Question

Milk yield is the example of

• A. specific repetition
• B. spatial repetition
• C. temporal repetition
• D. special repetition

Hint:

Temporal repetitions allow breeders to evaluate the permanent environmental effects influencing an animal's performance across different lactations or production cycles.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
In quantitative genetics, some traits can be measured multiple times on the same individual during its lifespan.
These repeated measurements are used to calculate the repeatability of a trait, which helps estimate the relative influence of permanent environmental effects.
Repetitions can occur across space, time, or specific physiological states.

Step 2: Detailed Explanation:
Temporal repetition refers to measurements of the same trait taken on the same individual at different points in time.
Milk yield in dairy animals is a classic example of temporal repetition.
A dairy cow produces milk over multiple successive lactations throughout her productive life.
The milk yield in the first lactation, second lactation, and third lactation represents the same genetic trait expressed at different times.
These sequential records are influenced by the animal's additive genetic value and permanent environmental factors, such as rearing conditions or permanent udder damage.
They are also affected by temporary environmental factors, like seasonal feed quality or weather during a specific lactation.
By measuring these repeated temporal records, breeders can calculate the repeatability coefficient to predict future performance based on early records.
In contrast, spatial repetition involves traits measured at different physical locations on the body, such as wool fiber diameter measured on the shoulder, side, and rump.

Step 3: Final Answer:
Thus, milk yield is categorized as an example of temporal repetition.