Which disease can be identified by the milk ring test in dairy surveillance?

Introduction:
The milk ring test is a simple screening assay used in dairy herds to detect antibodies against certain pathogens in bulk milk samples.

Given Data / Assumptions:

• Question targets the specific disease detected by the milk ring test.
• Common cattle diseases listed as options.

Concept / Approach:
The milk ring test detects anti-Brucella antibodies (primarily B. abortus) in milk. Antigen binds antibodies and forms a colored ring at the cream layer when positive.

Step-by-Step Solution:
Recall the purpose and antigen used in milk ring testing. Link the test to Brucella antibody detection in milk. Choose Brucellosis as the correct answer.

Verification / Alternative check:
Veterinary surveillance manuals specify the milk ring test for brucellosis screening in herds.

Why Other Options Are Wrong:

• Salmonellosis / Bovine tuberculosis / Leptospirosis: Not detected by the milk ring test; require other diagnostics.
• All of these: Incorrect because the test is specific for brucellosis screening.

Common Pitfalls:
Assuming all common cattle diseases are detected by one milk-based assay; tests are disease-specific.

Final Answer:
Brucellosis is identified by the milk ring test.