Learn what COI means on a Kunekune piglet listing, why it matters, and how buyers should use it when choosing breeder stock.

A low number on a piglet listing can make a buyer feel confident, and a high number can make them nervous. But COI is not a magic score that tells you whether a Kunekune piglet is “good” or “bad.” It is one tool that helps you ask better questions before choosing a piglet, especially if you are buying breeder stock.

What COI Means

COI stands for Coefficient of Inbreeding.

In plain language, it estimates how closely related the piglet’s parents are within the pedigree being measured. A higher COI means there is more shared ancestry behind that piglet. A lower COI means there is less shared ancestry showing in that pedigree.

COI is usually shown as a percentage.

For example:

  • 0% COI means no shared ancestors were found in the pedigree used for the calculation.
  • A low COI means there is some relationship, but not much.
  • A higher COI means the sire and dam share more common ancestors.

The important phrase is “in the pedigree used for the calculation.” COI depends on how many generations are included and how complete the pedigree information is.

Why COI Matters in Kunekune Pigs

Kunekunes are a smaller breed population compared with many common livestock breeds. That means responsible breeding decisions matter. When the same bloodlines are used too closely or too often, breeders can accidentally concentrate both good and bad traits.

COI can help breeders and buyers think about genetic diversity. It may also help avoid repeatedly doubling up on the same relatives without a clear purpose.

For someone buying a Kunekune piglet as breeder stock, COI is worth paying attention to because that piglet may influence future litters, future herd health, temperament, structure, and long-term usefulness.

COI Does Not Tell the Whole Story

A COI number should never be the only thing you look at.

A piglet with a low COI is not automatically a better pig. A piglet with a higher COI is not automatically a poor choice. The number does not tell you:

  • whether the piglet has good structure,
  • whether the feet and legs are strong,
  • whether the bite and teats look appropriate,
  • whether the parents have good temperament,
  • whether the piglet is healthy and growing well,
  • whether the bloodlines fit your goals,
  • or whether the breeder made thoughtful pairings.

That is why experienced breeders look at the whole animal, not just the number on the listing.

What Buyers Should Ask

If you see COI on a Kunekune piglet listing, use it as a starting point for a better conversation.

Good questions include:

  • How many generations were used to calculate the COI?
  • Are the sire and dam closely related?
  • Why did you choose this pairing?
  • What traits were you trying to improve or preserve?
  • What are the strengths and weaknesses of the parents?
  • Would this piglet be better suited for breeding, meat production, or a pet home?
  • Are there any known concerns in this line?

A responsible breeder should be willing to explain the pairing in plain language.

COI and Breeder Stock

For buyers who want Kunekunes for a breeding program, COI matters more than it might for someone buying a companion pig or a feeder pig. Breeder stock should be chosen with the future in mind.

A good breeding prospect should bring more than cuteness. You want to think about:

  • health,
  • temperament,
  • structure,
  • breed type,
  • growth,
  • manageability,
  • fertility potential,
  • and how that pig may fit with future breeding plans.

At BF Farm Kunekune Pigs, we look at breeder stock as a long-term decision. A piglet should be useful for the purpose it is being sold for, whether that is helping a family raise their own meat, building a small homestead herd, or starting a responsible breeding program.

Should You Avoid High COI Piglets?

Not always, but you should ask more questions.

A higher COI may mean the breeder was trying to concentrate certain traits. That can be done intentionally, but it also carries more responsibility. If a breeder cannot explain why the pairing was made, that is a concern.

For most new buyers, especially first-time breeders, it is wise to look for pigs with reasonable genetic diversity and strong overall quality. A lower COI can be helpful, but only when the piglet is also sound, healthy, well-managed, and suited to your goals.

The Bottom Line

COI is a useful number, but it is not the whole pig.

Use it to understand the pedigree. Use it to ask better questions. Use it alongside structure, temperament, health, breeder honesty, and your long-term goals.

The best Kunekune buying decisions are not made from one number on a listing. They come from looking at the full picture and choosing pigs that are a good fit for the life and purpose you are preparing for.

About the Author

BF Farm raises registered Kunekune pigs with attention to temperament, structure, bloodlines, and long-term breed quality. Our articles are based on real experience with breeding decisions, farrowing, piglet care, buyer education, and helping families choose Kunekunes that fit their farm or homestead.