1. Fractionation for improved utilization of alfalfa
M.F. Digman1, T.M. Runge2, R.D. Hatfield1, M.E. Boettcher1, K.J. Shinners2
, R.E. Muck1 and R.G. Koegel1
1U.S. Dairy Forage Research Center, USDA-ARS
2Biological Systems Engineering Department, UW-Madison

2. What is fractionation?

5. Why alfalfa?
 Protein
 Yield
 Quality
 Agronomic
 Forage rotation
 Synthetic N

6. Why alfalfa?

7. Why alfalfa?
 Fiber & protein could be more useful if separate
 Stems
 Fiber source for ruminants
 Fiber source for biochemicals & fuels
 Leaves
 Highly digestible/degradable fiber
 Protein for livestock, aquaculture, animal or human use

9. Fractionation Research

10. Can alfalfa fractionation?
 avoid field losses due to weather,
 avoid field losses due to plant and microbial respiration,
 ensure proper storage moisture for harvested leaves,
 promote rapid dry down of stems,
 improve the energy balance of the alfalfa harvesting system,
 create leaf-meal, protein, lactic acid and fiber co-product streams?

11. Step 1. Dry fractionation

13. Dry fractionation
Talbott et. al, 2005 | Currence and Buchele, 1967 | Klimes and Verosta, 1962

14. Dry fractionation
Shinners et al., 2007

15. What is fractionation?

16. Dry fractionation
Duncan and Shinners, 2010

17. What is fractionation?

18. Dry fractionation
USDFRC, Unpublished

19. Dry fractionation
USDFRC, Unpublished; Dien et al., 2006

20. A word on the stem fraction
Shinners et al., 2007

21. How are we doing?
 avoid field losses due to weather,
 avoid field losses due to plant and microbial respiration,
 ensure proper storage moisture for harvested leaves,
 promote rapid dry down of stems,
 improve the energy balance of the overall alfalfa harvesting system,
 create leaf-meal, protein, lactic acid and fiber co-product streams?

22. Step 2. Wet fractionation

26. Wet fractionation

28. How are we doing?
 avoid field losses due to weather,
 avoid field losses due to plant and microbial respiration,
 ensure proper storage moisture for harvested leaves,
 promote rapid dry down of stems,
 improve the energy balance of the overall alfalfa harvesting system,
 create leaf-meal, protein, lactic acid and fiber co-product streams?

29. Step 3. Anaerobic storage

32. Anaerobic storage

33. Press-cake fermentation profile

36. Anaerobic storage

37. Anaerobic storage

38. How are we doing?
 avoid field losses due to weather,
 avoid field losses due to plant and microbial respiration,
 ensure proper storage moisture for harvested leaves,
 promote rapid dry down of stems,
 improve the energy balance of the overall alfalfa harvesting system,
 create leaf-meal, protein, lactic acid and fiber co-product streams?

39. Summary

40. Anaerobic storage

41. Anaerobic storage

42. Anaerobic storage

43. Future Work at USDFRC engineering

44. What’s next?
 Optimize protein extraction/dewatering

45. What’s next?
 Next generation leaf-harvester
 The Boettcher butcher?
 Tractor-mounted
 Combined leaf harvesting and stem cutting

46. What’s next?
 Characterize fermented protein
 Functional properties
 AA composition
 Improved characteristics
 AA composition
 In storage stability
 Remove anti-quality factors
 Develop off-farm utilization form

47. What’s next?
 Economics of alfalfa fractionation
 Weather-independent harvest
 Protein and carbohydrates be realized by direct ensiling
 Reduced cuttings
 Segregated on-farm use of leaves, stems and fermented protein
 Market potential for fermented protein off-farm

48. Thank you for your attention.
Matthew Digman, Ph.D. | U.S. Dairy Forage Research Center