Factors Affecting Genetic Gain per Year
Genetic gain per year is depend upon-
- Lactation period
- Calving interval
- Generation interval — Correct Answer
- Calving index
Explanation:
Correct Answer: Generation interval
Annual genetic gain (ΔG) formula: ΔG = (i × h² × σA) / L, where L = Generation interval.
Since L is in the denominator, a shorter generation interval directly increases the genetic gain per year. This is why progeny testing (which increases generation interval) gives high accuracy but lower annual gain.
Factors Affecting Response to Selection (R = h²S)
| Factor | Effect |
|---|---|
| Intensity of selection (i) | Higher i → Higher R |
| Additive genetic variance (σA) | Higher σA → Higher R |
| Accuracy of selection (rAP) | Higher accuracy → Higher R |
| Generation interval (L) | Shorter L → Higher annual ΔG |
Why Other Options Are Wrong
- Lactation period and Calving interval are production parameters, not direct determinants of genetic gain per year.
- Calving index relates to reproductive efficiency, not genetic gain calculation.
📚 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.
