Effect of oocyte maturation time, sperm selection method and oxygen tension on in vitro embryo development in alpacas.

We evaluated the effect of in vitro maturation time, sperm selection and oxygen tension on alpaca embryo development. In Experiment I, Cumulus Oocyte- Complexes (COCs) were obtained from abattoir ovaries and in vitro matured in TCM-199 for 24 (n = 217), 28 (215), or 32 h (223) at 38.5 °C, high humidity and 5% CO2 in air. Oocytes from 24 (n = 392), 28 (n = 456) or 32 (n = 368) h groups were in vitro fertilized with epididymal sperm and cultured in SOFaa at 38.5 °C, high humidity and 5% CO2, 5% O2 and 90% N2 for 7 days. Embryo development was evaluated on Day 2, 5 and Day 7 of in vitro culture (Day 0 = in vitro fertilization). In Experiment II, a 2 by 2-factorial design was used to determine the effect of sperm selection (Swim-up vs Percoll) and oxygen tension (20% vs 5%) during embryo culture and their interaction on embryo development. COCs were in vitro matured for 32 h at 38.5 °C and 5% CO2 in air and then in vitro inseminated with epididymal sperm processed by swim-up or Percoll. Zygotes were cultured in SOFaa + cumulus cells at 38.5 °C under 20 or 5% of O2 tension and high humidity for 7 days. A total of 235, 235, 253 and 240 oocytes were assigned to: swim-up+20 O2, swim-up+5 O2 or Percoll+20 O2, Percoll+5 O2, groups respectively. The proportion of oocytes reaching MII stage was highest after 32 h of in vitro maturation (P < 0.05). Blastocyst rate (29.1 ± 2.7%) was also highest for COCs matured for 32 h (Exp I). In Experiment II, Blastocysts rate (26.03 ± 4.7; 27.7 ± 4.3; 29.7 ± 3.8 and 27.6 ± 4.2% for swim-up+20 O2, swim-up+5 O2 or Percoll+20 O2, Percoll+5 O2, respectively) was not affected by sperm selection method (P = 0.8), oxygen tension (P = 0.9) or their interaction (P = 0.5).

Identificación de ectoparásitos en Oso melero (Tamandua tetradactyla), Estado Lara, Venezuela / Identification of ectoparasites from an Lesser anteater (Tamandua tetradactyla), Lara State, Venezuela

Objetivo. Identificar especies de ectoparásitos encontrados parasitando naturalmente un Oso melero, el cual fue encontrado muriendo en una vía cercana al pueblo de Bobare, estado Lara, Venezuela. Materiales y métodos. Al ingresar el animal a la sala de anatomía del DCV-UCLA para ser sometido a la técnica de taxidermia, se procedió a revisar a través de la palpación toda la superficie corporal del Oso, con la finalidad de tomar muestras de ectoparásitos presentes en el hospedador; los especímenes encontrados fueron colocados en un envase de vidrio conservados en alcohol isopropílico y posteriormente fueron llevados al Laboratorio de Parasitología Veterinaria del DCV-UCLA para su identificación taxonómica. Los ectoparásitos fueron observados en lupa estereoscópica y clasificados con ayuda de claves taxonómicas. Resultados. Se identificaron dos especies de artrópodos infestando naturalmente el Oso Melero, de las cuales se encuentra una garrapata macho clasificada como Amblyomma nodosum; y una pulga hembra identificada como Pulex irritans. Conclusiones. Estos artrópodos se han reportado parasitando naturalmente algunas especies de mamíferos, dentro de los cuales el Oso Melero se ha visto afectado por la acción de estos ectoparásitos; en Venezuela es el primer reporte de Pulex irritans afectando esta especie animal.

Objectives. Identify species of ectoparasites found naturally parasitizing an anteater, which was found dying on the roadside close to Bobare Village, State of Lara, Venezuela. Materials and methods. A dead anteater was brought to the anatomy Lab of the Decanato de Ciencias Veterinarias (DCV), Universidad Centroccidental “Lisandro Alvarado” (UCLA) for taxidermic purposes. First, all the skin and hairy areas of the animal were manually checked looking for ectoparasites; secondly, all detected specimens were collected, and placed in vials containing a solution of isopropilic alcohol 70°. Following this procedure, the vials were taken to the Veterinary Parasitology Laboratory at DCV-UCLA to accomplish the taxonomic identification under a stereoscopic microscope, and with taxonomic keys. Results. Two specimens of arthropods were found, the first one was a male tick identified as Amblyomma nodosum, and the other one was a female flea of the genera Pulex irritans Conclusions. These ectoparasites have been reported as natural parasites of other mammals, and among them the anteaters have been often found parasitized by these arthropods. In Venezuela this is the first case of a Pulex irritans infecting Tamandua tetradactyla.