage stimulation, mechanical milkingThe electrical activity is an attribute of every living cell. Thanks to the difference in electric potential between the inside of the cell and the outside membrane, the cell has the ability to response to a stimulus. The recording of the udder myoelectrical activity may be an alternative method to study the function of the gland. The method could be used in the diagnosis of milk ejection disorders and other diseases of the mammary gland. The myoelectrical activity analysis is an advanced examination method for indirect tracking of the muscle contractility through reception of action potentials using implanted electrodes. The myoelectrical activity has a direct impact on the tissue contraction. It is a minimally invasive method, so the information obtained during the examination is a reflection of physiological process occurring in the organs.The aim of the study was to evaluate electrical properties of the mammary gland of dairy cow during manual and mechanical milking and to adapt the electrographic method to the analysis of udder physiology. Materials and Methods Animals and udder examinationUdder myoelectrical activity was measured on 10 highly productive dairy cows of Slovak Pied cattle breed. Before the recording, a sample of milk from each udder's quarter was collected in a sterile way for examination to rule out bacterial infection and inflammation. Only animals qualified as healthy in the milk test were used for the study.

Changes in the myoelectrical activity during electrical stimulation of healthy and mastitis-changed mammary glands in dairy cows

“…The groups of action potentials emerge with the frequency of 2.33 ± 0.6/min. It confirms our previous study on spontaneous electrical activity of the mammary gland and on the stimulating effect of manual and mechanical milking on this activity (Czerski et al 2013). In case of the registration from the surface it has to be taken into consideration that the recorded potential is a resultant of the sum of potentials occurring in the vicinity of the electrode, and in the case of using the bipolar electrodes it is a resultant of the potential between the electrodes.…”