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Why is Bull Selection Important?. The bull contributes 1/2 of the genetic makeup of his offspring He’s the most important individual in herd Use a bull to improve the quality and performance of your herd.

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Why is bull selection important
Why is Bull Selection Important?

  • The bull contributes 1/2 of the genetic makeup of his offspring

  • He’s the most important individual in herd

  • Use a bull to improve the quality and performance of your herd


Name these three breeds


Selection criteria sires
Selection Criteria: Sires herd are a result of the last 3 bulls in your cow’s pedigree.

  • Varies depending on the use of the calf and the age of the cow being bred

  • Low BW bulls are an advantage for heifers, but not necessary or desirable for larger, mature cows

  • Look for more growth and size when breeding larger framed, mature cows


Genetic tools selection
Genetic Tools - Selection herd are a result of the last 3 bulls in your cow’s pedigree.

  • Use EPD’s and other estimates of genetic potential to make permanent improvement in the genetic level of the herd

  • Effective when heritability is moderate to high

    • ex: growth- high heritability

    • ex: reproduction- low heritability


Why is heritibility important
Why Is Heritibility Important herd are a result of the last 3 bulls in your cow’s pedigree.

  • Commercial: sell cattle by weight

    ^ Weight at various ages is heritable

  • WW is estimated to be:

    ~ 30% heritable

  • YW is estimated to be:

    ~ 45% heritable


Genetic tools crossbreeding
Genetic Tools - Crossbreeding herd are a result of the last 3 bulls in your cow’s pedigree.

  • Breeds can be crossed to improve heratability traits that are low

    Ex: Reproductive Performance

    - Crossing Angus bulls on Brahman cows (Brahman cattle reach sexual maturity later than other breeds)


What is an epd
What is an EPD herd are a result of the last 3 bulls in your cow’s pedigree.

  • Expected Progeny Difference

  • The difference between EPD’s of two bulls is the expected difference in progeny averages when bulls are mated to similar cows in a herd

  • # expressed in pounds & can only be used as a comparison for animals in the same breed


Which bull would you select to use on mature cows when growth is the most important trait to you
Which Bull Would You Select herd are a result of the last 3 bulls in your cow’s pedigree.to use on mature cows when growth is the most important trait to you?


Use of epd s
Use of EPD’s herd are a result of the last 3 bulls in your cow’s pedigree.

  • Use only to compare two or more bulls

  • EPD’s allow valid comparisons of all bulls of the same breed, but they do not allow you to compare bulls from different breeds


Epd charts
EPD Charts herd are a result of the last 3 bulls in your cow’s pedigree.

  • Most breed associations provide EPD’s for :

    1. Birth Weight (BW)

    2. Weaning Weight (WW)

    3. Yearling Weight (YW)

    4. Maternal Milk

    5. Carcass


Birth weights
Birth Weights herd are a result of the last 3 bulls in your cow’s pedigree.

  • High Birth Weight EPD’s

    1. Calving Difficulty when bred to first calf heifers

    2. Increased Cost and death loss



Weaning yearling weights
Weaning & Yearling Weights birth weight EPD in excess of 3.0 pounds should not be used on first calf heifers in most cases



Scrotal circumference
Scrotal Circumference for yearling weight versus one that has an EPD of 5 pounds?

  • Yearling bulls with large scrotal circumference sire daughters that show estrus at an earlier age

  • Be sure to select a bull with a SC of at least 30 cm at one year of age


Milk for yearling weight versus one that has an EPD of 5 pounds?

  • Measured in terms of how it affects weaning weight of a calf

  • Milk EPD on a bull is an estimate of lbs. of a calf at weaning produced by the bull’s daughter due to her milking ability


Breeding plan replacement heifers
Breeding Plan for yearling weight versus one that has an EPD of 5 pounds?Replacement Heifers

  • Mate 1st calf heifers to bull with low BW, calving ease & large scrotal circumference

  • Expect to use as many heifers as possible from these matings as replacements


Breeding plan main cow herd
Breeding Plan for yearling weight versus one that has an EPD of 5 pounds?Main Cow Herd

  • Mate the remaining cows to bulls which have EPD’s that meet market criteria

  • Look for bulls with higher EPD’s for growth & carcass yield


How many bulls will i need
How Many Bulls Will I Need for yearling weight versus one that has an EPD of 5 pounds?

  • Age:

    1. Yearling (15 mos.) - 20-25 cows per 90 days

    2. 2-5 year old- ~ 40 cows per 90 days

  • Condition:

    1. Poor nutrition - influence semen quality

    2. Fat bulls lack stamina to breed a large number of cows


Factors affecting a bull s value
Factors Affecting A Bull’s Value for yearling weight versus one that has an EPD of 5 pounds?

  • # of calves the bull may sire

  • Performance level of the herd on which bull is to be used

  • Type of breeding system you select

  • Bull’s Pedigree


Summary
Summary for yearling weight versus one that has an EPD of 5 pounds?

  • Look for traits that are economically important to you

  • Demand & buy bulls with total performance records that will improve your herd

  • Selecting and buying a herd bull is the quickest way to make genetic improvements in your herd besides using Artificial Insemination


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