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Identifying Quality Hay
Sensory
evaluation of hay
Much can be learned from a careful sensory examination of hay. First, the plant species
present can be determined.Does thehay consist almost exclusively of a particular
forage crop? Does the foragecrop tend to be higher in quality than
other forages? Does the hay contain needs? If so, what percentage is
weeds and how much nutritional benefit do they provide to livestock?
Could they be toxic?
The maturity of the hay, one of the main factors determining forage quality, can be visually assessed.The
number and maturity of seed heads and blooms, and the stiffness and fibrousness of the stems are indicators of plant maturity.
Leafiness is particularly important; the higher the leaf content, the higher the forage quality. Leafiness can be affected by plant species, by stage of maturity at harvest, and (especially in legume hays) by handling that results in leaf loss.
Texture is a consideration. Softness usually results from early cutting, high leaf content, and a suitable moisture level at baling.When hay is “very soft” and pliable, it is difficult to distinguish between stems and leaves just by feeling the hay.“Soft” hay is soft to the touch, but stems can be detected easily.“Slightly harsh”hay has stems that are a little rough.“Harsh or brittle” hay is dry, stemmy, and unpleasant to the touch.“Extremely harsh”hay can injure an animal’s mouth, lowering intake.
Color helps sell hay to the average buyer. Color alone is not a good indicatorof forage quality, but it can be an
indicator of harvest and storage conditions A bright green color suggests
that hay was cured quickly and protectedduring storage. Slow curingprolongs plant respiration, which
reduces forage quality. Hay that is raindamaged after being partially dried
will lose color due to leaching.Mold growth on leaves and stems orexposure to sunlight will also bleach
hay. Baling at moisture contents at orabove 20 to 25% may cause high bale
temperatures that result in tan to brown or black colors (commonly called “tobacco hay”).
A pleasant odor indicates hay wascured properly.Moldy,musty odors may occur in hay stored at moisture
contents above 16 to 18% (above 14%for 1-ton square bales). Animals may respond to off-odors by going off feed.Odors caused by heating(>125?F) result from hay being baled at too high a moisture content or from ensiling forage that is too dry. Interestingly, hay with a slightly caramelized odor is often quite palatable
to livestock, even though the quality is reduced. (The odor of silage can indicate good or bad fermentation;
if it smells of butyric acid— similar to rancid butter—it may lack palatability, and low animal intake is
likely.)
Dusty hay is usually the result of soilbeing thrown into the hay by rake teeth hitting the soil.The presence or absence of molds, dust, and odor are referred to as organoleptic qualities.Visual inspection can also detect foreign matter (anything that has little or no feed value).Tools, sticks, rocks, wire, items of clothing, dead animals,and cow chips have all been found in hay and are obviously undesirable.
Dead animals in hay can cause botulism, a deadly disease that can kill farm animals.
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