What Role Does Late-Season Growth Play in Feed Value for Winter Stock?

Introduction

Late-season hay growth — whether in September, October or even November — can be a blessing or a disappointment.
Cooler weather often brings a fresh flush of grass, but this late growth behaves very differently from early-season forage.

So the question is:

➡️ Does late-season growth make good winter feed?
➡️ Or is it lower-quality hay you should avoid?

This guide explains how late-season hay affects nutrition, digestibility and livestock performance.


1. Why Late-Season Growth Happens

Late-season growth is driven by:

  • cooler temperatures
  • rainfall after summer drought
  • reduced evaporation
  • slowed plant maturity

Grasses enter a recovery phase, focusing on energy storage rather than stem elongation.

But lower daylight hours change everything.


2. Late-Season Growth Is Leafy — But Not Always Nutritious

Autumn hay tends to look green and leafy, but that doesn’t guarantee high feed quality.

Reasons:

  • low sunlight → reduced sugars
  • slow growth → lower protein accumulation
  • dew and moisture → slow drying and higher mould risk
  • early frost → cellular damage

The hay looks good but may test lower in energy (ME) and protein.


3. Fibre Levels Drop — Which Can Be Good or Bad

Late-season hay usually has:

  • lower ADF (Acid Detergent Fibre)
  • lower NDF (Neutral Detergent Fibre)
  • softer stems

This makes the hay:

✔ easier to chew
✔ more palatable
✔ good for cattle needing bulk

But…

Lower fibre means:

✘ less rumen stimulation
✘ reduced winter weight maintenance if nutrition is low
✘ risk of underfeeding high-demand animals


4. Protein Levels Vary Widely

Late-season hay may have:

  • 6–10% protein in grass-only fields
  • 10–16% if legumes (clover/alfalfa) are present

Protein content depends heavily on:

  • soil nitrogen
  • plant maturity at cutting
  • whether it’s a regrowth or a stressed stand

A forage test is essential for accurate feeding rates.


5. Sugar (WSC) and Energy Are Usually Lower

Shorter days = reduced photosynthesis.
This leads to:

  • lower sugar (WSC)
  • lower starch
  • lower ME (Metabolisable Energy)

Animals needing high-energy feed, such as horses or lactating cows, may struggle on late-season hay alone.


6. Drying Late-Season Hay Is More Difficult

Autumn hay’s biggest challenge is drying.

Late-season hay suffers from:

  • heavy morning dew
  • shorter drying days
  • cooler temperatures
  • higher humidity
  • slower evaporation

This increases the risk of:

  • mould
  • spoilage
  • heating
  • botulism (in wrapped haylage if baled too dry)

7. Frost-Damaged Growth: Use with Caution

A hard frost can:

  • rupture plant cells
  • encourage mould
  • reduce sugar content
  • decrease palatability

While cattle often eat frost-damaged hay, horses and high-performance livestock may refuse it.


8. Which Livestock Benefit Most from Late-Season Hay?

Beef Cattle

Excellent for maintenance feed.
Provides bulk with moderate nutrition.

Sheep

Good for dry ewes or maintenance feeding.

Goats

Acceptable if mould-free and leafy.

Dairy Heifers (Non-Lactating)

Good for body condition stability.


9. Which Livestock Need Higher-Quality Hay?

Horses (especially performance horses)

Typically require higher energy and cleaner forage.

Lactating Cows

Need more energy and protein.

Young Stock / Calves

Require higher ME for growth.

Goats in milk

High nutritional demand.

If feeding late-season hay to these groups, supplement with:

  • grain
  • alfalfa
  • mineral licks
  • higher-quality early-cut hay

10. Should You Cut or Leave Late-Season Growth?

Cut It If:

✔ ample regrowth
✔ dry weather window
✔ you need maintenance hay
✔ weeds are low
✔ frost hasn’t destroyed quality

Leave It If:

✘ yields are too low
✘ weeds dominate
✘ drying weather is poor
✘ ground is soft and risks damage
✘ it’s too close to winter for curing

Leaving growth can protect crowns and improve spring vigour.


Conclusion

Late-season hay growth can be a useful resource for winter feeding — but only if you understand its limitations.
It’s usually leafy, soft and palatable, but lower in energy, sugar and protein than early-season cuts.

It’s great for maintenance feed for cattle, sheep and goats, but less ideal for horses or milking animals without supplementation.

At PremiumHaySupply.com, we test and sort our hay by season and nutrient profile to ensure every customer gets the right feed for their livestock.

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