Person:
Crespo Castejón, Francisco

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First Name
Francisco
Last Name
Crespo Castejón
URI
https://hdl.handle.net/20.500.14352/80614
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Veterinaria
Department
Medicina y Cirugía Animal
Area
Medicina y Cirugía Animal
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20202
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Author: Consuegra González, Cesar × Start date: 2020 ×

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Now showing 1 - 2 of 2
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    Comparison of different mathematical models to assess seasonal variations in the longevity of DNA integrity of cooled-stored stallion sperm.
    (Andrología, 2020) Rizos, Dimitri; Hidalgo Prieto; Hidalgo Prieto, Manuel; Consuegra González, Cesar; Diaz Jiménez, María; Dorado Martín, Jesús; Crespo Castejón, Francisco
    Dynamic assessment of sperm DNA fragmentation (SDF) has shown to give fuller understanding of stallion semen quality; however, there have been limited attempts to use this parameter to investigate seasonal changes in productive functions. The aims of this study were to: (a) establish a reliable mathematical model to describe the longevity of cooled-stored sperm DNA integrity; (b) to examine the effect of seasonal variations on SDF. Ejaculates were cooled to 5°C, and SDF was analysed after 0, 6 and 24 hr of storage. The coefficient of determination (R2) was calculated after fine-tuning linear (LIN), exponential (EXP) and second order polynomial (POL) models. R2 was significantly higher (p < .001) for POL than for LIN and EXP. The rate of DNA degradation was calculated using the slopes of POL equations. After assessing the rate of change of the POL functions, significant differences between the acceleration of DNA fragmentation were found (p < .01) among seasons, being higher for winter and summer than spring and autumn. In conclusion, DNA analysis of stallion sperm fits better to a second order polynomial mathematical model, being spring the best season to collect and process cooled stallion semen in order to maintain the DNA integrity of the stallion sperm.
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    Fertilizing capacity of vitrified stallion sperm assessed utilizing heterologous IVF after different semen warming procedures
    (Animal Rerpoduction Science, 2020) Consuegra González, Cesar; Crespo Castejón, Francisco; Dorado Martín, Jesús; María Díaz Jiménez; Sánchez Calabuig, María Jesús; Beltrán Breña, Paula; Pérez Cerezales, Serafín; Rizos, Dimitri; Hidalgo Prieto
    The aim of this study was to evaluate the fertilizing capacity of frozen or vitrified stallion sperm after assessing different warming procedures. In Experiment 1, different warming procedures were compared after sperm vitrification: immersion in extender at 43 ◦C (C), or in a water bath at 37 ◦C/30 s (W37), 43 ◦C/10 s (W43) or 60 ◦C/5 s (W60). With the W60 treatment, there were greater values (P < 0.05) for VCL (83.93 ± 3.6 μm/s) and ALH (3.00 ± 0.2 μm) than freezing and with the C group, and greater values (P < 0.001) for PM (35.33 ± 2.5 %) than with the W43 treatment. In Experiment 2, the fertilizing capacity of vitrified and frozen sperm was assessed utilizing heterologous IVF procedures, using cattle oocytes. Vitrification resulted in greater values (P < 0.05) than freezing for the number of bound sperm (1.36 ± 0.3 and 0.69 ± 0.2, respectively). There were no differences between frozen or vitrified sperm in pronuclear formation (26 hours post-insemination - hpi; 14.08 ± 4.2 % and 22.78 ± 4.8 %, respectively) or cleavage rate (32.77 ± 4.3 % and 39.66 ± 4.6 %, respectively). In conclusion, vitrified stallion sperm warmed in a water bath at 60 ºC had the capacity to penetrate cattle oocytes, leading to pronuclear formation and hybrid embryo cleavage after heterologous IVF.