Effects of preweaning factors on sow lifetime productivity - Dr. Joe Cassady, from the 2012 Allen D. Leman Swine Conference, September 15-18, St. Paul, Minnesota, USA. More presentations at http://www.swinecast.com/2012-leman-swine-conference-material

1. Effects of Preweaning Factors on
Sow Lifetime Productivity
Dr. Joe Cassady, PhD. PAS
Department of Animal Science
North Carolina State University

2. Outline
● Introduction
● Background
● Justification
● Research Objective
● Project Description
● Current Status
● Future Direction

3. Introduction
● In 2009, more than 1 billion people worldwide
were undernourished, according to “The State
of Food Insecurity”, an annual report from the
United Nations Food and Agriculture
Organization (FAO).

4. Introduction
● American pork producers have remained
competitive in the global market despite higher
labor and input costs through adoption of
technology leading to greater productivity and
efficiency.

5. Introduction
● New methods must be devised for producing
pork that reduce inputs, minimize environmental
impacts, provide for improved pig welfare, and
ensure a safe, nutritious pork supply.
● Sow lifetime productivity is directly linked to
economic efficiency, biological efficiency, feed
costs, and pig welfare.

6. Introduction
● Many factors impact sow lifetime productivity.
— Gilt development
— Boar exposure
— Estrus detection
— Gestation housing
— Lactation feed intake
— Herd health
— Etc.

7. Introduction
● The impact of gilt preweaning management on
sow lifetime productivity is not well understood.

8. Background
● Donald HP, 1939, The relative importance of sow
and litter during the growth of suckling pigs: a
comparison of fostered and normally reared pigs.
Emp. J. Exp. Agric.
● He concluded that the dam and nurse dam
influenced growth rate equally.

9. Nelson and Robison 1976, J. Anim.
Sci., 43: 71--77
● Used cross-fostering to create litters of 6 and
litters of 14.
● Pigs were weaned at 8 weeks of age.
● Gilts from small litters were 4.5 kg heavier
then those from large litters at weaning.

10. Nelson and Robison 1976, J. Anim.
Sci., 43: 71--77

11. Robison, OW, 1981, Livestock
Production Science, 8:121--137
● Robison OW, 1981, The influence of maternal
effects on the efficiency of selection; a review,
Livestock Production Science.
● Concluded that gilts nursed in large litters grow
slower, reach puberty later, and produce smaller
litters

12. Robison, OW, 1981, Livestock
Production Science, 8:121--137
● These results suggest that maternal
performance should be measured at three to
four weeks of age and prior to the initiation
of creep feeding. Further, they suggest that
early weaning may alleviate the negative
association between direct genetic and
maternal effects. This would allow more
effective selection.

14. Holl and Robison, 2003, J. Anim. Sci.
● Published the results of 9 generations of
selection for increased litter size.
● Gilts in the select line were raised in litters no
larger that 10 pigs.

15. Holl and Robison, 2003 J. Anim. Sci.

16. Times have changed
● Average number born alive increased by 10%
from 1998 to 2008 (10.2 to 11.4) (PIGCHAMP
1998, 2008).
● Pigs are weaned earlier
● Diets have improved
● New health challenges exist.

17. Justification
● The impact of the preweaning environment
and management on sow lifetime
productivity in modern swine production is
not well understood.

18. Recent Work
● We have completed 2 projects related to
preweaning factors impacting pig
performance.

19. Fix et al. 2010

20. Birth wt. vs. Probability of being a full
value market hog.
Pigs that were classified
as full value, survived till
harvest, >100 kg BW, and
free of injuries, belly
ruptures, major health
issues, etc.

21. Fix et al., 2010, Livestock Science

22. Fix et al., 2010, Livestock Science

23. Bishop, 2011
http://repository.lib.ncsu.edu/ir/bitstream/1840.16/7079/1/etd.pdf
Table 3. Least squares means and standard errors for growth traits
Trait CF a NFb P - value
Number of pigs per litter
At birth 11.1 ± 0.26 11.7 ± 0.28 0.14
At weaning 8.5 ± 0.22 8.7 ± 0.23 0.59
At nursery exit 7.3 ± 0.21 7.4± 0.22 0.74
Average weight, kg
At birth 1.50 ± 0.018 1.45 ± 0.019 0.07
At weaning 5.9 ± 0.06 5.9 ± 0.07 0.34
Weight variance within litter
At birth 0.08 ± 0.005 0.08 ± 0.005 0.46
At weaning 1.2 ± 0.06 1.1 ± 0.06 0.42
Average daily gain, kg/ d
Pre-weaning 0.21 ± 0.003 0.20 ± 0.003 0.21
a
CF = Cross foster treatment
b
NF = Non-cross foster treatment

24. The 10K Gilt Project

25. Objective
● To estimate the impact of preweaning
environment and management of gilts on
subsequent sow lifetime productivity.

26. Production System
● Two 1200 sow multiplication units within the
Murphy-Brown, LLC system.
● After leaving the nursery gilts will go to 1 of 4
gilt development units.
● Finally gilts will be sent to one of 10
commercial sow farms.

27. Methods
● Born between June 1st and Dec. 1st, 2012
● 13,000 gilts will be tagged at birth.
● Both individual and litter birth weights will
be recorded

28. Methods
● Cross-foster status will be documented
● Sex ratio of the litter at birth, after cross-
fostering, and at weaning will be recorded.
● Weaning weights will be taken one or two
days prior to weaning.

29. Methods
● Mortality will be documented through 4th
parity
● Weaning weights will be taken one or two
days prior to weaning.

30. Methods
● Female performance will be documented on
each sow farm.
● Data will be submitted to a centralized data
base.
● Sow lifetime productivity is defined as pigs
per female per day of herd-life

31. Current Status
Number
Total tagged gilts 8,213
Gilts that were tagged for weaning 6,975
Tagged gilts that have been weaned 5,677
Deaths up to last weaning 1,298
Litters weaned 1,088
Nursery Deaths 90
Gilts moved to finishers 2,623

32. Projections
Number
Litters 2,000
Total tagged gilts 13,000
Gilts Weaned 10,500
Gilts Placed in the Finisher 9,500
Gilts Available for Selection 9,000
Gilts Entering Sow Farms 7,250
Gilts Farrowing 6,000
P4 litters produced 2,000

33. Future Direction
 We will continue to tag gilts and record data until
we have successful tagged 13,000 gilts.
 We will continue to record mortalities from birth
until entry into the sow farm and beyond.
 We will record performance on the sow farm
including

34. Future Direction
 Gilts were from single-sire matings.
 Tail tissue was retained on each gilt at birth as a
source of DNA.
 Pending the outcome of the initial experiment and
the availability of funding, we intend to genotype a
sample of the gilts to identify genomic regions
associated with variation in sow lifetime
productivity.

35. Funding
● National Pork Board
● Murphy-Brown, LLC
● Smithfield Premium Genetics
● North Carolina Agriculture Research Service

36. Acknowledgements
● Dr. Ashley DeDecker – Murphy-Brown, LLC.
● Dr. Kent Gray - SPG
● Dr. Perry Harms - SPG
● Dr. Justin Holl
● Dr. Mark Knauer – NCSU
● Dr. Mark Estienne – Virginia Tech
● Mr. Tom Hagood – Murphy-Brown, LLC.
● Ms. Amanda Cross - NCSU
● Ms. Emily Cook - NCSU
● Ms. Cassie Farring - NCSU
● Mr. Stewart Callahan– Virginia Tech