title: Endocrine changes during pregnancy, parturition and the early post-partum period in the llama (Lama glama).
abstract: Mean (+/- s.d.) pregnancy length for the 14 llamas in this study was 350 +/- 4.5 days. Plasma progesterone concentrations increased by 5 days after mating and remained elevated (greater than 2.0 ng/ml) throughout most of pregnancy. At about 2 weeks before parturition, plasma progesterone concentrations began to decline, dropped markedly during the final 24 h before parturition, and returned to basal concentrations (less than 0.5 ng/ml) by the day of parturition. The combined oestrone + oestradiol-17 beta and oestradiol-17 beta concentrations varied between 6 and 274 pg/ml and 4 and 114 pg/ml, respectively, during the first 9 months of pregnancy. Concentrations increased between 9 months after mating and the end of pregnancy with peak mean concentrations of 827 +/- 58 (s.e.m.) pg oestrone + oestradiol-17 beta/ml (range: 64-1658) and 196 +/- 10 pg oestradiol-17 beta/ml (31-294) during the last week of pregnancy. Concentrations then declined to 87 +/- 14 pg oestrone + oestradiol-17 beta/ml (7-488) and 25 +/- 5 pg oestradiol-17 beta/ml (2.5-142) during the first week post partum. Plasma cortisol concentrations varied between 2.6 and 51.9 ng/ml (14.0 +/- 0.5) from mating until 2 weeks before parturition when the concentrations began to decline. Only a slight increase in plasma cortisol concentrations was observed in association with parturition. Plasma triiodothyronine concentrations varied between 0.5 and 4.5 ng/ml (1.9 +/- 0.1) throughout pregnancy and the periparturient period.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Animal Science College of Agriculture, Oregon State University, Corvallis 97331.
authors.forename: J B
authors.initials: JB
authors.lastname: Leon
authors.forename: B B
authors.initials: BB
authors.lastname: Smith
authors.forename: K I
authors.initials: KI
authors.lastname: Timm
authors.forename: G
authors.initials: G
authors.lastname: LeCren
mesh_terms: D000818:Animals; D001188:Artiodactyla / Q000097:blood*; D002161:Camelids, New World / Q000097:blood*; D004958:Estradiol / Q000097:blood; D004970:Estrone / Q000097:blood; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006854:Hydrocortisone / Q000097:blood; D007743:Labor, Obstetric / Q000097:blood*; D049590:Postpartum Period / Q000097:blood*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000097:blood*; D011374:Progesterone / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
chemical_list: D012739:Gonadal Steroid Hormones; D014284:Triiodothyronine; D004970:Estrone; D011374:Progesterone; D004958:Estradiol; D013974:Thyroxine; D006854:Hydrocortisone