Here's why:
* Direct selection focuses on the traits of the individual being selected. For example, choosing the tallest cow in a herd.
* Indirect selection focuses on the traits of the individual's offspring. For example, choosing a cow based on the milk yield of her daughters.
Indirect selection is often used when:
* The desired trait is difficult or expensive to measure directly in the parent.
* The trait is influenced by environmental factors, making it hard to assess the parent's genetic contribution.
* The trait is only expressed later in life, such as disease resistance.
This method relies on the assumption that the offspring will inherit the desired traits from their parents. It is a common practice in animal breeding programs aimed at improving traits like milk production, meat quality, or disease resistance.