Improvement of llama (Lama glama) seminal characteristics for its subsequent use in assisted fertility techniques

GIULIANO SM; CARRETERO MI; GAMBAROTTA MC; NEILD DM; TRASORRAS VL; PINTO MR; MIRAGAYA MH

ANIMAL REPRODUCTION SCIENCE

Elsevier

Lugar: Amsterdam; Año: 2010 vol. 118 p. 98 - 102

0378-4320

Llama semen is characterized by great structural viscosity and minimal sperm progressive motility. These characteristics, inherent to South American Camelid ejaculates, have slowed down the development of assisted reproductive techniques in these species. The aim of the present research was to evaluate the effect of different combinations of dilutions and incubation time with H-TALP-BSA medium, with and without adding 0.1% collagenase, on the qualitative and quantitative semen characteristics, for its use in assisted fertility techniques. Ejaculates (n=8; r = 3)were obtained using electroejaculation. Each ejaculatewas evaluated and then split into four aliquots. Two of these were diluted 4:1 and 8:1 in 0.1% collagenase in H-TALP-BSA (treatments 1 and 3) and the other two 4:1 and 8:1 in H-TALP-BSA without collagenase (treatments 2 and 4). Treatments 1 and 2 were incubated 4 min at 37 ◦C while treatments 3 and 4 were incubated 8 min. All aliquots were centrifuged at 800×g for 4 min immediately after incubation. Supernatantswere pipetted to observe thread formation and pellets were re-diluted in H-TALP-BSA. Supernatants fromsamples treated with collagenase did not form a thread when pipetted, while the ones from samples that were not treated with the enzyme did. Only semen samples treated with collagenase showed progressive sperm motility, with averages over 40%. There were no significant differences (P > 0.05) for the percentage of live spermatozoa and for the percentage of detached heads between raw and treated semen samples. Percentages of spermatozoa with functional membranes were significantly higher (P≤0.05) in samples treated with collagenase than in raw semen and in samples incubated without collagenase. These results show that treating semen with 0.1% collagenase in H-TALP-BSA improves semen rheological properties while facilitates the separation of spermatozoa from seminal plasma in llama; it also promotes sperm progressive motility, while maintaining spermmembrane functionality and integrity. Consequently, this protocol could be used for in vitro llama embryo production with ejaculated spermatozoa.