Managing to Prevent Calf Scours: The Sandhills Calving System

1. Managing to Prevent Calf Scours: The Sandhills Calving System David R. Smith1 Dale Grotelueschen2 Tim Knott3 Steve Ensley1 1University of Nebraska–Lincoln2Pfizer Animal Health3Sandhills Veterinary Hospital

2. Calf Scours:Death loss Performance loss Treatment costsLabor, medicationHuman tollRisk for injury, frustration

3. Therapy Replace fluids, electrolytes, bicarbonate Treat septicemia

4. The faith in “cures” and the practice of dealing with disease problems only after they have arisen... is antagonistic to disease prevention. Dr. Leunis Van Es Lincoln, NE 1932

5. Does the “solution” come in a bottle?

6. POPULATION perspective on preventing infectious disease Host Agent Environment

7. Infectious disease triad Host Agent Environment

8. Agents • Bacteria • E. coli, Salmonella • viruses • rotavirus, coronavirus • protozoa • cryptosporidia • fungi • mycotic superinfection

9. Concept #1Agents of calf scours • Diarrhea-causing organisms are widespread in cattle populations • including herds without scours problems.

10. Infectious disease triad Host Agent Environment

11. Immunity Exposure Time

13. Immunity Antibodies from colostrum Time Passive

14. Immunity Active immune response Antibodies from colostrum Time Passive Acquired

15. Immunity Window of vulnerability Time Passive Acquired

16. Immunity Immunity Window of vulnerability Scours Exposure Time

17. Immunity Immunity Scours Exposure 0-5 6-10 11-15 16-20 21-25 26-30 Days

18. Frequency histogram age of calves at death 25 20 15 Count 10 5 0 5 10 15 20 25 More 0 6 11 16 21 26 Age at death (days) Concept #2Age specificity of calf scours • Calves at highest risk for scours at 1-2 weeks of age And to begin shedding scours agents

19. Immunity Scours Exposure Time

20. Immunity Exposure Time

21. Immunity Scours Exposure Time

22. Immunity SCOURS Exposure Time

23. Level of Exposure

24. Concept #3 • The level of pathogen exposure is a function of TIME and: • ANIMAL DENSITY (crowding -rapid environmental contamination) • MULTIPLIER EFFECT • Cows carry, shed diarrhea-causing organisms at “low” levels. • Calves are exposed, shed at “high” levels, serve as multipliers.

25. The “multiplier” effect

29. Biosecurity/Pathogen Containment Host ? Increase resistance Prevent effective contacts X Agent Environment Remove the agent

30. Biosecurity / Pathogen Containment • Prevent effective contacts -decrease the number of contacts that result in transmission. • physical separation: dilution, segregation, quarantine • minimize dose-load: prophylactic medicines, sanitation • minimize contact-time

31. Prevent effective contacts -decrease the contacts that result in transmission. Ex. calf hutches

32. Beef Systems Can they be modified to reduce effective contacts?

33. Sandhills Calf Scours Project Frequency of births 120 100 • Prevent contacts • Segregate calves by age to prevent the multiplier effect • Move pregnant cows to new calving pastures to minimize dose-load and contact time 80 Count 60 40 20 0 5/1 5/8 5/15 5/22 5/29 6/5 6/12 6/19 6/26 7/3 More 5/2 5/9 5/16 5/23 5/30 6/6 6/13 6/20 6/27 7/4 Date

34. Sandhills Calf Scours Project • Prevent contacts • Segregate calves by age to prevent the multiplier effect • Move pregnant cows to new calving pastures to minimize dose-load and contact time Enough Theory! Let’s put it to work...

35. Sandhills Calving SystemWeek 1&2 Calving Pasture

36. Sandhills Calving SystemWeek 3 1-2 week old Pairs Calving Pasture

37. Sandhills Calving SystemWeek 4 2-3 week old pairs 1 week old pairs Calving Pasture

38. Sandhills Calving SystemWeek 5 2 week old pairs 1 week old pairs Calving Pasture

39. Sandhills Calving SystemWeek 6 Calving Pasture 2 week old pairs 1 week old pairs

40. Sandhills Calving SystemWeek 7 Calving Pasture 1 week old pairs 2 week old pairs

41. Sandhills Calving SystemWeek 8 Calving Pasture 1 week old pairs 2 week old pairs

42. Sandhills Calving SystemWeek 9 Calving Pasture -Finish out 1 week old pairs 2 week old pairs Groups commingled after youngest calf is 4 weeks of age

43. Case Herd 1 • 800-900 March-calving cows • paired out from calving lot • Mortality due to scours • 14% 1995 • 6.5% 1996 • 8.2% 1999 (similar losses in ‘97 and ‘98) • Treatment expenses $3114 /yr (‘95-’99) 55-120 dead calves every year attributed to scours

44. Case Herd 1 • Sandhills Calving System in ‘00, ’01, ‘02 • Greatly reduced morbidity and mortality • 4 calves treated for scours (2000) • No deaths due to neonatal calf diarrhea (p<0.01) • $128.83 /yr in veterinary expenses • a 24-fold reduction (p<0.01)

45. Case Herd 1 • Owner estimates the change was worth $40,000-$50,000 /yr • greater number of weaned calves • improved calf performance • reduced expenses for treatment

46. Case Herd 2 • 300-400 Summer calving cows • Intensive grass management • cattle move through pastures every 2-3 days • Mortality (1° due to scours) • 6.5% in 1999 • 11.9% in 2000 Summer calving and rotating calving pastures did not prevent calf scours!

47. Case Herd 2 • Sandhills Calving System in ‘01-’02 • Modified for intensive grass management • Split off groups every 100 pairs or 10 days • multiple groups moving through different pastures • Mortality significantly reduced • “all cause” death loss 2.3% and 1.5% (p<0.01) • NO deaths from neonatal scours (‘01, 02)

48. Sandhills Calving System • Prevent Effective Contacts to Control Calf Scours • Move “Heavy” Cows to Clean Calving Pastures • Segregate Calves by Age

49. Sandhills Calving System • Prevent Effective Contacts to Control Calf Scours • Calf Health and Well-Being • Productivity • Labor Efficiency

50. [those concerned with] food-producing animals must think in terms of hygiene, for their success is in no small measure dependent upon their knowledge of the subject... Dr. Leunis Van Es Lincoln, NE 1932