1. Genetic Evaluations & Decision Support to Improve Feed Efficiency Dorian Garrick Department of Animal Sciences Colorado State University

2. Knee-Jerk Logic Natural to think we should strive to become more efficient producers We have been indoctrinated into using EPDs as tools to aid selection –Use WWD EPDs to increase weaning weight –CED EPDs to increase ease of calving Therefore natural to want efficiency EPDs to become more efficient

3. Animal Breeding Breeding Objective Selection Criteria Dissemination System Economic Analysis Goal Breeding Scheme Design Mating Plan

4. Goal Cow-Calf –(Future) profit from sale of weanlings produced from grazed (otherwise low-value) forage while enhancing wildlife and environmental factors –Ranch is the unit of interest Feedlot –(Future) profit from finishing a pen or line of weanlings considering food safety, environment, human health –Pen is the unit of interest

5. What do you do with the Goal? Define the breeding or selection objective –List of traits that (directly) influence the goal –The relative emphasis of each trait in the list

6. List of Traits Most producers can define this list more easily than the goal Suppose our list includes: –Outputs (eg total sale weight) –Inputs (eg purchased feed) –Efficiency (eg lbs net sale weight/lbs feed) This list dictates the EPDs we desire

7. Index Approach Simultaneously consider the EPDs for each trait in the list in terms of their contribution to our goal (profit) $INDEX = r 1 EPD wt - r 2 EPD feed + r 3 EPD effic

8. Relative Trait Emphasis Relative Economic Value (REV) Value of a unit change in that trait, all other traits in the list held constant –Separately calculate this value for sale weight, feed requirements, and efficiency

9. REV for Sale Weight What is the “value” (increased profit) from a unit change in sale weight, with no changes in the other traits in our objective (ie feed requirements or feed efficiency)?

10. REV for Sale Weight What is the “value” (increased profit) from a unit change in sale weight, with no changes in the other traits in our objective (ie feed requirements or feed efficiency)? –The answer is the sale price

11. Index Approach $INDEX = (beef price) EPD wt - r 2 EPD feed + r 3 EPD effic

12. REV Feed Intake What is the “value” (increased profit) from a unit change in feed requirements, with no changes in the other traits in our objective (ie sale weight or feed efficiency)?

13. REV Feed Intake What is the “value” (increased profit) from a unit change in feed requirements, with no changes in the other traits in our objective (ie sale weight or feed efficiency)? –The answer is the feed price

14. Index Approach $INDEX = (beef price) EPD wt - (feed cost) EPD feed + r 3 EPD effic

15. REV Efficiency What is the “value” (increased profit) from a unit change in efficiency, with no changes in the other traits in our objective (ie sale weight or feed costs)?

16. REV Efficiency What is the “value” (increased profit) from a unit change in efficiency, with no changes in the other traits in our objective (ie sale weight or feed costs)? –The answer is there is no change in profit

17. Index Value $INDEX = r 1 EPD wt - r 2 EPD feed +r 3 EPD effic $INDEX = (beef price) EPD wt – (feed cost) EPD feed We don’t need an EPD for efficiency

18. REV Efficiency Efficiency is therefore not an economically relevant trait (ERT) provided sale weight and feed intake are included in our objective –Efficiency is not a “line item” in our financial statements Sale revenue and feed costs are line items –Efficiency is however a useful fundamental or key performance indicator (KPI)

19. Graphical Consideration of Issue

20. Points form an ellipse Shape of ellipse depends upon genetic correlation

21. O Average Performance

22. O Average Performance 650 lb / 4000 lb 0.1625

23. Feed Efficiency Efficiency typically measures output divided by input –Big numbers are “desirable” –Lbs gain per lbs feed (eg 1/6 =0.16 lb/lb) Alternative is feed conversion rate –input over output –Small numbers are “desirable” –Lbs feed per lb gain (eg 6 lb/lb) Rankings are “equivalent”

24. O Average Performance 650 lb / 4000 lb 0.1625 488 lb / 3000 lb 0.1625

25. O Average Performance 650 lb / 4000 lb 0.1625 488 lb / 3000 lb 0.1625 814 lb / 5000 lb 0.1625

26. O Average Performance 650 lb / 4000 lb 0.1625 488 lb / 3000 lb 0.1625 814 lb / 5000 lb 0.1625 Iso-efficiency Line

27. Iso-efficiency All animals on the line have the same efficiency –If efficiency was your goal, you would be equally happy with any of those animals

29. O Average Performance Where do you want to move the average ?

30. O Average Performance Increased Sale weight Increases Revenue $0.86/lb BWT $100/116 lb

31. O Where do you want to move the average ? Increased Sale weight Increases Revenue $0.86/lb BWT $100/116 lb Decreased feed costs $5.70 per 100 lb DM 1750 lb costs $100

32. O

33. O Iso-income line

35. Least Profitable Most Profitable Least Efficient Most Efficient Do you want efficiency or profitability ?

36. Summary so far We need good EPDs –For outputs (Sale weight & Value) –For inputs (Feed intake, Health, Labor) Selection on overall value that rewards output and penalizes inputs will increase efficiency –We don’t need an efficiency (or conversion) EPD

37. Determining Feed Intake Feed requirements are determined by: –Maintenance requirements Metabolic body weight, condition score, milk potential –Activity & Climate (if not thermo-neutral) –Production Gain, pregnancy, lactation, (replacements) –Unique (unknown) factors that differ from one animal to another (eg proton leak) (ie RFI)

38. Predicting Feed Intake Could measure feed intake –Easier in a feedlot than extensive grazing –Subject to measurement & other errors Could predict expected feed intake from knowledge of productivity –Will account for most of the variation in feed requirements –Will not account for variation in “efficiency” known as “residual feed intake” or RFI

39. Index Value $INDEX = (beef price) EPD wt – (feed cost) EPD feed $INDEX = (beef price) EPD wt – (feed cost) EPD predicted feed – (feed cost) EPD RFI

40. Index Value If we don’t have intake observations all animals will have the same EPD for RFI –Cannot predict it from correlated characters, as if we could, we can come up with a better “predicted feed” RFI is the part of feed intake we cannot explain

41. National Perspective With or without individual feed intake –Predict feed intake from “performance” –Don’t need feed intake EPD per se Depends upon for eg rate of gain Account for the cost of predicted feed in decision support using performance (& repro) EPDs With individual feed intake –Predict an EPD for residual feed intake Account for the cost/saving of RFI along with predicted feed in decision support

42. Feed Intake Milestone Before we get individual feed intakes –Use predicted requirements –For cow-calf Need mature weights & CS Need heifer pregnancy & stayability –Need Total Herd Recording (THR) After we get individual feed intakes –Only change will be EPDs for RFI

43. Getting Feed Intake No standards/guidelines for calculating feed intake –Role for BIF No existing infrastructure for collecting feed intake –Role for Breed Association

44. Summary Selection for profit requires measures of outputs and inputs –Don’t need an EPD for efficiency or intake –Predict inputs from knowledge of production Better estimates of cow-calf inputs require THR –Immediate opportunity to improve existing cow-calf recording practices and more fully account for expected feed requirements Future opportunity to collect actual feed intake – outcome will be RFI

46. Alternative List of Traits Suppose our list of traits had only included: –Sale weight –Feed Efficiency

47. Economic Values What is the value of a unit change in sale weight with no change in feed efficiency? –The answer is no longer the sale price

48. Sale Wt Economic Values What is the value of a unit change in sale weight with no change in feed efficiency? –The answer is no longer the sale price If sale weight increases, and efficiency of gain is unchanged, more feed will be required –The answer is the sale price less the cost of the feed required for the extra gain But marginal and average efficiency may differ

49. Feed Effic Economic Values What is the value of a unit change in feed efficiency with no change in sale weight? –The answer is not straightforward – it depends upon the feed cost and the amount of feed consumed –We cant put a value on feed efficiency without considering feed intake