Improving piglet survival in large litters

1. Improving piglet survival in large litters Flemming Thorup DVM, Ph. D.

2. Danish Pig Production • Is lead by a board of pig producers • Secretariat • Breeding department (DAN bred) • Veterinary department • Dept. for Barn (equipment) and Production Systems • Department for Feeding and Reproduction • Feeding of weaners and finishers • Reproduction • Quality of boar semen • AI techniques • Feeding of sows • Sow longevity • Female reproduction

3. Objects • On farm investigations • Large scale balanced comparative studies • Observational studies • Report writing • Presentations • Advisers, technicians, veterinarians, farmers, co-workers • Information • Teaching • Vet. and anim. sci. students, graduation projects • Handling general problems • Herd problems

4. Improving piglet survival in large litters

5. Production herd results 1992-2005

6. Development 1992-2005

7. Piglet age at death 15 per cent mortality 11 per cent mortality

8. Most piglets die during the first 3-5 days • Not much time to save the piglets • - or • Only 3 days of work to save the piglets?

9. Causes of mortality, percent of dead

10. Primary diagnosis for crushed piglets?

11. Causes of mortality • Crushed-crushed-crushed and weak • What comes first? • Sepsis?

12. Mortality with increasing litter size

13. Number at birth. Effect on mortality.

14. Late born piglets have the highest postnatal mortality • Increase from 9-12 • No increase from 12 to 18? • Late born piglets have to fight more for milk (Barnes and Quainoo, IPVS 1982)

15. Antibody level and mortalityIg 12 hours after birth

16. Antibody level 12 hours after birth • Average 45 g/liter • Large variations between piglets • 0 at 12 hours = death • 5 to 10 at 12 hours = hope for survivial • 15 to 55 at 12 hours = fair chance • > 55 = will survive • > 20 per cent of the piglets

17. Distribution of birth weights 12 10 8 Per cent of live born piglets 6 4 2 0 0,3 0,5 0,7 0,9 1,1 1,3 1,5 1,7 1,9 2,1 2,3 2,5 Birth weight, kg

18. Weight at birth and mortality 80 4,5 per cent 6,0 per cent 2,5 per cent 13,0 per cent 70 60 50 Mortality, per cent. 40 30 20 10 0 0,5 0,7 0,9 1,1 1,3 1,5 1,7 1,9 2,1 2,3 Birth weight, kg

19. Underweight piglets and litter size

20. Piglet mortality • The piglets die by crushing • - during the first days • They are the smallest piglets • They are the last born piglets • They are the piglets with a low antibody intake • Piglets going to be crushed can be predicted at birth • Piglets that are going to survive can be predicted at birth • Most piglets are in between!

21. Effect of birth weight and birth order on mortality Birth weight < 1 kg ≥ 1 kg Number of piglets 29 173 Mortality, per cent 45 5

22. Effect of birth weight and birth order on mortality Birth weight < 1 kg ≥ 1 kg Number of piglets 29 173 Mortality, per cent 45 5 Birth order 1-7 > 7 1-7 > 7 Number of piglets 13 16 101 72 Mortality, per cent 8 75 3 8

23. Birth weight, birth order and Ig Low Ig means < 10 gram/liter. (Average = 45 gram/liter)

24. Hypotheses for piglets born in large litters • The first born piglets have readily access to colostrum and milk • The last born piglets must compete with the fortunate first born piglets • The smallest piglets loose this competition

26. Solution • Litter size must be adjusted • Moving piglets to small litters • Using nurse sows • When? • After colostrum uptake • Before the piglets die • Before ranking

27. Colostrum uptake • Registration of birth order and birth weight • Assay 12, 24 and 48 hours after birth • Assay for non specific Ig’s • Registration of mortality until weaning

28. Effect of birth order

29. Effect of birth weight

30. What is the optimal nurse sow for 12 hours old piglets? • Parity • A second to fourth litter sow have the highest milk production • Stage of lactation • Milk composition • Increasing or decreasing production • Empty period • Milk pressure, motivation or forgetting her own piglets? • Accept of piglets • Relaxants • Oxytocin

31. One step nurse sow 21 day old piglets New born piglets

32. Two step nurse 7 day old piglets 21 day old piglets New born piglets

33. One or two step nurse?

34. Set up of trial • Collecting pairs of newborn piglets after colostrum-uptake • All piglets were earmarked and weighed • One piglet stayed with the mother • One piglet went into the trial

35. Nurse sows • Piglets randomly entered a one step or a two step nurse sow • All nurse sows were 1. Litter sows • Both nurse sows had an equal profile • Number of piglets born • Number of piglets weaned • Lactation length • Video for 24 hours • Mortality and weight at weaning was recorded

36. Results

37. Results

38. Two step nurse 7 day old piglets 21 day old piglets New born piglets

39. The first step piglets • Piglets earmarked and weighed at transfer at 7 days and at weaning • Compared with a similar litter not transferred

40. Transferred two step nurse piglets

41. Gilts or sows as nurse sows

42. Piglet mortality at first litter or older nurse sows.

43. 11 or 13 piglets per litter? • 31 pairs of sows with 24 piglets • Piglets were app. 24 hours old • 11 and 13 piglets were allocated to the two sows • No transfer of piglets after allocation • Piglets at both sows were weaned at the same day

44. 11 or 13 piglets per litter? * P = 0,08

45. Control Adjusting litter size after 12 hours Small or large piglets could be transferred Trial Reducing litter size to 10 after 6 hours by removal of the largest piglets Adjusting litter size after 12 hours Small or large piglets could be transferred Trial Ensuring colostrum to the smallest piglets

46. Ensuring milk to the smallest piglets * A difference of 15 per cent would be significant.

47. Ensuring milk to the smallest piglets • No effect on the survival of the smallest piglets, when reducing the litter to 10, to ensure colostrum to the smallest piglets . • Were there an effect of removing (collecting) the smallest piglets? • Is mortality in small piglets primarily a cause of lack of sows milk? • Large piglets may be removed from the mother after 6 hours

48. Conclusions • Crushing may be the visible cause of death, but a number of precursors seems to exist • Understanding these precursors may lead into ways of reducing piglet mortality

49. A number of other management factors have been shown to reduce piglet mortality, eg. observation during and after birth, drying off small piglets, climate control, vaccinations and treatments of disease. Intensive daily care must be continued, when introducing new strategies in the farrowing department.

50. Thank you for your attention