For
starters horses need a minimum of 1% forage but in reality a horse will want
to, and naturally, consume 1.5-2% of their diet in forage to meet their energy
needs. Hay is your forage. So if your
horse weights 1200 lbs you should not give them less than 12lbs of forage a day
with 18-24lbs/day being more realistic to their natural and desired
consumption.
If
you have a horse that is susceptible to obesity do not reduce the volume of
hay, reduce the quality of hay. By that I do not mean get moldy cow hay. I mean
get lower energy, lower protein hay that the horse can eat all day long without
gaining. A full gut round the clock is a happy gut.
The
below information is based on the factors tested by Colorado State University
standard forage test. In 2016 it was a $35 test. There are more tests for minerals
available but the below information is just for the basic test that they
provide for the hay test. The test from Colorado State University was selected
for this post because they are well known. Other institutions may give other
reports with other components.
Moisture - Ideal is
10-17%, when it reaches 18% it’s at high risk of mold. Hay over 25% poses a
huge heat and fire risk.
Crude protein (CP) --
Is
actually an estimation of total protein based on the amount of nitrogen in the
hay. So areas with high nitrogen may falsely read high protein. It does not tell you anything about the amino
acid composition or the protein quality.
High
quality proteins are usually found in legumes, like Alfalfa. Combining the two
makes a more balanced protein diet for the horse. Ideally a horse needs around 10% protein (Lactating, Pregnant and Growing foals need more)
Grain hays (oat, rye) generally have a lower CP than grass hay
grass hay contains 8 to 10%
legumes (alfalfa, clover, perennial peanut) can range from 17-20+%.
Neutral Detergent fiber (NDF) – Measures insoluble fibers. Since
fibers are digested by the microbes living in the hindgut (cecum and large
colon), a healthy microbial population is important for your horse to derive
calories from fiber. This figure is a good indicator of Net Energy (NEL, NEM,
NEG see below) they are inversely related so when NDF goes down NE_ increases. This
measurement is also the best indicator of how much forage a horse will eat. The
lower the # the more the horse will eat. Legumes (alfalfa) are lower in NDF so
horse will want to eat more legume than grass. But as most people know high
alfalfa diets can risk founder, bloating and other issues. So just because they
like Legumes doesn’t mean that is what they should eat 24/7.
40-50% are
good65% the horses may not want to consume them
Acid detergent fiber (ADF) ADF is
composed of cellulose, lignin (not digestable), and other poorly digested
components. The lower the ADF value, the more digestible the nutrients in the
hay. Lignin increases in mature plants and more hay will end up in the manure.
30-35% is desirable45% and above you will have to feed more hay
40 to 55% is desired.
Equine Digestible energy (DE): Measure of the digestible energy in the hay. Horses in light work should
get about 20 Mcal/day. So if hay is DE 1 Mcal/lb you need to feed 20lbs to that
horse. Horses usually have a loss of 35-40% DE in feces, so don’t be stingy on
feeding hay to your horses.
Most hays are 0.76 to 0.94 Mcal/lb of DE.The DE requirements for a 1,102 lb horse (500kg) can range from 15.2 Mcals to 34.5 Mcals
Net Energy (NE): There are 3 types of Net Energy
Maintenance (NEm) –maintenance of the animalGain (NEg) – Growth and gain for that animal
Lactation (NEL) – Lactation (mainly dairy cattle)
This is highly dependent on the animals actual intake of the forage.
Estimated Net Energy (ENE) A term expressing available energy in a forage. The higher the number, the greater the energy to the animal.
Net Energy Lactation
(NEL) this is usually used for cattle to help determine if the forage will meet
the needs for lactation. Mostly used for the dairy industry but it can also be helpful
for horses.
An average NE Lactation is 0.5-0.95When TDN is 50 (DM%) NEL is around 0.5
When TDN is 90 (DM%) NEL is around 0.95
So very closely related
Net Energy Maintenance
(NEm)
This is the energy available for
maintaining the animal An average alfalfa maintenance is around 0.4-1.02
When TDN is about 50 (DM%) NEm is around 0.44
When TDN is about 90 (DM%) NEm is around 1.02
Net Energy Gain
(NEg)
This is the energy available for the
horse to gain. An average around 0.19-0.7
When TDN is about 50 (DM%) NEg is around 0.19
When TDN is about 90 (DM%) NEg is around 0.7
Metabolizable Energy (ME)
Range from 0.82 – 1.48 when TND (DM%) is around 50 ME will be around 0.82,
when TND (DM%) is around 90 ME will be around 1.48
Relative Feed Value (RFV)-
Combines ADF and NDF to estimate consumption of the hay. So in theory it’s the
expected consumption, or the animals want to consume the hay . As ADF and NDF
increase, RFV decreases. It’s mostly
used for Cattle. There is no formula for horses yet for RFV because this
formula is based on fiber and cattle have a better fiber conversion because of
the rumen digestive system. But it’s a number CSU gives for their hay
evaluation so it’s one that we are going to explain.
Average RFV for alfalfa is 100 (ADF 41,
NDF 53). The higher the # the better the quality
Alfalfa can be up above 150, 185+ is
considered Supreme quality. Low quality alfalfa will be around 70.
Keep in mind that horses do not need
the higher quality forages that a dairy or meat cattle need. And horses
digestive systems are not equipped to handle the higher levels of RFV and CP. Feeding
strait Alfalfa with a 100 RFV could risk
obesity, founder and other health issues, So please consider other values that
are more tailored for horse feed to base your feed choice on. If you pick a lower
TDN grass hay you could supplement with Alfalfa to meet your horse’s needs, or
free choice the grass hay so the horse has a full gut (much more healthy for
them than sporadic feeding)
But when in doubt test your hay, soil
and water. Take those results with your current grains and supplements to an equine
nutritionist to balance your ration. You may find that a few simple changes
could reduce your feed cost and ultimately have a healthier horse. Do not grain
your horses blindly, know what they are eating so you don’t throw them off balance.