Sheep - AgRIS

seem to have most significance in sheep feeding are Vitamins A and D. The symptoms of
vitamin deficiencies are anorexia, reduced growth, dermatitis, weakness and staggering gait. In
sheep vitamin A is more important and its deficiency can cause various kinds of blindness.
Vltamin deficiency also leads to abnormal bone development, weak and still-born lambs and
respiratory problems.
Vitamin A
This vitamin is synthesized by animals from the carotene of plants. Carotene is abundant in
the green parts of plants and is also plentiful in the yellow coloring matter of corn carrots and
sweet potatoes. Its importance explains why sheepmen had long insisted and even insist today
that there were certain things of great nutritive value in such things as carrots clorers in alpine
postures that had not been revealed by the usual analysis pertaining only to nitrogen-free
extract, protein, minerals, and dry matter. Vitamin A promotes growth and aids in protection
against respiratory infections and impaired vision. A deficiency ofthis vitamin in sheep is
characterized by night blindness, sore eyes, poor appetite, poor condition, and weakness.
Affected ewes may be, or their lambs may be very weak and die soon after birth. Although the
carotene of feeds may decrease rapidly during curing and storage, high grade legume hay of
good green color, good silage, and roots, such as carrots, are fair to good sources of vitamin A.
Green pastures, however, are the best natural sources for sheep. It is not unreasonable to
suggest that some ofthe difhculties that develop during the late winter months, especially after
periods of summer drought, may be associated with a deficiency of this vitamin. It is stored in
the liver of sheep, but there may be cases where storage is not ample to meet all the needs of
breeding ewes and their lambs.
Vitamins B
Sheep seldom suffer from any lack of B vitamins, for it has been shown that they have the
ability to synthesize practically all of the known vitamins (the B-complex) the rumen. It is
generally thought that all ofthe vitamins thus formed become available to the sheep as the feed
is later digested. The B vitamins furnish a stimulation to the appetite, protect against nervous
disorders, and are essential for reproduction and lactation. There may be cases of deficiencies
in newborn lambs, but none has been thoroughly demonstrated, and it is unlikely that they
occur in older lambs and sheep, since, in addition to the synthesis in the rumen. Yeast is very
high in some of the B vitamins.
Vitamin C
Except in the case of newborn lambs, it is not likely that sheep require a dietary source of
this vitamin due to internal synthesis by microorganisms.
Vitamin D
For sheep the only important sources of vitamin D in feeds are in field-cured hays, as
growing plants and grains have very little or none of the material. When sheep are exposed to
sunshine, vitamin D is formed in the body by the action ofthe ultraviolet rays. Hence, any
deficiency is most likely to be evident late in the winter after periods of cloudiness and when
the sunshine is not so effective. Vitamin D is an essential for the metabolism of calcium and
phosphorus and for the formation of bone. Without adequate vitamin D young animals develop
rickets or a "bent-leg" condition. Vitamin D cannot make up for a lack of calcium and
phosphorus, but these minerals cannot be effectively used in the absence ofthis vitamin. Some
spasms and sudden death in winter lambs of few weeks of age have been associated with
inadequate vitamin D.
Vitamin E
In some animals normal reproduction is impossible without vitamin E, but there are few
reports regarding its need by sheep. "Stiff lamb" or white mub,te disease in newborn lambs
results from vitamin E deficiency. Sheep can eat many types of fodders, grains and cakes. It can
also eat some types of shrubs and leaves of variety of tree species. Sheep is also able to meet all
its requirements of nutrients from grass lands except during winter season. Since most feeds,
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