There was fierce interest in somatic cell count (SCC) at the Teagasc national dairy conference, with a number of packed workshops.

Don Crowley set the scene, saying that 66% of the milk being produced has an SCC of less than 200,000 cells/ml, with 30% between 200,000 and 400,000 of a cell count.

Don said that while the co-op penalty kicks in when the geometric average goes above 200,000, there are strong winds in terms of additional milk when the SCC is less than 100,000, so the focus was on getting the SCC below 100,000 in the first 100 days of calving.

This early spring period was identified as a problem period on many farms, something which Pablo Silva said shouldn’t necessarily be the case.

New infections

He said that new infections in the early lactation period point to a problem in the dry period.

“The highest risk period is two weeks after drying off and two weeks before calving. Preventing exposure to infection during this period is critical, because the teat canal is open and the animal is therefore exposed,” he said.

According to Don, genetically, cows are bred now for fasting milking speed, which means the teat canal is wider and this may be the reason why some cows no longer form their own or form a weaker keratin plug than in the past.

This is another reason why cows are more exposed to infection during the dry period.

He said that a milk recording must be carried out inside the first 30 days of calving to identify the high SCC cows and get them treated before they start spreading infection to other cows.

Vulnerable

He said that first calvers are particularly vulnerable within a herd in early lactation and that these need special treatment.

According to the SCC expert, many farmers are treating these as a separate bunch in early lactation where they can dedicate more time to them and by milking them first, there is less likelihood of them picking up infections from other cows in the herd.

He said that, in some cases, up to 30% of heifers can be getting infected with mastitis whereas the average of the herd may be 15% to 16% infection rate, indicating a particular problem with heifers.

The following is a list of pointers that were discussed at the workshop:

  • New liners should be put on the milking machine at the start of the calving season.
  • Consider putting freshly calved cows in a colostrum group and only let them out of this group after they have passed a CMT test.
  • Mastitis recording is very important because if incidences of mastitis are not properly recorded, then high SCC may not show up on the milk recording report. Don says a farmer won’t cull their way out of the problem in that case because they’ll be culling the wrong cows.
  • A milk sample should be taken in a sterile milk sampling bottle before treating a cow for mastitis. These samples should be frozen and sent for analysis before deciding on what dry cow tube to use.
  • Hair on tails, flanks and udders is a big issue in causing cows to be dirty. The advice was to singe hair on udders in August and keep tails clipped every few months.
  • Cleaning cubicles twice per day rather than once per day is more effective at reducing infection.
  • The quality of winter housing is very important. A brisket board is a great help at keeping cubicle beds clean and passages should be cleaned multiple times per day.