title: Maturation competence of swamp buffalo oocytes obtained by ovum pick-up and from slaughterhouse ovaries.
abstract: This study was designed with the final goal of improving in vitro embryo production in the Thai swamp buffalo (Bubalus bubalis carabensis). Oocytes were collected by ovum pick-up (OPU) from six non-lactating multiparous swamp buffalo twice per week for 10 consecutive sessions followed by once-weekly collection for 10 consecutive sessions without hormone stimulation. In addition, oocytes were collected from slaughterhouse ovaries that were classified as follows: ovaries from non-pregnant cows with a visible corpus luteum (NPCL); pregnant cows with a corpus luteum (P); and non-pregnant cows without a corpus luteum (NP). Follicles in each group of ovaries were categorized as small (2-4 mm), medium-sized (5-8 mm) or large follicles (≥ 9 mm). The quality of the oocytes was assessed by their capacity to undergo in vitro maturation. The total number of observed follicles per session (all sizes combined) was larger in the once-weekly OPU group compared with the twice-weekly OPU group. In particular, the numbers of small and large follicles were higher in the once-weekly OPU group (5.2 ± 0.7 and 0.9 ± 0.2, respectively) than in the twice-weekly OPU group (3.9 ± 0.5 and 0.5 ± 0.1). The number of medium-sized follicles did not differ between the groups. The percentages of oocytes with an abnormal spindle morphology were not different between oocytes from the twice-weekly (30.0%) and the once-weekly (28.6%) OPU groups. A higher percentage of oocytes obtained in vitro (49.5%) exhibited nuclear abnormalities compared with those obtained in vivo (≤34.8%) after in vitro maturation. In conclusion, oocytes can be successfully collected by OPU in the swamp buffalo, without hormonal pretreatment, and per week more good-quality oocytes can be collected by twice-weekly OPU. In addition, oocytes collected from slaughterhouse ovaries can be used with the reproductive status of the cow having no influence on the maturation competence of oocytes.
authors.affiliation: Faculty of Veterinary Science, Department of Obstetrics Gynecology and Reproduction, Chulalongkorn University, Bangkok, Thailand.
authors.forename: M
authors.initials: M
authors.lastname: Yindee
authors.forename: M
authors.initials: M
authors.lastname: Techakumphu
authors.forename: C
authors.initials: C
authors.lastname: Lohachit
authors.forename: S
authors.initials: S
authors.lastname: Sirivaidyapong
authors.forename: A
authors.initials: A
authors.lastname: Na-Chiangmai
authors.forename: B A J
authors.initials: BA
authors.lastname: Roelen
authors.forename: B
authors.initials: B
authors.lastname: Colenbrander
mesh_terms: D000003:Abattoirs; D000818:Animals; D002020:Buffaloes / Q000502:physiology*; D005260:Female; D009865:Oocytes / Q000502:physiology*; D010053:Ovary / Q000502:physiology*; D010060:Ovulation; D020858:Tissue and Organ Harvesting / Q000379:methods / Q000662:veterinary*; D014463:Ultrasonography / Q000662:veterinary*