Learn why BF Farm breeds Kunekune pigs once a year for spring farrowing, including timing, sow care, piglet health, and responsible litter planning.

I keep BF Farm to one breeding season, with the goal of spring litters. Concentrating breeding and farrowing into one part of the year fits the way I want to manage the herd: deliberate pairings, a defined farrowing window, and time to focus on the litters rather than spreading them across the calendar.

Why We Plan for Spring Farrowing

Illustrative straw-bedded wooden farrowing barn with a mature black-and-tan spotted sow nursing four newborn piglets beside a separate warming area with a caged heat lamp.
Illustrative scene, not BF Farm documentary photography: spring litters still require dry shelter and a carefully protected heat source.

Spring usually gives newborn piglets a more forgiving environment than mid-winter, but it is not a guarantee. We still prepare dry shelter and a piglet-safe heat source because Missouri temperatures can change quickly.

Preparing Sows and Boars Before Breeding

Before breeding, we review body condition, feet and legs, appetite, general health, and parasite risk. We do not treat routine deworming as a universal calendar rule. Outdoor pigs can face meaningful parasite exposure, but the best control program depends on the farm, the parasites present, sanitation, pasture history, and the animal's condition. [2]

If an antiparasitic such as doramectin (Dectomax) is used, we follow the current swine label and applicable slaughter-withdrawal requirements. Dectomax is doramectin; it is not simply a long-acting form of ivermectin. Follow the current product label and veterinarian guidance for food-animal use and withdrawal requirements. [3]

Breeding preparation begins with soundness, reproductive history, and the condition of both animals. The Kunekune reproduction guide explains the wider reproductive cycle and why a breeding calendar is not a substitute for observation.

Body Condition Matters

Illustrative handler using both hands to check the back and rib coverage of a mature black-and-cream Kunekune-style sow in a straw-bedded barn handling area.
Illustrative prebreeding examination: assess body condition and soundness early, rather than waiting until the sow is heavily pregnant.

Breeding animals should enter the season in sound, moderate body condition. Both excessive thinness and excessive fat can make breeding, pregnancy, movement, farrowing, and lactation harder to manage. [1] We adjust feed gradually rather than trying to change condition at the last minute.

I want condition assessed before breeding, not discovered as a problem after the sow is heavily pregnant. The body-condition scoring guide describes how to evaluate cover consistently without relying only on weight.

How Long We Keep Boars With Sows

Original two-cycle timeline showing a six-week, 42-day boar exposure period divided into two approximate 21-day estrous cycles, with markers at days 0, 21, and 42 and a reminder to observe heat and record breedings.
Illustrative cycle timing, not confirmation of pregnancy: sows vary and mating observations remain necessary.

The normal estrous cycle in domestic pigs averages about 21 days. [1] Keeping a boar with a sow group for roughly six weeks gives the group exposure across about two cycles. We still observe behavior and keep breeding records rather than assuming every sow settled on the first opportunity.

Breeding for Low COI

Conceptual pedigree diagram showing one common ancestor appearing on both the sire and dam sides of a proposed Kunekune pairing, plus the need to consider soundness, health history, temperament, and pedigree accuracy.
Conceptual pedigree only; it is not a BF Farm pedigree or a COI calculation. Lower COI does not guarantee healthier piglets.

COI, or coefficient of inbreeding, is a pedigree-based measure of how much ancestry the sire and dam share. I aim for the lowest COI responsibly achievable because lower shared ancestry is one tool for maintaining genetic diversity.

Low COI is not the same thing as genetic soundness and does not guarantee healthier piglets. We also consider health history, structure, temperament, parents and pedigree, breed quality, and the purpose of the pairing.

When planning the season, I aim for the lowest responsible pairing COI alongside healthy structure, temperament, and suitable pedigrees. The COI guide explains the strengths and limits of that number.

Estimating Farrowing Dates

Original farrowing-planning timeline distinguishing the day a boar is introduced from an observed service date, then showing typical pig gestation of 114 to 116 days and a variable estimated farrowing window.
Estimate from the best-supported service date, not simply the day the boar enters the pen. A broad service window widens uncertainty.

Pig gestation is commonly remembered as “three months, three weeks, and three days,” but it is only a rule of thumb. Modern swine references put normal gestation around 114–116 days. [1] Because a boar may breed a sow more than once during a group breeding period, we use breeding observations and date ranges rather than relying on the day the boar was first introduced.

A planned service window gives a useful estimate, not a guaranteed farrowing date. The pregnancy-signs guide helps owners track signs and understand when veterinary confirmation is preferable to guesswork.

What We Prepare Before Farrowing

As the expected window approaches, we prepare a clean, dry, low-stress farrowing area and a warm protected zone for newborn piglets. For more detail, see our Kunekune farrowing guide and farrowing-stall guide.

Why We Prefer One Main Breeding Season

Illustrative late-fall breeding paddock with two mature differently colored Kunekune-style pigs beside a fenced gate, water trough, straw, barn, and a handler recording observations on a clipboard.
Illustrative planned-season management: grouping mature breeding animals and keeping records can concentrate breeding without maximizing litter numbers.

For me, one planned season is a management choice, not a rule every breeder needs to copy. It gives the sows recovery time, concentrates farrowing observation into one part of the year, and lets me focus on careful pairings and well-raised litters instead of maximizing litter numbers.

© 2026 BF Farm Kunekune Pigs

Sources & References

  1. MSD Veterinary Manual: Breeding Management of Pigs
  2. Merck Veterinary Manual: Overview of Gastrointestinal Parasites of Pigs
  3. FDA NADA 141-061: Dectomax (doramectin) Freedom of Information Summary

About the Author

This article describes Mark Bengtson's current breeding-season choice: one planned season aimed at spring litters. That schedule reflects how he wants to manage farrowing and herd capacity at BF Farm; the reproductive biology and medication guidance remain tied to the cited sources.