Animal board invited review: An update on the methods for semen quality evaluation in swine - from farm to the lab

Identifier:  imarina:9412902

Handle: https://hdl.handle.net/20.500.11797/imarina9412902

Authors:  Maside, Carolina; Recuero, Sandra; Salas-Huetos, Albert; Ribas-Maynou, Jordi; Yeste, Marc

Abstract:
Pig breeding is mainly conducted through artificial insemination with liquid-stored semen. It is, there-fore, crucial to ensure that sperm quality is over the standard thresholds, as reduced sperm motility, mor-phology or plasma membrane integrity are associated with reduced farrowing rates and litter sizes. This work aims to summarise the methods utilised in farms and research laboratories to evaluate sperm qual-ity in pigs. The conventional spermiogram consists in the assessment of sperm concentration, motility and morphology, which are the most estimated variables in farms. Yet, while the determination of these sperm parameters is enough for farms to prepare seminal doses, other tests, usually carried out in spe-cialised laboratories, may be required when boar studs exhibit a decreased reproductive performance. These methods include the evaluation of functional sperm parameters, such as plasma membrane integ-rity and fluidity, intracellular levels of calcium and reactive oxygen species, mitochondrial activity, and acrosome integrity, using fluorescent probes and flow cytometry. Furthermore, sperm chromatin conden-sation and DNA integrity, despite not being routinely assessed, may also help determine the causes of reduced fertilising capacity. Sperm DNA integrity can be evaluated through direct (Comet, transferase deoxynucleotide nick end labelling (TUNEL) and its in situ nick variant) or indirect tests (Sperm Chromatin Structure Assay, Sperm Chromatin Dispersion Test), whereas chromatin condensation can be determined with Chromomycin A3. Considering the high degree of chromatin packaging in pig sperm, which only have protamine 1, growing evidence suggests that complete decondensation of that chro-matin is needed before DNA fragmentation through TUNEL or Comet can be examined.(c) 2023 The Authors. Published by Elsevier B.V. on behalf of The Animal Consortium. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).