Justification of machine milking physiological principles

Abstract

The article summarises the world experience of studying the issue of the negative mechanical impact of milking equipment on the health of cows in the process of machine milking. The design, principle of operation and results of experimental studies the special inserts for serial milking cups and teat rubber are presented. Special inserts for liners and milking cups ensure the implementation of physiologically safe principles of machine milking. Compared to a conventional two-chamber teat cup, the teat cup insert ensures pressure equalisation in the teat and interwall spaces during the sucking phase, while the rubber insert reduces the vacuum pressure in the teat space during the compression phase compared to the pressure in the collector chamber. The most common teat liner today has a circular cross-section and is characterised by a sharp transition from the sucking phase to the compression phase, when its cylindrical shell loses stability under the influence of evenly distributed pressure in the intercellular space of the milking cup. In addition, during the compression phase, at the point of closure such a liner has a cross-section in the form of a figure eight, which means that it does not completely disconnect the teat space from the vacuum pressure, which leads to injury to the tip of the teat, especially during dry milking. It was found that when using nipple liners with an insert, the vacuum pressure in the teat spaces of milking cups increases to 17-18 kPa throughout the entire milking period. The pressure in the milk collection chamber of the collector rises to 20-22 kPa. Such indicators largely correspond to the natural suckling of a calf. During production trials over 30 days, the percentage of cows with mastitis decreased by 1.5% and the milk yields increased by 2.2%.