Dr. Rob Knox - Gilt Management/Puberty Induction and Sow Longevity/Productivity

Gilt Development and Induction Management for Fertility and Longevity

Rob KnoxDepartment of Animal Sciences

University of Illinois, Champaign-Urbana, IL USA 61801

2012 Leman Pre-Conference Reproduction Workshop

University of Illinois Champaign-Urbana

Premise of Gilt Development and Sow Longevity

• How we develop Gilts impacts their maturity/fertility at mating and in subsequent parities

– Problems in development result in : • >days to 1st service • >non-productive days• Reduced fertility• >health problems • higher fallout rate


-High culling rates-an old problem?

– From 1960 to 2000 (NHF Review 2004) • Culling rate No. of Studies• 20-30% 9• 30-40% 8

– PigCHAMP 2007 50.0%

– Koketsu 2007 JAS 85:1086-91 40.6%


Why a gilt won’t make it to parity 5

CULL

Puberty delayNo puberty

Low litter size

Poor conditionbody weight,

Feet/legs, health

Poor litters

Failure to rebreed after weaning

Conception failure

return to service


The realities of Gilt Replacement

• Great variation in – gilt growth/body development – Days to pubertal estrus – symptoms of standing and vulva swelling

• Some never express puberty

• Many are culled before their 1st, 2nd or 3rd litter

In prepubertal gilts, proportions of gilts showing brain and ovary maturation by age

50 100 150 200 2500

102030405060708090

100

Med Foll

LH Pulses

Series3

Days of Age

Per

cen

t

GnRH

The Physiology of Gilt Puberty• Ovaries/uterus can grow and respond by 120 d of age • (Guo, et a., 1998 JAS 163-68)

• Hypothalamic-pituitary axis is fully mature in LH response to estradiol feedback and external stimuli by 210 d (not 150 d). • Barb et al., 2010 ARS 122:324-7

• Increased LH pulses increase all reproductive measures• Estrogen, ovary and uterus weight ) Beltranena et al., 1993 JAS

71:471-80

• Maturity relies on• Estrus behavior (symptoms/duration)• Ovulation (rate and timing) • Uterus Size (capacity)• Cycle length and repeatability

0 5 10 15 20 25 30 35 40 45 50 55 60 >60 none0

5

10

15

20

25

30

Estrus in gilts following Boar Exposure at 180 days of Age.

Days

Pe

rce

nta

ge

72.5% (n = 700/965) estrus in 80 days (AASV Pre Conf. Symp. Foxcroft, 2002)

Most but not all gilts express estrus by 260 d of age


Puberty Can be influenced by Farm, Breed, Management

Hughes et al., 1990; J. Reprod. Fertil. Suppl. 40:323-341


Where Can Selection Pay Off for Gilt Fertility?

• Merks et al., 2000 RDA 35:261-66

AVG SD CV h2

AAP 210 26 12 0.32 *

Vulva symptoms 0.83 0.38 *

Standing response 0.87 0.29 *

Ovulation rate 14 3 19 0.24 *

ES 0.8 0.2 23 0.14

Born alive 10.3 3 29 0.10

WEI 7.7 6.9 90.1 0.10


Selection of gilts for standing and Vulva symptoms at pubertal estrus improves subsequent generations

Rydhmer et al., 1994 J. Anim. Sci. 72:1964-1970 (Yorkshire)


Gilt Selection for fertility • In Mothers of Gilts

– Offspring of early puberty mothers (d 185) cycle earlier with more BF than those selected for late puberty (d 235)

• Hixon et al., JAS 1987 64: 977-82

• In Litter size– Gilts from large litters where uterine crowding occurred have smaller placentas and

smaller fetuses (h2 = 0.10).• Van der waaij et al., 2010 JAS 88:2611-9

• Gilts– low BF at early AAP (<d 185)– Heavy birthweight in large litters (relative to herd)– estrual score and early AAP– Growth rate and BF at AAP


Higher Growth Rate Reduces AAP

Growth rate (g/d) n AAP with BE start at 144 d

Pubertal by 190 d

577 58 155 d 76%

724 58 164 d* 95%*

Kummer et al., 2009; Reprod. Dom. Anim. 44:255-9 *1.21 lb/d = 0.55 kg/d = 550 g/d1.30 = 590 g/d1.45 = 660 g/d1.60 = 727 g/d

• Higher growth rate (>600 g/d) to 140-165 d (r = -0.40) with AAP• Tummaruk et al., 2009 ARS 110:108-22 (tropics)• Foxcroft, 2005 from Beltranena 1991 (CAN)


Feeding the developing gilt • Energy intake in G-F changes growth, weight and BF not reproductive

measures • (FF E2, plasma E2, repro tract wgt, or LH) Beltranena et al., 1993 JAS 71:471-80

• Feeding method has few effects on reproduction but reduces weight variation at farrow

– Schneider eta al., JAS 2007 85:3462-9

• Weight gain from 161-171 d (500 vs. 1000 g/day) • High increased medium follicles (25 vs. 34) and oocyte meiotic competence

– Van Wettere et al., 2011 Therio 75:1301-10

• Ad lib to 235 or restrict feeding from 123-235 days• AL increases estrus by 235 (98 vs 91%) reduces AAP (174 vs 178 d). Miller et al., JAS 2011 89:342-54


Effect of gilt development diets differing in lysine energy ratio on response to puberty induction in

replacement gilts at 175 d

0 1 2 3 4 5 6 7 8 9 10 11 12 13 40

50

60

70

80

90

100

110

120

130

140

diet 1

d2

d3

Week

kg

112,000 g = 640 g/d97,000 g = 554 g /d

(100 days) (175 days)


Effect of Lysine:energy ratio on PG600 effects on Puberty induction

High Medium Low P N 34 36 36Estrus (%) 90.9 83.0 72.2

<.05*Durest (h) 47 56 52 nsOV (%) 91.9 89.5 86.4 nsCL 16.4 18.5 21.5 ns

Knox et al., 2004, unpublishedCia et al., 1998; Anim. Sci. 66:457-63


TreatmentNBE NBE BE BE

Item 160 180 160 180

N 43 38 45 39

Estrus, %a 46.5 38.5 58.7 60.0*

Ovul., %b 65.1 71.8 77.8 72.2

Effect of 4-Day Boar Priming For 160-180 d old Gilts On PG600 Estrus Response

30 minutes of fence-line BE for 4 days or no exposure prior to PG600


Effect of PG600 and No Daily Boar Contact or Daily Boar Contact on 1st and 2nd Estrus

NBE BE

1st estrus 49% 81% *

1st Ovulation 84% 88%

2nd Estrus 76% 100% *

Barlett et al., 2009. Anim. Reprod. Sci. 114:219-227.


Effect of adjacent boar housing on cyclic activity following hormone induction of puberty in gilts

No Boar Boar2nd estrus 12/23 20/23 *2nd ovulation 12/23 18/23 *

Paterson and Lindsay, 1981 Anim. Prod. 32:51-54


Boar Exposure and Gilt Management

• Certain procedures are critical and must be done well (Gadd 2004 Pig progress 20: 14)

• Gilts exposed to boars at 140 to 170 d show puberty at 180 to 200 d ± 28 d (Farms range from 188-251)

– Tummaruk et al., 2009 ARS 110:108-22 (tropics)– Foxcroft, 2005 from Beltranena 1991 (CAN)

• Provide good stressors to to stimulate hormone release

• Minimize Bad stressors that inhibits hormone release


140 160 180 200 220 240 2600

102030405060708090

100

140

160

190

210

Days of age

cum

mul

ativ

e es

trus

(%

)A good stress:

Boar exposure advances estrus expression


Age at start of boar exposure on synchrony

Age at BE AAP D to estrus Estrus in 10 d

160 d 179 18.9 24%

180 d 191 10.4* 67%*

200 d 210 8.3* 70%*

Van Wettere et al., 2006. Anim. Reprod. Sci. 95:97-106.


Early Exposure:Age at puberty from Boar exposure (%)

140150

160170

180190

200210

220230

240250

260270

2800

5

10

15

20

25

30

35

Day of ageJohnson 2003, N = 244; Avg. 180 d (135-276) SD 24 d


Later ExposureModern Genetic Lines Differ

Line bf 1st estrus % AAP FR % TBAmerican diamond .79 91 225 77 10.2Danbred USA .56 87 222 77 11.0DK Monsanto DK44 .70 87 222 75 11.6DK Monsanto MXP200 .71 97 209 92* 12.0Natl. Swine Reg (Y x L) .66 90 222 77 10.6Newsham Hybrids USA .58 88 223 78 10.5 Diff 0.21 4 16 17 1.8

Moved from pens of 25 into crated 1600 sows facility at 180 d and exposed to a V boar 2/x /d

Moeller et al., JAS 2004 82: 41-53


Daily Boar Exposure and Twice daily reduces AAP

• Hughes, 2004 Pig Intl. 34:18-20

Days to puberty0 51 d2x/week 34 d5x/week 29 d1x/d 19 d

% cycling in 2 weeks0X 01x/d 19%2x/2 81%

Fenceline or Physical Boar Exposure On Accumulative Estrous Expression

Zimmerman et al., 1998

0102030405060708090

100

10 20 30 40 50 60 70 80

Day of age

Cum

mul

ativ

e E

stru

s (%

)

FBE-2x

FBE-1x

PBE-2x

PBE-1x

160 d exposure, 10 min/day

Duration of daily boar exposure on puberty

0 2 10 300

10

20

30

40

50

60

70

Minutes of exposure/day

days

Paterson et al., 1989; Anim. Reprod. Sci. 21:115-124


Good StressorsBoar Exposure Frequency and Transport on Gilt Puberty

BE (20 min)

Transport (20 min) 0 1X/d 3 X/dYes 0% 56% (187) 62%

(171)

No 29% (186) 25% (179) 44% (183)

Hughes et al., 97

Hughes et al, 2007 ARS 46:159-65


Effect of boar choice

Maturity of BoarsStimulus APNo Boar 2036.5 mo. old Boar 20611 mo. Old boar 18224 mo old boar 182Exposure at 160 d

Activity of boarType AP

Control 217Vocal 199Boar + Vocalization 178

30 min/day begin @ 140 d

Percent of gilts pubertal and days to puberty in response to LIBIDO

No Boar Low Libido High Libido

Puberty 20 d 0 19 59 *

Puberty 40 d 8 62 81 *

Puberty 60 d 35 88 89 *

Days to Puberty

48 d 34 d 19 d *

Hughes, 2001 VIth Intl. Conf. Pig Reprod. Pre-conf. Workshop.


Bad StressorsImpact of gilt floor space on puberty

Floor space

Gilts/pen at 75 d of age

Pens/TRT 140 d PBE to a V-Boar

AAP Pubertal by 200 d

1.13 m2 15 ~42 + 8 min/d 182 d 37%0.77 m2 22 ~30 + 12 min/d 184 d* 30%*

Young et al., 2008 J. Anim. Sci. 86:3181-93

1.13m2 = 12 sq. ft


Bad stressorsGroup Size on Induction

No. Gilts/Group % Cyclic by 270 d

3 579 7817 8027 81

• Not >40 and <4// give 16-22 sq. ft

• Ratio of gilts to boar should be 6:1 and if greater then exposure time may need to be > 10 minutes

Hughes 2001 , Intl. Conf. Pig Reprod. Pre conf. workshop


Bad stressorsHigh Ammonia negates boar exposure

• >10-20 ppm in development delays puberty• (Malayer et al., 1987; Zimmerman et al., 1988)• 5.0 ppm ammonia can be achieved by running fan more

which improves puberty • Malayer et al., 1987 JAS 64:1476-83


Gilt Maturity at Breeding

• > Wgt. gain in 1st gestation = > FR (favors intermediate age)

• Hoving et al., ARS 122:82-9

Age 1st mating

Wgt 1st mating

Wgt at 1st farrow

Wgt at 1st wean

Not Preg BA P1 BA P2

Farm A 230 124 181 156 11% 10.7 11.6

Farm B 275 145 189 165 15% 11.8 11.6

* * * *


Gilt Age at 1st Service on Productivity

Early Intermediate late

Intervals +21 d +21 d

AI 222 243 264

Age at farrow 337 356 371

Age at Cull 982 1014 1024

Parity at cull 4.8 5.0 4.9

BA 52.0 53.8 53.6

Cozler et al., 1998 pig progress 14:8-9; favors intermediate


Gilts age at service on TB

• Goss, 2003 Pig Intl. 33:21-24 (Brazil, C-22 13,000 litters); favors intermediate

<190 200 210 220 230 240 250 >25010

10.2

10.4

10.6

10.8

11

11.2

11.4

11.6

11.8


Gilt maturity and born alive

• Schukken et al., 1994 JAS 72:1387-92 (14,000 gilts; favors older age )

195 205 215 225 235 245 255 265 275 285 2958

8.5

9

9.5

10

10.5

11

11.5

12

Age of mating


Gilt weight at mating and P2 BF (mm) and total pigs to 4th parity

• Goss, 2003 Pig Intl. 33:21-24 (Challinor et al., 1996); favors intermediate BF and weight

115 125 135 145 155 1650

10

20

30

40

50

60

70

P2 at AItotal pigs

Weight at mating

Impact of weight at first service on Productivity (total born P 1-3)

Source: Williams et al., 2005

135 140 154 166 >170 favors intermediate kg


Gilt maturity and herd life

• Schukken et al., 1994 JAS 72:1387-92 (favors intermediate age) • Breeding before 275 d reduces risk by 20% compared to older (Engblom et al., 2008

JAS 86:432-41)

195 205 215 225 235 245 255 265 275 285 295600

650

700

750

800

850

900

Days at mating

days


Age at Puberty and Herd Longevity

Young et al., 2008 JAS 86:3181-93

<185 >185 favors

n 165 945

BW 200d 131 128 +

GR (g/d) 784 760 * AAP/Faster/heavier

BF 20.6 17.8 * >BF

1st serve 258 261 ns

P 1-3 Born alive 24.8 22.5 * All the above

Age at removal 513 509 ns

Greater productivity with mating at 2nd estrus than later cycles on total born P 1-3

Source: Williams et al., 2005


AAP and Sow Fertility

• First 1/3rd of gilts expressing puberty associated with estrus in 10 d post weaning (r = -0.50)

• Sterning et al., 1998 JAS. (favors younger ages)

• Lines selected for early AAP have a shorter wean to estrus, and more sows reaching P5

• Holder et al., Anim. Sci. 1995 61:115-21


Thoughts on developing gilts• Genes for rapid growth inherent in modern selection

• Immune system and reproductive maturity do not develop as quickly as growth traits– High culling/replacement rates will not allow herd immune stability which increases following

P2

• Growth management appears critical to allow reproductive maturity without excessive body maturity

– Gilts need a period of slow down or else they will get too big• Fatter/slower growing gilts less likely to be culled (Hoge and Bates 2011 JAS 89:1238-45)

– How and when this is done is important (lysine/energy/stress)

– Diet manipulation from puberty to breeding no effect on longevity/productivity(Rozeboom et al., 1996 JAS 74:138-150)


Gilt and Reproductive failures lead North American Farm (%) Fertility Concerns

Sows bred within 7 daysIrregular returnsRegular returns

Gilt estrusNIP

Irregular estrus intervalsLow born alive

No declineMultiple matings

AbortStillbornsMummies

0 10 20 30 40 50 60% of farms

• Knox et al., unpublished• Associated with higher culling: returns, stillborns

• Hoge and Bates 2011 JAS 89:1238-45; Engblom et al., 2008 JAS 86:432


Getting gilt fertility right the first time is critical for longevity

Gilts conceiving at 1st AI

Gilts returning at 1st AI

P value

Age entry 180 180

Age at 1st mating 257 257

Age at 1st conception 259 320 *

Parity at removal 6.2 5.6 *

Lifetime pigs born 69.7 61.9 *

Koketsu et al., J. Vet med. Sci. 61:1001-1005 1999


Repeat Service Females Pregnancy Failures

• Farrowing rate– decreases 10% in re-serviced females

• Japan; (Koketsu 2003 J vet med sci. 65:1287-91 (N= 539 herds)

– Repeated service females 13% less likely to farrow• Tummaruk et al Prev. vet med 2010 96:194-200 (Thailand, ~9000 females

– Previous reproductive failure = 17% more likely to be open – Average re-service rate is 16% (gilts) and 14% (P1-2 sows).

– Vargas et al., Prev. vet Med 2009 89:75-80 and ARS 2009 113:305-10– PIC females in Brazil


Diagnosing Sources of Reproductive Failure

• By 260 days of age 16% of gilts fail to show estrus (but had ovulated and had a red swollen vulva)

• Eliasson ARS 1991 25:255-64

• Return to estrus after mating the most common failure• Vargas et al., Prev. vet Med 2009 89:75-80 • ARS 2009 113:305-10

• Reproductive Tract Lesions• 52% None• 25% Inactive ovaries• 23% Paraovarian cysts• 6% Ovarian cysts• 1% Uterine disorders

– Heinonen et al., 1998 (1700 tracts)


Reproductive Failure Diagnostics

• In a herd with evident reproductive failures• 67% culled for repeat breeding and irregular returns

– Diagnostics• 50% no pathology• 69% cycling • 17% inactive ovaries (61% endometritis)• 14% cysts• 27% endometritis

– Dalin et al., 1997 Acta vet scand. 38:253-62


Gilt Health• Data suggests farm specific impact not system type

• Krietr et al., dtsch Tierarztl Wochenschr 2004 111:462-6• Lesions, Respiratory, GI, Genitourinary,

• High rates of gilt replacement destabilizes herd health– Gilts have lower immunity for offspring– Greater incidence of Mycoplasma, PRRS

• Moore NHF April 2004 6-10

• Diseases that impact reduce feed intake and nutrient absorption will reduce growth rate, health and Immune status and impact puberty• PCV2• PRRS• iletis


2006 USDA Disease Prevalence in US Swine Herds

Breeding herd

Breeding herd vaccination

G-F G F vaccinates

PRRS 18.8 27% 23.0Mycoplasma 8.8 5.0Ileitis 24.0Mycoplasma 35% 24.0H1N1 5.6 28% 23.1Gastric ulcers 9.3 14.5Hemorrhagic bowel 18.9


Specific Factors Influencing Gilt health

• Sanitation in barn– Assoc. with discharges

• Immunity affected by time of cross fostering– Ab and CMI transferred over 12 h from dam

• Bandrick et al., Vet Rec. 2011 168:100-

• Diseases with potential impact on future gilt fertility– PCV2 (PR)

– Madson et al., Vet pathol. 2009 46:707-16

– SI • Increased mortality in piglets, growers, finishing, aborts

– Pejsak et al., Medycyna Weterynaryjna 61:1154-59 2005


Take Home• Gilt replacement rates are an old problem we have not addressed well

– Herd differences are real and multi-factorial for all below

– Days to maturation of gilt system takes time

– Gilt health management in G-F allows GR

– 1st breeding success a key

– Selection approach involves mother, litter comparisons, traits– – Growth management

– Breeding age has targets for age, weight, maturity, BF

– There are ways to maximize ESTRUS induction using boar exposure and management approaches


Thanks for your attention!

Dr. Rob Knox - Gilt Management/Puberty Induction and Sow Longevity/Productivity

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Transcript of Dr. Rob Knox - Gilt Management/Puberty Induction and Sow Longevity/Productivity