Heat Stressed Fetuses Make Different Growing

and Grown Pigs

Dr. Tim SafranskiUniversity of Missouri

(573) 884-7994safranskit@missouri.edu

Missouri Pork ExpoFebruary 10th, 2015

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

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Describing the Heat Stress Problem

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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…

Quantifying the Heat Stress Problem

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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

An

nu

aliz

ed M

ort

alit

y R

ate

(%)

USDA data courtesy Steve Meyer

Influence of season on 28-day RTU Influence of season on 28-day RTU pregnancy diagnosispregnancy diagnosis

NCR-57, 2002NCR-57, 2002

56 herdsSimilar management, facilities, feed & genotype

Daily temperature cycles

HS

TN

Brody Environmental

Center

TN

HS

TN

HS

Gestation and Breeding

Farrowing

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 20oC) or heat stress (HS; 24 to 30oC) that the sow experienced in gestation-farrowing-breeding.

Trt P < 0.001Group NSTrt*group NSDay P < 0.001Trt*day P < 0.001

Rectal temperatures

Amanda Minton

Whitney Martin

Trt P<0.036Group NSTrt*group NSDay P<0.001Trt*day p < 0.001

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 20oC) or heat stress (HS; 24 to 30oC) that the sow experienced in gestation-farrowing-breeding.

Trt P < 0.002Group P < 0.076Trt*group NS

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 20oC) or heat stress (HS; 24 to 30oC) that the sow experienced in gestation-farrowing-breeding.

Trt P < 0.006Group P < 0.002Trt*group NS

Trt NSSex NSTrt*sex NS

Trt P<0.001Sex P<0.044Trt*sex NS

Trt P<0.001Sex P<0.020Trt*sex NS

a

RR

RTST

Body weight gain

RR RTST

FI

IGF-I

Milk

Piglet growth

(-) Energy balance

Follicle growth

Body weight loss

Safranski et al., 2013

Safranski et al., 2013

Does heat stress in utero affect piglets later in life?

28-34°C18-22°C

GTN G

GTN GHS

TN HS

IUTN IUHS

Pro

tein

Acc

reti

on

(g/

d)

60

80

100

120

140

160

180

200A

P < 0.01

IUTN IUHS

Ad

ipo

se :

Pro

tein

(g/

g)

0.5

1.0

1.5

2.0

2.5

3.0

3.5C

P < 0.01

IUTN IUHS

Ad

ipo

se A

ccre

tio

n (

g/d

)

120

160

200

240

280

320

360 B

P < 0.07

Johnson et al., 2014

60-80kg pigs

GTN G

GTN GHS

Wei

ght,

g

Barrow Feed Disappearance

Wilmoth et al., 2014

SE 0.08SE 0.05SE 0.08

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

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

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

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

Lynch et al., 2014

Lynch et al., 2014

Lynch et al., 2014

Lynch et al., 2014

Lynch et al., 2014

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)

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

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)

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

Lactation Feed Intake*

• tended to differ (P=.07)

– GHS 11.95 ± 0.25 lb/d– GTN 11.31 ± 0.26 lb/d

*>5% difference

Piglet Numbers Per Litter*

a

b

*~3/4 of litters

Piglet Numbers Per Litter*

*all litters; # weaned no longer statistically different

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

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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

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Elanco

Solving the Heat Stress Problem

• Air conditioning• Check and calibrate ventilation systems• Use of exogenous hormones• Feed accordingly (especially in lactation)

Solving the Heat Stress Problem

• Air conditioning• Check and calibrate ventilation systems

– Fan controls– Inlets– Drippers (0.8 gal/hour)– Cool cells

Solving the Heat Stress Problem

• Use of exogenous hormones

– Label approved• PG-600

– Research setting• prostaglandin• oxytocin

Solving the Heat Stress Problem

• Feed accordingly (especially in lactation)– maximize feed intake– wet feed?– feed often or automatic/self feeders