Animal Selection and Evaluation

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Animal Selection and Evaluation

• Livestock Evaluation

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Why Evaluate Livestock?

• Success in the production of livestock depends on
  the ability to select animals efficient in their
  production and reproduction capabilities.
• Develop ability to recognize carcass and breeding
  merit, as well as, understand the economic value
  differences when comparing livestock.

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To Predict Production Performance...

• Rate of gain is amount of weight gained on a per
  day basis.
• Feed efficiency is the amount of feed consumed
  divided by the amount of weight gained.
  Approximate estimate for each specie (lbs. of
  feed/lbs. of gain) Cattle 71, Sheep 51, Swine
  31.

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To Predict Production Performance...

• Livestock with greater length, width, and depth
  of body tend to have a greater ability to grow
  and gain at a faster rate.
• Performance capabilities are difficult to predict
  from visual evaluation. Production and
  performance records of relatives are good
  indicators.

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To Predict Production Performance...

• Performance records of relatives help to estimate
  growth potential of the individual. Terminology
  used is
• Cattle birth weight, weaning weight, yearling
  weight, etc.
• Swine 21 day litter weight, days to 230 lbs.,
  sow productivity index, etc.
• Sheep type of birth (single, twins, triplets),
  90 day weight, ewe index, etc.

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To Predict Production Performance...

• There is no agreement as to the ideal size or
  weight of any species. This is influenced by
• Economy feed prices, production costs, supply
  and demand for meat.
• Consumer fat content and portion size of
  product.
• Environment Amount and quality of feed
  resources, temp., rainfall, etc.

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To Predict Reproductive Performance in Beef Cattle

• Calving ease may be estimated to a certain extent
  by estimating
• Width b/t pin bones. More width generally
  indicates greater width in the birth canal.
• Slope of rump. Pin bone should be slightly below
  the hook bone when the animal is viewed from the
  side.
• Shoulder should blend smoothly into the neck at
  both the top and bottom of the shoulder when
  viewed from the front.

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To Predict Reproductive Performance in Beef Cattle

• Milking ability may be estimated by
• Udder development, teat placement, and teat
  quality.
• Examine past production record of the dam and
  female offspring of the sire.
• Production records from the parents are the best
  way to evaluate reproductive performance and
  capabilities.

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To Predict Reproductive Performance in Beef Cattle

• Skeletal soundness
• If properly designed, an animal should have free,
  easy movement.
• If an animal has mobility problems at an early
  age and light weight, it will only be magnified
  in later life.
• The animals feet, legs and body should indicate a
  long, productive life.

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Correct (Right) / Incorrect (Left) Structures
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To Predict Reproductive Performance in Sheep

• Production records from the dam are used
  extensively. They should provide the following
• Multiple birth ability.
• Number of lambs raised vs. number born.
• Weaning weight, milking ability.

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To Predict Reproductive Performance in Sheep

• Skeletal correctness
• Straight lined, level top, and legs are straight,
  and set wide apart, both front and rear.
• Must have freedom of movement.
• Growth potential
• Select sheep that have the ability to grow
  rapidly
• Capacity length, width, and depth of body

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Correct Structure
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To Predict Reproductive Performance in Swine

• Production records are very useful in identifying
  superior individuals.
• Litter size, number of pigs born vs. number
  raised.
• Litter weight.
• Slow productivity index.
• Days to 230 lbs.

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To Predict Reproductive Performance in Swine

• Skeletal correctness
• It is essential that hogs are structurally
  correct because many are raised in confinement
  systems (i.e., concrete slotted floor buildings)
• More early level rump and top, sound feet and
  legs, width of body, and long and fluid stride.
• Growth potential Hogs with more capacity have a
  tendency to grow more rapidly.

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Correct (left)/Incorrect (right) Structure
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To Predict Reproductive Performance in Swine

• Milking ability
• Select gilts that have a minimum of 6 functional,
  evenly spaced nipples on each side of the
  underline.
• Nipples should be prominent.
• Avoid an underline that has several abnormalities
  (i.e., pin nipples, inverted, etc.)

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Correct Nipple Structure
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What is an Ideal Market Animal?
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Beef

• Ideal market beef should
• Quality grade few choice which means marbling in
  the meat and under 24 months of age.
• Yield grade 1 or 2 which means a minimum of fat
  and more muscle.
• Average back fat of .4 in. (measured at 12th rib.)

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Location of 12th Rib
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Beef

• Ideal market beef should
• Required ribeye area Base 600 lb. carcass needs
  11.0 square in.
• Yield a carcass weighing between 500 and 750 lbs.
  to best fit market demand.

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Beef

• The consumers recent trend toward health
  awareness has influenced the meat industry
  tremendously. For example
• USDA grading procedures have changed. Greater
  value for lean, heavy muscled cattle.
• Poultry and fish consumption have increased
  greatly due to their lower fat and lower
  cholesterol content.

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Beef

• The fat content in 7 cuts of beef rank between
  the chicken breast and thigh. (Not as fat as
  consumers think.)
• The beef market is now focusing its promotion on
  what consumers want - - convenience.

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Beef

• Packer concerns
• Cattle are purchased by the pound - fat is worth
  about 1/10 of what lean meat is worth.
• Consequently, the packer loses money on fat
  cattle.

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Beef

• Producer concerns
• Fat is less efficient to produce than muscle so
  cattle gaining fat eat the same amount of feed
  but gain less efficiently.
• Packers do not want to buy cattle that are
  excessively fat.

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Swine

• Ideal market hog should
• Be lean and heavy muscled.
• Have a width through a ham equal to or greater
  than the width through the shoulder and both
  should be wider than the back.
• Have average back fat thickness of less than 1.0
  inches (measured at the 10th rib).
• Have a minimum of 5.0 in. of loin eye.

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Location of 10th Rib
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Swine

• Ideal market hog should
• Should be yield grade U.S. No. 1, which depends
  on the amount of back fat and muscle.
• Carcass merit is an indication of the amount of
  muscle/meat the carcass contains.

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Sheep

• The ideal market lamb should
• Be heavily muscled with superior conformation and
  correctness.
• Have a 2.5 square in. ribeye or larger.
• At market weight have .1 to .2 in. of back fat
  (measured at 12th rib) and be uniform in its fat
  cover.
• Have a leg score of low choice or better.
• Be uniform in its thickness from head to dock.

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Location of 12th Rib
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Sheep

• The reasons for the change in the market lamb
  desired today are very similar to the reasons for
  the change in the type of market steer.