Question

Molybdenum toxicity in ruminants is known as

• A. Milk fever
• B. Grass staggers
• C. Teartness
• D. None of these

Hint:

Trace Element Disorders:
Molybdenum Toxicity $\rightarrow$ Teartness Teart Scours (Secondary Copper deficiency).
Magnesium Deficiency $\rightarrow$ Grass Staggers Tetany.
Calcium Deficiency $\rightarrow$ Milk Fever.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Trace element antagonism: excess dietary molybdenum reacts with ruminal sulfur to form thiomolybdates that irreversibly bind copper, inducing severe secondary hypocuprosis (Teart disease).
Key Formula or Approach:
\[ \text{Dietary Molybdate (MoO}_4^{2-}\text{)} + \text{Ruminal Sulfide (S}^{2-}\text{)} \longrightarrow \text{Thiomolybdates (MoS}_4^{2-}\text{)} \xrightarrow{\text{Binds Cu}} \text{Insoluble Cu-Thiomolybdate} \]

Step 2: Detailed Explanation:
Pathology of Molybdenum Toxicity (Molybdenosis Teart Disease) in cattle:
- Occurs in ruminants grazing pastures on high-molybdenum soils (teart soils, containing $> 20 - 100\text{ ppm Mo}$).
- In the rumen, molybdenum condenses with sulfide to form tetrathiomolybdate, which forms an insoluble complex with dietary copper, completely blocking copper absorption and systemic utilization.
- Manifests as severe debilitating watery scours (teart scours), achromotrichia (depigmentation of hair coat around eyes - 'spectacle eye'), and emaciation, clinically known as Teartness Teart Disease.

Step 3: Final Answer:
Therefore, Molybdenum toxicity in ruminants is known as Teartness, matching option (C).