Deaths in Dairy Cows at Drying Off

Drying off cows is a critical management period on dairy farms. The dry cow period provides the udder a chance to recover after lactation.

When all goes well this gives the udder a chance to clear persistent intramammary infections, to rest and repair, allowing the cow to produce sufficient optimum quality colostrum for the developing calf, and it prepares the udder for the forthcoming lactation.

Unfortunately, AFBI through its postmortem rooms in Omagh and Stormont, has detected a sharp rise in deaths of dairy cows from toxic mastitis due to infections occurring at drying off.  In one County Tyrone case four cows from a batch of 13 cows which were dried off died four to five days later.  Two cows were submitted for postmortem examination and toxic mastitis was present in multiple quarters of each cow.  In a separate County Armagh case six cows died within eleven days of drying off.  One of the cows aborted five days after drying off and died five days later.  When examined at AFBI there was toxic mastitis in multiple quarters.  Insufficient attention to hygiene and cleanliness is likely to have been a significant factor in these and in other similar incidents recently examined at AFBI.

To avoid such detrimental outcomes drying off procedures should be carefully planned.  Planning for drying off should begin in the weeks before drying off. A sixty-day dry period is considered ideal and the timing of drying off should reflect this.  Cows should be in appropriate condition at drying off and body condition scores between 2.5 -3.5 are considered optimal and will reduce the risk of metabolic problems in the subsequent lactation.  Levels of concentrate feeding should be reduced in the week prior to drying off in cows producing more than 10 kg of milk per day.  Normal milking intervals should be maintained before drying off and it is not recommended to practice ‘once a day’ milking as part of the drying off routine, this may actually increase the risk of mastitis.

Antimicrobials are essential to both veterinary and human medicine to treat infectious diseases. Continued availability of all existing antimicrobial classes and the development of new ones for veterinary use are essential to maintain the health and welfare of animals and the protection of public health.  Blanket use of intramammary antibiotics at drying off is not sustainable and careful choices must be made in selecting which cows are dried off with intramammary antibiotic and teat sealant and which cows are dried off with teat sealant only.  It is recommended to involve your vet in deciding which cows to dry off with sealant only and which cows require sealant and antibiotic.  Cows which have had a somatic cell count below 200,000 over the last three milk recordings and which have not had a case of clinical mastitis in the last three months are suitable candidates for teat sealant only.  In cows with recent high cell counts or a case of mastitis in the last three months antibiotic is indicated but selection of the antibiotic in the dry cow tube should be based on effectiveness against the bacteria responsible for the mastitis.

Good technique at drying off is critical.  Suboptimal technique not only increases the risk of mastitis in the immediate period post drying off, but it also increases the risk of coliform intramammary infections into the next lactation.

Plenty of time should be allocated for drying off cows and it is recommended not to dry off too many cows at any one time.  Operators should not be overly tired, rushed or hungry at drying off.  Usually, cows will be dried off in the milking parlour.  This should be done after the last milking is completed and after the milking parlour has been washed and disinfected.  Cows should not be dried off during the milking.  Cleanliness and hygiene are of paramount importance.  Arms and hands should be thoroughly washed.  Gloves should be worn, and they should be changed between cows.  Individual paper towels should be used for each teat.  It is good practice to start at the teat furthest away from the operator.  When the teat is clean it should be sterilised using cotton wool and 70% alcohol repeating this process until dirt is not observed on the cotton wool and the teat orifice is completely clean.

If dry cow antibiotic tubes are being used the teat should be held just above the tip of the teat.  Only the end of the nozzle should be inserted into the teat canal and then the plunger squeezed.  The teat should then be gently massaged to move the antibiotic in the direction of the udder.  Teat sealant should then be applied.

When using teat sealant, the teat should be held at its base.  While gently pinching the base of the teat sealant should be infused into the teat until the pressure builds up but prevented by the grip at the teat base from entering the udder.  The teat should not be massaged.  To finish the teat should be dipped or sprayed with fresh disinfectant, and the cows should be allowed to stand in a clean yard for 30 minutes before moving to clean pasture or housing in a clean well bedded environment.  It is not recommended to perform hoof paring at drying off time because of the risk of contamination of the teat end and udder.

After drying off cows should be checked daily for signs of illness or mastitis.  If heat, hardness, redness, pain, inappetence, dullness or fever are detected advice should be sought from your veterinarian.  It is important however not to strip the udder as part of the post drying off checks unless mastitis is suspected. 

Notes to editors: 

AFBI is an arms-length body of DAERA delivering research and development, diagnostic and analytical testing, emergency response capability and expert scientific advice for DAERA and other government departments, public bodies and commercial companies in Northern Ireland, and further afield.

AFBI’s Vision is “Scientific excellence delivering impactful and sustainable outcomes for society, economy and the natural environment”.

AFBI’s Purpose is to deliver trusted, independent research, statutory & surveillance science, and expert advice that addresses local and global challenges, informs government policy and industry decision making, and underpins a sustainable agri-food industry and the natural and marine environments.

AFBI’s strategic priorities:

• Leading improvements in the agri-food industry to enhance its sustainability;
• Protecting animal, plant and human health;
• Enhancing the natural and marine environment;
• Delivering quality outcomes and impact;
• Enabling world class science through excellence in people, places & technology.

Share this page