host-defence of the teat canal and resistance of cows to mastitis.

A REVIEW of the latest scientific literature indicates that there is a marked difference in teat end closure after milking dependent on the condition of the teat end score.

Not all cows are the same!

The teat cistern and the gland cistern are connected by the annular ring. The teat canal is surrounded by muscle in the form of a sphincter which has the function of closing teat canal.

The teat end is the first barrier against invading pathogens. The structural and physical features of the teat canal determine the regeneration rate of teat canal keratin to inhibit penetration of udder pathogens. It is theorised that up 40% of the keratin lining is removed at each milking and, therefore, it requires constant regeneration. Consequently, it is important to ensure that the Teat canal is closed post milking.

It is assumed that as milk production increases, more keratin is lost during milking.

This is the reason why it is recommended that cows should stand for at least 30 minutes post milking in a clean manure free area before returning to the cow housing.

During the post milking period cows close the teat with a keratin plug, some cows never form a complete keratin plug post milking.

After bacteria breach the teat end, they are taken up and destroyed by the cow’s immune defence.
Cows with ketosis have a lower defence and immune response.

Ketosis is a metabolic disorder that occurs in cattle when energy demands (e.g. high milk production) exceed energy intake and result in a negative energy balance. Ketosis cows often have low blood glucose (blood sugar) concentrations.

When large amounts of body fat are utilised as an energy source to support production, fat is sometimes mobilised faster than the liver can properly metabolise it. If this situation occurs, ketone production exceeds ketone utilisation by the cow, and ketosis results.

This also varies dependant on the cows, Clinical ketosis has been shown to increase in the risk of clinical mastitis and ketotic cows can experience more severe clinical mastitis.

These findings provide new insights into understanding host-defence of the teat canal and resistance of cows to mastitis.