title: Enhanced or reduced fetal growth induced by embryo transfer into smaller or larger breeds alters post-natal growth and metabolism in pre-weaning horses.
abstract: In equids, placentation is diffuse and nutrient supply to the fetus is determined by uterine size. This correlates with maternal size and affects intra-uterine development and subsequent post-natal growth, as well as insulin sensitivity in the newborn. Long-term effects remain to be described. In this study, fetal growth was enhanced or restricted through ET using pony (P), saddlebred (S) and draft (D) horses. Control P-P (n = 21) and S-S (n = 28) pregnancies were obtained by AI. Enhanced and restricted pregnancies were obtained by transferring P or S embryos into D mares (P-D, n = 6 and S-D, n = 8) or S embryos into P mares (S-P, n = 6), respectively. Control and experimental foals were raised by their dams and recipient mothers, respectively. Weight gain, growth hormones and glucose homeostasis were investigated in the foals from birth to weaning. Fetal growth was enhanced in P-D and these foals remained consistently heavier, with reduced T3 concentrations until weaning compared to P-P. P-D had lower fasting glucose from days 30 to 200 and higher insulin secretion than P-P after IVGTT on day 3. Euglycemic clamps in the immediate post-weaning period revealed no difference in insulin sensitivity between P-D and P-P. Fetal growth was restricted in S-P and these foals remained consistently lighter until weaning compared to S-D, with elevated T3 concentrations in the newborn compared to S-S. S-P exhibited higher fasting glycemia than S-S and S-D from days 30 to 200. They had higher maximum increment in plasma glucose than S-D after IVGTT on day 3 and clamps on day 200 demonstrated higher insulin sensitivity compared to S-D. Neither the restricted nor the enhanced fetal environment affected IGF-1 concentrations. Thus, enhanced and restricted fetal and post-natal environments had combined effects that persisted until weaning. They induced different adaptive responses in post-natal glucose metabolism: an early insulin-resistance was induced in enhanced P-D, while S-P developed increased insulin sensitivity.
authors.affiliation: INRA, UMR1198 Biologie du Développement et Reproduction, Jouy en Josas, France; ENVA, Maisons Alfort, France.
authors.forename: Pauline
authors.initials: P
authors.lastname: Peugnet
authors.affiliation: IFCE, Station Expérimentale de la Valade, Chamberet, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Wimel
authors.affiliation: INRA, UE1293, Nouzilly, France.
authors.forename: Guy
authors.initials: G
authors.lastname: Duchamp
authors.affiliation: Clinique équine, Faculté de Médecine Vétérinaire, CORD, Université de Liège, Liège, Belgique.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Sandersen
authors.affiliation: INRA, UMR1198 Biologie du Développement et Reproduction, Jouy en Josas, France; ENVA, Maisons Alfort, France.
authors.forename: Sylvaine
authors.initials: S
authors.lastname: Camous
authors.affiliation: INRA, UMR85, Physiologie de la Reproduction et Comportements, Nouzilly, France; CNRS, UMR7247, Nouzilly, France; Université François Rabelais de Tours, Tours, France; IFCE, Nouzilly, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Guillaume
authors.affiliation: INRA, UMR1198 Biologie du Développement et Reproduction, Jouy en Josas, France; ENVA, Maisons Alfort, France.
authors.forename: Michèle
authors.initials: M
authors.lastname: Dahirel
authors.affiliation: IFCE, Station Expérimentale de la Valade, Chamberet, France.
authors.forename: Cédric
authors.initials: C
authors.lastname: Dubois
authors.affiliation: INRA, UMR1198 Biologie du Développement et Reproduction, Jouy en Josas, France; ENVA, Maisons Alfort, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Jouneau
authors.affiliation: INRA, UE1293, Nouzilly, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Reigner
authors.affiliation: INRA, UMR791 Modélisation Systémique Appliquée aux Ruminants, Paris, France; AgroParis Tech, Paris, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Berthelot
authors.affiliation: INRA, UMR1198 Biologie du Développement et Reproduction, Jouy en Josas, France; ENVA, Maisons Alfort, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Chaffaux
authors.affiliation: INRA, UMR1198 Biologie du Développement et Reproduction, Jouy en Josas, France; ENVA, Maisons Alfort, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Tarrade
authors.affiliation: Clinique équine, Faculté de Médecine Vétérinaire, CORD, Université de Liège, Liège, Belgique.
authors.forename: Didier
authors.initials: D
authors.lastname: Serteyn
authors.affiliation: INRA, UMR1198 Biologie du Développement et Reproduction, Jouy en Josas, France; ENVA, Maisons Alfort, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Chavatte-Palmer
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development* / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism; D001947:Breeding; D004624:Embryo Transfer / Q000662:veterinary*; D005260:Female; D047109:Fetal Development; D013006:Growth Hormone / Q000378:metabolism; D006736:Horses / Q000254:growth & development* / Q000378:metabolism; D007333:Insulin Resistance; D008297:Male; D011247:Pregnancy; D014886:Weaning; D015430:Weight Gain
chemical_list: D001786:Blood Glucose; D013006:Growth Hormone