Prevention and control of mastitis in heifers

SOURCE: http://www.milkproduction.com/Library/Scientific-articles/Animal-health/Prevention-and-control-of-mastitis/

Prevention and control of mastitis in heifers

 

Mastitis in heifers is a major problem that causes massive economic losses on most dairy farms. When optimising farm management does not result in a significant reduction of the heifer’s udder health status, the administration of a three way broad spectrum dry cow product has been shown to be effective in reducing the number of clinical mastitis cases in first lactation dairy cows.

Source: International Dairy Topics #5 2004

Mastitis is still one of the most devastating diseases on dairy farms. It causes massive economic losses, even on farms with a low incidence of clinical mastitis. It is becoming painfully clear that heifers can also be affected by udder infections, even prior to calving.
Approximately 60% of all heifers have an intramammary infection at calving. Some 16% of these heifers will suffer from clinical mastitis during their first lactation and 30% of these mastitis cases will occur within 14 days after calving. This results in a reduced milk yield in the first lactation, causing severe economic losses.

Farmers frequently ask: ‘How can heifers be infected when they have never been in contact with the milking machine?’
There are several reasons for this:

·         Bacteria on the teat skin.

·         Bacteria in the environment of the heifer.

·         Bacteria transmitted by flies

·         ‘Sucklers’ (animals that suckle other animals) in a group of young stock.

The same bacteria that are found in older dairy cows can be detected in heifers. Most frequently isolated are E. coli, Staphylococci (coagulase negative staphylococci (CNS) and Staphylococcus aureus) and streptococci.

The economic loss from one single case of clinical mastitis in Western Europe ranges from 200-300 euro. The magnitude of loss depends upon the bacteria involved, the herd’s production level, and the accuracy of veterinarian and farmer in detecting and treating animals with clinical mastitis.

The losses consist of veterinary costs (treatment and visits), the value of milk discarded during treatment and withholding periods, additional farm labour, reduced production for the remaining lactation period, occasional deaths and involuntary culling.

Most clinical mastitis cases occur in the first trimester of lactation. The proportion of heifers with mastitis around calving varies from 30-35%; stress, negative energy status and metabolic disorders are believed to be important risk factors. However, heifers can already be infected several weeks before their first calving.

Mastitis in heifers can be prevented. In the first place by managerial measures that eliminate the sources of infection:

·         Optimise hygiene, starting directly after birth.

·         Reduce the amount of bacteria in the environment (clean housing and bedding).

·         Optimise insect control.

·         Remove ‘sucklers’ from groups of young stock.

In addition, changes that reduce or eliminate risk factors associated with mastitis should be considered:

·         Reduce stress on the animals.

·         Optimise nutrition.

·         Optimise ventilation.

·         Optimise housing.

When the above measures do not result in a significant improvement then the treatment of heifers with a dry cow product can be considered. This treatment should be applied approximately six weeks prior to the expected calving date.
A significant reduction in the rate of clinical mastitis has been shown by using a three way broad spectrum dry cow product, such as Nafpenzal DC from Intervet.

The photographs show the procedure of how to administer an intramammary injector to heifers.

All heifers are locked in the feeding fence. The barn is clean. Floors have been freed from manure.

The heifers are clean.

The injectors are spread on a table, ready to use.

Cleaning towels are taken out of the box.

The heifer is fixed: an assistant lifts the tail for fixation of the animal.

Disinfection of the teats with alcohol.

Forestripping. The small drop of milk indicates that the teat end is open.

Insertion of the injector. Only the tip of the cap is removed, allowing partial insertion.

Gentle emptying of the injector.

Mastitis in heifers is a major problem that causes massive economic losses on most dairy farms. When optimising farm management does not result in a significant reduction of the heifer’s udder health status, the administration of a three way broad spectrum dry cow product has been shown to be effective in reducing the number of clinical mastitis cases in first lactation dairy cows. The infusion of Nafpenzal DC was found to be very well tolerated by heifers.

On several dairy farms our veterinary practice treats heifers approximately six weeks prior to the expected calving date with a dry cow product. We do this on farms where too many heifers suffer from clinical mastitis around calving, varying from several days before to several days after calving.
Before introducing this treatment, it is of great importance that all possible causes have been thoroughly investigated. After that, dry cow treatment can be considered. Administration needs to be performed under proper hygienic conditions. With this we have booked huge successes; the problem of heifer mastitis is largely disappearing. So far, we have not seen any problems with the infusion of dry cow injectors. In cases where we did not manage to infuse an injector it turned out that anatomical changes were the cause.

G. W. Tiddens, DVM, dairy veterinarian
Kollum-Buitenpost Veterinary Practice

Before we introduced the concept of treating heifers with a dry cow product prior to calving, we feared that the administration of the injectors would be a major problem. However, reports from our own staff as well as from practicing vets indicate that the administration of dry cow injectors to heifers is surprisingly easy.
The specially designed dual cap insertion system proves to be of great help. This system, that we use for all our dry cow products, including Cobactan DC and Nafpenzal DC, allows partial insertion of the injector’s tip to prevent damage to the teat canal. Treatment of heifers enables farmers to tackle an important source of intramammary infections and so reduce their losses due to mastitis. This concept once again proves Intervet’s commitment to the dairy sector.