Husbandry Unit 10.5: 

Technical Notes 

Note: Numbers in brackets refer to illustrations in the Extension Materials.
 

1 Mastitis is an inflammation of the mammary glands and may be:
- acute
- chronic.

2 You should know:
- the signs
- the tests.

3 If your cow's teats are not healthy and clean, bacteria may enter and cause Mastitis. 

4 You should:
- always call the vet if one of your cows has mastitis
- make sure your cows have good health, hygiene and housing.
 

In many dairy countries mastitis may be the most costly disease of the dairy industry.

Most dairy farmers see the obvious costs:

- Fees for veterinary treatment and drugs;

- Lost production from acutely affected udders;

- Withdrawal time for milk and meat due to antibiotic residues after treatment.

There are also hidden costs.

- Cows with subclinical mastitis may have low milk production.  Low milk production from subclinical mastitis usually costs more than the treatment of acute mastitis.

- Milk from cows with mastitis is lower in quality than milk from cows with normal glands:

 - the cell count is higher;
 - the milk contains less lactosis, fat, protein and other desirable 
   substances.

 This means less payment from the dairy.

Mastitis in buffalo

Generally mastitis is regarded to be of low economic importance where most types of buffalo are raised for draught power.  In lactating herds, however, the disease is of tremendous importance.
 

You must pay for veterinary fees and medicines.
 

8 Any kind of mastitis leads to lower milk production and therefore you get less money.

The different stages of mastitis are:

Acute mastitis  (10-12)
.
The cow's condition is generally affected with fever and reduced feed intake.
The mammary gland is swollen, hot and painful and the milk is visibly changed.
 

The udder consists of 4 glands.
Mastitis may infect 1, 2, 3 or all 4 glands.
 

Acute Mastitis
10 The cow shows general poor condition:
- high fever
- low food intake.
 

Chronic, subclinical mastitis ("hidden" mastitis)

General condition: udder and milk are not visibly changed.  Only laboratory or cow side tests, for example CMT, show mastitis.

Chronic, mild mastitis

The udder may be slightly swollen and hard and the appearance of milk slightly abnormal.  Paddle tests/ laboratory tests will confirm diagnosis.

Chronic, indurative mastitis

The glands with mastitis cannot produce milk and gland tissue is replaced by hard, sometimes nodular, connective tissue.  Clinical examination is sufficient to establish diagnosis.  The milk producing ability of the gland will not return to normal.

Table 1 summarises key points in acute and clinical mastitis.

Remember that these categories of mastitis are not separate but all part of one disease: Mastitis.

The Strip Test  (17-20)

You can do the strip test by stripping a few streams of milk onto the floor of the milking parlour or onto the boot: clean immediately afterwards.  For hygienic reasons, it is better to use the strip cup.

Perform the strip test before each milking for the following reasons:

- It helps to detect clinical mastitis;
- It flushes out bacteria in the teat canal;
- It stimulates milk let-down.

Clean and sanitize the strip cup between each milking
 

Chronic hidden mastitis

Your cow and milk appear satisfactory.
But:
- you get less milk
- your milk is poor quality.

You can do the strip test by stripping a few streams of milk onto the floor of the milking parlour or onto the boot: clean immediately afterwards.  For hygienic reasons, it is better to use the strip cup.

Perform the strip test before each milking for the following reasons:

- It helps to detect clinical mastitis;
- It flushes out bacteria in the teat canal;
- It stimulates milk let-down.

Clean and sanitize the strip cup between each milking.
 

You can use CMT to detect subclinical mastitis in the barn.  You can also use it for a rough bulk-milk test.

CMT measures the number of somatic cells present in the milk and a CMT-score is normally used as follows:

     CMT Score                       Somatic Cells (cells/millilitre)

        0                                                   100,000
     trace (T)                                          300,000
        1                                                   900,000
        2                                                2,700,000
        3                                                8,100,000

There are other tests similar to CMT which can be used in a similar way, such as the Whiteside Test or the Wisconsin Mastitis Test (WMT).

Remember that CMT and similar tests give a useful, but rough indication of somatic cells present, and only laboratory cell counts give exact figures.

The age of the cow, stage of lactation, teat or udder injury, stress, or other disease also affect the somatic cell count.
 

24 The tests show the number of cells and bacteria present in the milk.
 

Infection with bacteria or fungi is the usual cause of mastitis.  The normal route of infection is through the teat canal and then through the mammary gland.  Mastitis may also be part of general disease and affect other organs.

The most common bacteria to cause mastitis are Staphylococcus aureus, Streptococcus agalactiae, and other Streptococcus bacteria.  Coliform bacteria, Pseudomonas and Corynebacterium pyogenes may also cause mastitis.

Streptococcus agalactiae needs to be in the cow udder to survive.  Therefore, it is not difficult to eradicate if you treat all cows in the herd.

The other bacteria mentioned above can survive in the surroundings - in the barn, on milking tools, on hands etc.  This means that general hygiene is an important part of mastitis control.
 

Treat mastitis as soon as you diagnose it.  Infusion of an antibiotic preparation into the teat canal is the normal treatment.  In acute cases, systemic treatment may be necessary.

Note:
- Penicillin is the traditional antibiotic used, but Staphylococcus bacteria especially are resistant.  If bacterial resistance is a problem, a milk sample (taken before treatment) should be sent to the laboratory for culture and antibiotic sensitivity testing.

You can buy a wide range of antibiotics prepared especially for udder infusion.

- Before infusion, clean, dry and disinfect (e.g. with alcohol) the teat.

- When infusing the udder, do not push the cannula of the syringe too far into the teat canal.  This may damage the canal and cause further bacterial infection.  Partial introduction (3-4 mm) into the teat opening gives much better treatment results.
 

Some people are allergic to even small amounts of antibiotics in their food.  They may even suffer an anaphylactic shock and resulting death from eating food with an antibiotic content:  Penicillin especially has caused this kind of allergic reaction.

Because of this danger, you must observe withdrawal times for antibiotics strictly.

Discard milk from all 4 quarters from treated cows, even if you only infused one quarter.

Antibiotics deposited by the intramuscular or intravenous route, as food additive or deposited in the uterus, will also leave residues in both milk and meat.

In short, you must discard milk and not send animals for slaughter for a number of days after any antibiotic treatment, whether you infused through the teat canal or by other means.  The length of withdrawal time is normally subject to the official regulations of each country.
 

Contaminated milk is sometimes delivered to the dairy, even with recommended clean milking procedures.

Milking utensils that are not sufficiently clean may cause this.

You must:

- thoroughly clean and disinfect milk cans, buckets and other 
  utensils after use;
- keep them in a clean dust free place where they can dry properly.

This place should never be a corner of the cow barn - even the cleanest cow barn houses lots of bacteria that will contaminate milking utensils - and later on the milk.

Storing of utensils in a clean, well ventilated place, after proper cleaning, is an essential point to remember, if good quality milk is to be delivered to the dairy plant.
 

Before milking

36 Always wash dirty buffalo after wallowing and your dairy cows if they get dirty.

38 Clean your hands thoroughly before milking.
Rinse in disinfectant after washing.

Farmers often neglect teat dipping.  They think that udder cleaning before milking is sufficient.

However, even the cleanest milking procedure cannot avoid bacteria on the teat after milking.  You must dip the teat to make sure that these bacteria do not invade the teat canal and cause mastitis.  You can only control mastitis in the herd if you also use teat dipping on every cow after every milking.
 

41 Wash the teats in clean (or sanitised) running water.

43 Plan the order in which you milk your cows.
First, milk cows which do not have mastitis.

Many experiments have shown that the best time to treat subclinical mastitis is in the beginning of the dry period - that is:  following the last milking.  The reasons for recommending dry cow therapy are many.

- The cure rate of dry cow therapy is higher than the cure rate from treatment during lactation.
- The number of new mastitis infections during the dry period are reduced.
- If udder tissue has been damaged it has time to recover before next lactation.
- The number of clinical mastitis cases at the beginning of next lactation is reduced.
- Since the cow is dry, no milk is withdrawn because of antibiotic content.

Some veterinarians advise treating all quarters of all cows at drying off.  The advantage is that all infected glands are treated and testing for subclinical mastitis is not necessary.

You can buy long acting antibiotic preparations, made for intramammary dry cow treatment.  Never use these for treatment during lactation.
 

47 Dip the teats in disinfectant solution, for example:
- Hypochlorite solution (4% available chlorine)
- Chlorhexidine solution (0.5%)
- Idophor solution (5,000 p.p.m.iodine).

48 Look out for changes in milk, udder and general condition of your cow.

49 Treat all teat and udder wounds immediately.

51 Cull cows:
- with repeated mastitis (3-5 times during one lactation)
- which do not get treatments.

52 Check new animals for mastitis before mixing them with your old animals.

53 Protect your cow from wounds.
Avoid:
- short boxes
- bad tyings.

It is important to follow the occurrence of mastitis, not only for each cow, but also for the herd as a whole.

Keep records, giving information on:

- Identity of infected cows;
- Time of infection;
- Symptoms;
- Treatment;
- Cell counts (if available).
 

The higher susceptibility of milking buffaloes to mastitis could be due to one of the following reasons.

- The buffaloes predilection for water and muddy places.
- Very dirty and unhygienic milking places, sheds etc.  The animals consistently sit in dirty places.
- The close contact between healthy and diseased animals in common grazing, wallowing places.
- Over-crowding in periurban herds and common milkers moving from place to place.
- Wrong milking procedures with unhygienic conditions.  The teats are exposed to injury with inverted thumbs. 
- Pendulous udder and large teats are liable to injury and infection.
- Unweaned calves can cause injury and create a focus for infection. 

This observation is relevant in periurban herds where most of the milk must be sold rather than fed to calves.  The calves when unable to feed cause injury due to biting, pulling and hitting the udder.

- While taking out for grazing, wallowing and driving the animals are made to run.  The large pendulous udder is liable to injury and infection.
 

 

Importance of mastitis

Cows with mastitis cost you money because of:
1 Veterinary fees	(5)
2 Lower quality milk	(6-7)
3 Lower milk production	(8)

Mastitis

is Inflammation of the mammary glands

(9)

1 Acute mastitis

- Your cow
- high fever	(10)
- low food intake
- hot, swollen, hard, painful udder	(11)
- Your milk
- watery and thin
- flecks and clots
- yellow or brownish	(12)

2 Chronic mastitis

- Chronic, hidden mastitis	(13)
- Your milk
- less	(14)
- poor quality
- Chronic, mild mastitis
- Your cow
- slightly hard, swollen, painful udder	(15)
- Your milk
- slightly abnormal, watery, discoloured
- Chronic mastitis, gland shrinkage
- Your cow
- hard, shrunken gland with scar tissue	(16)
- Your milk
- no milk

Identification of mastitis

1 Your cow	(17)
2 Strip test	(18-20)
3 California Mastitis Test	(21-23)
4 Laboratory Test	(24)

Reasons for getting mastitis

Bacteria enter teat when:	(25-27)
- dirty
- unhealthy

Treatment

Your vet can:
1 Sample for tests	(28-29)
2 Inject antibiotics	(30-31)
Do not deliver milk or meat during or shortly after treatment with antibiotics.
Consult your extension worker	(32-35)

Prevention

You can prevent mastitis generally by:
1 Hygiene before milking	(36-42)
2 Planning the order of milking	(43-45)
3 Ensuring complete milking	(46)
4 Dipping teats after milking	(47)
5 Early detection of mastitis	(48)
6 Early treatment at the right time	(49-50)
7 Culling	(51)
8 Checking new animals before mixing	(52)
9 Good, clean housing	(53-57)
10 Keeping accurate records	(58)
You can prevent mastitis in buffalo by:
11 Careful washing before milking	(59)
12 Correct milking technique	(60)
13 Early weaning	(61)
14 Gentle treatment	(62)

Danger periods for mastitis

1 Just after calving	(63)
2 Beginning and end of the dry period	(64)