Examinando por Materia "Alpaca spermatozoa"

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Effects on the quality of frozen-thawed alpaca (Lama pacos) semen using two different cryoprotectants and extenders
(Wolters Kluwer Medknow Publications, 2005-09-01) Santiani, Alexei; Huanca López, Wilfredo; Sapana Valdivia, Rómulo; Huanca Mamani, Teodosio; Sepúlveda, Néstor; Sánchez, Raúl
Aim: To evaluate two extenders and two cryoprotectant agents (CPA) for alpaca semen cryopreservation. Methods: Semen samples were obtained from four adult alpacas (Lama pacos) and frozen using extender I (TRIS, citrate, egg yolk and glucose) or extender II (skim milk, egg yolk and fructose), each containing either glycerol (G) or ethylene glycol (EG) as CPA. Consequently, four groups were formed: 1) extender I-G; 2) extender I-EG; 3) extender II-G; and 4) extender II-EG. Semen was diluted in a two-step process: for cooling to 5 °C (extenders without CPA), and for freezing (extenders with CPA). Viability and acrosome integrity were assessed using trypan blue and Giemsa stains. Results: When compared, the motility after thawing was higher (P < 0.05) in groups II-EG (20.0 % ± 6.7 %) and II-G (15.3 % ± 4.1 %) than that in groups I-G (4.0 % ± 1.1 %) and I-EG (1.0 % ± 1.4 %). Viable spermatozoa with intact acrosomes in groups II-EG (18.7 % ± 2.9 %) and II-G (12.7 % ± 5.9 %) were higher than that in groups I-G (5.7 % ± 1.5 %) and I-EG (4.0 % ± 1.0 %). Conclusion: The skim milk- and egg yolk-based extenders containing ethylene glycol or glycerol to freeze alpaca semen seems to promote the survival of more sperm cells with intact acrosomes than the other extenders.
Spermatozoa Obtained From Alpaca vas deferens. Effects of Seminal Plasma Added at Post-thawing
(Frontiers Media S.A, 2021-02-10) Aisen, Eduardo G.; Huanca López, Wilfredo; Pérez Durand, Manuel G.; Torres Mamani, Edita; Villanueva Mori, Juan C.; Ousset, María J.; Medina, Víctor H.; Pérez Guerra, Uri Harold; Huanca Mamani, Teodosio
The viscous seminal plasma (SP) is currently a major impediment to the handling of ejaculate and the development of some biotechnologies in South American camelids. The vas deferens-collected spermatozoa of alpacas is a useful technique to avoid this problem. On the other hand, SP contains a large protein component that has been implicated in the function of spermatozoa within the female reproductive tract. In this sense, the low fertility achieved using transcervical insemination with frozen-thawed spermatozoa in alpacas could be improved by adding SP. This study aimed to evaluate the effect of the whole SP on some in vitro parameters of alpaca spermatozoa after the freezing-thawing-process and the fertility after artificial insemination. It would contribute to a better understanding of the interaction between thawed sperm cells and SP. Spermatozoa were obtained by surgically diverted vas deferens. The samples were diluted with a Tris-based extender, packaged in straws, and frozen. At thawing, each straw was divided into two post-thawing conditions: with the addition of 10% of PBS (control) or with 10% SP (treatment). The sperm cells were evaluated using dynamic parameters, sperm cell morphology, and morphometry. Fertility was assessed by an artificial insemination trial. All in vitro parameters were analyzed by ANOVA. A heterogeneity test was scheduled for the fertility trial. After the freezing-thawing process, motility and plasma membrane functionality was improved when SP was added. No differences were found for post-thaw viability between the control and treatment samples. The percentage of normal cells was higher with SP at post-thawing, and a decrease of the presence of bent tailed spermatozoa with a droplet in the SP group was observed. The length of the head spermatozoa was 3.4% higher in the samples with PBS compared to those in which SP was added. Females pregnant at day 25 post-insemination were 0/12 (with SP inside the straw) and 1/10 (without SP inside the straw). In conclusion, the presence of 10% SP at post-thawing improves sperm cells' motility, functionality, and morphology, indicating that it would be beneficial to improve the frozen-thawed alpaca's physiology spermatozoa. More fertility trials must be developed to increase this knowledge.