During the 1960’s researchers in the United Kingdom investigated and reported what became known as the first comprehensive plan to control mastitis. This mastitis control plan has been successful since being introduced and is based on the notion that the infection rate of mastitis is directly related to the number of bacteria present on teat skin when the unit is attached to a cow. Teat disinfection is the basis of a mastitis control plan.
The main function of any teat dip is to flush off the milk film that is left on the teats wherever they were exposed to vacuum during milking. Failure to flush off the milk film will result in a nearly perfect food for bacteria to grow on the teat skin before the cows are milked at the next milking. Once the milk film has been flushed off, the teat dip leaves a disinfectant on the skin of the teat to kill any current bacteria. Teat disinfection does not affect existing infections.
While it is recommended to cover the teat end and bottom one-third of the teat barrel, this is insufficient. The teat should be completely covered with teat dip. Although teat dip can be sprayed onto teats with a teat sprayer, in most cases, the teat coverage will not be sufficient and uses significantly more solution than proper dipping. The most common failure in most teat dipping/ spraying programs is not adequately covering teats with a good quality germicidal teat dip immediately after milking.
Because the role of teat dipping is to avoid bacteria colonization on the teat skin as well as the teat canal, it is critical to regularly and correctly cover the entire area of the teat that had contact with the milking unit. Teat dip coverage should be checked on a regular basis
The typical use rates for various application methods are as follows: spraying approximately 20 ml per cow, non-return dipper 6 ml to 8 ml, foaming 4 ml to 6 ml.
Think about storage and contaminating the teat dip, leaving lids off containers allowing air to possibly enter the container may have an adverse effect on your solution.
Cows with chronic mastitis problems act as a reservoir of infection for the rest of the herd, they cost you money in treatment costs and lost milk production, and they spend more time in the hospital shed requiring time-consuming care – increasing your time. Cows that should be considered for culling include:
Cows with persistently high SCCs.
Cows that do not respond to treatment and continue to flare-up repeatedly with clinical mastitis.
Cows with infections that persist in spite of dry cow treatment.
Cows with mycoplasma mastitis.
Of course, other factors must be considered before culling (type of infection, milk yield, replacement options, etc.) but, many times removing a few highly problematic cows will yield big dividends on your SCC report and will be well worth the loss in the long run. Culling should never be considered a substitute for solving the underlying problem with high SCCs or increased cases of clinical mastitis on your dairy. Culling is just one component to a comprehensive mastitis control plan.
Can somatic cell counts get too low?
That seems to be a question I receive often from producers who are trying to achieve optimum milk quality.
Low SCC herds usually have low levels of contagious bacteria and limit the spread with good milking procedures and management practices. When these herds do get an infection it is usually environmental. These organisms are opportunistic, not invasive, meaning most animals that get these infections are immune suppressed or stressed, such as dry cows or early lactation animals. Low SCC cows are not more susceptible to environmental organisms, but clinical signs tend to be more visible and grab the attention of producers.
High cell counts cost money. The cost of a high cell count doesn’t just come from the penalties imposed or bonuses foregone when targets are not met; high cell count cows produce less milk than low cell count cows. A high cell count herd will also have more clinical mastitis. So reducing cell count can provide substantial savings – on average, reducing the bulk cell count from 250,000 to 150,000 will result in savings of around £50 per cow per year, most of which comes from a reduction in production of around 0.5L more of milk per day. So cell counts are a valuable tool which can be used to identify a problem, assess the cost of the problem, give a guide as to the solution, and to monitor the response to control programmes.
What is a somatic cell count (SCC)?
When the udder is infected somatic cells from the blood (white blood cells) move to the udder and into the milk to defend the organ against the invading bacteria. Without this response, elimination of mastitis, even mild cases, would be very slow and tissue damage greatly increased.
For an individual cow the ideal cell count is 100 – 150,000. Below 50,000, there is some evidence that cows respond more slowly to infection, particularly with E. coli, so they have an increased risk of mastitis. So as reducing bulk milk below 100/150,000 may increase the proportion of very low cell count cows, it may also increase the risk of clinical mastitis. Nevertheless because of the other benefits of low bulk cell count the answer is not to increase cell count but to maximise immunity (such as by minimising negative energy balance) and to keep the cows in as good an environment as possible