Bactoscan failures arise from one of four main causes:
Contaminated Plant: if the plant is not being sufficiently cleaned, then bacteria will survive between milking’s and begin to contaminate milk from the next milking. ‘Just 5ml of milk residue (teaspoon) can contain sufficient bacteria to cause a failure on thousands of litres of milk’ (Laven, 2016). This is the most common cause of bactoscan failures.
Mastitis: Mastitis, especially environmental pathogens is the second most common cause of bactoscan failure. The presence of Strep Uberis pathogens, even at a sub clinical level can cause cows to excrete large numbers of bacteria, resulting in high bactoscan results.
Refrigeration Failure: if milk fails to cool quickly to below 7˚c, it can cause bacteria within milk to multiply causing high bacterial counts.
Environmental Bacteria: Bacteria from mud, manure, feed and other sources can contaminate the teats. If teat preparation is not effective, the risk of contamination during milking when the cluster is put on is very high.
1) Plant cleanliness:
a) Make sure that the tepid water rinse after milking removes the majority of milk residues
b) The plant should be cleaned and disinfected after every milking and the tank should be rinsed and cleaned after every collection. The milk filter should be inspected and changed after every milking.
c) Ensure air lines are free from dust and milk-split liners area common cause of milk in air lines.
d) Regular inspection of the plant is essential to ensure there is no build-up of milk residues.
e) Check rubber wear regularly and replace it if it is cracked or perished.
3) Milking routine
a) Wear rubber gloves and disinfect them regularly during milking.
b) Ensure clusters which fall or are kicked off during milking are clean before replacing.
c) Make sure units are placed on clean dry teats.
4) Bulk tank and Milking machine maintenance
a) Check that the temperature of the milk entering the tank is no more than180C, and that of the milk in the tank is below 70C within three hours of milking. This should be done at least 4 times per year
b) Maintain the milking machine in good working order. Testing at least once per year is essential.
Bulk tank analysis is a useful tool for examining and investigating the underlying causes of high SCC, mastitis incidence and milk hygiene problems