As summer transitions into fall, many ranchers begin taking stock of hay inventories, pasture conditions, and winter feeding plans. While it’s easy to focus on how much forage is available, an equally important question is often overlooked:
What is the quality of the forage you have?
Forage testing is one of the most cost-effective management tools available to livestock producers. A relatively inexpensive analysis can provide valuable information that helps reduce feed costs, improve livestock performance, and support sustainable grazing management throughout the winter months. Texas A&M AgriLife Extension specialists consistently emphasize that successful winter feeding programs begin with knowing the nutrient value of available forage resources.
Why Forage Quality Matters
Winter feeding decisions are often based on assumptions. Hay that appears green and leafy may seem adequate, while coarse or weathered hay may be dismissed as low quality. However, visual appearance is not always a reliable indicator of nutritional value.
Forage quality is influenced by numerous factors, including:
- Plant species and variety
- Stage of maturity at harvest
- Fertility management
- Rainfall and weathering
- Leaf-to-stem ratio
- Harvest and storage conditions
As a result, nutrient levels can vary significantly between hay cuttings, fields, and even bales harvested from the same operation.
Without testing, producers are left guessing about the protein and energy content being delivered to their livestock.
Winter Feeding Costs Start with Forage Quality
Feed costs often represent the largest annual expense for cow-calf operations. Every dollar spent on supplements should be targeted toward an actual nutritional need.
A forage test provides information that helps answer critical management questions:
- Will this hay meet the needs of dry cows?
- How much supplementation will lactating females require?
- Can replacement heifers maintain desired gains?
- Are protein supplements necessary?
- Is energy the limiting nutrient?
Making supplementation decisions without this information can result in either underfeeding or spending money on unnecessary feed. Both scenarios affect profitability.
Match the Forage to the Livestock
One of the greatest advantages of forage testing is the ability to allocate resources strategically.
Different classes of livestock have different nutrient requirements. Lactating cows, first-calf heifers, growing replacement females, and mature bulls all require different levels of protein and energy.
Rather than feeding the same forage to all animals, producers can use test results to:
- Reserve higher-quality hay for animals with greater nutrient demands.
- Utilize lower-quality forage where requirements are lower.
- Reduce unnecessary supplementation.
- Improve overall feed efficiency.
This approach helps maximize the value of stored forage while maintaining animal performance throughout the winter.
Grazing Management Benefits Too
Forage testing is not just for hay. Many producers rely on stockpiled forage, winter annuals, crop residues, or dormant native rangelands to extend grazing and reduce feeding costs. Understanding the nutritional value of those forage resources provides important information for winter grazing decisions.
Testing standing forage can help determine:
- When supplementation may become necessary.
- How long available forage can support livestock requirements.
- Whether stocking rates are appropriate.
- How grazing pressure may affect winter pasture condition.
These decisions influence both livestock performance and long-term rangeland health. When producers understand forage quality, they can better balance animal needs with available resources while avoiding excessive grazing pressure during vulnerable periods.
Protein Is Important. Energy Is Essential.
Many producers immediately look at crude protein when a forage analysis arrives.
Protein is certainly important, but AgriLife forage specialists frequently note that energy values can be equally important, and in some cases even more critical, when evaluating winter feeding programs. Total Digestible Nutrients (TDN) provide an estimate of the energy available in forage and play a major role in maintaining body condition and supporting production.
When cows lose condition during winter, energy deficiencies are often a major contributor. Understanding both protein and energy levels allows producers to build more effective supplementation programs.
Don’t Overlook Minerals
While protein and energy often receive the most attention, minerals are another critical piece of winter nutrition. Forage quality is not just about crude protein and Total Digestible Nutrients (TDN). Mineral concentrations can vary significantly among forage species, seasons, and environmental conditions, making it difficult to know whether livestock nutritional requirements are being met without testing.
One mineral that deserves particular attention is phosphorus. Research conducted by Texas A&M University on native forage species in the Edwards Plateau documented considerable variation in phosphorus concentrations among grasses, forbs, and browse species, as well as across seasons. In general, nutrient levels are highest during periods of active growth and decline as plants mature and enter dormancy. The study found that forbs and browse species often contained higher concentrations of nutrients, including phosphorus, than warm-season perennial grasses. Researchers also observed that nutrient levels generally decline with advancing maturity and during dormant periods.
These seasonal changes are particularly important as rangelands enter the fall and winter months. Livestock grazing dormant native rangeland, mature hay, or weathered forage may not be receiving adequate amounts of key minerals even if sufficient forage quantity is available.
Mineral deficiencies can impact:
- Reproductive performance
- Growth rates
- Immune function
- Milk production
- Overall animal health
Because mineral availability varies widely among forage resources, forage testing provides valuable information that can help producers develop more targeted mineral supplementation programs instead of relying on a one-size-fits-all approach.
The long-term Edwards Plateau research also highlights another important lesson for range managers: diverse plant communities often provide a wider range of nutritional benefits than single-species forage systems. Researchers concluded that plant diversity provides greater opportunities for animals to select high-quality diets and meet nutritional needs throughout the year.
As you evaluate winter feeding programs, remember that a forage test can help identify not only protein and energy deficiencies but also potential mineral gaps that may affect livestock performance. The information gained can help improve supplementation decisions while supporting more efficient use of both forage and feed resources.
Getting an Accurate Sample
A forage analysis is only as good as the sample submitted.
Texas A&M AgriLife Extension recommends using a hay probe to collect representative samples from multiple bales within a lot. Samples should be combined into a composite sample that accurately reflects the forage being fed. Proper sampling is critical because pulling hay by hand from a single bale rarely provides representative results.
Many county Extension offices can assist producers with sampling recommendations and may have hay probes available for use. Producers can also submit samples through the Texas A&M AgriLife Extension Soil, Water and Forage Testing Laboratory.
Planning Ahead for a Better Winter
The best time to address nutritional challenges is before cattle begin losing body condition.
Fall forage testing provides time to:
- Evaluate forage inventories.
- Budget winter feed costs.
- Purchase supplements before they are urgently needed.
- Adjust stocking plans if necessary.
- Develop targeted feeding programs.
Ultimately, forage testing transforms winter feeding from guesswork into a management decision based on data.
As producers prepare for the months ahead, understanding both the quantity and quality of available forage can help stretch feed resources, maintain livestock performance, and protect rangeland health.
Winter feeding may never be inexpensive, but having accurate information allows producers to make smarter decisions that benefit both their livestock and their land.
Source: Huston, J.E., B.S. Rector, L.B. Merrill, and B.S. Engdahl. Nutritional Value of Range Plants in the Edwards Plateau Region of Texas. Texas Agricultural Experiment Station Bulletin B-1357, Texas A&M University System










