Browsing by Author "Bueno Leon, Hernan Patricio"

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Análisis morfométrico y funcional de ovocitos bovinos obtenidos de ovarios de matadero y por aspiración folicular transvaginal en vacas criollas del altiplano ecuatoriano
(2020) Alvarado Ulloa, Jhonatan Marcelo; Perea Ganchou, Fernando Pedro; Soria Parra, Manuel Elías; Méndez Álvarez, María Silvana; Bueno Leon, Hernan Patricio; Iñiguez Gutierrez, Carlos Ulises; Argudo Garzón, Daniel; Galarza Lucero, Diego Andrés
This study assessed the morphometric and functional characteristics of oocytes from 10 native cows to the Ecuadorian Andes, collected by transvaginal follicular aspiration (OPU) and oocytes collected post mortem (PM) from abattoir ovaries. For this purpose, 1157 cumulus-oocyte complexes (CCOs) of the OPU group (n=271) and PM group (n=886) were recovered in 10 repetitions per group by follicular aspiration at 90 mm Hg pressure and classified as A, B or C, according to the characteristics of the cytoplasm and cumulus cells. The activity of the enzyme glucose 6 phosphate dehydrogenase (G6PD) and the integrity of the plasma membrane was determined by staining two groups of CCOs with cresyl brilliant blue (BCB +) and trypan blue, respectively. The size (diameter and volume) of the oocytes was evaluated using CaptaVisio® software v. 5.1. The data were analysed by logistic regression and by the SAS general linear model, and the means were compared by the least square method. The results showed that the oocytes of the PM group had a larger diameter (126.0 ± 0.48 vs. 122.7 ± 0.79 μm; p<0.01) and integrity of the plasma membrane (86.0 vs. 76.8%; p<0.05) than the OPU group. However, quality A and B oocytes did not show significant differences between groups with respect to plasma membrane integrity and BCB + values. The results suggest that, although the fact that the size and viability were more affected in the oocytes aspirated by OPU, those of quality A and B from both sources showed similar values regarding the integrity of the plasma membrane and metabolic condition to continue maturation.
Efecto de la temperatura de almacenamiento de epidídimos de toro sobre la calidad espermática de semen criopreservado
(2018) Valverde Peralta, Edwin Enrique; Argudo Garzon, Daniel Ernesto; Bueno Leon, Hernan Patricio; Quintero Moreno, Armando; Galarza Lucero, Diego Andrés
Epididymis sperm conservation is a technique widely used in animals of high genetic value as well as in wild animals dead unexpectedly. One factor that most influence in motility and sperm membrane integrity (plasma and acrosomal) as well as the fertilizing ability of epididymal spermatozoa recovered is post-mortem temperature storage of epididymis. The objective of this study was determinate sperm quality pre-freezing and post-thawed of bull epididymal sperm (Bos taurus) from the Ecuadorian Amazon recovered from testicles stored to 5 or 20ºC for short-time. For this propose, ten pairs of testicles were collected from slaughterhouse. Left and right testicles of each bull were storage at 5ºC (T-5 group) or 20ºC (T-20 group), respectively during 6 hours (h). Sperm recovery was performed by retrograde flow of the epididymis tail and the liquid obtained was diluted in AndroMed® extender at concentration of 200 x 106 spermatozoa/ mililiters mL and packed in 0.25 mL straws. Both straws T-5 (n = 30) and T-20 (n = 30) groups were frozen in vapors of nitrogen liquid and thawed at 37ºC for 60 seconds (sec). The effect of storage temperature of epididymis post-mortem were assessment by ANOVA-one way. The results showed that in pre-freezing analysis, the percentage of motility (analyzed by optical microscopy), sperm vitality (V, plasma membrane integrity analyzed by eosin- nigrosine stain) and total morphological abnormalities (TA) of spermatozoa of T-5 group did no showed significant differences (P>0.05) compared with T-20 group. In post-thawed analysis, likewise the motilities variables (assessed by CASA system, SpermVision®, Minitube, Germany) as well as TA did no showed significant differences (P>0.05) between T-5 and T-20 groups. Sperm vitality (V) in samples thawed was higher (P<0.05) with T-5 group than T-20 group (63.0 ± 2.6% y 52.9 ± 3.0%, respectively). However, in plasma membrane functionality analysis assessed by hypoosmotic test (HOST) showed higher values (P<0.05) with T-20 group than T-5 group (40.4 ± 3.26% and 31.3 ± 1.99%). In conclusion, the results suggest that, despite the controversies found in the integrity and functionality plasma membrane post-thawed, the epididymis from Bull slaughtered under environment conditions of Ecuadorian Amazon may be storage at 5 or 20ºC during short-term. Additional studies should be made to evaluate the fertilizing ability of these epididymal sperm after artificial insemination (AI) under filed conditions.
Methods of collection, extender type, and freezability of semen collected from creole bulls raised in the tropical highlands of Ecuador
(2019) Argudo Garzon, Daniel Ernesto; Galarza Lucero, Diego Andrés; Bueno Leon, Hernan Patricio; Iñiguez Gutierrez, Carlos Ulises; Méndez Álvarez, María Silvana; Soria Parra, Manuel Elías; Torres Inga, Carlos Santiago; Perea Ganchou, Fernando Pedro; Alberio Null, Ricardo Horacio
This study was conducted to determine the best combination between two collection method and two extenders in the cryopres-ervation of semen from creole bulls adapted to highlands of the Ecuadorian Andes. Sixty ejaculates from three adult Creole bulls were evaluated after collection by artificial vagina (AV) and electroejaculation (EE). Semen samples were split into two aliquots and diluted with a soy lecithin extender (Andromed®; A) or an egg yolk-containing extender (Triladyl®; T) and packed in straws of 0.25 ml with 20 × 106 sperms. Optical microscopy and computer-assisted semen analysis system (CASA) were used to evaluate semen quality characteristics. The effects of collection methods and extender type as well as its interaction were evaluated by a factorial ANOVA and Bonferroni’s test. Semen samples collected with EE and frozen with T (EE-T) and A (EE-A) had greater proportion of spermatozoa with optical assessed individual progressive motility (IPM), plasmatic membrane intact (HosT), and lower tail abnormalities than those obtained with AV and frozen with the same extenders (AV-T and AV-A);however, differences were significant only between EE-A and AV-T. CASA assessment indicated that the total mobility (TM) was greater (P < 0.05) in semen samples diluted with T, although these samples had a greater proportion (P < 0.05) of sperms with local motility (LM) and fewer immobile sperms (IS), than those extended with A. Generally, semen samples obtained with EE or AV and diluted with T seems to be the best option to ciopreserve gametes of Creole bulls raised in highlands of Ecuadorian Andes.