title: Successful artificial insemination in the Asian elephant (Elephas maximus) using chilled and frozen-thawed semen.
abstract: BACKGROUND
  Artificial insemination (AI) using frozen-thawed semen is well established and routinely used for breeding in various mammalian species. However, there is no report of the birth of elephant calves following AI with frozen-thawed semen. The objective of the present study was to investigate the fertilizing ability of chilled and frozen-thawed semen in the Asian elephant following artificial insemination (AI).
  
  
  METHODS
  Semen samples were collected by from 8 bulls (age range, 12-to 42-years) by manual stimulation. Semen with high quality were either cooled to 4 degrees C or frozen in liquid nitrogen (-196 degrees C) before being used for AI. Blood samples collected from ten elephant females (age range, 12-to 52-years) were assessed for estrus cycle and elephants with normal cycling were used for AI. Artificial insemination series were conducted during 2003 to 2008; 55 and 2 AI trials were conducted using frozen-thawed and chilled semen, respectively. Pregnancy was detected using transrectal ultrasonography and serum progestagen measurement.
  
  
  RESULTS
  One female (Khod) inseminated with chilled semen became pregnant and gave birth in 2007. The gestation length was 663 days and the sex of the elephant calf was male. One female (Sao) inseminated with frozen-thawed semen showed signs of pregnancy by increasing progestagen levels and a fetus was observed for 5 months by transrectal ultrasonography.
  
  
  CONCLUSIONS
  This is the first report showing pregnancy following AI with frozen-thawed semen in the Asian elephant. Successful AI in the Asian elephant using either chilled or frozen-thawed semen is a stepping stone towards applying this technology for genetic improvement of the elephant population.
authors.affiliation: Faculty of Veterinary Medicine, Kasetsart University, Nakhonpathom 73140, Thailand. fvetnit@ku.ac.th
authors.forename: Nikorn
authors.initials: N
authors.lastname: Thongtip
authors.forename: Sittidet
authors.initials: S
authors.lastname: Mahasawangkul
authors.forename: Chatchote
authors.initials: C
authors.lastname: Thitaram
authors.forename: Pornsawan
authors.initials: P
authors.lastname: Pongsopavijitr
authors.forename: Kornchai
authors.initials: K
authors.lastname: Kornkaewrat
authors.forename: Anuchai
authors.initials: A
authors.lastname: Pinyopummin
authors.forename: Taweepoke
authors.initials: T
authors.lastname: Angkawanish
authors.forename: Saran
authors.initials: S
authors.lastname: Jansittiwate
authors.forename: Ronnachit
authors.initials: R
authors.lastname: Rungsri
authors.forename: Khajornpat
authors.initials: K
authors.lastname: Boonprasert
authors.forename: Warut
authors.initials: W
authors.lastname: Wongkalasin
authors.forename: Pongpon
authors.initials: P
authors.lastname: Homkong
authors.forename: Suthathip
authors.initials: S
authors.lastname: Dejchaisri
authors.forename: Worawit
authors.initials: W
authors.lastname: Wajjwalku
authors.forename: Kulnasan
authors.initials: K
authors.lastname: Saikhun
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D004606:Elephants; D005260:Female; D005615:Freezing; D015907:Hysteroscopy / Q000662:veterinary; D007315:Insemination, Artificial / Q000379:methods / Q000662:veterinary*; D008297:Male; D011247:Pregnancy; D055101:Semen Analysis / Q000662:veterinary; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*