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The impact of either a Meishan or Yorkshire uterus on Meishan or Yorkshire fetal and placental development to days 70, 90, and 110 of gestation.
J Anim Sci. 1998 Aug; 76(8):2169-76.JA

Abstract

Straightbred Yorkshire (Y) conceptuses are larger than straightbred Meishan (M) conceptuses throughout gestation and at farrowing. In contrast, when Y and M conceptuses were gestated together in Y recipient females, the birth weight of M pigs was similar to that of their Y littermates. Even though placentae of M pigs remained markedly smaller than placentae of Y littermates, they were significantly more vascular. The objective of this study was to compare and contrast the changes in Y and M conceptus growth and placental-endometrial vascularity throughout late gestation in Y or M uteri. Gravid uteri were recovered at slaughter from M and Y females that were gestating either M or Y conceptuses on d 70, 90, or 110 of gestation. Uterine and conceptus measurements were recorded, and a section of the intact endometrial-placental attachment site for each conceptus was fixed, embedded, and later evaluated for placental and endometrial vascular density. Placental surface area and weight were greater (P < .001) when M or Y conceptuses were recovered from Y uteri compared with M uteri on each day of gestation examined. Further, by d 110, the surface area of Y placentae was greater (P < .001) than that of M placentae, regardless of uterine type in which they were gestated. The vascular density of M placentae and adjacent endometrium doubled (P < .05) between d 70 and 110 of gestation (3.0 and 2.5 vs 6.0 and 5.1%, respectively), with no significant increase in placental surface area. In contrast, the surface area of Y placentae doubled in size (P < .001) between d 90 and 110 of gestation, but placental and adjacent endometrial vascular density remained relatively constant, averaging 3.2 and 3.8%, respectively. These data are consistent with the premise that placental size is largely determined by the uterus in which a conceptus is gestated until approximately d 90. After d 90, fetal breed-specific mechanisms maintain optimal fetal growth. Between d 90 and term, M fetal growth depends on progressive increases in placental blood vessel density and requires no increase in placental size. In contrast, Y conceptuses seem to rely exclusively on placental growth to increase placental-endometrial surface area for nutrient exchange.

Authors+Show Affiliations

Department of Animal Science, Iowa State University, Ames 50011-3150, USA.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

9734868

Citation

Biensen, N J., et al. "The Impact of Either a Meishan or Yorkshire Uterus On Meishan or Yorkshire Fetal and Placental Development to Days 70, 90, and 110 of Gestation." Journal of Animal Science, vol. 76, no. 8, 1998, pp. 2169-76.
Biensen NJ, Wilson ME, Ford SP. The impact of either a Meishan or Yorkshire uterus on Meishan or Yorkshire fetal and placental development to days 70, 90, and 110 of gestation. J Anim Sci. 1998;76(8):2169-76.
Biensen, N. J., Wilson, M. E., & Ford, S. P. (1998). The impact of either a Meishan or Yorkshire uterus on Meishan or Yorkshire fetal and placental development to days 70, 90, and 110 of gestation. Journal of Animal Science, 76(8), 2169-76.
Biensen NJ, Wilson ME, Ford SP. The Impact of Either a Meishan or Yorkshire Uterus On Meishan or Yorkshire Fetal and Placental Development to Days 70, 90, and 110 of Gestation. J Anim Sci. 1998;76(8):2169-76. PubMed PMID: 9734868.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The impact of either a Meishan or Yorkshire uterus on Meishan or Yorkshire fetal and placental development to days 70, 90, and 110 of gestation. AU - Biensen,N J, AU - Wilson,M E, AU - Ford,S P, PY - 1998/9/12/pubmed PY - 1998/9/12/medline PY - 1998/9/12/entrez SP - 2169 EP - 76 JF - Journal of animal science JO - J Anim Sci VL - 76 IS - 8 N2 - Straightbred Yorkshire (Y) conceptuses are larger than straightbred Meishan (M) conceptuses throughout gestation and at farrowing. In contrast, when Y and M conceptuses were gestated together in Y recipient females, the birth weight of M pigs was similar to that of their Y littermates. Even though placentae of M pigs remained markedly smaller than placentae of Y littermates, they were significantly more vascular. The objective of this study was to compare and contrast the changes in Y and M conceptus growth and placental-endometrial vascularity throughout late gestation in Y or M uteri. Gravid uteri were recovered at slaughter from M and Y females that were gestating either M or Y conceptuses on d 70, 90, or 110 of gestation. Uterine and conceptus measurements were recorded, and a section of the intact endometrial-placental attachment site for each conceptus was fixed, embedded, and later evaluated for placental and endometrial vascular density. Placental surface area and weight were greater (P < .001) when M or Y conceptuses were recovered from Y uteri compared with M uteri on each day of gestation examined. Further, by d 110, the surface area of Y placentae was greater (P < .001) than that of M placentae, regardless of uterine type in which they were gestated. The vascular density of M placentae and adjacent endometrium doubled (P < .05) between d 70 and 110 of gestation (3.0 and 2.5 vs 6.0 and 5.1%, respectively), with no significant increase in placental surface area. In contrast, the surface area of Y placentae doubled in size (P < .001) between d 90 and 110 of gestation, but placental and adjacent endometrial vascular density remained relatively constant, averaging 3.2 and 3.8%, respectively. These data are consistent with the premise that placental size is largely determined by the uterus in which a conceptus is gestated until approximately d 90. After d 90, fetal breed-specific mechanisms maintain optimal fetal growth. Between d 90 and term, M fetal growth depends on progressive increases in placental blood vessel density and requires no increase in placental size. In contrast, Y conceptuses seem to rely exclusively on placental growth to increase placental-endometrial surface area for nutrient exchange. SN - 0021-8812 UR - https://www.unboundmedicine.com/medline/citation/9734868/The_impact_of_either_a_Meishan_or_Yorkshire_uterus_on_Meishan_or_Yorkshire_fetal_and_placental_development_to_days_70_90_and_110_of_gestation_ L2 - https://academic.oup.com/jas/article-lookup/doi/10.2527/1998.7682169x DB - PRIME DP - Unbound Medicine ER -