Heat Stressed Fetuses Make Different Growing & Grown Pigs - Dr. Tim Safranski, University of Missouri, from the 2015 Missouri Pork Expo, February 10 - 11, 2015, Columbia, MO, USA. More presentations at http://www.swinecast.com/2015-missouri-pork-expo

1. Heat Stressed Fetuses
Make Different Growing
and Grown Pigs
Dr. Tim Safranski
University of Missouri
(573) 884-7994
safranskit@missouri.edu
Missouri Pork Expo
February 10th
, 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. 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…

5. Quantifying the Heat Stress Problem
5
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

6. 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

7. Daily temperature cycles
HS
TN

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

9. 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

10. Rectal temperatures
Amanda Minton

11. Whitney Martin

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

13. Least squares means for 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 < 0.002
Group P < 0.076
Trt*group NS

14. Least squares means for 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 < 0.006
Group P < 0.002
Trt*group NS

15. 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

16. RR
RT
ST
Body weight gain

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

18. Safranski et al., 2013

19. Safranski et al., 2013

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

21. 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

22. GTN G
GTN GHS

23. Weight,g

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

25. Table 1. Effect of heat stress, Lysine, and Paylean® on carcass quality measures
Heat Stress Lysine Paylean
HS TN SEM 100% 110% SEM 0 6.5 g/ton SEM
HCW, kg 98.8 97.81 1.19 98.78 97.82 1.19 96.36b
100.24a
1.19
LEA, cm2
53.07a
50.66b
1.06 51.25 52.48 1.06 48.85b
54.89a
1.06
10th Rib BF, cm 22.78 22.42 0.88 23.15 22.05 0.88 23.4 21.8 1.08
Last Rib BF, cm 28.83 26.51 1.08 27.65 27.68 0.99 28.07 27.27 1.08
Dressing, % 74.5 75.12 0.58 74.93 74.71 0.58 74.15b
75.49a
0.58
Lean, % 52.84 52.54 0.49 52.33 53.05 0.31 51.82b
53.56a
0.49
Callahan et al., 2014

26. Table 2. Effect of heat stress, Lysine, and Paylean® on Pork quality measures
Heat Stress Lysine Paylean
HS TN SEM 100% 110% SEM 0 6.5 g/ton SEM
pH 5.58 5.6 0.02 5.58 5.6 0.02 5.56b
5.62a
0.02
Color 2.1 2.35 0.092 2.33 2.13 0.09 2.2 2.25 0.09
Firmness 2.22 2.38 0.11 2.33 2.27 0.11 2.33 2.27 0.11
Marbling 1.18 1.15 0.06 1.18 1.15 0.06 1.23 1.1 0.06
Wetness 1.66 1.9 0.13 1.9 1.66 0.13 1.8 1.76 0.13
Callahan et al., 2014

27.  Differences exist
 Most are still within ‘normal’
 Most not detectable by consumer
 Muscling difference intriguing
 Muscle fiber analyses being performed

28. 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

29. Lynch et al., 2014

30. Lynch et al., 2014

31. Lynch et al., 2014

32. Lynch et al., 2014

33. Lynch et al., 2014

34. 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)

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

36. 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)

37. 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

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

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

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

42. 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
42

43. Future Directions
• Assess milk production and composition
and whether effects persist to progeny
– Michelle Rhoads, VT (funded by Checkoff)
• Intense data collection during pregnancy
– proposed
• Endocrine profiles by parity
43

44. Elanco

45. Solving the Heat Stress Problem
• Air conditioning
• Check and calibrate ventilation systems
• Use of exogenous hormones
• Feed accordingly (especially in lactation)

46. Solving the Heat Stress Problem
• Air conditioning
• Check and calibrate ventilation systems
– Fan controls
– Inlets
– Drippers (0.8 gal/hour)
– Cool cells

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

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