22 Feb 2016
Peter Edmondson on the 30th mastitis seminar in Gloucester, where visitors were made aware of the benefits of using two topical areas in avoiding the condition.
Peter Edmondson
Job Title
Recycled manure solids need to be used as soon as possible.
Delegates from Egypt, the Netherlands, Denmark, Ireland and the UK made the 30th mastitis seminar in Gloucester – organised by the author and Roger Blowey – the most cosmopolitan course to date.
The combination of vets and representatives from the pharmaceutical and dairy industries created a great mix of expertise in mastitis. The interactive seminar is aimed at giving attendees an understanding of mastitis theory and practical skills to troubleshoot problems.
Two new topical areas introduced this year were selective dry cow therapy (SDCT) and recycled manure solids (RMS).
SDCT is not new, as many Nordic countries – such as Denmark – have never had blanket dry cow therapy and organic herds are urged to use SDCT.
More than 90% of UK cows get antibiotics at dry-off, yet less than 25% have subclinical mastitis at dry-off, so many cows will not get any benefit from this treatment. However, only 55% of cows get an internal teat sealant, but this will benefit more animals as a high proportion of teats are open after dry-off and at high risk of dry period infections, even after treatment with SDCT.
It, therefore, makes sense to swap things around so SDCT is only used in cows that have subclinical mastitis at dry-off, or had a case of clinical mastitis during lactation. This will reduce antibiotic use.
SDCT provides many benefits; including increasing the use of internal teat sealants (which must be used if you are not applying antibiotics at dry-off), which will reduce clinical mastitis by 25% to 30%. There will be a reduction in Escherichia coli mastitis by not using antibiotics in low cell count cows at dry-off.
If cows calve early, their milk can go into the tank and the risk of antibiotic bulk tank failure is reduced. There is a reduced risk from introducing infection during the dry cow treatment process if you use one syringe through the teat end rather than two. The calf will be fed colostrum free from any antibiotic residues. This will also save money for the farmer.
The practical aspects of approaching SDCT were discussed and gave delegates more confidence and reassurance in moving clients to it.
RMS has become popular, with farmers using it to save money on bedding. One of the farms visited has 300 cows and began using RMS at the start of 2015.
There were some teething problems, and a mastitis increase in spring, but this reduced once teat preparation was improved to ensure they were clean and dry before clusters were attached. Nobody was sure if the risk in clinical mastitis was associated with RMS.
It is essential the bedding is used on the day it is produced. The farm mastitis rate is around 20 cases per 100 cows per year, under the target of 30 and the UK average of between 40 and 50.
RMS is about 65% water and, once cows start to lie on the bedding, it dries out further and is very comfortable for cows.
The farmer invested more than £100,000 to install the system and a capital grant reduced this cost significantly. He estimated there was a three-year payback.
This 300-cow herd was milked through a 50 point rotary parlour and the delegates had to assess the milking routine, cow comfort and teat condition after milking. The milking routine is important because there is an increased risk of clinical mastitis, due to environmental bacteria, if teats are not cleaned properly. If hygiene measures were poor there was a risk of spreading contagious mastitis.
Problems with the milking routine can be difficult to address with some farmers. The course explained ways to manage this diplomatically. For example, high coliform counts in bulk milk indicate the teat prep is poor, so rather than telling the farmer he or she is a dirty milker, you can use the results to convey this message by removing a subjective assessment.
The herd had installed a rotating brush washer to prepare teats. This uses high-speed rotating brushes to clean off debris and is quite a cumbersome device applied to each teat individually.
Delegates noticed about half of the cows resented this as they were lifting their legs and trying to kick when the brush was applied to the teats. Everybody put their fingers between the brushes to experience what it felt like and many didn’t like it. A cow teat is about 25 times more sensitive than our fingers.
The owner was unaware as he spent little time in the parlour and the milkers were busy prepping each cow. There were two milkers doing the teat prep most of the time and each stayed on their coloured mats to ensure the correct time lag from teat stimulation to attachment and maximising the let down reflex.
The brush was installed to speed up teat prep time, which it did, but biphasic let down of milk was noticed in some cows, likely due to the discomfort of the machine.
This herd was also fitted with an airwash system that automatically applies teat dip just before the unit is removed and flushes the cluster with dilute peracetic acid. The teat dip is blasted up towards the base of the teat and can be good at covering that area, but very poor at applying it to the sides.
The poor teat dip cover was noticed. Some cows had hardly any at all while others had only teat dip at the teat end. Teat dip must be applied to the entire surface of every teat to help kill bacteria spread during milking and to keep teat skin in optimal condition.
The seminar made people familiar with the function of milking machines and how they can contribute to mastitis. A lack of understanding is a real barrier to mastitis investigations. If the farmer’s dealer says there is nothing wrong with the machines, but there are problems or issues with it, the vet or advisor is at an impasse.
In addition, most parlour testing is carried out when cows are not being milked and the most important time to assess is during milking to see the interaction between the machine and the cows. The range of simple parlour tests and assessments during milking were explained.
The importance of teat scoring was discussed and demonstrated at the herd visit and delegates had the opportunity to assess teat condition after milking. This is something all vets are encouraged to do as part of a mastitis investigation.
There were two parlour quizzes, one at each of the two farm visits, where delegates had to identify 20 different parts of the milking machine, what they do and how you assess their performance.
By the end of the second farm visit, everyone was confidently able to work their way around the parlour and carry out simple tests to assess vacuum reserve and stability. This is to complement tests carried out by the farmer’s dealer. Vets need to be able to pinpoint potential problems rather than come up with the cause and solution.
Environmental management is best taught on-farm. The first farm had cows in cubicles and straw yards. The importance of keeping the udder and teats clean is of paramount importance as all mastitis bacteria enter through the teat canal.
Straw yards are an expensive and time-consuming way of bedding cows, as they need to be bedded daily and cleaned out every three or four weeks, depending on the weather.
The farmer, who enjoys having the seminar vets visit, explained he liked straw yards for the comfort they give freshly calved and lame cows, but he ended up with some damp straw and was concerned about the potential risk of Streptococcus uberis mastitis. It is invaluable having farmer input to explain how and why he or she manages and prefers his or her environmental conditions.
The next mastitis control seminar in Gloucester will take place on 26 to 28 September. For more information, email [email protected]
