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Research
Breed differences in placental development during late gestation between Chinese Meishan and White crossbred gilts in response to intrauterine crowding
Jeremy Miles
USDA-ARS Roman L Hruska US Meat Animal Research Center
Corresponding Author
ORCiD: https://orcid.org/0000-0003-4765-8400
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This work is licensed under a CC BY 4.0 License. Read Full License
Background: The porcine placenta plays a critical role on uterine capacity, fetal growth, and survival as well as postnatal piglet growth and survival. The objective of this study was to evaluate placental development during late gestation between Chinese Meishan (MS) and White crossbred (WC) gilts following intrauterine crowding. To induce uterine crowding, MS (n = 7) and WC (n = 5) gilts were unilaterally hysterectomized-ovariectomized, bred to sires from their same breed, and the remaining uterine tract was collected at day 100 of gestation. Gross placental morphology and areolae density as well as histological morphology (i.e., folded bilayer and placental stroma) were analyzed using computer-assisted morphometry from placentas of the smallest and largest fetuses within each litter. All data were analyzed using MIXED model procedures for ANOVA.
Results: Fetal and placental weight were not different (P > 0.10) between MS and WC pregnancies. In contrast, within-litter fetal weight variation and allometric growth relationship between fetal and placental weights were decreased (P < 0.08) in MS gilts compared to WC gilts indicating greater fetal sparing within MS gilts. There was a breed by fetal size interaction (P < 0.01) for areolae density in which placentas from large MS fetuses had greater areolae density compared to small MS fetuses, but the density of areolae was greater from MS fetuses compared to WC fetuses, irrespective of fetal size. The width of the folded bilayer was greater (P < 0.01) in placentas from WC gilts compared to MS gilts, irrespective of fetal size. Placentas from small fetuses had greater (P < 0.01) folded bilayer width compared to large fetuses, irrespective of breed. The placental stromal width was greater (P < 0.01) in placentas from large fetuses compared to small, irrespective of breed. However, the difference between stromal width in placentas between divergent-sized littermates was greater (P = 0.05) in WC gilts compared to MS gilts, suggesting limited response to intrauterine crowding in MS gilts.
Conclusions: These results demonstrate altered placental development during late gestation in MS pregnancies compared to WC pregnancies corresponding to different mechanisms for responding to intrauterine crowding between breeds.
Keywords
Uterine capacity, intrauterine crowding, placental development, Meishan, swine
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This is a preprint. It has not completed peer review.
Research
Breed differences in placental development during late gestation between Chinese Meishan and White crossbred gilts in response to intrauterine crowding
Jeremy Miles
USDA-ARS Roman L Hruska US Meat Animal Research Center
Corresponding Author
ORCiD: https://orcid.org/0000-0003-4765-8400
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
History
CURRENT STATUS: Posted
Version 1
Posted 21 Sep, 2020
No community comments so far
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background: The porcine placenta plays a critical role on uterine capacity, fetal growth, and survival as well as postnatal piglet growth and survival. The objective of this study was to evaluate placental development during late gestation between Chinese Meishan (MS) and White crossbred (WC) gilts following intrauterine crowding. To induce uterine crowding, MS (n = 7) and WC (n = 5) gilts were unilaterally hysterectomized-ovariectomized, bred to sires from their same breed, and the remaining uterine tract was collected at day 100 of gestation. Gross placental morphology and areolae density as well as histological morphology (i.e., folded bilayer and placental stroma) were analyzed using computer-assisted morphometry from placentas of the smallest and largest fetuses within each litter. All data were analyzed using MIXED model procedures for ANOVA.
Results: Fetal and placental weight were not different (P > 0.10) between MS and WC pregnancies. In contrast, within-litter fetal weight variation and allometric growth relationship between fetal and placental weights were decreased (P < 0.08) in MS gilts compared to WC gilts indicating greater fetal sparing within MS gilts. There was a breed by fetal size interaction (P < 0.01) for areolae density in which placentas from large MS fetuses had greater areolae density compared to small MS fetuses, but the density of areolae was greater from MS fetuses compared to WC fetuses, irrespective of fetal size. The width of the folded bilayer was greater (P < 0.01) in placentas from WC gilts compared to MS gilts, irrespective of fetal size. Placentas from small fetuses had greater (P < 0.01) folded bilayer width compared to large fetuses, irrespective of breed. The placental stromal width was greater (P < 0.01) in placentas from large fetuses compared to small, irrespective of breed. However, the difference between stromal width in placentas between divergent-sized littermates was greater (P = 0.05) in WC gilts compared to MS gilts, suggesting limited response to intrauterine crowding in MS gilts.
Conclusions: These results demonstrate altered placental development during late gestation in MS pregnancies compared to WC pregnancies corresponding to different mechanisms for responding to intrauterine crowding between breeds.
Figure 1
Figure 2
Figure 3
Figure 4