Keeping Gilts in the Breeding Herd and Productive

9/6/12

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Keeping Gilts in the Breeding Herd and Productive

Donald G. Levis, PhD Professor of Animal Science Extension Swine Specialist Department of Animal Science University of Nebraska-Lincoln Haskell Agricultural Laboratory Concord, Nebraska 68728 Telephone: 402 584 3816 E-mail: [email protected]

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Key aspects of a good gilt management program

§ Worker knowledge, attitude, skills, motivation §  Implementation of a “strict” selection program § Achieving appropriate body weight/condition at

first breeding § Minimizing accumulated non-productive days in

the gilt pool §  Implementing a feeding strategy that starts with

the replacement gilt and supports the sow through each successive litter.

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Schematic diagram of an efficient gilt management system

Pre-select 1 Requirements: • Confirmation • 12-14 nipples • No ruptures • No hernias • Acceptable growth

Market gilt

Selectable Pool

Non- Select Gilts

Nursery

Non- Select gilts

Yes

No

Modified from Foxcroft, London Swine Conference, 2005. 4


Pre-select 2 Requirements: • Confirmation • 12-14 nipples • No ruptures • No hernias • Growth rate ≥ 1.3 lbs/day (185-198 lbs)

Pre-select 1 Requirements: • Confirmation • 12-14 nipples • No ruptures • No hernias • Acceptable growth

Market gilt

Selectable Pool

Non- Select Gilts

Grower 140-150 d

of age Nursery

Non- Select gilts

Opportunity gilts

Yes

No No

Modified from Foxcroft, London Swine Conference, 2005.

Desired weight at breeding: 298 to 330 lbs

Yes

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“If” 1st estrus at 160 days of age § 20 days x 1.43 lbs = 28 lbs § Wt. at puberty 228 lbs

2nd estrus at 181 days of age § 21 days x 1.5 lbs = 31 lbs § Wt. at 2nd estrus – 259 lbs

3rd estrus at 202 days of age § 21 days x 1.6 lbs = 33 lbs § Wt. at 3rd estrus – 292 lbs

4th estrus at 223 days of age § 21 days x 1.7 lbs = 38 lbs § Wt. at 4th estrus – 330 lbs

Predicting Estrus and Weight at breeding [1.43 lbs/day x 140 days = 200 lbs @ 140 days of age]

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Effect of live weight at 175 days of age on puberty attainment and follicular growth

0.3

0.9

0.2

0.4

00.10.20.30.40.50.60.70.80.9

1

Light wt., 187 lbs Heavy wt., 253 lbs

Gilt weight at 175 days of age

Perc

enta

ge

Proportion of gilts pubertal by 28 days of boar exposureProportion of follicles 3 to 6 mm

W.H.E.J. van Wettere (University of Adelaide) & P. E. Hughes (Pig & Poultry Production Institute), Roseworthy, South Australia. 2005.

a

b a

b

ab P<.05

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Effect of live weight at 175 days (25 wks) of age on response to boar exposure

0

0.28

0

0.26

0.89

0.220.190.17

0.690.81

00.10.20.30.40.50.60.70.80.9

1

0 7 14 21 28

Accumulated days of boar exposure

Acc

umul

ated

pub

erty

, %

Light wt., 187 lb (n=36) Heavy wt., 253 lb (n=36)

W.H.E.J. van Wettere (University of Adelaide) & P. E. Hughes (Pig & Poultry Production Institute), Roseworthy, South Australia. 2005.

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Pre-select 2 Final - select Requirements: • Confirmation • 12-14 nipples • No ruptures • No hernias • Growth rate ≥ 1.3 lbs/day (185-198 lbs)

Pre-select 1 Requirements: • Soundness • 125% of breeding needs • Direct boar contact 160-190 d • Record heat

Requirements: • Confirmation • 12-14 nipples • No ruptures • No hernias • Acceptable growth

Market gilt

Selectable Pool

Non- Select Gilts

Opportunity gilts

Nursery

Non- Select gilts

Opportunity gilts

Yes

No


Select Naturally

Cyclic gilts (75-80% cycle)

Grower 140-150 d

of age


Yes

Yes

No No

Feet Legs

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Full Direct Contact is an absolute requirement! § Direct snout-to-snout contact between

the boar and gilt is required for physical transfer of pheromones from the boar to the gilt.

§ Pheromones in boar saliva are non-volatile substances.

§ Therefore, direct physical tactile contact between the boar and gilt will ensure the maximal response to the full boar effect.

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Boar stimuli act synergistically to elicit the boar effect Stimuli % Standing Back pressure test (BPT) by human

48

BPT + sound of the boar 70

BPT + boar odor 80

BPT+ sound + odor + sight 97

Physical contact with boar 100

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Exposure Method

Age (d)

Days to estrus

Wt. at estrus, lb

Backfat (mm)

DGB 180.9a 21.8a 273 .62 DBG 183.8ab 24.0a 286 .62 FnBG 191.1b 32.0b 306 .68 P 0.039 0.039 0.12 0.45

DGB – direct contact with v-boar (purposely built for boar stimulation) Gilts taken to boar area DBG – direct contact with v-boar in gilt group pens FnBG – fenceline contact with v-boar and gilts in stalls

Theriogenology 57:2015-2025, 2002

Direct boar exposure/contact is best!

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Effect of full boar or fenceline contact on age at puberty of gilts

160

170

180

190

200

Age

at p

uber

ty, d

ays

Full boar Fenceline No boar contact

Study 1 Study 2 Study 3

b c

B

a

b

b

a

A

abc (P < .01) AB (P < .02)

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Effect of boar libido on average age at puberty of gilts

160170180190200210

High libido Low libido No boarexposure

Age

at p

uber

ty, d

ays

Study 1 Study 2

b

c

C

a

A B

A vs B (P < .06) A & B vs C (P < .01)

a vs b (P < .05) a vs c (P < .01) b vs c (P < .05)

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Method of boar exposure on puberty attainment of gilts

Method of exposure

Age (days)

Wt. (lb)

BF (in.)

Pub. (%)

Gilts in stalls 186.2a 306a .68 85 Gilts to boar 179.7ab 273b .62 96 Boar to gilts 176.2b 284ab .59 81

ab (P < .05)

Patterson et al., 1999.

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Pre-select 2 Final - select Requirements: • Confirmation • 12-14 nipples • No ruptures • No hernias • Growth rate ≥ 1.3 lbs/day (185-198 lbs)

Pre-select 1 Requirements: • Soundness • 125% of breeding needs • Direct boar contact 160-190 d • Record heat


Market gilt

Selectable Pool

Non- Select Gilts

Opportunity gilts

Nursery

Non- Select gilts

Opportunity gilts

Yes

No


Select Naturally


Grower 140-150 d

of age


Yes

Yes

No No

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Effect of recording estrus on average age at mating and total born per litter

Dr. Paul D. Ruen, Allen Leman Conference, 2004.

258

249

266 263

11.6

12.9

12.5

11.8

240

245

250

255

260

265

270

Farm A - No record

Farm A - Recorded

Farm B - No record

Farm B - Recorded

Avg

age

at m

atin

g, d

ays

10.5

11

11.5

12

12.5

13

Avg

tota

l bor

n pe

r litt

er

Avg age mated, days Total born per litter

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Estrous number at mating Item First Second Third Study 1 (3 litters) 30.9 32.9 31.6

Study 2 (3 litters) 29.1 29.3 28.6

Study 3 (4 litters) 37.8 39.1 38.8

Study 4 (5 litters) 51.6 52.6 50.5

Effect of estrous number at first mating on number of piglets born live

Anim. Prod. 24:333-342, 1977; J. Anim. Sci. 74:138-150, 1996; Can.. J. Anim. Sci. 70:483-492, 1990; 14th IPVS, p 586, 1996

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Impact of breeding gilts at 2nd, 3rd, 4th of 5th estrus on total number of piglets born

33.9

33.1

33.433.6

32.632.833.033.233.433.633.834.0

2nd 3rd 4th 5th

Estrus at first mating

Tota

l bor

n

Williams et al., Advances in Pork Production 16:281-289, 2005.

PIC gilts – 3 parities

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Pre-select 2 Final - select Breed Group Management Requirements:

• Confirmation • 12-14 nipples • No ruptures • No hernias • Growth rate ≥ 1.3 lbs/day (185-198 lbs)

Pre-select 1

Breeding at: • 298-330 lbs • 1st (10%) , 2nd (32%), or 3rd (58%)

estrus

Requirements: • 125% of breeding needs • Direct boar contact 160-190 d • Record heat


Market gilt

Selectable Pool

Non- Select Gilts

Bred gilts

Opportunity gilts

Nursery

Non- Select gilts

Opportunity gilts

Opportunity gilts


Select Naturally


Grower 140-150 d

of age

No No No

Yes

Yes

Yes

Market gilt Market gilt Market gilt 20

Impact of body weight at first service on total number of piglets born through 3 parities (PIC gilts)

31.1

32.8 32.833.1

32.3

30.030.531.031.532.032.533.033.5

<298 298 - 326 326 - 350 350 - 375 > 375

Body weight, lbs

Tota

l bor

n

Williams et al., Advances in Pork Production 16:281-289, 2005.

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Impact of backfat at first service on total number of piglets born through 3 parities (PIC gilts)

32.54

33.68

32.79

33.33

33.7 33.58

31.5

32.0

32.5

33.0

33.5

34.0

< .47 .47 - .55 .55 - .63 .63 - .71 .71 - .78 > .78

Backfat, inches

Tota

l bor

n

Williams et al., Advances in Pork Production 16:281-289, 2005. 22

Nutrition

§ Heat-check and stall gilts at pubertal estrus and breed them at 2nd or later estrus ü Undergo adjustment to stall ü Adjust to a decrease in feed intake

§ Limit feeding § Full feeding

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Gilt Development Unit Design § A properly designed gilt development

unit with a boar exposure area is the key to successful puberty stimulation, estrus detection, breeding of gilts, and labor management.

Photograph from Jennifer Patterson University of Alberta, Edmonton, Canada

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Effectively heat-checking replacement gilts is a challenge!!

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2.44 to 2.74 m 4.88 m

BEAR = Boar Exposure ARea

Gilt pen - Boar stimulation Estrus detection

Beltranena et al., Pre-Conference Reproduction Workshop Allen D. Leman Swine Conference, 2005.

26 Beltranena et al., Pre-Conference Reproduction Workshop Allen D. Leman Swine Conference, 2005.

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Step 1. BEAR system provides signaling pheromones for heat detection § Immediate fenceline exposure

(auditory, visual and olfactory) with several boars is accomplished in the BEAR system.

§ Gilts are identified in heat using the back pressure test by workers.

Photographs from Jennifer Patterson University of Alberta, Edmonton, Canada

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Step 2. BEAR system provides priming pheromones for puberty stimulation

§ Fenceline exposure (sight, sound, and smell) with several boars.

§ Direct exposure (sight, sound, smell, physical contact) with one mature V-boar

§ Gilts found in heat for the first time should be recorded and bred at 2nd estrus.

Photographs from Jennifer Patterson University of Alberta, Edmonton, Canada

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Benefits of the BEAR system

§ Layout is simple, cost effective to adopt and to implement in new or refurbished barns

§ Layout provides two gilt checking areas and a worker pass-thru space between the two areas.

§ One person can simultaneously work two groups of gilts

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§ Layout provides housing for up to six boars.

§ The crates allow the teaser boars to face and enter/exit both gilt checking pens.

§ Layout provides initial fenceline exposure to boars that are aroused, pheromone-loaded, and salivating.

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§ Gilts identified standing can be parked in a small pen. A teaser boar can then let into the pen for additional physical contact to the remaining non-standing gilts.

§ To establish the breeding at the desired weight range, a scale and crowding gate(s) are positioned to weigh gilts after the pubertal heat-no-serve estrus.

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Benefits of the BEAR system § Layout provides protection posts round

corners to prevent gilts from getting injured by the boar.

§ Both the pass-thru space and corner posts offer protection for the safety of the worker.

§ Litter size at first farrowing is increased.

§ Sow longevity is enhanced.

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The End

D. G. Levis (New Zealand)

Documents

Keeping Gilts in the Breeding Herd and Productive