Evaluation of cooling and freezing systems of bovine semen

Autor(es):Mostrar menos -

Ribeiro Dias, Erika Aline ^[1] ; Campanholi, Suzane Peres ^[2] ; Rossi, Guilherme Fazan ^[2] ; Freitas Dell'Aqua, Camila de Paula ^[3] ; Dell'Aqua Junior, Jose Antonio ^[3] ; Papa, Frederico Ozanam ^[3] ; Zorzetto, Mariana Furtado ^[3] ; Paro de Paz, Claudia Cristina ^[1] ; Oliveira, Leticia Zoccolaro ^[4] ; Zerlotti Mercadante, Maria Eugenia ^[1] ; Monteiro, Fabio Morato ^[1]

Afiliação do(s) autor(es)

^[1] IZ APTA, Ctr APTA Bovinos Corte, Sao Paulo - Brazil

^[2] Univ Estadual Paulista, FCAV, UNESP, Via Acesso Prof Paulo Donato Castellane S-N, BR-14884900 Sao Paulo - Brazil

^[3] Univ Estadual Paulista, FMVZ, UNESP, Sao Paulo - Brazil

^[4] Univ Fed Fluminense, Rio De Janeiro - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Animal Reproduction Science; v. 195, p. 102-111, AUG 2018.
• Citações Web of Science: 1

Resumo

Semen cryopreservation comprises different steps, among them are the cooling and freezing rates which significantly influence the quality of thawed sperm. Different systems with variable freezing rates are used for freezing bull semen in the field, with a consequence of variable success rates. The objective of this study was to compare different systems for freezing bull semen in the field. Five cooling methods of semen and two methods for the subsequent freezing phase (5 x 2 factorial scheme) were used. Two to four ejaculates were collected from 12 bulls with an electroejaculator. The ejaculates were diluted in BotuBov to a concentration of 50 x 10(6) spermatozoa/mL in 0.5-mL straws. After dilution, the straws were cooled to 5 degrees C in five cooling systems: TK 4000 (R) at a cooling rate of -0.25 degrees C/min (R1); TK 4000 (R) at a rate of -0.5 degrees C/min (R2); Minitube (R) refrigerator at a rate of -2.8 degrees C/min (R3); Botutainer (R) at a rate of -0.65 degrees C (R4), and domestic refrigerator at a rate of -2.0 degrees C/min (R5). After stabilization at 5 degrees C for 4 h, these straws were then submitted to two freezing systems: TK 4000 at a freezing rate of-15 degrees C/min (C1) and Styrofoam box with liquid nitrogen at a rate of -19 degrees C/min (C2). Sperm kinetics were evaluated by computer-assisted sperm analysis at four time points: in fresh semen, after cooling, post-thawing, and after the rapid thermal resistance test (TRT). In addition, plasma and acrosomal membrane integrity, mitochondrial potential and intracellular H2O2 were analyzed after thawing by flow cytometry. The R1, R2 and R4 cooling systems were the most efficient in preserving sperm viability, membrane integrity and intracellular H2O2. Samples frozen in the Cl system exhibited better post-thaw and post-TRT kinetics than C2 samples. In conclusion, slower cooling curves in conjunction with a constant freezing rate obtained with the programmable unit were more efficient for freezing bull semen in the field. (AU)

• Processo FAPESP: 14/20360-4 - Avaliação de cinco sistemas de refrigeração na cinética espermática e integridade de membrana plasmática de sêmen bovino
• Beneficiário: Erika Aline Ribeiro Dias
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 14/11304-3 - Efeito do sistema de refrigeração na criopreservação de sêmen bovino
• Beneficiário: Fabio Morato Monteiro
• Modalidade de apoio: Auxílio à Pesquisa - Regular