Echografie als diagnostisch hulpmiddel bij reproductieproblemen

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Department of Animal Science Wageningen University
Adaptation Physiology
Aquaculture and Fisheries
Breeding and genetics
Cell Biology and Immunology
Nutrition
Experimental Zoology
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Intermittent suckling possibilities to establish
pregnancy during lactation benefits to piglets
Marieke Berkeveld Rosemarijn Gerritsen Pieter
Langendijk In cooperation with Veterinary
Faculty in Utrecht
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Weaning-induced growth check
weaning
after Weary et al., 2002
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Feed intake shortly after weaning
Many piglets hardly eat after weaning
Bruininx et al., 2002
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• Weaning related problems, due to
• age at weaning
• not familiar with dry feed
• Possible solution
• Make pigs familiar with dry feed before weaning

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Intermittent suckling Suckling inhibited for 12
h per day from D14 of lactation
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Feed intake before and after weaning
Eat before weaning eat after weaning
Kuller et al., 2000
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Feed intake before and after weaning
Kuller et al., 2000
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Distribution of feed intake during lactation
Intermittent suckling increases feed intake
during lactation
Kuller et al., 2000
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Intermittent suckling increases feed intake
during lactation, But weaning at conventional
age still induces a growth check Possible
solution Also extend lactation without
postponing next pregnancy
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Growth in the IS model
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Feed intake in the IS model
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Relative growth from milk and dry feed
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Conclusions

• Intermittent suckling results in better
  adaptation to weaning
• Feed intake at weaning is considerably higher
  than normally
• There is hardly any growth check at weaning
• If sow is mated, lactation can be extended
• Consequences for reproduction ?

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Past experience with IS
Source Stage of lactation h IS/day Boar contact? Sows in estrus
Crighton, 1970 D21-D31 12 yes 1/5
Stevenson and Davis, 1984 D14-D28 D14-D28 6 12 no no 13/20 5/10
Grinwich and McKay, 1985 D21-D35 D21-D35 3 22 yes yes lt10 80
Newton et al., 1987a D13-D20 D13-D20 D13-D20 D13-D20 3 6 6 6 yes yes yes no 13/30 15/19 5/28 4/28
Newton et al., 1987b D20-D28 6 yes 10/10
Kuller et al., 2004 D16-D27 12 no 11/49
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Past experience with IS

• Litter separation
• Number of sows with estrus VARIABLE
• Occurrence of estrus ASYNCHRONISED
• Important factors
• Stage of lactation
• Duration of separation
• Boar contact
• Parity
• Breed

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Intermittent suckling model
Intermittent suckling from D14 (or later) of
lactation Suckling inhibited for 12 h IS12
0800-2000 IS6 0800-1400 and 2000-0200 Weaning
at 6 w of lactation Reference continuous
lactation and weaning at 21 d Dalland sows
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LH secretion during IS regime
START IS
614 B LO D6.5
LH (ng/ml)
Day 1
2000
2000
400
800
period of suckling
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Cortisol secretion during IS regime
Total separation more effective in triggering LH
release and increased chance of estrus
N6 N5




TOTSEP sows taken away from farrowing
unit PHYSEP sows only separated physically from
piglets treatment effect
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Estrus and ovulation
C IS12 IS6
sows in exp start IS/weaning 23 14 13
lactational oestrus () 26 100 92
oestrus after weaning () 74 - -
ovulation () 100 93 83
cystic follicles 0 1 4

2 of 4 sows ovulated and developed cystic
follicles
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Follicle development during IS regime
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Peri-ovulatory endocrine changes
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Estradiol
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Pre-ovulatory LH surge

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Post-ovulatory progesterone rise





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Cystic sows
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• LH surge and progesterone after ovulation are
  lower in the IS regime
• This does not seem to influence the number of
  sows ovulating and showing estrus
• Although IS6 sows seem to run a higher risk of
  developing cysts, and have delayed LH surge,
  estrus, and ovulation
• What about pregnancy?

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Conception
C (n16) IS12 (n9) IS6 (n7)
Pregnant D23 () 94 77 78
Ovulation rate 251.1 26.40.9 24.82.6
Embryonic survival () 626 586 577

a,b different superscripts in one row Plt0.05
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Embryo development
Treatment Treatment Treatment Treatment
C (n16) IS12 (n9) IS6 (n7)
Embryo weight (g) 0.20 0.01a 0.18 0.02a,b 0.14 0.01b
Rump length (mm) 19.5 0.4 20.2 0.5 20.1 0.5
Placental length (cm) 20.4 0.9a,cd 19.7 1.1ab,c 15.9 1.1b,d
Implantation area (cm2) 121.5 6.5a 107.4 8.0a,b 92.1 8.5b
a,b different superscripts in one row Plt0.05,
c,d different superscripts in one row Plt0.10
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Preliminary conclusions

• Lactational estrus/ovulation easily induced in
  IS12 model
• Ovulation IS6 sows seems affected
• Pregnancy rate (?) and early embryonic survival
  not affected in IS12
• Placental characteristics, embryonic development
  seems affected by IS6
• But
• LH surge? stage of lactation
• Progesterone output? LH surge, feed intake,
  growth factors
• All breeds?
• Conceptus development during later stages of
  gestation?

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Feed intake afer ovulation and progesterone
High/low feed intake from O to 6d after
ovulation, subsequently weaning High fed to
requirements Low High 2.5 kg
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Restoration of preovulatory LH centre in
Hypothalamus.
Bevers et al. 1981
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LH surge and luteal function
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New experiment
Stage of lactation influences LH surge and
luteinisation? 3 treatments 1. IS starts at
D14 2. IS starts at D21 3. Control weaned
at D21
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IGF around weaning
weaning
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IGF and luteal function
2004 IS model 2005 IS model 1997 weaned,
primiparous sows
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New experiment
Stage of lactation influences LH surge and
luteinisation? 3 treatments 1. IS starts at
D14 2. IS starts at D21 3. Control weaned
at D21
Wean at ovulation or 30d after
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IS in a different breed
IS12 model, using Dutch Landrace x Yorkshire Boar
contact 3x/d, from start of IS (D14)
BOAR NO BOAR
N16 N16
Spontaneous ovulation 5 4
Cystic 1 1
Anovulatory 10 11
Treated with PG600 9 9
Of the 21 anovulatory sows, 3 sows were removed
from the experiment before treatment with PG600
Sows with ovulation showed estrus, whereas
anovulatory sows did not
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Estradiol
ovulation no ovulation cystic
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Follicle development
max
min
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Estradiol in relation to follicle growth
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Conclusion

• IS model is promising, but room for improvement
• Timing of start of IS luteinisation
• Timing of weaning developing conceptus
• Breed differences

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Thank you !
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Nutrients and villous atrophy
UW unweaned SMH sow milk high WD weaned on dry
feed SML sow milk low
Day 4 ME intake 1470 589 557 kJ/BW0.75
The drop in nutrient supply is a major cause of
intestinal atrophy
Van Beers-Schreurs, 1998
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SISP small intestine segment perfusion test
Kuller et al., 2002
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Feed intake and absorptive function
Piglets that eat already during lactation have
better intestinal absorptive function post weaning
Kuller et al., 2002
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Intermittent suckling
From 2 weeks of lactation, sows and piglets are
separated for 12 h per day