Agriculture Reference
In-Depth Information
Carbohydrates
Carbohydrates make up about three-fourths of the dry matter in plants, so
they're one of the most signifi cant nutrients in a sheep's diet. Sugars, starches,
and fi ber are all classes of carbohydrates, and their proportions in an individ-
ual plant vary, depending on the plant's age, the environmental factors, and
the type of plant. For example, sugars make up a higher proportion in young
plants and fi ber is in a higher proportion in older plants.
Carbohydrates are named after their atoms of carbon (atomic symbol
C), which are attached to molecules of water (H
2
O). A simple sugar mol-
ecule might be made up of six carbon atoms attached to six water molecules
(C
6
H
12
O
6
), and it's a readily usable nutrient, providing an instant burst of
energy. Starches are composed of groups of sugars, strung together like holi-
day lights. Since both sugars and starches are easily digested, they provide
high feed value.
Fiber is made up mostly of lignins and cellulose. Lignins are virtually indi-
gestible, but the cellulose is readily digested by the bacterial fermentation
that takes place in the rumen. Sheep, like other ruminants, can make use of
this feed supply that's abundant in grass, hay, and other forages.
Fats
Like the carbohydrates, fats (and fatty substances) are made up of carbon,
hydrogen, and oxygen, but the proportions are very different. For example,
olein, a kind of fat that's commonly found in plants, has a chemical formula
of C
57
H
104
O
6
, meaning that there are 57 carbon atoms, 104 hydrogen atoms,
and only 6 oxygen atoms.
Fat is an essential nutrient — especially for young, growing animals
(including people). It provides almost twice as much energy as carbohydrates
do, and it helps an animal control its body temperature.
What and when you feed is dependent on the animal's stage of life and its
point in production. The same quality and quantity of feed supplement is not
needed at all times. Lambs and young animals need more and higher-quality
feed (relative to their size) than mature animals; lactating ewes need more
than dry ewes; and during the breeding season, rams need more than they do
during the off-season.
