Testing Forage Quality for Cattle
Cattle nutrition is crucial for health, growth, and production. The major component of most cattle diets is forage, including pasture, hay, and silage. Testing the nutritional quality of forages is crucial in formulating balanced rations that meet cattle requirements.
In this blog article, we will provide cattle owners with a practical guide on forage quality testing, including:
- Why Test Forage Quality
- Forage Analysis Labs
- Forage Sampling Methods
- Key Nutritional Components to Test
- Using Forage Test Results
Why Test Forage Quality
Forages vary widely in nutritional content depending on plant species, stage of maturity, soil fertility, and growing conditions. The same forage species can provide significantly different nutrition based on management and environmental factors.
Visual inspection and physical characteristics like leafiness, color, and smell provide limited information on actual nutritional value. Testing is the only way to accurately determine the energy, protein, minerals, and other nutrients a given forage supplies.
Knowing the nutritional profile enables cattle owners and nutritionists to:
- Accurately evaluate forage quality
- Make adjustments through supplementation or ration balancing
- Reduce feeding costs
- Maximize animal performance
Given the significant role forages play in cattle diets and operations, forage analysis provides an excellent return on investment.
Forage Analysis Labs
University laboratories, private analytical laboratories, and feed testing companies provide forage testing services. Select a reputable lab that follows standard testing methodologies.
Ask about turnaround time to get results rapidly for decision-making. Expect 3-7 day turnaround for wet chemistry testing. Some labs offer very fast 24-48 hour results for key components using NIR (near-infrared reflectance spectroscopy).
Work with a lab with experience testing forages and interpreting results for cattle. Check if consulting with lab analysts is available for assistance in applying test results.
Many extension services have partnerships with testing labs and offer discounted analysis. Compare pricing between labs to find the best value.
Forage Sampling Methods
Proper sampling technique is crucial so test results reflect the actual field conditions. Follow best practices when taking and handling forage samples:
- Sample at the consistent stage of maturity for valid comparisons
- For hay, sample each cutting and field separately
- Walk a zig-zag pattern across the field, taking sample slices from random spots
- Take sample slices from an entire height of the forage stand
- Mix pieces thoroughly to create a combined representative sample
- The sample amount depends on the lab, often around 1 pound of material
- Use clean, dry containers; avoid contaminating sample
- Label samples immediately with field ID, forage type, and date
- Complete the lab’s sample information form accurately
- Ship samples quickly and with proper packaging to prevent spoilage
Careful sampling allows producers to obtain a precise nutritional analysis of their forages.
Key Nutritional Components to Test
Forage analysis will provide results on the following vital nutritional components:
Energy Content
Energy is necessary for cattle maintenance, growth, lactation, reproduction, and weight gain. The primary measurement of forage energy is total digestible nutrients (TDN).
Higher TDN values indicate forages can meet more of an animal’s energy needs. TDN typically declines as forages mature.
Net energy (NE) is also used and is reported in variations such as NE for maintenance (NEm), NE for gain (NEg), and NE for lactation (NEl).
Crude Protein
Protein provides essential amino acids for development and production. Requirements depend on weight, age, and production stage.
Reporting crude protein (CP) content as a percentage allows for evaluating of whether protein is adequate or deficient in a ration. Protein levels below 7% are considered low-quality forage.
Excess protein is excreted as waste, making testing important for optimum supplementation and efficiency.
Fiber
Fiber content affects forage energy value and potential intake. High-quality forages have optimal fiber for rumen function.
Standard fiber measures are acid detergent fiber (ADF) and neutral detergent fiber (NDF). High fiber levels limit animal consumption.
NDF measures total fiber content, while ADF indicates the indigestible and slowly digestible fiber portions.
Macro and Micro Minerals
Minerals like calcium, phosphorus, potassium, magnesium, and sulfur are required for growth, health and production. Deficiencies impair animal performance.
Micro or trace minerals like copper, zinc, manganese and iron are also essential for cattle in small amounts.
Forage mineral profiles help determine optimal supplementation when balancing rations.
Nitrates
Drought conditions can cause forages like corn, sorghum and small grains to accumulate nitrate to potentially toxic levels.
Nitrate testing protects herd health by avoiding high-nitrate feeds or limiting intake until safe nitrate levels are confirmed.
Using Forage Test Results
Forage analysis provides the objective data needed to evaluate quality and properly utilize forages in cattle feeding programs.
Assess Forage Quality
Compare test results to forage quality guidelines to determine if the forage is high, medium or low nutritional value.
Group forages by quality for ration formulation – higher quality forages for high-producing animals, lower quality forages for dry cows or backgrounding cattle.
Evaluate nutrition over time by testing each harvested forage batch and comparing results across years.
Compare Forage Sources
Testing different forage types and sources side-by-side provides relative feed quality comparisons.
This allows ranking forages for use first by the highest animal production groups down to maintenance groups based on nutritional content.
Cost and availability along with quality help determine which forages to utilize most.
Ration Balancing and Evaluation
Incorporate lab analysis into cattle ration balancing software or worksheets to formulate well-balanced cost-effective rations meeting animal requirements.
The forage quality results input the actual nutrients being supplied instead of using typical “book values” that may over or under-estimate.
Revisit rations using updated forage analysis when new batches are fed to ensure adequate nutrition.
Identify Shortfalls for Supplementation
Use forage testing to identify nutritional deficits like low protein or minerals that require supplementation for optimum nutrition and performance.
Testing each forage batch provides the flexibility to adjust supplementation to meet animal needs as quality changes each harvest season.
Reduce Feed Costs
Accurate forage quality data helps avoid overfeeding expensive supplements and ingredients. Testing can save $15-$30 per head annually through strategic supplementation.
Higher quality forages can be fed at higher inclusion rates, displacing costly concentrates. Identifying top-quality forages enables maximum use to reduce purchased feeds.
Conclusion
Forage analysis provides cattle owners invaluable information on the nutrients supplied by forages to optimize animal nutrition, health and productivity while controlling costs.
Proper sampling techniques and choosing a reputable lab are vital to getting meaningful test results. Use forage testing strategically for balanced ration development and quality forage management practices. Learn here more about cattle nutrition guide and tips.