Week 5: Mammary gland examination

finished - but look at classification section (last).
🐮 Mammary Gland Anatomy and Examination

The mammary gland, or udder, is crucial for dairy cows due to its role in milk production, which significantly impacts farm economics. A healthy mammary gland is essential for optimal milk yield and overall animal well-being.

Anatomy: 4 glands, each with 1 teat, inguinal region.

Number of Glands and Lactiferous Ducts

The number of glands and lactiferous ducts varies among species:

🩺 Examination of the Mammary Gland

Key steps (Overview):

1. Case History: Gathering information on previous lactation, stage of lactation, husbandry conditions, and hygiene of milking.

2. Clinical Examination: Inspection, palpation, and examination of mammary gland secretion.

3. Special Examination: Biopsy of tissue and ultrasonography (USG).

Case History Details

Important factors to consider in the case history include:

• Previous lactation (milk yield, diseases)

• Stage of lactation (calving, insemination, current yield)

• Husbandry conditions (housing, grazing-land, pasture, type of bedding - can be a factor to mastitis)

• Hygiene of milking (pulsation rate 40 to 50, vacuum 50.6kPa, teat cup attachment and removal, udder towels, milker's hand cleanliness, equipment cleaning and disinfection)

• Other cases of disease in the herd and their treatments

I. Inspection

Visual inspection involves assessing:

• Shape

• Size (L, M, S)

• Symmetry

• Skin - color, presence of lesions, parasites etc.

• Teats

• Dribbling of secretion (milk, blood, pus, etc.)

• Floor under the udder and soiling

• Animal's behavior

A. Udder Shapes:

8 udder shapes can be observed:

1. Milking machine or key-shaped udder: Four quarters are of similar size, closely attached, and relatively flat.

2. Abdominal udder: Extends forward along the belly.

3. Large udder: Extends along the belly and upwards between the legs.

4. Udder in the thighs: Located between the thighs, bulging backward.

5. Round udder: Relatively small base, swings as the cow walks.

6. Stepped udder: Hindquarters are better developed than forequarters.

7. Goat-like udder: Sharp division between fore and hindquarters, large teats.

8. Primitive udder: Small, often hairy, with small teats.

B. Size Abnormalities

We assess size as small, medium or large. Changes in udder size can indicate several conditions:

• Enlargement:

  • Oedema (physiological in late pregnancy)

  • Rupture of suspensory ligaments (medial and lateral, anterior)

  • Haematomas and rupture of the abdominal wall - can feel elasticity, fluid like.

  • Mastitis

  • Abscess - can indicate presence of nodules, can feel hard consistency.

  • Tumour (neoplasia)

  • Ductus lactiferous obstruction

• Reduction in size:

  • Dry udder

  • Mastitic atrophy - can be linked to chronic mastitis

C. Symmetry

Asymmetry can result from atrophy of one or more quarters.

D. Udder Skin

Inspection of the udder skin involves assessing:

• Hair

• Color - red (inflammation), cyanotic (bluish - mastitis - bacteria post-mastitis makes toxins to make skin cyanotic)

• Odour

• Temperature

• Efflorescences

• Soiling - clean/acceptable/doubtful/dirty/unacceptable

• Parasites (lice, mites)

• Lesions (scratches, crusts, vesicles, pustules, papules, ulcers)

Soiling can be categorized as clean, acceptable, doubtful, dirty, or unacceptable.

E. Teats examination

Evaluation of teats includes assessing:

• Size

• Shape

• Accessory teats

• Teat tip

I. Teat Size

Measurements for judging udder quality include:

• Teat length - should be 8-10cm.

• Distance between the teat tip and the ground

II. Teat Shapes

Different teat shapes include:

• Optimum form: Cylindrical, 8-10 cm long, gradually merging into the udder.

• Bottle-shaped teat: Long teat, bulging at its tip.

• Conical teat: Well distended at the base when full, collapses into folded skin after milking.

• Short teat: 2-4 cm long, poorly demarcated from the udder.

• Collapsed teat: Considerable dilatation of the teat cistern, often seen in old, high-yielding cows.

• Fleshy teat: Thick, fairly short, of solid consistency, often difficult to milk.

• Pencil teat: Particularly seen in young heifers, associated with hard milking.

III. Supernumerary (Accessory) Teats

Types of accessory teats:

• Cranial or forward teat

• Accessory teat arising from a main teat

• Intermediate teat between fore and hindquarters

• Accessory teat very close to a main teat

• Caudal or posterior supernumerary teat

IV. Shape of the Teat Tip

Variations in teat tip shape include:

• Normal teat with rounded tip

• Dished teat with flattened tip and concentric circles of raised tissue

• Funnel- or crater-shaped teat with an indentation at the teat orifice

• Teat with a pocket at its tip

• Pointed tip (often associated with a long and narrow teat canal)

2. 🖐 Palpation

Palpation should be performed after milking to assess:

• Parenchyma: Consistency and structure.

• Teats: Gland cistern and teat canal.

  • Sphincter (teat tip): Firmness.

• Temperature

• Tenderness

• Pain

• Lymph nodes: Normally cannot be palpated when the parenchyma is normal.

Parenchyma Structure

• cow: normal (fine-grained) vs. pathological (lumpy)

• others (homogenous) vs. pathological (hardening, swollen)

Supramammary Lymph Nodes

These nodes can typically be palpated on the caudal aspect of the udder and may be slightly enlarged in cases of mastitis.

🥛 Collection of Milk

Milking Techniques

• Milking with the whole hand (standard milking method): Least harmful method. Milk inside teat cistern is prevented from flowing back by pressure from thumb + index finger. Gripping remaining fingers to form fish → forces milk out.

• Bent thumb technique: Safe only when correctly applied. Upper part of teat is squeezed.

• Stripping: Used only on short teats. Compression is done, sliding fingers + thumb down teat. Can cause trauma, inflammation if not correctly.

• Machine milking

🧪 Mammary Gland Secretion

Amount of Milk

The amount of milk produced varies depending on the species and individual factors, as known from the case history.

A. Color

• Normal: White, milky.

• Changed: Yellow (inflammation, mastitis, cholestrum, carrots), bluish (linked to chronic mastitis), bloody (red), brown.

B. Odour

• Typical: Milky, species-dependent.

• Atypical: Due to inflammation, nutrition and metabolic disorders (ketosis), chemicals, or drugs.

C. Consistency

• Watery

• milky: Lightly viscous. (everything milky is good)

• Viscous (cholestrum is viscous)

• Slimy (typical for mastitis)

Tasting of milk, mastitis is typically salty.

D. Abnormal Contents

Examined using a strip cup:

• Blood

• Flakes

  • Casein (normal, white, firm)

  • Fibrin (pathological, yellowish, firm)

  • Pus (pathological, yellowish, slimy)

  • Blood clots (pathological, reddish)

  • Sandy content (calcium)

Classification of Changes

Changes in color, consistency, and presence of flakes are important diagnostic indicators.

1. Normal milk

2. pregant heifers + dry cows is normally serous or honey like

3. etc.

🧪 Diagnostic Tests

California Mastitis Test (CMT)

The CMT reagent contains alkylarylsulphonate and phenyl red.

Judgment of CMT Results

Note: A positive result is not always due to bacterial colonization.

Biochemical Examination of Milk

🐮 Classification of Udder Status

🔬 Special Examinations

Specialized examinations include ultrasonography (USG) and punction.