Sheep

Sheep lol

Sheep are exclusively mammals. Most breeds prefer to graze on and other short , avoiding the taller woody parts of plants that goats readily consume. Both sheep and goats use their and to select parts of the plant that are easier to digest or higher in nutrition. Sheep, however, graze well in pastures where most goats fare poorly.

Ruminant system of a sheep

Like all ruminants, sheep have a complex composed of four chambers, allowing them to break down from stems, leaves, and seed hulls into simpler . When sheep , vegetation is chewed into a mass called a , which is then passed into the , via the . The rumen is a 19- to 38-liter (5 to 10 gal) organ in which feed is . The fermenting organisms include bacteria, fungi, and protozoa. (Other important rumen organisms include some archaea, which produce methane from carbon dioxide.) The bolus is periodically regurgitated back to the mouth as for additional chewing and . After fermentation in the rumen, feed passes into the and the ; special feeds such as grains may bypass the rumen altogether. After the first three chambers, food moves into the for final digestion before processing by the . The abomasum is the only one of the four chambers analogous to the human stomach, and is sometimes called the "true stomach".

Other than forage, the other staple feed for sheep is , often during the winter months. The ability to thrive solely on pasture (even without hay) varies with breed, but all sheep can survive on this diet. Also included in some sheep's diets are , either in a trace mix or in . Feed provided to sheep must be specially formulated, as most cattle, poultry, pig, and even some goat feeds contain levels of that are lethal to sheep. The same danger applies to mineral supplements such as .

Grazing behavior

Sheep follow a pattern of activity, feeding from dawn to dusk, stopping sporadically to rest and chew their . Ideal pasture for sheep is not lawnlike grass, but an array of , and . Types of land where sheep are raised vary widely, from pastures that are seeded and improved intentionally to rough, native lands. Common plants toxic to sheep are present in most of the world, and include (but are not limited to) cherry, some oaks and acorns, tomato, , rhubarb, potato, and .

Sheep grazing on public landEffects on pasture

Sheep are largely herbivores, unlike animals such as goats and deer that prefer taller foliage. With a much narrower face, sheep crop plants very close to the ground and can a pasture much faster than cattle.For this reason, many shepherds use , where a flock is rotated through multiple pastures, giving plants time to recover. Paradoxically, sheep can both cause and solve the spread of . By disturbing the natural state of pasture, sheep and other livestock can pave the way for invasive plants. However, sheep also prefer to eat invasives such as , , and over native species such as , making grazing sheep effective for . Research conducted in compared lamb grazing with for control in seedling fields. Three trials demonstrated that grazing lambs were just as effective as herbicides in controlling winter weeds. also compared grazing lambs to for insect control in winter alfalfa. In this trial, lambs provided insect control as effectively as insecticides.

BehaviorSheep showing flocking behavior during a Flock behavior

Sheep are animals and strongly gregarious; much sheep behavior can be understood on the basis of these tendencies. The of sheep and their natural inclination to follow a leader to new pastures were the pivotal factors in sheep being one of the first domesticated livestock species. Furthermore, in contrast to the and (two other ungulates of primary importance to meat production in prehistoric times), sheep do not defend although they do form . All sheep have a tendency to congregate close to other members of a flock, although this behavior varies with breed, and sheep can become stressed when separated from their flock members. During flocking, sheep have a strong tendency to follow and a leader may simply be the first individual to move. Relationships in flocks tend to be closest among related sheep: in mixed-breed flocks, subgroups of the same breed tend to form, and a ewe and her direct descendants often move as a unit within large flocks. Sheep can become to one particular local pasture (heft) so they do not roam freely in unfenced landscapes. Lambs learn the heft from ewes and if whole flocks are culled it must be retaught to the replacement animals.