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 4 th, 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 Stud 2 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 (Flowers,NCR-57,2002, unpublished) 2 means are from ~ 2000 ejaculates / stud / season.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. –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 USDA data courtesy Steve Meyer

9. Influence of season on 28-day RTU pregnancy diagnosis NCR-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 20 o C) or heat stress (HS; 24 to 30 o C) that the sow experienced in gestation-farrowing- breeding. TrtP < 0.001 GroupNS Trt*groupNS DayP < 0.001 Trt*dayP < 0.001

14. Rectal temperatures Amanda Minton

15. Whitney Martin

16. TrtP<0.036 GroupNS Trt*groupNS DayP<0.001 Trt*dayp < 0.001

17. TrtNS SexNS Trt*sexNS TrtP<0.001 SexP<0.044 Trt*sexNS TrtP<0.001 SexP<0.020 Trt*sexNS 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 GTNG GHS TNHS

22. Johnson et al., 2014 60-80kg pigs

23. GTNG GHS

24. Weight, g

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

26. GTNG 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

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* GHSGTN 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