Mitigating Impact of Seasonal Loss of Productivity - Dr. Tim Safranski, University of Missouri, from the 2015 World Pork Expo, June 3 - 5, 2015, Des Moines, IA, USA. More presentations at http://www.swinecast.com/2015-world-pork-expo

1. Mitigating Impact of
Seasonal Loss of Productivity
Dr. Tim Safranski
University of Missouri
(573) 884-7994
safranskit@missouri.edu
P.O.R.K. Academy
World Pork Expo
June 4th
, 2015

2. Quantifying the Heat Stress Problem
• $300 million annually in U.S.
– St. Pierre et al., 2003
• “Seasonality costs me more than PRRS”
– Steve Pollman, Director of Operations Murphy-Brown Western Operations
• Wild pig
– seasonal breeder
– temperature
– photoperiod
– other
2

3. Describing the Heat Stress Problem
3

4. Thermoregulatory Mechanism of Testis
Rectal temperature:
38.24° C (Boar 1)
37.75° C (Boar 2)
Testis is 5 to 6°F cooler
Levis
1. Scrotum
2. Pampiniform plexus
3. Cremaster muscle
4. Tunica dartos muscle
Pampiniform plexus: Convolution of veins
and arteries for cooling blood entering
testis

5. Effect of season on percent discarded ejaculates
Stud2
Winter (%) Summer (%)
A 6.7 + 1.0 21.4 + 3.4
B 8.2 + 1.3 10.7 + 2.8
C 2.4 + 0.9 18.8 + 3.7
D 4.5 + 1.1 35.4 + 8.9
1
% motility or % normal morphology was < 70% in ejaculates not used.
(Flowers,NCR-57,2002, unpublished)
2
means are from ~ 2000 ejaculates / stud / season.

6. Describing the Heat Stress Problem
6

7. Describing the Heat Stress Problem
– delayed puberty
– weaker, shorter and more irregular cycles
– increased embryonic death (if early gestation)
– increased stillborns (if late gestation)
– increased aborts and NIP
– decreased lactation feed intake
• decreased piglet growth
• increased weight loss
• prolonged WEI
– increased sow mortality
– I’m running out of room…

8. Quantifying the Heat Stress Problem
8
6
7
8
9
10
11
12
13
12/14/05
2/2/06
3/24/06
5/13/06
7/2/06
8/21/06
10/10/06
11/29/06
1/18/07
Date
AnnualizedMortalityRate(%)
USDA data courtesy Steve Meyer

9. Influence of season on 28-day RTUInfluence of season on 28-day RTU
pregnancy diagnosispregnancy diagnosis
NCR-57, 2002NCR-57, 2002
56 herds
Similar management, facilities, feed & genotype

10. Daily temperature cycles
HS
TN

11. Brody
Environmental
Center
TN
HS
TN
HS
Gestation and Breeding
Farrowing

12. RR
RT
ST
Body weight gain

13. Least squares means treatments denoted as TN-TN-TN, TN-HS-TN, HS-TN-HS or HS-HS-
HS where the series of abbreviations represent the environmental temperature (TN; 18 to
20o
C) or heat stress (HS; 24 to 30o
C) that the sow experienced in gestation-farrowing-
breeding.
Trt P < 0.001
Group NS
Trt*group NS
Day P < 0.001
Trt*day P < 0.001

14. Rectal temperatures
Amanda Minton

15. Whitney Martin

16. Trt P<0.036
Group NS
Trt*group NS
Day P<0.001
Trt*day p < 0.001

17. Trt NS
Sex NS
Trt*sex NS
Trt P<0.001
Sex P<0.044
Trt*sex NS
Trt P<0.001
Sex P<0.020
Trt*sex NS
a

18. RR
RT
ST
FI
IGF-I
Milk
Piglet growth
(-) Energy balance
Follicle growth
Body weight loss

19. Safranski et al., 2013

21. Does heat stress in utero affect piglets
later in life?
28-34°C18-22°C
GTN G
GTN GHS
TN HS

22. IUTN IUHS
ProteinAccretion(g/d)
60
80
100
120
140
160
180
200
A
P < 0.01
IUTN IUHS
Adipose:Protein(g/g)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
C
P < 0.01
IUTN IUHS
AdiposeAccretion(g/d)
120
160
200
240
280
320
360
B
P < 0.07
Johnson et al., 2014
60-80kg pigs

23. GTN G
GTN GHS

24. Weight,g

25. Barrow Feed Disappearance
Wilmoth et al., 2014
SE 0.08SE 0.05SE 0.08

26. GTN G
GTN GHS
From 2-4 months of age progeny gilts (n=165) were evaluated for several
measures twice weekly
-At 6am and 2pm rectal temperatures, ear and rump skin temperatures,
and respiration rate (RR) were recorded
-Percentage of pigs standing, lying, standing at feeder, standing at water,
and sitting was recorded at the top of every hour using video cameras
-Body weights were recorded every three weeks

27. Lynch et al., 2014

28. Lynch et al., 2014

29. Lynch et al., 2014

30. Lynch et al., 2014

31. Lynch et al., 2014

32. Management
• <150d estrous detection with 15 min/d BE
• 6/123 showed estrus within 40d
• 81/117 responded to PG-600 (Sept. 28)
• 123 shipped to Suffolk, VA (Oct. 7)

33. Distribution of PG-600
induced estrus (~69% responded)

34. Management
• Group housed
• Mated AI to Yorkshire boars
• Limit fed in gestation
• ad lib fed in lactation (2x/d)
• Minimal fostering (w/in treatment only w/in 24hr)
• PRRS negative
• Mycoplasma and ileitis seropositive (no symptoms)

35. Production Measures*
GHS GTN
Gestation length, d 115.0 ±.25 114.8 ±.21
Weight at breeding (lbs) 353.26 ± 6.90 353.73 ± 6.69
Gestation weight gain (lbs) 105.46 ± 9.54 101.69 ± 6.40
Lactation weight loss (lbs) 49.99 ± 7.50 41.87 ± 7.54

36. Lactation Feed Intake*
• tended to differ (P=.07)
– GHS 11.95 ± 0.25 lb/d
– GTN 11.31 ± 0.26 lb/d
*>5% difference

37. Piglet Numbers Per Litter*
a
b
*~3/4 of litters

38. Piglet Numbers Per Litter*
*all litters; # weaned no longer statistically different

39. possible carry-over effects of GHS on
subsequent reproductive performance
of P1 sows. Although not significantly
different, P1 sows from GTN farrowed
a greater percentage of litters
comprised of 13-14 or 15-16 total born
compared with P1 sows from GHS

41. Conclusions
• Direct effect of thermal stress on pregnant
females beginning to be understood
• Mediated through the dam, subsequent
progeny are also affected
• True cost of heat stress is underestimated
– Reduced feed efficiency
– Effects on carcass
– Reproductive performance and efficiency
41

42. Future Directions
• Assess milk production and composition
and whether effects persist to progeny
– Michelle Rhoads, VT (funded by Checkoff)
• Intense data collection during pregnancy
- Mizzou (funded by Checkoff)
• Endocrine profiles by parity
– Not yet funded
42

44. Solving the Heat Stress Problem
• Air conditioning
• Check and calibrate ventilation systems
– Fan controls
– Inlets
– Dusty fan blades reduced flow (80%)
– Drippers (0.8 gal/hour)
– Cool cells

45. Solving the Heat Stress Problem
• Use of exogenous hormones
– Label approved
• PG-600
– Research setting
• prostaglandin
• oxytocin

46. Solving the Heat Stress Problem
• Feed accordingly (especially in lactation)
– maximize feed intake
– manage cooling systems
– wet feed?
– feed often or automatic/self feeders