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Copyright 2005, Board of Trustees, University
Agronomy Research Report 85-1 September 1984
HAY FOR HORSES
SD. Baltensperger, E. Ott, E. Johnson, and G. Prinel
JUN 1 2 i'i 5
.F.A.S. -Univ. of Floridc
Department of Agronomy
Agricultural Experiment Station
Institute of Food and Agricultural Sciences
University of Florida
Gainesville, Florida 32611
HAY FOR HORSES
D. Baltensperger, E. Ott, E. Johnson, and G. Prinel
Horses are a big business in Florida. A horse population of over
200,000 generates in excess of one billion dollars a year in Florida.
In most areas of Florida, 4-5 months of hay feeding is necessary for
these horses. Some horse classes such as show and performance animals
are stalled all year and subsequently require a year-round supply of
hay. The latter is also true of pleasure horses that are kept with no
available pasture space.
Twenty years ago, "horse hay" meant grass hay -- dry, dust-free,
sweet-smelling, mature grass hay. Ninety-five percent of all race and
show horses were fed grass hay. What was "best" for race horses should
also be "best" for one's pleasure horse. Horse people were convinced
that forages like alfalfa or clover would provide too much protein and,
hence, be "hard" on the horse's kidneys, that the high calcium level in
legumes would cause abnormal bone development, or that legumes caused
excessive sweating and thinned out the blood.
These old wives' tales are easy to accept by the unknowing and
hard to dispel from horse lore. But a significant change has occurred
in the choice of feed for horses. High quality alfalfa hay is becoming
the hay of choice at many race tracks, in many show barns, and among
some'of the 3 to 4 million pleasure horse owners who buy a few bales at
a time to feed the 10 million horses in the U.S.A. The tremendous
increase in horse husbandry education as conducted by agricultural
extension, 4-H, and horse curriculums at colleges has led to an
increased knowledge of horse nutrition. Regardless of the specific
species of forage used, the current generation of horse owners has
become aware that forage quality is the most significant determinant of
not only how much forage is required per horse daily, but also how much
1 Assistant professor, agronomy; professor and assistant professor,
animal science; and professor, agronomy, respectively.
and what kind, if any, of a supplement is required to augment the daily
Nutrient intake is equal to the nutrient composition of the feed x
feed intake. Nutrient composition and feed intake will vary both by
species (Table 1) and by quality within species. An important aspect
of quality forage is feed intake or acceptance. Regardless of species,
quality forage is higher in protein, carbohydrates, lower in cell wall
content, and higher in dry matter digestibility than poor quality
forages. All of those traits influence feed intake and rate of passage
through the digestive tract. Quality forage is more than a filler,
bulk or something to satiate the appetite. For those purposes straw or
poor quality hay would be of equal value provided they will eat it.
Quality forage is the basis around which sound feeding programs should
Chemicals and Antimetabolites Regardless of the energy or.protein
content of forages, if they possess toxins that reduce intake or result
in abnormalities, they are low quality feeds. Alkaloids may reduce
feed acceptance and intake possibly via reduction in digestibility and
rate of passage. Tall fescue has been associated with agalactia,
abortion, retained placentas, and thick-walled placenta in mares fed
fescue grass during late gestation. Sorghum x sudangrass hybrids, are
potentially dangerous to the grazing animal because of high prussic
acid content which is reduced by haying but, urinary cystitis in mares
may result from eating both sorghum x sudangrass, hay and pasture.
Maturity There is a wide range in the quality of hay produced from a
given forage species as illustrated in Table 1 for some common Florida
hays. Increased maturity of the forage cut as hay is associated with
lower quality. Much of the hay put up in Florida is over mature
because of rainy weather conditions at the time the-hay should be
harvested for high.quality. High quality bermudagrass hay may contain
as much as 14% crude protein when harvested on 5 week intervals, but
Table 1. Nutrient concentration of various Florida hays.
Energy Protein Calcium Phosphorus
Mcal/Ib % % %
CLASS OF HAY
Crimson clover 2
1. Range of protein
2. Range of protein
each hay type.
3. Range of protein
and other quality parameters for low quality hay of each
and other quality parameters for intermediate quality hay of
and other quality parameters for high quality hay of each hay
this drops to 6-8% when the interval is extended to 9 weeks. Higher
protein contents are also associated with higher rates of nitrogen
fertilization in the grass hays and conversely lower protein with lower
levels of nitrogen fertilization. Digestibility of the forage as well
as other nutrients all decrease with increased maturity.
Hay Contaminants Good hay will contain few or no weeds. Poisonous
weeds in the hay can cause serious problems for horses. Poisonous
weeds to watch out for include showy crotalaria, coffee weed, sesbania,
cocklebur, horsenettles, nightshade, hemp dogbane and wild mustard.
Other weeds, while not necessarily poisonous, may have spines or
stickers that make the hay hard to handle and much less palatable to
the horse. Most weeds are simply lower in quality and/or palatability
than the hay plant. Not all weeds are a problem in hay. Florida
pusley and beggarweed may even add to the quality of most grass hays if
they are not overly mature and are properly cured.
Various insects will sometimes attack hay and reduce its quality
and/or acceptance. This includes insects which remove leaves so that
resulting hay consists of stems and insect feces. Recently, several
horses were killed or made ill by blister beetles contained in alfalfa
hay imported from out-of-state. Blister beetles can also occur on hay
grown in the state. All alfalfa hay should be examined for blister
beetle contamination at feeding time.
Many pesticides can be safely applied to hay production fields.
Care needs to be taken to see that label requirements for time
intervals prior to harvest for the last application are met.
High quality hay must be free of mold. Horses are very
susceptible to respiratory problems (heaves). Unfortunately moldy hay
is frequently associated with otherwise high quality hay that was baled
before adequately curing or hay that was rained on after being cut and
prior to being baled and stacked.
HAY VS. REQUIREMENTS
Table 2 presents the nutrient content in horse diets that is
required to meet their nutrient requirements at various stages of
production. The nutrient content of some of the typical legume and
grass hays produced in Florida is shown in Table 1. When fed alone
Table 2. Nutrient concentration required in horse diets (100% dry matter).
Digestible Crude Daily
Energy Protein Calcium Phosphorus Vit. A Feed
Mcal/lb % %% I.U./lb lb
CLASS OF HORSE
Maintentance 1.0 8.5 0.30 0.20 750 16.4
Gestation, last 1.1 10.0 0.50 0.35 1550 16.2
Lactation 1.3 14.0 .50 .35 1275 22.2
Weanling 1.5 16.0 0.70 0.50 900 11.0
Yearling 1.3 13.0 0.55 0.40 900 13.2
Work 1.3 8.5 0.30 0.20 750 22.2
most grass hays provide an inadequate concentration of almost all
nutrients. For lactation and growth they-are particularly deficient.
Conversely, high quality legume hays contain adequate protein and
calcium for almost all classes of horses, but may require
supplementary energy and phosphorus for all classes other than
Intake, or the amount of a given feed that a horse can consume
daily, can be a limiting factor to adequate nutrition. Assuming that
a yearling needs 13.2 pounds of 13.0% crude protein feed to meet his
requirements, the horse will not do well, if because of stems or other
anti quality factors it can consume only 10 pounds. Intake can be
particularly limiting with average and below average grass hays.
The data in Table 3 suggests typical legume hay, when fed with
grain in conventional proportions, provides adequate levels of all
nutrients, except for a modest deficiency in calcium and protein for
weanlings and a deficiency in phosphorus for all classes other than
maintenance and work. Conversely, grass hay fed with grain in the
same proportions is inadequate for all nutrients and for all classes
of horses, except for mature horses. It is this type of information
that-the "serious" horse owner must keep in mind when purchasing hay.
The high level of protein and calcium, and the palatability of legumes
are the characteristics that contribute most to their value in a horse
RECOGNIZING QUALITY HAY
Once the value of quality hay is recognized along with the need
for it in a horse feeding program how does one recognize and purchase
it? Perhaps the first and easiest is to deal with an honest and
reliable hay dealer, but beyond that -- quality hay will be bright,
green, weed free (especially poisonous weeds), fresh smelling, leafy,
fine-stemmed and immature. Ask what type of cutting interval was used
in harvesting it as well as how it was fertilized. Avoid hay that has
been excessively sun bleached or rain leached. Remember that it is
difficult to put up quality hay in Florida during the rainy season and
be prepared to pay a premium to those who make the effort to do so.
The recent release of 'Florigraze' rhizoma peanut and 'Florida 77'
alfalfa along with the continued availability of alyceclover and
Table 3. Composition of two types of hay-grain diets when fed at typical
Class of Hay:Grain Legume:Grain1,2 Grass:Grain2,3
Horse Ratio Protein Ca P Protein Ca P
% % % % % %
Weanling 1:1 14.04 .654 .294 10.04 .214 .284
Yearling 1:1 14.0 .65 .294 10.0 .214 .284
late gestation 3:1 15.0 .92 .264 9.04 .26 .254
peak lactation 1:1 14.0 .65 .294 10.04 .214 .284
Maintenance 9:1 15.6 1.09 .24 8.4 .30 .23
Work 2:1 14.6 .83 .27 9.3 .254 .26
Assumes an average legume with 16% crude protein, 1.2% calcium and .23%
Assumes an average grass with 8% crude protein, .32% and .22% phosphorus.
Assumes an average grass hay providing 8% crude protein, .32% calcium and
Inadequate, see Table 1.
crimson clover hays will provide an increasing source of locally
produced high quality legume hay for horse owners. A premium price is
justified for those premium hays.
The authors were greatly influenced in writing this report by a
talk given by R. M. Jordan, Professor, Animal Science, University of
Minnesota, St Paul, Minnesota, entitled "Quality Forage for Horses A
New Market," at the 1982 Forge and Grassland Conference in Rochester,
Minnesota. We have used liberally from the ideas and parts of this