Mastitis & Once-a-Day Milking
Dexcel has been doing research in Taranaki for last six years on OAD milking and comparing it with TAD milking. The first trial involved comparison of Jerseys and Friesians, and Dexcel measured the incidence of mastitis and changes in somatic cell counts looking for any differences. They were small herds (around 40) run in a small farm system and they were on their treatment for the whole of the lactation.
Dawn Dalley, regional scientist with Dexcel, says they found no difference in the incidence of clinical mastitis between OAD and TAD milking.
A lot of farmers are concerned that they will get a lot more mastitis with once-a-day milking, but with all the work we have done we haven't found any difference in the number of clinical cases, says Dawn.
At the Waimate West demonstration farm which is run more as a commercial operation, in the first year of a trial of once-a-day milking we actually got a milk quality certificate from Fonterra for supply of low somatic cell count milk. So that shows that even though there are some issues converting to once-a-day milking you can still supply good-quality milk.
There are two OAD scenarios milking OAD all season, or changing from TAD to OAD at Christmas as a way of managing the falling production of cows later in the season.
Dawn says that before farmers change to OAD they have to be quite ruthless with cows that have had repeated bouts of mastitis because they can cause problems of high somatic cell counts (SCC). (There are penalties if SCC go over 400,000 cells/ml, and each collection from farm vats is tested). Usually, when switching from TAD to OAD milking, the vat SCC has to be able to accommodate approximately doubling for the first 2-3 days, but will then subside and return to levels that are only marginally higher than before the switch.
Cows on OAD milking tend to have higher somatic cell counts than TAD cows, which is associated with the lower milk volume that they are producing so that there is less dilution effect. That may cause problems just after calving when SCC are naturally high, and at the end of lactation when milk volumes drop.
Colostrum cows should be carefully tested before their milk goes into the bulk milk tank, and if their SCC is still high and bulk milk SCC are high then they might have to remain in the colostrum mob for another day or so.
At the end of lactation it is important to keep OAD cows milking well so that milk volumes remain reasonably high and the dilution effect will keep SCC under the penalty limit. High SCC cows should be dried off if there are bulk milk SCC problems.
On the other hand there are advantages with cows milked OAD.
When they do get clinical mastitis it is really highly visible and easy to pick up, probably because the milk has been in the udder for 24 hours and there has been more time for the cells to create clots. Changes in udder condition due to mastitis are also easier to pick up uneven udders, swelling, redness, says Dawn.
Also when a cows cell count is rising, farmers can pick it up quite quickly from the daily bulk milk SCC reading on the tanker docket. It might be tracking along at 120,000 and all of a sudden it goes up to 180,000, and often that coincides with a cow developing clinical mastitis.
Once-a-day milking does highlight any weaknesses in mastitis control, so you need to be proactive in management of mastitis and high SCC cows.
For farmers converting to OAD at Christmas, if their bulk milk SCC was running at about 300,000 a couple of undetected cases of mastitis could put them over the 400,000 penalty mark, so they need to be vigilant.
Managing mastitis in early spring
Farmers need to be checking cows as they calve, during the colostrum period, and doing a thorough check at the end of the colostrum period before they put them into the main herd using the Rapid Mastitis Test (RMT).
Teat spraying is critical immediately after milking for all cows. Complete coverage of the teat is essential spray the udder from below. This should kill any bacteria transferred to the teat from the cup liner or milkers hands, and reduces the risk of infection getting in when they are back out in the paddock.
Any cows with mastitis should be milked last so that infection is not spread by the machine to healthy cows.
Be vigilant in watching bulk milk somatic cell counts, and if they start to creep up consider stripping the whole herd to identify any new clinical cases.. Hand stripping each quarter is fine, and do a RMT, or conductivity check on any suspect animals. Farmers who are doing herd testing will have additional tests that will identify high SCC cows, and they can follow up with a RMT or conductivity test. .
For more information on managing mastitis go to www.dexcel.co.nz, Cows & Grass, Animal Health section, Managing Mastitis Booklet A practical guide for New Zealand dairy famers
Or contact Livestock Improvement www.lic.co.nz
You can buy a Rapid Mastitis Test paddle from your local vet or rural supplier.
CALL TO DAIRY FARMERS READ MASTITIS REPORT
With calving now behind them, the National Mastitis Advisory Committee hopes dairy farmers will make the time to read a recently-published report into the costs of one of farmings most persistent bugbears.
The report has resulted from Dairy InSight-funded research.
Ted Coats, a director of Dairy InSight and chairman of the National Mastitis Advisory Committee, says the report had demonstrated that a farmer dropping the cell count in their herd from 220 000 cells/ml to 150 000 cell/ml would achieve a production gain of 2.8 kg of milksolids per cow.
In the case of a herd of 315 cows, that represents over $4,000 in extra earnings.
The report and its findings and recommendations, have been posted on the Dairy InSight and Dexcel websites.
This is a wakeup call to the industry and I would encourage every dairy farmer to take the opportunity to read it, Mr Coats said.
The report is available to all farmers at www.dairyinsight.co.nz, or by calling 0800 44 67 44.
Dawn Dalley, regional scientist with Dexcel, says they found no difference in the incidence of clinical mastitis between OAD and TAD milking.
A lot of farmers are concerned that they will get a lot more mastitis with once-a-day milking, but with all the work we have done we haven't found any difference in the number of clinical cases, says Dawn.
At the Waimate West demonstration farm which is run more as a commercial operation, in the first year of a trial of once-a-day milking we actually got a milk quality certificate from Fonterra for supply of low somatic cell count milk. So that shows that even though there are some issues converting to once-a-day milking you can still supply good-quality milk.
There are two OAD scenarios milking OAD all season, or changing from TAD to OAD at Christmas as a way of managing the falling production of cows later in the season.
Dawn says that before farmers change to OAD they have to be quite ruthless with cows that have had repeated bouts of mastitis because they can cause problems of high somatic cell counts (SCC). (There are penalties if SCC go over 400,000 cells/ml, and each collection from farm vats is tested). Usually, when switching from TAD to OAD milking, the vat SCC has to be able to accommodate approximately doubling for the first 2-3 days, but will then subside and return to levels that are only marginally higher than before the switch.
Cows on OAD milking tend to have higher somatic cell counts than TAD cows, which is associated with the lower milk volume that they are producing so that there is less dilution effect. That may cause problems just after calving when SCC are naturally high, and at the end of lactation when milk volumes drop.
Colostrum cows should be carefully tested before their milk goes into the bulk milk tank, and if their SCC is still high and bulk milk SCC are high then they might have to remain in the colostrum mob for another day or so.
At the end of lactation it is important to keep OAD cows milking well so that milk volumes remain reasonably high and the dilution effect will keep SCC under the penalty limit. High SCC cows should be dried off if there are bulk milk SCC problems.
On the other hand there are advantages with cows milked OAD.
When they do get clinical mastitis it is really highly visible and easy to pick up, probably because the milk has been in the udder for 24 hours and there has been more time for the cells to create clots. Changes in udder condition due to mastitis are also easier to pick up uneven udders, swelling, redness, says Dawn.
Also when a cows cell count is rising, farmers can pick it up quite quickly from the daily bulk milk SCC reading on the tanker docket. It might be tracking along at 120,000 and all of a sudden it goes up to 180,000, and often that coincides with a cow developing clinical mastitis.
Once-a-day milking does highlight any weaknesses in mastitis control, so you need to be proactive in management of mastitis and high SCC cows.
For farmers converting to OAD at Christmas, if their bulk milk SCC was running at about 300,000 a couple of undetected cases of mastitis could put them over the 400,000 penalty mark, so they need to be vigilant.
Managing mastitis in early spring
Farmers need to be checking cows as they calve, during the colostrum period, and doing a thorough check at the end of the colostrum period before they put them into the main herd using the Rapid Mastitis Test (RMT).
Teat spraying is critical immediately after milking for all cows. Complete coverage of the teat is essential spray the udder from below. This should kill any bacteria transferred to the teat from the cup liner or milkers hands, and reduces the risk of infection getting in when they are back out in the paddock.
Any cows with mastitis should be milked last so that infection is not spread by the machine to healthy cows.
Be vigilant in watching bulk milk somatic cell counts, and if they start to creep up consider stripping the whole herd to identify any new clinical cases.. Hand stripping each quarter is fine, and do a RMT, or conductivity check on any suspect animals. Farmers who are doing herd testing will have additional tests that will identify high SCC cows, and they can follow up with a RMT or conductivity test. .
For more information on managing mastitis go to www.dexcel.co.nz, Cows & Grass, Animal Health section, Managing Mastitis Booklet A practical guide for New Zealand dairy famers
Or contact Livestock Improvement www.lic.co.nz
You can buy a Rapid Mastitis Test paddle from your local vet or rural supplier.
CALL TO DAIRY FARMERS READ MASTITIS REPORT
With calving now behind them, the National Mastitis Advisory Committee hopes dairy farmers will make the time to read a recently-published report into the costs of one of farmings most persistent bugbears.
The report has resulted from Dairy InSight-funded research.
Ted Coats, a director of Dairy InSight and chairman of the National Mastitis Advisory Committee, says the report had demonstrated that a farmer dropping the cell count in their herd from 220 000 cells/ml to 150 000 cell/ml would achieve a production gain of 2.8 kg of milksolids per cow.
In the case of a herd of 315 cows, that represents over $4,000 in extra earnings.
The report and its findings and recommendations, have been posted on the Dairy InSight and Dexcel websites.
This is a wakeup call to the industry and I would encourage every dairy farmer to take the opportunity to read it, Mr Coats said.
The report is available to all farmers at www.dairyinsight.co.nz, or by calling 0800 44 67 44.