Predicting Feed Consumption and Dry Matter
general, the first step of the ration evaluation process is to
determine daily dry matter intake or how much feed should your
horse be eating. Feeds are composed of two basic components -
1) water and 2) dry matter. The dry matter is composed of protein,
fiber, carbohydrates, fat, minerals, etc.. Animals consume feed
to meet their daily needs for these nutrients and therefore, it
is important to establish the amount of feed potentially consumed.
consumption or intake calculations are based on body weight, level
of activity, reproductive status and growth stage. These physiological
factors also influence energy requirements and therefore, the
percentage of forage and grain required to meet energy needs.
Feed Consumption Table
is adapted from the 1989 NRC for horses. These values are averages
based on typical horses and forages. Individual intakes may vary
from the average, but should be within the reported range. If
intake is substantially different, check the following:
weight - use a livestock scale or heart girth tape to get
a reliable weight.
- check the scales used to weigh the feed for accuracy. Weigh
a variety of objects of known weight (such as dumbbells or
plate weights) and adjust as required. Use several weights,
such as 2, 5, and 10 lbs. to check accuracy across a range
feed - horses will often toss hay around their stall when
pulling it from the manger or sometimes, from boredom. Both
hay and grain refusals should be weighed. Weigh the refused
feed and deduct it from the total to determine actual consumption.
Consumed = Feed Offered - Feed Refused
dry matter intake is simple. From the Feed
Consumption Table, locate the class that best describes your
horse and calculate as follows:
Lbs. dry matter intake = Body Weight x (%Dry Matter Intake/100)
An 1100 lb. horse under light work consumes about 1.8% of it's
body weight per day.
Lbs. dry matter intake = 1100 x (1.8/100) = 19.8 Lbs.
this a step further, based on forages of average quality, approximately
65% of the diet should be forage and 35% grain to meet daily energy
Forage dry matter = 19.8 x (65/100) = 12.87 Lbs.
Lbs. Grain dry matter = 19.8 x (35/100) = 6.93 Lbs.
the diet consists of only hay and grain, the amounts to feed can
be calculated by assuming both feeds are 90% dry matter.
Amount fed = Lbs. dry matter / (Dry Matter %/100)
Lbs. Hay fed = 12.87 / (90/100) = 14.3 ~ 14 Lbs.
Lbs. Grain fed = 6.93 / (90/100) = 7.7 ~ 8 Lbs.
dry matter intake values presented are averages. An individual
horse may consume more or less than predicted, but should be within
the estimated range. The percentages of forage and grain are guidelines
based on average quality forage. The percentages will vary depending
upon forage quality. Typically, the better the forage quality,
the lower the amount of grain required. Use your forage analysis
to determine the proper level of grain to feed. Always consult
with your nutrition professional to determine the best feeding
program for your horse.