Milk gases, mastitis and milking machines
Noorlander, D.O.; Heckmann, R.A.; Gardner, R.W.; Checketts, M.
Modern Veterinary Practice 62(8): 590-594
1981
ISSN/ISBN: 0362-8140 PMID: 7290067 Document Number: 172634
Artificial teats of differing wall thickness were used to study conditions that enhance the acquisition of mastitis-causing bacteria. Results showed that the thicker and more resistant the teat wall is to collapse after the end-point of milking, in response to the vacuum space that may form inside the teat, the greater is the possibility of droplets of milk on the outside of the teat orifice being forced back into the teat lumen. The space formed inside the teat cistern by the expansion of dissolved gases depends on the vacuum level and duration of exposure to it, and can be reduced by designing the machine so that the teatcup liner collapses before the vacuum shuts off. The potential danger, arising from milk back flow into the teat, is the presence of mastitis-causing bacteria on the inner surface of the liner. Recent research showed that there were 3.75 clinical cases of mastitis in a parlour using rubber liners for every case in a parlour using silicone liners.