Hay Terminology Explained
At AgriTec International, our mission is to equip farmers with the knowledge and tools to grow healthier crops, raise more productive livestock, and increase profits, field by field. When it comes to producing top-quality hay and forage, understanding the terminology behind feed analysis and soil fertility is key. Whether you’re growing alfalfa, grass hay, or mixed forage, knowing the science behind the numbers can help you make better decisions for your livestock and your wallet.
Let’s break down some of the most important agricultural terms, and how you can use AgriTec’s proven solutions to turn this knowledge into results.
1. RFV - Relative Feed Value
Relative Feed Value (RFV) is a common index used to rank forage quality, especially for legume hays like alfalfa. It estimates how digestible and consumable the forage is for livestock, based on two key factors: ADF (Acid Detergent Fiber) and NDF (Neutral Detergent Fiber).
- Higher RFV = Better quality hay.
- RFV of 100 is considered average (like full-bloom alfalfa).
- RFV above 150 is considered premium or dairy-grade.
Higher RFV forage means animals eat more and digest more, leading to faster weight gain, better milk production, and less wasted feed.
Products like Bio-Act and Advanced-Cal help improve photosynthesis, protein content, and digestibility in plants, leading to higher RFV forage naturally, without excessive synthetic fertilizers.
2. ADF - Acid Detergent Fiber
ADF measures the indigestible portion of forage, mainly cellulose and lignin. The lower the ADF, the more digestible the hay is.
- Low ADF (<30%) = higher digestibility
- High ADF (>40%) = more stemmy and less digestible
Hay with lower ADF allows cows and livestock to get more energy per bite.
Improving soil health with Pro-Cal, Humic Acid, or Aerate enhances plant structure and lowers fiber concentration, producing softer, leafier hay that animals love.
3. NDF - Neutral Detergent Fiber
NDF measures total plant fiber, including digestible and indigestible parts. It impacts how much an animal can and will eat.
- Lower NDF = Higher intake potential
- NDF over 60% often means lower intake and reduced gains.
For dairy or beef operations, even small reductions in NDF can lead to higher dry matter intake (DMI), which translates to more milk, faster weight gain, and improved reproductive performance.
When soil lacks calcium or proper microbial balance, plants become stem-heavy. Using Advanced-Cal or Foliar-Act ensures complete nutrition, leading to better fiber ratios and more palatable forage.
4. NIR - Near Infrared Reflectance Spectroscopy
NIR is the technology used to rapidly analyze forage samples for ADF, NDF, protein, moisture, and more.
- It’s fast, accurate, and cost-effective.
- Allows farmers to compare multiple fields or cuttings quickly.
Using NIR, you can pinpoint which fields need attention, and apply the right AgriTec program to improve forage before the next cutting.
Always follow up high-NDF or low-RFV results with a soil test and consider applying Bio-Act or Alt-15 to promote healthier growth on future cuttings.
5. RFQ - Relative Forage Quality
RFQ is the modern replacement for RFV. It factors in fiber digestibility, making it a better predictor of animal performance, especially for grass hays.
- RFQ over 140 is excellent for lactating dairy cows.
- 100-130 is fair to good for beef and horses.
RFQ shows how hay performs in the animal, not just in the lab. It’s a better guide for pricing and ration formulation.
By improving root health, mineral uptake, and microbial activity, AgriTec products make grass and legume forages richer in digestible energy and protein. Apply Form-14 or Nitro-Maxx+ for fast-acting improvements in plant vigor and RFQ.
6. RNV - Relative Neutralizing Value
RNV is used to measure the effectiveness of liming materials, like ag lime, in raising soil pH.
- An RNV of 100 = fully effective material.
- Many limes on the market test around 50-70 RNV.
Lime with low RNV may take years to work, wasting both money and opportunity for higher yield. Pro-Cal and Advanced-Cal are liquid calcium soil treatments with immediate and long-lasting effects.
- 2 gallons of Pro-Cal = 1 ton of ag lime
- Raises pH in weeks, not months
- Chelated formula ensures calcium is plant-available
With a high RNV equivalent and a fast-acting formula, Pro-Cal is your best value when you need fast results and improved forage uptake.
7. NPK - Nitrogen, Phosphorus, Potassium
This is the classic trio of primary macronutrients:
Nitrogen (N) = leaf and stem growth
Phosphorus (P) = root development and energy transfer
Potassium (K) = water regulation, disease resistance
Why it matters for forage:
Too much N and you get lush, watery hay with low fiber and high nitrate risk.
Too little K and the crop wilts early in drought.
Insufficient P reduces early root strength and regrowth after cutting.
Use AgriTec’s 10-20-10+ or 3-18-18+ liquid fertilizers. These contain orthophosphate P (immediate uptake), slow-release nitrogen, and micronutrients that improve not just yield but forage nutritional value.
How These Save Farmers Money
Understanding and acting on these metrics delivers real savings and returns:
- Higher RFV/RFQ = Less supplemental feed needed
- Lower ADF/NDF = More intake, faster weight gain
- Better NPK balance = Fewer disease and drought losses
- RNV with Pro-Cal = Faster pH correction, no wasted lime
- NIR + Soil Testing = Smarter, targeted applications
AgriTec products are designed for real-world conditions, offering field-proven results without the long delays of traditional methods. Whether it’s Pro-Cal for calcium, Humi-Tec for organic matter, or Foliar-Act during stress, our full line of liquid fertilizers, foliar feeds, and soil treatments improves hay quality, animal performance, and your bottom line.
Ready to Upgrade Your Forage?
Don’t let poor-quality hay hold your farm back. Whether you’re a hay producer or a livestock operator, AgriTec International is here to help you take your forage program to the next level. Call us at 833-247-4832 to talk to a soil advisor and get started.