Hay for Cattle: Harvesting, Storing, and Feeding It Right
Hay is the cornerstone of cattle nutrition. It supplies the long-stem fiber that keeps the rumen functioning normally — something no other feed can fully replicate. No matter how much silage or concentrate a farm uses, dairy cows still need a minimum daily allowance of good-quality hay. Skimping on it invites rumen acidosis, reduced cud-chewing, and a cascade of production problems that cost far more than the hay saved.
Why Hay Matters for Rumen Health
Cattle are ruminants. Their first stomach compartment — the rumen — holds 100–150 liters of fermenting feed and the microbial population that breaks it down. For fermentation to work correctly, rumen pH must stay between 6.2 and 6.8.
Long-stem fiber from hay is what drives chewing time. A cow that chews thoroughly produces more saliva, and saliva acts as a natural buffer, keeping pH in the safe range. The chain reaction of inadequate hay looks like this:
Less hay → less chewing → less saliva → rumen pH drops → subclinical or clinical acidosis
Acidosis suppresses feed intake, reduces milk fat percentage, and predisposes cattle to laminitis and liver abscesses. Quality hay, fed consistently, is one of the cheapest ways to avoid these problems.
Source: Journal of Dairy Science, Forage Quality and Rumen Health, 2023
When to Cut Hay
Cutting timing is the single most influential decision in hay production. Early cutting yields higher protein and energy but less total dry matter per hectare. Delayed cutting increases bulk yield but drives down quality as fiber lignifies and protein digestibility falls.
Alfalfa: Cut at 10–20% bloom — when the first flowers just begin to open. At this stage, crude protein runs 18–22% and ADF (acid detergent fiber) sits around 28–32%, giving a highly digestible product.
Grass-legume mixtures: Cut grass species at boot-to-heading stage, legumes at early bloom. Waiting until full bloom or seed-set for either means significant quality loss.
Field drying time: Hay should reach 14–18% moisture before baling. Drying speed depends on sunshine, air circulation, and windrow density. Tedding and raking accelerate drying but can cause leaf loss in legumes — leaves carry most of the protein, so rough handling is costly.
Source: Penn State Extension, Hay Quality and Management, 2023
How to Assess Hay Quality
Visual and Sensory Checks
| Indicator | Good Hay | Poor Hay |
|---|---|---|
| Color | Green to light yellow | Brown, dark, or bleached |
| Smell | Clean, sweet, dry | Musty, sour, moldy |
| Leaf-to-stem ratio | Leafy (especially alfalfa) | Mostly stemmy |
| Moisture feel | Dry, brittle, crumbles cleanly | Tacky, clumped, or dusty |
| Visible mold | None | Visible dark patches or powder |
Laboratory Analysis
Visual inspection gives a rough guide; laboratory testing gives numbers you can use to balance rations. Key parameters to request:
| Parameter | Target (Alfalfa) | Target (Grass Mix) |
|---|---|---|
| Crude Protein (CP) | 18–22% | 10–14% |
| ADF | 28–32% | 35–42% |
| NDF | 38–45% | 55–65% |
| Moisture | 12–18% | 12–18% |
| Relative Feed Value (RFV) | >150 (premium) | >100 |
Lower ADF means better digestibility. Lower NDF means the cow will eat more of it voluntarily — both are desirable. When purchasing hay or pricing your own, a forage test is the only way to know what you are actually feeding.
How to Store Hay Properly
Moisture damage is the primary enemy of hay quality. Wet hay generates heat through microbial activity; at high temperatures this destroys vitamins, caramelizes sugars, reduces protein availability, and — at extremes — can spontaneously combust.
Practical storage rules:
- Keep hay off the ground. Use pallets, wooden beams, or crushed gravel to prevent moisture wicking up from the soil.
- Store under cover. A pole barn or solid roof protects from rain and sun bleaching. Outdoor stacks lose 10–30% of dry matter and quality within one season.
- Ensure side ventilation. Stacked bales need airflow between and around them.
- Wrap round bales in quality stretch film if storing outside — it excludes light and moisture and preserves quality well when applied correctly (6 layers minimum).
- Rotate stock. Use older hay first; never stack new bales on top of last season's stock and forget the bottom layer.
- Monitor temperature. A stack running above 55°C in the first week of storage has excess moisture. Temperatures above 65°C indicate a fire risk and require immediate intervention (spread bales, allow cooling with caution).
How Much Hay to Feed per Day
Daily hay allowance depends on the animal's category, the rest of the ration, and your forage quality. The table below gives practical starting points for farms in Uzbekistan and similar climates.
| Animal Category | Daily Hay (kg) | Notes |
|---|---|---|
| Dry cow | 6–10 | Maintain body condition, no silage needed |
| Mid-production dairy cow | 4–8 | Alongside silage and concentrate |
| High-production dairy cow | 3–5 | Silage carries more of the forage load |
| Calf (3–6 months) | 0.5–1.0 | Introduce gradually; rumen developing |
| Growing/finishing beef | 5–8 | Adjust based on growth targets |
Source: University of Minnesota Extension, Dairy Cattle Nutrition, 2024
These figures assume average-quality hay (CP ~14–18% for alfalfa, ~10–12% for grass). Higher-quality hay can be fed at slightly lower quantities; poor-quality stemmy hay should be fed more liberally to meet fiber needs, but this drives up ration cost and may limit energy intake.
Can You Manage Without Hay?
If a well-made silage is available, it can replace most of the hay in a ration — but not all of it. The key difference is particle length. Short-chopped silage does not stimulate the same level of chewing as long-stem hay. Even when total NDF from silage is adequate, the physical form falls short for rumen buffering.
Minimum daily hay for a dairy cow on a silage-based ration: 1–2 kg of long-stem hay. This amount maintains rumination time and salivary buffering without displacing the high-energy silage.
If no silage is available and hay is the sole forage, quality becomes paramount. Poor hay fed as the only forage leads to energy deficiency, weight loss, and declining milk output — especially in early lactation when cows need maximum feed intake.
FAQ
1. What is the best hay for dairy cows?
Alfalfa hay cut at early bloom consistently delivers the highest crude protein (18–22%) and energy among common forages. For farms that cannot grow or afford premium alfalfa, a well-managed grass-legume mixture cut at early heading is the next best option.
2. How do I know if hay has gone bad?
Brown color, a musty or sour smell, visible mold patches, or excessive heat when you push your arm into a bale are all signs of compromised quality. Moldy hay should not be fed — mycotoxins from common molds can suppress immunity and reproduction.
3. How long can hay be stored?
Properly dried and covered hay retains good nutritional quality for 12–18 months. Beyond two years, significant vitamin and protein degradation typically occurs even in good storage conditions.
4. Is hay different from straw?
Yes. Hay is made from whole green plants (grasses, legumes) that are cut and dried before seeding. Straw is the dry stem residue left after grain harvest. Straw is low in protein and energy and serves as bedding or a low-quality fiber filler, not a primary feed.
5. Can I feed wet hay in an emergency?
Slightly damp hay (15–20% moisture) can be fed immediately if no mold is present, but it should not be stored — it will heat and mold within days. Hay above 20% moisture at baling should never go into long-term storage.
6. Does cutting hay more times per year reduce yield?
Frequent cutting (every 28–35 days for alfalfa) produces higher-quality hay at each cut but somewhat less total tonnage over a season than waiting longer. The higher quality — especially protein and digestibility — usually justifies the frequency for dairy operations.
7. How does silage compare to hay for rumen health?
Both provide fiber, but hay provides longer particles that drive chewing and salivation more effectively. A ration combining quality silage with even a small amount of long-stem hay consistently outperforms an all-silage ration for rumen pH stability.
Sources and References
- Penn State Extension. Hay Quality and Management. 2023. extension.psu.edu
- University of Minnesota Extension. Dairy Cattle Nutrition. 2024. extension.umn.edu
- Journal of Dairy Science. Forage Quality and Rumen Health. 2023. journalofdairyscience.org
- Merck Veterinary Manual. Feeding Dairy Cattle. 2024. merckvetmanual.com