The Right Time to Breed Your Sow: Heat Signs, Maturity & Weight Explained

As a pig farmer and someone who offers boar services, one of the most important — yet misunderstood — topics I come across is when to breed a sow. Many farmers get excited the moment their gilt or sow shows signs of heat and rush to the boar. But this often leads to poor breeding outcomes, low litter sizes, and unnecessary blame on the boar.

This article will walk you through the signs of heat, how to know if your sow is mature enough, and why weight matters more than age when deciding the right time to breed.

Signs That a Sow Is on Heat

Heat (also called estrus) is the period when the sow is ready to mate. Look for these signs:

• Swollen and reddened vulva
• Clear mucus discharge
• Restlessness or increased grunting
• Mounting behavior or standing to be mounted
• Standing still when you apply pressure to her back (standing heat)

Important: Heat signs only mean the sow is fertile — not necessarily that she’s mature or ready for pregnancy.

When Is a Sow Ready to Breed?

There are two conditions you must check before breeding:

1. Sexual maturity — Most gilts start cycling at 5–7 months old.

2. Sufficient body weight — More critical than age.

✅ Ideal weight for breeding: 100–120 kg
✅ Minimum age: About 7–8 months (but only if weight is right)

Bringing a young or underweight sow to the boar may result in:

• Very few piglets (sometimes just 2–4)
• Weak piglets that struggle to survive
• Farrowing difficulties
• Poor milk production

Why Weight Is More Important Than Age

Some farmers believe that once a pig shows heat, it’s ready. Not quite.

An underweight pig may:

1. Fail to support a full litter during pregnancy
2. Produce fewer eggs during ovulation
3. Have trouble farrowing
4. Take longer to come back into heat after farrowing

Breeding before the sow reaches 100 kg is like planting seeds in poor soil — results will be disappointing.

✅ Benefits of Waiting Until the Sow Is Mature and Heavy Enough

1. Higher conception success
2. Larger, healthier litters (8–12 piglets)
3. Stronger piglets that grow faster
4. Better milk production and mothering ability
5. Less stress on the sow, faster recovery

My Experience as a Boar Service Provider

I provide boar services at a fee of Kshs. 1000 upfront or one piglet after delivery — your choice.

However, I sometimes have to turn away farmers who bring immature or underweight sows. It’s not to frustrate them — it’s to protect both their investment and my boar’s performance. If a pig is too small, the litter will likely be poor, and I end up blamed unfairly.

That’s why I always advise: Wait until your sow is mature and heavy enough.

Final Advice

Before taking your sow to the boar, ask yourself:

• Is she showing clear signs of heat?
• Is she at least 7 months old and weighs 100–120 kg?
• Is she healthy and well-fed?

If yes — she’s ready.
If no — feed her well, wait for the next cycle, and avoid costly mistakes.

Let’s breed smart, not fast. A little patience goes a long way in pig farming.