Texas FFA Livestock Judging PracticeTest

Which trait for swine has the lowest heritability estimate?

1. Weight gain

2. Fleece quality

3. Litter size

4. Meat quality

The correct answer is: Litter size

The trait with the lowest heritability estimate among the options provided is litter size. Heritability estimates indicate the proportion of variation in a trait that can be attributed to genetic factors, as opposed to environmental influences. Litter size in swine is influenced by a variety of environmental factors, including nutrition, health, and management practices. Because these external elements play a significant role in determining how many piglets a sow can produce in a single litter, the genetic contribution to this trait tends to be lower compared to others. In contrast, traits such as weight gain, fleece quality, and meat quality generally have higher heritability estimates because they are more directly related to the genetics of the animals. For example, weight gain is closely linked to the efficiency of feed conversion, which is largely a genetic trait in livestock. Meat quality, influenced by muscle structure and fat distribution, is also heavily governed by genetic lines. Fleece quality in sheep relates closely to genetic traits as well. Therefore, the heritability of litter size being the lowest reflects the complexity and influence of environmental factors in comparison to the relatively more straightforward genetic mechanisms behind the other traits mentioned.