Mastitis Management For Future Benefit

Mark Scott, Greenmount Campus, CAFRE and Hugh McCluggage, John Thompson & Sons

This article is one of a series prepared jointly by CAFRE and John Thompson & Sons, focusing on the key management issues facing dairy farmers during 2008. The articles draw on experiences from the management of the Future Herd at Greenmount Campus, CAFRE, managed in partnership with Thompson’s using data from Thompson’s Milk Manager which is collated from dairy herds across Northern Ireland.

Mastitis in the Northern Ireland Herd

Mastitis control on the average Northern Ireland dairy farm is a reactive response to the clinical signs of the disease. Treatment is normally by antibiotic use with little attention paid to the causal pathogen. Control and more importantly prevention of mastitis in the dairy herd can be much better focused where the pathogen at the cause of the disease is identified.

Bacteriology results from the AFBI laboratories in Stormont and Omagh during the period April 07 to March 08

Result	% of samples
2 or more organisms	8.2
No bacteria isolated	15.9
E.coli	22.7
Streptococcus uberis	17.6
Staphylococcus aureus	8.8
Streptococcus dysgalactiae	3.2

(Source AFBI, Northern Ireland disease surveillance, quarterly reports; April 2007 to March 2008)

Firstly, from the table it is evident that almost 25 percent of submitted samples are inconclusive. These results occur where there are two or more organisms present or where no bacteria can be isolated. This means that correct sampling technique is not being used in all cases. Where two or more organisms are present in a sample contamination has occurred through dirty hands, inadequate disinfection of teats or the use of non sterile sample bottles. If results show that no bacteria can be isolated the animal may have already been treated with antibiotics for the mastitis case or another ailment, eg. lameness. In either of these cases, the sample will be of no use.

Almost another 25 percent of the submitted samples show E. coli as the isolated pathogen making this the single largest cause of mastitis on Northern Ireland dairy farms. This is closely followed by Strep. uberis at 18 percent of samples submitted to VSD. Combining these two figures shows that in Northern Ireland over 40 percent of mastitis in dairy cows originates from environmental sources. Reducing the threat from these pathogens will require attention to detail in all aspects of management including:

cleanliness in dry cow and calving box accommodation
regular scraping of passages
bedding and liming of cubicles
cubicle dimensions to suit the size of your cow
pre and post milking teat dipping
letting cows stand after milking to allow closure of teat end
regular milking machine testing to ensure optimum teat condition and to prevent environmental mastitis spread

Contagious sources of mastitis are becoming less of a problem, indicating that milking machine settings and milking routine are improving from a mastitis management point of view. However farmers need to continue to focus on these areas as any slip will lead to recurrence of contagious pathogens.

Pathogens of significance in the Future Herd

Mastitis is monitored closely in the Future Herd. All cases and treatments are recorded and this information is analysed through our health benchmarking project to identify repeat offenders and high risk times of year for the herd. A milk sample is taken from each new mastitis case before treatment and is sent for culturing to identify the causal pathogen. This information is used to build up a picture of the pathogens prevalent in the herd and is useful when it comes to choosing milking and dry cow tubes. The most significant pathogens currently present in the herd mirrors that of the Northern Ireland herd with E. coli and strep. uberis being the main offenders. It is therefore important to focus on management of the cows environment to ensure a reduction of exposure to these pathogens as described above.

Mastitis Pathogen Testing

Mastitis pathogen testing will be the most effective tool in the fight against mastitis on the dairy farm and should be part of an overall mastitis control plan. Once a pathogen profile is built up for your herd it will be possible to select treatment products which best suit rather than using the blanket-based approach to all mastitis cases through treatment with a broad spectrum antibiotic.

It must be remembered at all times that the value of the bacteriological examination of milk significantly depends on the ability of the sampler to collect samples without contamination. In other words the time and money invested in culturing is wasted unless the proper technique is used.

Bacteria are everywhere - on the skin, legs, udder of the cow, hands, equipment and environment - but we only want to test for the bacteria that are inside the udder not on the outside or at the teat end.

Sampling Technique

It is good practice to discuss sampling technique with your vet

Clean and dry teats if necessary
Pre-dip if available
Clean and disinfect teat with 70 percent ethyl or isopropyl alcohol wipes
Strip quarter 3-4 times
Again clean & disinfect teat with 70 percent alcohol
Take sample
-strip milk horizontally in pot
-don’t touch lid or pot with teat
Replace lid and label
Send off or freeze

Use a Sterile bottle

Summary

Around a quarter of samples submitted to AFBI for culturing are contaminated
Over 40 percent of submitted samples are identified as environmental mastitis
Mastitis pathogen testing allows a picture of offending organisms to be built up and allows selection of specific treatment products
Sampling technique is critical as contamination renders results useless