Sire Selection Basis in ONBS
In ONBS (open nucleus breeding system), sire is selected on the basis of:
- Progeny testing
- Sibling test — Correct Answer
- Individual Selection
- Pedigree selection
Explanation:
Correct Answer: Sibling test
In both Open and Closed Nucleus Breeding Schemes (NBS), sire selection is based on the Sibling test (performance of sisters/brothers) rather than progeny testing. This is because sibling testing provides a much shorter generation interval while still giving reasonably high accuracy.
ONBS vs CNBS — Comparison
| Feature | CNBS (Closed) | ONBS (Open) |
|---|---|---|
| Gene flow | Unidirectional: N → M → V | Bidirectional: N ↔ M ↔ V |
| Nucleus herd | Closed — no entry from outside | Open — superior animals can enter from village/base herd |
| Inbreeding rate | Higher | Lower |
| Genetic progress | Lower | Higher (10–15% more than CNBS) |
| Used in | Pigs & Poultry | Cattle, Buffalo & Sheep |
| Sire selection basis | Sibling test | Sibling test |
Why Sibling Test over Progeny Testing in NBS
- Sibling test: shorter generation interval → higher genetic gain per year
- Progeny testing: more accurate BUT very long waiting period (2–5 years for daughters to perform)
- In NBS: genetic gain/year is more important than accuracy per generation
📚 About this Topic — Animal Genetics & Breeding
This multiple choice question is from Animal Genetics & Breeding, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Genetics & Breeding to strengthen your preparation.
