Sheep Grazing Behavior * * * * Sheep Fencing

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Sheep Grazing Behavior
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Sheep Grazing Behavior

• Grazing animals are looking for green plant
  material
• Order of preference is
• new green leaves
• older green leaves
• green stems
• dry leaves
• finally dry stems
• Grazing animals are also looking for palatable
  plants

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Sheep Grazing Behavior

• Sheep have narrower mouths, more flexible lips
  than cattle - can be more selective - individual
  bites
• Ruminants swallow their food as soon as it is
  lubricated
• After consuming a certain amount, they rest
  ruminate
• Cattle usually graze for four to nine hours a day
• Sheep and goats for nine to 11 hours a day
• Sheep rest and ruminate more than cattle
• 7 to 10 hours a day for sheep
• 4 to 9 hours a day for cattle.

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Sheep Grazing Behavior

• Sheep graze more rugged terrain than cattle.
• Sheep reluctant to graze areas with natural
  predator cover
• Sheep may walk from three to five kilometers for
  water (depending on topography)
• Greater distance to water more energy and time
  needed to satisfy sheeps requirements.
• Sheep need 7.5 to 10 litres of water per day

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Sheep Grazing Behavior

• Livestock seek shade and cool during hot summer
  periods
• excessive grazing under trees and in riparian
  areas.
• Livestock overuse dry southern exposures in
  Spring, then switch to riparian and shaded areas
  during hotter times
• North-facing slopes usually remain underused.
• Sheep have strong flocking instinct
• Maintain social spacing and orientation in pens
  as well as pasture.
• Breed, stocking rate, topography, vegetation,
  shelter and distance to water may influence this
  instinct
• Isolation of individual sheep usually brings
  about signs of anxiety and may cause the sheep to
  try to escape.
• Sheep tend to follow one another
• grazing, bedding down, reacting to obstacles and
  feeding.

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Multi-Species Grazing

• Different animals prefer different forages
• Cattle diets consist primarily of grass.
• Sheep tend to prefer forbs over grass and browse
• Goat and deer diets contain large amounts of
  browse compared to cattle and sheep diets.
• Because of the different dietary preference,
  mixing kinds of livestock under certain
  conditions is possible, however
• forage source must have necessary diversity and
  production for animals to meet dietary
  preferences
• cattle and sheep will compete if grazed together
  in predominately grass pasture
• Grazing cattle and sheep together will place
  increased management requirements on operator
• Fencing and other infrastructure needed to handle
  two kinds of livestock are different
• Herd health issues (recognizing, treating and
  dealing with sick animals) will also be
  different.

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Relative Proportions of Grass, Forbs andBrowse
in the Diets of Cattle, Sheep and Goats

• Kind of Forage Cattle Sheep Goats
• Grass 60 40 20
• Forbs 20 40 30
• Browse 20 20 50

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Sheep Production Cycle

• The most critical periods in the sheep production
  cycle are
• Breeding season through very early pregnancy
• Late pregnancy through the neonatal period
• Lactation
• Weaning
• Selection of breeding season dictates when each
  of the critical periods falls in relation to the
  forage cycle
• Nutrients in forages are highest soon after the
  forage emerges and before it matures
• Animals with low production potential or with low
  nutritional requirements (dry, non-pregnant
  adults) should graze mature forage
• Animals in breeding, late pregnancy or lactation
  periods, or newly weaned lambs, should use
  pasture producing high quality forage

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Bloat Management

• Bloat
• ruminants
• gas produced during fermentation
• becomes trapped inside rumen
• normally expelled - eructation or belching
• rumen distension exerts physical pressure
• respiratory and circulatory systems
• death

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Bloat Management

• Pasture bloat
• rapid intake of immature green legumes (alfalfa
  or clovers)
• when plants are in a vegetative state
• contribute high levels of ruminally degradable
  protein
• high levels of carbohydrates
• digested quite rapidly
• This causes
• drop in rumen pH
• increase in gas production
• binding of protein molecules into surface film or
  froth over ruminal contents
• consequently, trapped gas

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Bloat Management

• Bloat - reduced through pasture management
  methods
• plant pastures - no more than 50 percent alfalfa
  or clover
• plant non-bloating legumes
• birdsfoot trefoil
• sainfoin
• cicer milkvetch
• (AC Grazland is an alfalfa variety that can
  reduce but not eliminate bloating)
• fill animals on dry roughage or grass pastures
  before turning them out onto legume pastures
• move livestock onto alfalfa at mid-day instead of
  morning (when the dew is gone) or evening
• avoid a feast and famine routine of grazing
  management
• encourage even, regular consumption
• not a grazing pattern of engorgement

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Birdsfoot Trefoil
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Sainfoin
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Cicer Milkvetch
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Bloat Management

• Birdsfoot trefoil is less likely to cause bloat
  than alfalfa and many types of clovers
• Not because it does not have a high protein
  content
• but, because the rate of digestion is
  considerably slower
• grasses do not usually cause bloat, because the
  protein content is lower than legumes.

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Bloat Management

• Minimize bloat by turning animals onto alfalfa
  that has reached bloom stage or later
• more mature alfalfa less risk of bloat
• once alfalfa has flowered, risk of bloat greatly
  reduced
• Bloat more prevalent if animals eat only upper
  portion of the plants, (high in rapidly
  degradable protein)
• grazing animals at high stocking rates reduces
  problem
• Provide animals with grass pasture, hay, crop
  residue or grain along with legume (while on
  pasture)
• reduces consumption of legume.
• Graze in rotation, using different grass and
  legume pastures, or strip-graze (with electric
  fencing)
• force animals to eat most of plant material
  rather than just succulent top growth.

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Sheep Grazing Behavior

• Grazing animals are looking for green plant
  material
• Order of preference is
• new green leaves
• older green leaves
• green stems
• dry leaves
• finally dry stems
• Grazing animals are also looking for palatable
  plants

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Bloat Management

• Other management techniques to reduce the
  likelihood of pasture bloat in sheep
• Check them closely a couple hours after turnout
  (especially, early in grazing season or to a new
  pasture with significant legume content
• Poloxalene is a nonionic surfactant
• helps prevent foam production in rumen
• main constituent in bloat preventive mineral
  blocks for cattle
• Poloxalene feeding to sheep
• rate of two to three grams/head/day
• If cattle bloat block blocks are used
• check Copper levels
• high levels of copper copper toxicity in sheep

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Copper Levels

• Sheep require about 5 ppm (parts per million or
  mg/kg) of Cu in total diet
• Toxicity can occur at levels above 25 ppm
• 3 kg diet intake requires 15 mg Cu and allows for
  max of 75 mg
• Cattle require about 10 ppm of Cu in their diet
  and can tolerate Cu levels ten times higher than
  sheep
• Non-ruminants, such as pigs and chickens,
  tolerate even higher levels of Cu
• Growing pigs often fed 100 to 250 ppm to improve
  performance
• According to the Salt Institute, toxic level of
  Cu in diet of chickens ranges from 250 to 800ppm.

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Bloat Management

• Treat bloated sheep with care.
• build-up of pressure in rumen can actually cause
  partial collapse of lungs
• Furthermore, blood from body is forced out of
  body cavity to extremities and can cause a form
  of acidosis
• Stressing these animals complicates situation.
• Catch animals use stomach tube to help release
  free ruminal gas.
• Mild agitation of ruminal contents can aid in
  release of trapped gas bubbles
• Mineral or vegetable oils can be used as
  antifoaming agents and help release gas.
• Treatment with commercially available
  anti-bloating agents can also be done at this
  time.

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Bloat Management

• Another bloat management tool is rumenotomy
• puncturing rumen - located high on left side of
  lumbar region
• in severe, life-threatening situations
• procedure not for weak stomached
• pressure results in expulsion of significant
  amount of rumen contents
• area will need cleaning (suturing) after
  rumenotomy
• trochar and cannula
• genetic propensity to bloat susceptibility (?)
• some breeds or lines appear more susceptible to
  bloat
• may be practical to cull individuals with bloat
  history

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Using Pasture to Lower Costs

• Lambing on pasture can be labor saving
• Drift lamb on the edge of Spring and Summer
• Before lambing, graze paddocks quickly - get
  ahead of explosive Spring flush grass growth
• If pasture conditions allow, early turnout works
• grass growing at rate that provides ewes enough
  nutrients while lambing
• as demands increase, grass growth increasing
• minimize clipping expense 

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Using Pasture to Lower Costs

• Drift lambing involves
• drifting (moving) pregnant ewes out of paddock
  every few days
• leaving ewes that have lambed behind.
• ewes stay in the same paddock with their lambs
  for 30-50 days
• less likelihood of lambs getting orphaned.
• shoot for 5 ewes/acre
• Lambing on pasture reduces stress level of ewes
• plenty of space to have lambs away from the rest
  of flock
• yet, security of having flock close 
• relative security from predators

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Using Pasture to Lower Costs

• Main challenges to pasture lambing are weather
  and predators
• Newborn lambs are particularly susceptible to
  cold and rain
• tents and other portable structures provide
  shelter
• shepherds should develop protocols
• involving dextrose and warming - when lambs get
  chilled
• predators always big problem coyotes, wolves,
  dogs, eagles
• deal with them
• guard dogs - Pyrenees, Anatolian, and Marema
• extra vigilance
• animal control

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Using Pasture to Lower Costs

• Drift lambing allows manager to focus predator
  and newborn management
• Newborn lambs especially vulnerable to predation
  and hypothermia
• with drift lambing
• manager can allocate guard dogs
• manage lambs in poor weather more easily
• newest born lambs are separated from older ones
• Set stocking another form of pasture lambing
• spreads out newborns and mothers over many
  paddocks
• focused management more difficult. 

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Using Pasture to Lower Costs

• Keep lambing groups together for 30-50 days after
  lambing
• Then, combine ewes and their lambs into two big
  groups
• Begin rotationally grazing
• Separate ewes with triplets from those with only
  singles or twins
• Allow the triplet group access to pasture first
  and then follow with the other group.
• Aim for a density of around 100 ewes per acre
  since this level of density leads to good grazing
  pressure  

• After 30-50 days of staying in one

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Using Pasture to Lower Costs

• Utilize small herd of beef cows (20) to help with
  both parasite and grass management on sheep
  pasture
• Sheep very sensitive to parasites
• level of parasites on sheep pastures builds up
  over time
• Cattle and sheep are not susceptible to same
  parasites
• alternating cattle and sheep grazing can help
  lower parasite load
• This dual species grazing is effective if
• grazing is alternated over the course of the year
• sheep and cattle should not graze in the same
  pasture at the same time if parasite control is
  goal
• Cattle also useful for cleaning up overgrown
  pastures in the late Spring

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Using Pasture to Lower Costs

• Grazing turnips can help the manager get through
  the Fall stall of lamb growth
• Goal - finish lambs - one growing season -
  without grain
• tough to do using only native pastures
• normally, native grass-fed lambs do not grow well
  (Fall-stall) in Oct-Nov
• Turnips seeded into plowed hayfields that need
  renovation
• early July - grazed lightly in late August and
  September
• Lambs graze them heavily through Oct and Nov
• eat all of the turnip tops and some of the roots
• Lambs grow well on turnips
• forage quality is excellent and palatable
• Turnips also extend ewe grazing into the winter

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Using Pasture to Lower Costs

• Ewes in good condition (3.5 BCS) will do well
  grazing stockpiled forage
• even if they need to dig through snow
• 6-8 inches of snow covering 6-10 inches of
  stockpiled forage growth can be managed easily
• snow will provide the sheep with all the water
  they need  
• If the snow is too deep, place round bales in the
  pasture
• ewes do well with outside feeding
• do not waste much feed
• Small amount of wasted forage serves as a nice
  place for ewes to lamb in the Spring

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Sheep Fencing-Irrigated Pasture

• Sheep more difficult to control with electric
  fencing than any other livestock species
• Training is critical if sheep are to be
  controlled
• And, fence design must be more elaborate
• Sheep can be controlled on irrigated pasture
• 3 hot wires at 8-10, 18-20, and 28-30 inches
• 4 hot wires at 8-10, 15-17, 24-26, and 34-36
  inches
• Posts are generally spaced 40 to 50 feet apart.

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Sheep Fencing - Rangeland

• Five wires are generally required to effectively
  control sheep on rangeland
• 5 wires at 6, 13, 21, 30 and 40 inches
• 2nd, 3rd, and 5th wires hot
• 4th wire is a ground wire
• 1st wire (bottom wire) is switchable
• when soil moisture is adequate this wire is hot
• when soil moisture is lacking this is switched to
  additional ground wire
• Posts typically 40 to 50 feet apart.

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Sheep Fencing Predator fences

• Several fence designs protect sheep from
  predation
• Even temporary electric fences help
• A simple design consists of
• 3 hot wires mounted on plastic off-set brackets
• attached to posts of existing woven wire/barbed
  wire fence
• hot wires are installed at heights of 4, 22, and
  42 inches.
• More elaborate designs are often needed
• 9-wire high-tensile fence design (effective vs-
  dog and coyote
• install wires _at_ 5, 11, 17, 23, 30, 37, 44, 52, 60
  inches
• every other wire is hot (including both top and
  bottom wires)
• every non-hot wire becomes a part of ground
• wood posts spaced 75 -100 feet
• fiberglass stays installed at 20 foot intervals

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Sheep Fencing
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Sheep Fencing