title: Hormonal indicators of pregnancy in llamas and alpacas.
abstract: OBJECTIVE
  To determine concentrations of estrone sulfate in serum, estrone sulfate in urine, relaxin in serum, and progesterone in serum in pregnant llamas and alpacas and to assess the potential of these hormones as pregnancy indicators.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  19 parous pregnant camelids (8 llamas and 11 alpacas).
  
  
  METHODS
  Estrone sulfate concentrations (in serum and in urine) and progesterone concentrations (in serum) were determined by enzyme immunoassay. Relaxin concentrations (in serum) were measured by radioimmunoassay. Serum and urine samples were collected daily for the first 30 days after breeding and, thereafter, once weekly until parturition.
  
  
  RESULTS
  Estrone sulfate concentrations (in serum and in urine) peaked twice during pregnancy. The first took place 21 days after breeding and the second during the last month of pregnancy. Relaxin concentrations increased at 3 months of gestation to > 20 ng/mL, decreased at 5 months to 5 ng/mL, then increased from 8 months of pregnancy until parturition. Progesterone concentrations were detectable 4 days after breeding and were maintained > 2 ng/mL throughout pregnancy.
  
  
  CONCLUSIONS
  The first increase in estrone sulfate concentration over basal values may indicate early interaction between mother and embryo, whereas the second increase may reflect fetal viability. Use of estrone sulfate concentration to diagnose pregnancy in llamas and alpacas is highly dependent on time of sampling. Relaxin concentration in serum is a superior indicator of pregnancy after the second month in the Ilama and alpaca because its existence is suggestive of interaction between mother and fetus, and concentrations are greater than basal values for a long period of pregnancy. Progesterone is not a direct product of the embryo or fetus and only indirectly confirms a diagnosis of pregnancy.
authors.affiliation: Centro Experimental La Raya, Universidad Nacional San Antonio Abad, Cusco, Peru.
authors.forename: P W
authors.initials: PW
authors.lastname: Bravo
authors.forename: D R
authors.initials: DR
authors.lastname: Stewart
authors.forename: B L
authors.initials: BL
authors.lastname: Lasley
authors.forename: M E
authors.initials: ME
authors.lastname: Fowler
mesh_terms: D000818:Animals; D002161:Camelids, New World / Q000097:blood* / Q000502:physiology; D004966:Estrogens, Conjugated (USP) / Q000097:blood / Q000652:urine; D004970:Estrone / Q000031:analogs & derivatives* / Q000097:blood / Q000652:urine; D005260:Female; D007124:Immunoenzyme Techniques / Q000662:veterinary; D011247:Pregnancy; D011258:Pregnancy Tests / Q000662:veterinary; D011270:Pregnancy, Animal / Q000097:blood*; D011374:Progesterone / Q000097:blood*; D011446:Prospective Studies; D011863:Radioimmunoassay / Q000662:veterinary; D012065:Relaxin / Q000097:blood*; D013045:Species Specificity
chemical_list: D004966:Estrogens, Conjugated (USP); D004970:Estrone; D011374:Progesterone; D012065:Relaxin; C017296:estrone sulfate