How old is a pig when it has its first heat?

Pigs typically reach puberty and have their first heat cycle, also known as estrus, between 4 to 7 months of age.

However, there are factors that can affect this age:

* Breed: Some breeds mature earlier than others.

* Nutrition: A well-nourished pig will reach puberty sooner than a poorly nourished one.

* Environment: Stress can delay puberty.

It's important to note that these are just general guidelines. If you're concerned about a pig's sexual development, it's best to consult a veterinarian.