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B66 Heritability, EPDs & Performance Data

B66 Heritability, EPDs & Performance Data. Heritability. Heritability is the measurement of how much of a trait is passed on to its offspring by genes. Those traits that are more highly heritable can be used by the producer in selecting breeding stock. Heritability Estimates. Heritability.

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B66 Heritability, EPDs & Performance Data

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  1. B66 Heritability, EPDs & Performance Data

  2. Heritability • Heritability is the measurement of how much of a trait is passed on to its offspring by genes. • Those traits that are more highly heritable can be used by the producer in selecting breeding stock.

  3. Heritability Estimates

  4. Heritability • Low: Reproductive traits • Medium: Growth Traits (birth weight, wean weight, yearly weight, rate of gain) • High: Carcass traits

  5. Calculating Genetic ImprovementUsing Heritability Estimates • A producer currently has ewes that wean 70 lb. lambs. • They want to raise weaning wt. to 110 lbs. • They select a ram with a wean wt. of 110 lbs. • The heritability of weaning wt. is 30%. • What can the producer expect the new lamb crop to weigh at weaning?

  6. Heritability • What is the difference in current weaning wt. and that of the new ram? 110 - 70 = 40 lbs. • Heritability % x difference 30% x 40 = 12 lbs. • Can expect a gain in weaning wt of 12 lbs. • 70 lbs + 12 lbs = 82 lbs.

  7. Heritability • Activity: Do the Heritability problems

  8. EPDs Expected Progeny Differences • Expected progeny differences predict the expected difference in performance of a sire’s or dam’s progeny when compared to the average for that breed. • Breed Specific (can’t compare EPDs of different breeds) • Performance data is researched, collected, and computer analyzed to provide the predicted outcome or genetic merit.

  9. EPDs & Units of measurement • Expressed as + or - • Birth weight in pounds • Weaning weight in pounds at 205 days • Yearling weight in pounds at 365 days • Gestation length in days • Yearling height in inches • Scrotal circumference in centimeters

  10. EPDs & Units of measurement • Carcass weight in pounds • Marbling in USDA marbling degrees • Ribeye area in square inches • Fat thickness in inches

  11. Performance Data • Data is collected in three important areas: • Ancestry • Individual performance • Progeny

  12. Ancestry • If you were breeding race horses, what information would you want to see to help you select the right stallion? • The performance records of ancestors are a valuable tool and should be considered in the selection process. • The performance records on ancestors are analyzed in the equation and they offer a good indication what the EPD of the animal might be.

  13. Individual Performance • If the animals in a herd are raised under similar environmental conditions, the top producing animals must have had a genetic advantage over the average or poor producing animals. • Records on the individuals performance provide a way to ensure that the genetics of the ancestors were passed on to the individual and are used to calculate EPDs.

  14. Progeny Records • Progeny records are the best indication of the three genetic merits of the sire. • This is especially true if the progeny are distributed in different herds and under different environmental conditions, but still constantly out produce the animals in the contemporary group.

  15. Accuracy • Accuracy value reflects the amount of and distribution of information included in the evaluation.

  16. Accuracy

  17. What an EPD Looks Like

  18. Important EPDs for Beef Cattle Unit of Change EPD Impact Birth Weight(BW) Fewer lbs = Fewer Calving Problems Pounds (lbs) More lbs = faster calf growth More lbs = Heavier Feeder Calves Weaning Weight(WW) Pounds (lbs) Milk - maternal(MILK) Pounds (lbs) More lbs = More Cow Milk Production More lbs = faster steer growth More lbs = Reach market faster More lbs = greater mature size Yearling Weight(YW) Pounds (lbs) Rib Eye Area REA Inches2 More in2 = heavier muscled calves Higher % = more intramuscular fat Higher % = higher quality grade Percent % Marbling (MARB)

  19. Question 1 Which bull would be the best choice to breed to heifers? Yearling Weight(YW) Weaning Weight (WW) Birth Weight(BW) Bull Milk (MILK) Rib Eye Area (REA) Marbling (MARB) A 0.0 +20 +15 +40 -0.3 +0.05 B -1.6 +16 +22 +32 +0.8 -0.02 C +2.1 +42 +21 +55 +0.4 +0.08 D -0.2 +35 +30 +44 -0.7 +0.12 Bull B - He has the lowest birth weight (BW) EPD.

  20. Question 2 Which bull would produce the lightest feeder calves? Yearling Weight(YW) Weaning Weight (WW) Birth Weight(BW) Bull Milk (MILK) Rib Eye Area (REA) Marbling (MARB) A 0.0 +20 +15 +40 -0.3 +0.05 B -1.6 +16 +22 +32 +0.8 - 0.02 C +2.1 +42 +21 +55 +0.4 +0.08 D -0.2 +35 +30 +44 -0.7 +0.12 Bull B - He has the lowest weaning weight (WW) EPD birth weight (BW) EPD.

  21. Question 3 Which bull will produce calves with the highest quality grade? Yearling Weight(YW) Weaning Weight (WW) Birth Weight(BW) Bull Milk (MILK) Rib Eye Area (REA) Marbling (MARB) A 0.0 +20 +15 +40 -0.3 +0.05 B -1.6 +16 +22 +32 +0.8 - 0.02 C +2.1 +42 +21 +55 +0.4 +0.08 D -0.2 +35 +30 +44 -0.7 +0.12 Bull D - He has the highest marbling (MARB) EPD.

  22. Question 4 Which bull will sire steers that reach market weight the quickest? Yearling Weight(YW) Weaning Weight (WW) Birth Weight(BW) Bull Milk (MILK) Rib Eye Area (REA) Marbling (MARB) A 0.0 +20 +15 +40 -0.3 +0.05 B -1.6 +16 +22 +32 +0.8 - 0.02 C +2.1 +42 +21 +55 +0.4 +0.08 D -0.2 +35 +30 +44 -0.7 +0.12 Bull C - He has the highest yearling weight (YW) EPD.

  23. Question 5 Which bull will sire the poorest milk-producing daughters? Yearling Weight(YW) Weaning Weight (WW) Birth Weight(BW) Bull Milk (MILK) Rib Eye Area (REA) Marbling (MARB) A 0.0 +20 +15 +40 -0.3 +0.05 B -1.6 +16 +22 +32 +0.8 - 0.02 C +2.1 +42 +21 +55 +0.4 +0.08 D -0.2 +35 +30 +44 -0.7 +0.12 Bull A - He has the lowest milk (MILK) EPD.

  24. Question 6 Which bull will produce the heaviest muscled calves? Yearling Weight(YW) Weaning Weight (WW) Birth Weight(BW) Bull Milk (MILK) Rib Eye Area (REA) Marbling (MARB) A 0.0 +20 +15 +40 -0.3 +0.05 B -1.6 +16 +22 +32 +0.8 - 0.02 C +2.1 +42 +21 +55 +0.4 +0.08 D -0.2 +35 +30 +44 -0.7 +0.12 Bull B - He has the highest rib eye area (REA) EPD.

  25. Question 7 Which bull’s calves will be the oldest when sold as feeder calves weighing 500 pounds? Yearling Weight(YW) Weaning Weight (WW) Birth Weight(BW) Bull Milk (MILK) Rib Eye Area (REA) Marbling (MARB) A 0.0 +20 +15 +40 -0.3 +0.05 B -1.6 +16 +22 +32 +0.8 - 0.02 C +2.1 +42 +21 +55 +0.4 +0.08 D -0.2 +35 +30 +44 -0.7 +0.12 Bull B - He has the lowest weaning weight (WW) EPD.

  26. Question 8 Which bull will sire the heaviest calves at birth? Yearling Weight(YW) Weaning Weight (WW) Birth Weight(BW) Bull Milk (MILK) Rib Eye Area (REA) Marbling (MARB) A 0.0 +20 +15 +40 -0.3 +0.05 B -1.6 +16 +22 +32 +0.8 - 0.02 C +2.1 +42 +21 +55 +0.4 +0.08 D -0.2 +35 +30 +44 -0.7 +0.12 Bull C - He has the highest birth weight (BW) EPD.

  27. Question 9 Which bull will make the most improvement in milking ability? Yearling Weight(YW) Weaning Weight (WW) Birth Weight(BW) Bull Milk (MILK) Rib Eye Area (REA) Marbling (MARB) A 0.0 +20 +15 +40 -0.3 +0.05 B -1.6 +16 +22 +32 +0.8 - 0.02 C +2.1 +42 +21 +55 +0.4 +0.08 D -0.2 +35 +30 +44 -0.7 +0.12 Bull D - He has the highest milk (MILK) EPD.

  28. Question 10 Which bull will sire the most growth? Yearling Weight(YW) Weaning Weight (WW) Birth Weight(BW) Bull Milk (MILK) Rib Eye Area (REA) Marbling (MARB) A 0.0 +20 +15 +40 -0.3 +0.05 B -1.6 +16 +22 +32 +0.8 - 0.02 C +2.1 +42 +21 +55 +0.4 +0.08 D -0.2 +35 +30 +44 -0.7 +0.12 Bull C - He has the highest weaning weight (WW) and yearling weight EPDs.

  29. Additional Scenarios • The situation or environment that these cattle (bulls or heifers) are going to placed into once the selection process is complete should always be considered, so you can determine what traits to emphasize when evaluating the EPD and the phenotype. • Here are some examples:

  30. Scenario 1 • 1. All offspring are sold at weaning. • This indicates that the weaning weight EPD should be emphasized heavily.

  31. Scenario 2 • 2. These bulls will be mated to first calf heifers and their offspring will be kept as replacements. • This indicates that birth weight EPD should be strongly evaluated and that weaning and yearling EPDs should be considered as well. Moreover, since the scenario says that all replacements are being kept, then the milk EPD is important also.

  32. Scenario 3 • 3. Forage is low quality for the heifers. • This should indicate that moderate milking ability should be emphasized. Thus, a high milk EPD should be discouraged in the decision making process.

  33. Scenario 4 • 4. Forage and feed are high in quality and abundant. • This signals that a high milk EPD should be emphasized.

  34. Scenario 5 • 5. The producer is retaining ownership through the feedlot. • This indicates that the owner does not sell the castrated bull calf (steer) or heifer until after they are fed in the feedlot and go to harvest. Growth data (weaning and yearling EPD ) are important. Specifically, the yearling weight EPD is by far the most important trait to evaluate in this scenario.

  35. Scenario 6 • 6. The ranch labor is limited. • This means that there is no one there to pull calves if cows or heifers are having trouble calving. Thus, a low birth weight EPD in potential sires is a much more desirable economic trait.

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