A thorough overhaul of key aspects of cow management as well as a detailed look at every aspect of the milking parlour routine is the only way to effectively tackle mastitis.
Vet Roger Blowey told dairy farmers at an event hosted by Lancashire cheese makers Ruth, John and Graham Kirkham, Goosnargh, that relying on tubes of antibiotic as the primary means of defence was only achieving short-term control.
“I can’t stress enough how important it is to spend time getting to grips with the areas of management that can be at the root cause of the problem – both in and out of the parlour.”
Mr Blowey urged farmers at the event, organised by Livestock North West, to recognise the importance of the dry-cow period and its influence on future mastitis infection.
“In the dry cow period the teat should seal itself with a keratin plug. But, over the years, as cows have become easier milkers the teat end has become more open and it’s harder for the plug to form. This means high-yielding cows are now 25 times more susceptible to mastitis than they used to be during the dry period.”
After research indicating the dry cow period as a possible trigger for mastitis occurring up to two and three months after the calving date, Mr Blowey questioned the trend for shortening the dry cow period.
“Research shows 8.4% of cows with quarters infected with E coli during the dry period suffer mastitis problems during the lactation, whereas only 1.4% of cows suffer from mastitis where E coli weren’t identified in the udder during this time.
“While farmers assume they are tackling mastitis in their lactating cows, it’s the dry cows on the farm that could be harbouring even more problems for the future.”
Mr Blowey said a six-week dry cow period gave two fortnight-long “windows” of high infection risk – after drying off and just before calving – which only gave the cow two weeks in middle of the period to cope with any build-up of pre-calving infection.
“When you reduce the dry-cow period to four weeks you are taking out any opportunity for the cow to recover. But, from a metabolic point of view, there are some theoretical advantages to having cows dry for a shorter time.”
While strict parlour routines and regular liner replacement would help reduce cross-infection between cows, drying-off an individual troublesome quarter suffering repeatedly from mastitis during lactation, using only lactating cow tubes was a practice now proving popular and successful.
Research involving 4500 cows that had 250 individual quarters dried-off to tackle mastitis showed 68% of cows coming back into normal production. But where those dried-off quarters were treated with a dry-cow tube at the end of the lactation – along with the other three quarters – the response rate was almost 90%.
“This tends to be a practice that’s popular in certain regions of the country, but those who do it are finding the dried-off quarters suffer no ill-effects.”
He said dairy farmers with mastitis problems should look closely at a range of issues that may be triggering infection, including lameness, ketosis and milk fever.
“Cows with milk fever are 23 times more likely to get toxic mastitis, while cows that have had assisted calvings are 11 times more likely to suffer from mastitis. But metritis is becoming a big issue in high-yielding cows and it can trigger mastitis as the cow’s response.
“Over the next five years we need to get to grips with the part played by problems like metritis and its influence in causing mastitis.”