Animal Selection and Evaluation

Livestock Evaluation

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.

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 7:1, Sheep 5:1, Swine 3:1.

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.

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.

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.

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.

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.

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.

Correct (Right) / Incorrect (Left) Structures

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.

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

Correct Structure

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.

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.

Correct (left)/Incorrect (right) Structure

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.)

Correct Nipple Structure

What is an Ideal Market Animal?

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.)

Location of 12th Rib

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.

Beef

• The consumer’s 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.

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.

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.

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.

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.

Location of 10th Rib

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.

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.

Location of 12th Rib

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.