Small-Scale Dairy Farming Manual

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Small-Scale

Dairy Farming Manual

Volume 5

Husbandry Unit 10.5
  MASTITIS


page 107
 
MASTITIS

Husbandry Unit 10.5: 

Technical Notes 

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

page 109


Extension Materials
What should you know about Mastitis? (5-16)

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

How can you know if your cow has mastitis? (17-24)

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

Why do your cows get Mastitis? (25-27)

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

How can you treat and prevent mastitis? (38-64)

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

 

page 110


The cost of mastitis  (5-9)

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.
 

page 111


5 Mastitis costs you money.

You must pay for veterinary fees and medicines.
 

6 You get less money from the collection centre if your milk is low quality (from an udder with mastitis).
7 If your milk contains antibiotics from mastitis treatment, the centre will reject your milk and pay you no money.

 

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

  page 112

Definition of mastitis  (9-12)

To make examination, diagnosis and treatment clear and uniform, mastitis cases can be grouped according to the character of symptoms.
Relationship between the amount of mammary gland tissue involved and the form of mastitis which results.

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.
 

page 113



 
What is mastitis?
9 Inflammation of the mammary glands.

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

What are the types of mastitis?

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

11 The udder is:
- hot
- swollen
- hard
- painful.
12 Milk in the strip cup is abnormal:
- watery and thin
- flecks and clots
- yellow or brownish colour.
 

 

  page 114


Chronic mastitis  (13-16)

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
 

page 115



 

Table 1:
 
Acute Mastitis
Chronic Mastitis
Hidden
Mild
With gland shrinkage
(Indurative mastitis)
General Condition high fever satisfactory satisfactory satisfactory
low food intake
Mammary gland swollen normal slightly: hard
hard -hard shrinks
painful -swollen
-painful
Milk Texture watery normal watery (ceased production)
thin
flecks
clots
Milk Colour yellow normal normal or (ceased production)
brownish slightly 
chaned
Milk Production low decreased decreased none
Diagnosis Clinical examination:  cow side  clinical,  clinical examination
milk appearence test (for supported 
ext.CMT)  by cowside 
laboratory tests/lab 
tests tests
 

page 116



 
 Chronic Mastitis
13 The cow shows satisfactory general condition.
But you know your cow has mastitis if you check your milk carefully.
14 There are 3 types of chronic mastitis.

Chronic hidden mastitis

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

Chronic Mild Nastitis
15 Your cow appears satisfactory.
But:
- the glands are slightly hard, swollen, painful
- the milk is slightly abnormal,watery, discoloured.
Chronic Mastitis with Gland Shrinkage
16 Without treatment, scar tissue replaces gland tissue.
The gland becomes hard, shrinks and cannot produce milk any more.
 

 

  page 117


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.
 

page 118


Cow
17 Check for fever and low food intake.
Udder
Check if glands are swollen, hard, red, hot, painful.
Strip Test
18 Before each milking:
- milk a few streams of milk into the strip cup (a small black container) from one teat only
19
- spread the milk on the plate of the strip cup
- check carefully.
20 Clean the strip cup and then check milk from the next teat.
 

 

  page 119


California Mastitis Test (CMT)  (21-23)

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.
 

page 120



 
 California Mastitis Test
21 Milk a few streams of milk from each teat into a different hole in the paddle.
22 Add 2 ml of reagent to the foremilk in each hole.
Move the paddle gently.
23 Easy flow with no gel shows no mastitis.
Slow flow with some gel shows possible mastitis.
Stringy or lumpy milk shows certain mastitis.
Laboratory Tests

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

 

  page 121


Agents causing mastitis  (25-27)

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.
 

page 122


25 In healthy teats, few bacteria enter because:
- the skin protects against bacteria
- the teat opening is tight
- a waxy substance seals the opening.
26 If the teat is unhealthy, has a lesion, or is very dirty:
- many bacteria can enter
27
- the cow's system cannot protect it from the bacteria
- they increase in number and spread to other parts of the gland
- the cow gets mastitis.
Cows can also get mastitis because other diseases such as metritis, pneumonia, digestive problems or low nutrition, make them weak.

  page 123



Treatment of mastitis  (28-31)

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.
 

page 124


28 In any case of mastitis, call the veterinarian.
29 He may take a sample of milk for testing
30
- inject antibiotics into the teat
31
- sometimes also inject antibiotics into the muscle or blood stream if the cow shows poor general condition.
 

 

  page 125



Drug residues  (32-35)

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.
 

page 126



 
32 After antibiotic treatment:
- do not send your milk to the collecting centre for some days
- ask your veterinarian when you can send your milk
33
- do not send your animal for slaughtering for some days
- consult your veterinarian about the length of time.
34 Some people may become sick after taking milk or meat which contains antibiotics.
35 Many countries have laws against delivering milk or meat which contain antibiotics.
You could be held responsible!
 

 

  page 127


Clean milk utensils  (38-39)

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.
 

page 128


Hygiene 

Before milking

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

37 Clean anywhere your animals are likely to lay down.
Always:

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

39 If you use a milking machine;
- clean and disinfect it thoroughly after each milking
- make sure it works correctly.
 

 

  page 129


Teat dipping  (40-42, 47)

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.
 

page 130



 
 40 Milk 2 or 3 streams of foremilk from each quarter into a strip cup:
- examine carefully.

 

After wallowing

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

42 Dry the teats and udder with a disposable paper towel or clean, dry cloth.
Use only one cloth per cow.
If you cannot use only one cloth per cow, use only clean hands.

  page 131



 During milking

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

44 Secondly, milk cows with suspected mastitis.
45 Finally milk cows with mastitis.
46 Make sure milking is complete, especially when you do not let your calf suckle.
 

 

  page 132


Dry cow treatment  (50)

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.
 

page 133



 
 After milking

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).

Early detection

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

Early treatment

49 Treat all teat and udder wounds immediately.

50 Treat all cows with visible mastitis (udder change) as soon as possible.
Treat cows with hidden mastitis at drying off
 

 

  page 134


 Culling

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

Checking

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

Housing

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

54 Take away manure and dirt and clean the barn:
- mastitis bacteria breed in dirty places.
 

 

  page 135


Records  (58)

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).
 

page 136



 
55 Keep floors dry and provide bedding.
56 Keep flies out e.g. with netting:
- flies carry mastitis bacteria.
57 Avoid:
- untrimmed hooves
- slippery floors.
Your cow may damage her udder and get mastitis.
Records
58 Keep records of mastitis and treatment:
- this can help you find problem cows.
 

 

  page 137


Preventing mastitis in buffalo  (59-62)

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.
 

page 138


59 Buffaloes like to wallow in water and muddy places.
This makes infection easier - wash them before milking.
60 Milk your buffalo with your thumb up not down.
61 If your calves suckle, wean them early.
Biting, pulling and hitting the udder causes damage which can lead to mastitis.
62 Your buffalo's udder and teats may be large.
Treat them gently and do not drive them with sticks or make them run.
 

 

  page 139

Important:
Injury or damage to your cow's udder leads to mastitis.
Protect your cow from injury and damage.
63 Your cow has high-risk periods for mastitis:
Early lactation
Just after calving discharge from the uterus contains bacteria which can cause mastitis:
- keep your cow and box very clean.
Beginning and end of dry period
64
- dip teats 2 times a day for the first week after drying off.

  page 140


What do you know about mastitis?
     
    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 
    3 California Mastitis Test 
    4 Laboratory Test 
    (24)
    Reasons for getting mastitis
    Bacteria enter teat when: 
    - dirty
    - unhealthy
    Treatment
    Your vet can:
    1 Sample for tests 
    2 Inject antibiotics 
    Do not deliver milk or meat during or shortly after treatment with antibiotics.
    Consult your extension worker 
    Prevention
    You can prevent mastitis generally by:
    1 Hygiene before milking 
    2 Planning the order of milking 
    3 Ensuring complete milking 
    (46)
    4 Dipping teats after milking 
    (47)
    5 Early detection of mastitis 
    (48)
    6 Early treatment at the right time 
    7 Culling 
    (51)
    8 Checking new animals before mixing 
    (52)
    9 Good, clean housing 
    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)

page 142

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