Right attitude to reducing cell counts is key to profitable milk production

Trying to condense a six hour presentation into two hours is no easy task, but it was successfully achieved by Dr Andy Johnson during his flying visit to Lancashire last week when he spoke to a group of dairy farmers at Ribby Hall Village, Wrea Green.

Dr Andy, or "The Udder Doctor" as he is also known, is a vet from Wisconsin, America whose specialism is the production of quality milk and reducing the incidence of mastitis. Below are the main points from the meeting, but you can view Andy's indepth presentation in it's entirety by downloading it HERE

This meeting was organised by DairyCo and Myerscough College for the Livestock Programme. 

Farms producing quality milk will be competitive

Andy began by looking at the UK milk market, which is constantly changing and evolving. Demand is ultimately dictated by the consumer and they will only buy a quality product which they have confidence in. One of the main determinants of milk quality is SCC (somatic cell count), and so those farms producing high quality low SCC milk will be more competitive and hence more profitable.

Attitude is key

Andy has worked with hundreds of dairy farms over the years and commented that the SCC of any particular farm is a true reflection of the management decision made by that farm and their overall attitude. In other words those farms that strive for excellence and quality in all that they do will produce consistently good quality milk in comparison to those that always have an excuse as to why they can’t reduce their SCC. In Andy’s opinion all herds are capable of producing milk with a SCC less than 200,000 regardless of the herd size – the most important thing being to have the right attitude.

Clinical cases

The vast majority of mastitis cases today are due to environmental bacteria, with the dry period and calving time being the greatest risk time for picking up new infections. Infections picked up during this time will have a detrimental effect on the cow for the rest of that lactation.

To put this into a practical perspective, Andy’s findings have shown that animals that calve with an SCC greater than 200,000 will yield over 600kg of milk less in that lactation compared to animals with a lower SCC. Additionally these animals will also have lower pregnancy rates and more cases of clinical mastitis. All this will have a negative impact on overall herd profitability.

To help overcome the problem of high SCC in freshly calved cows Andy recommended that at 2-3 days post-calving all animals should have a CMT (California mastitis test) to determine whether or not they have a high SCC, which could potentially develop into a clinical infection. Any animals reacting positively to the test should be treated accordingly and re-tested a few days later to see whether or not treatment has been effective.

Dry cow treatment

Andy then briefly discussed the use of dry cow therapy, which is an effective method of treating chronically infected cows as it helps in the healing process of damaged tissue. In addition to therapy teat sealants are a useful aid in helping to reduce infections picked up during the dry period.

External sealants should be applied a minimum of three times – once after dry cow treatment is administered; again when the cow enters the pre-calving transition group; and finally when the cow enters the calving pen.

Internal sealants are administered at the last milking before drying off.  As 97% of the clinical infections picked up during the dry period will be in ‘open’ quarters immediately after drying off and before the keratin plug forms, the internal seal helps to mimic the effect of the plug.

Research has also shown that cows yielding over 21kg at drying off will form the keratin plug much more slowly than lower-yielding cows, hence putting them at greater risk of picking up infection in open quarters. Andy recommended that pre-drying cows should be fed on a straw diet to help reduce milk yields at this time. He also questioned the traditional 60-day dry period and suggested that a 42-day break may be more suitable for the modern high-yielding dairy cow. This option would also make more financial sense as there will be more milk in the tank due to cows being milked longer, and the need for dry cow housing would also be reduced.

Where is the best place to start producing quality milk?

Milk quality is determined by the three elements of the mastitis triangle – cow, milker and machine. It is important to remember though that each of these factors does not function independently and that all three interact and so must all be taken into consideration.

 

Cleanliness

The number one goal in controlling mastitis must be to reduce the bacterial load on every cow’s teats as the probability of mastitis increases with increasing bacterial load on teat ends. The key to achieving this is to have a consistent milking protocol which is adhered to by every milker at every milking. Andy recommended that the procedure is actually written down and explained to all staff so that they fully understand the importance behind it. The routine will depend on the type of parlour you have and also the number of staff employed and milking at any one time.

All new employees must also be properly trained and understand your farms’ individual milking routine to ensure consistency. However it must be remembered that the longer staff work on a farm the faster they will become and it is important that adjustments are made to the milking routine to accommodate this and ensure timings remain consistent.

Milking routine

1)      Stripping out

Stripping cows out is the first thing that should be done after the cows enter the parlour. There are many benefits to this including: stimulation of milk let-down; removal of the worst quality milk; earlier detection of mastitis; faster milking and increased yields. Studies have shown that pre-stripping can reduce milking times by at least one minute per cow, which soon adds up when you are milking a lot of cows and more than compensates for the time spent actually stripping out.

2)      Pre-dipping

After stripping out, teats must be pre-dipped to reduce teat bacteria. However it is essential that complete teat coverage is achieved, the dip is left on the teat for a sufficient length of time to kill the bugs, and that the correct product is used (not just watered down post-dip!).

3)      Drying

Teats must then be dried off thoroughly using what Andy calls the ‘twist method’ whereby the teat is twisted twice while drying and then the teat end is also cleaned. Pre-dipping and dry wiping has been shown to reduce bacteria on teats by 85%. It is the drying action which removes most of the bacteria.

 

Golden rule - IF THE TEAT IS NOT CLEAN ENOUGH TO GO IN YOUR MOUTH, IT IS NOT CLEAN ENOUGH FOR THE MACHINE TO BE ATTACHED!!

 

Top Tip

Dry wiping teats BEFORE stripping and pre-dipping will greatly reduce the organic load on teats and will increase the effectiveness of your pre-dip.

 

4)      Applying cluster

Andy then discussed the importance of lag times (the time between stripping out and attachment of the cluster). Data has shown that lag times greater than 60 seconds will give better milk flow rates and hence more rapid and complete milk out, and prevent over-milking. Therefore it is beneficial if your milking routine reflects this and timings are such to ensure a lag time of 90 seconds where possible. Units should never be applied to empty teats.

 

5)      Post-dipping

The primary reason for post-dipping teats after milking is to remove the film of milk left on the teats with a layer of germicide.

 

All milkers MUST wear gloves

This is essential to reduce bacterial load on teat ends as the skin on hands is the main source of staph aureus bacteria. However it is vital that the gloves are kept clean throughout milking and also that gloves fit correctly and are not too big.

 

Parlour cleanliness

There is no point cleaning the teats prior to milking if a dirty cluster is then put on. Andy recommended that clusters are washed regularly throughout milking (ideally after every side of cows) with water and sanitiser through a hose. The same solution can also be used to flush out any clusters which have been used on cows with high SCC.

 

All clusters should also be thoroughly cleaned after milking before they are put onto the cleaning jetters.

 

Milking machine maintenance

The milking machine is the most important machine on a dairy farm and should be regularly tested and maintained. It is essential that the machine is tested during milking time – a dynamic test whilst the machine is actually working will give an accurate reflection of what the machine is actually doing.

 

The action of the pulsators should be tested regularly and the results displayed on a graph to ensure that the open and closed phases are the correct length and timing. If pulsator function is not correct then the teat end won’t be being massaged, leading to teat end damage and subsequently sore teats which are irritated during milking. In addition if the health of the teat end is good then the risk of mastitis is reduced as bacteria cannot enter the teat canal as easily.

 

Rapid milk out

The benefits, to both cow and milker, of a rapid milking out time were also discussed. Cows can be trained to milk out more rapidly (goal – less than 5 minutes) by making alterations to the milking routine and taking off all clusters at a certain time regardless of whether or not the cow has finished milking. The longer the unit is on the cow the greater the risk of over-milking leading to teat end damage and increased likelihood of mastitis. Alternatively very slow milkers can be culled as they disrupt the milking routine for the rest of the cows, particularly in a swing-over herringbone parlour.

 

To determine whether or not your cows are being over-milked, Andy recommended strip milking a sample of cows immediately after the cluster has been removed into a measuring jug. If there is less than 250ml of milk remaining in the udder (evenly split between the four quarters) then the cow has been completely milked out. This also indicates if the unit is improperly aligned as some quarters have more milk in than others. Other signs of cows being milked too dry include rough teat ends, tender sore teats, cows kicking units off during milking and dirty sleeves!

 

Cubicle design

Whilst cleanliness is key in the parlour, it must not be forgotten in the building as the higher the level of teat contamination, the higher the risk of mastitis. When the cow lies in a cubicle her udder rests on her back feet so if passages are kept scraped clean it follows that the feet will be cleaner and ultimately the teats as well. Cubicle cleanliness is often determined by the lying position of the cow in the bed – too far forward and she will make the bed dirty.

 

See Andy’s recommendation for cubicle size by clicking on his website here http://www.theudderdoctor.com/seminars/ (then click on Free Stall Guidelines)

 

Conclusion

Andy concluded with the four points that the most successful mastitis control programs must adhere to:

1)      Control the environment of cows - Keep cows clean, dry, and comfortable at all times

2)      Ensure strict hygiene controls are adhered to in the parlour - Only milk clean and dry teats

3)      Ensure milking equipment is properly maintained

4)      Proper therapy on proper bacteria:

-          Know the bacteria

-          Select the correct drug for the bug

-          Treat for proper duration for bug

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