Abstract
The successful application of assisted reproductive techniques (ARTs) in ovine as in other mammal species relies on many factors among which the quality of the semen used. After collection, semen samples are generally processed for storage (liquid storage or cryoconservation) before being used for insemination or in vitro embryo production. During the liquid storage process, sperm cells are exposed to artificial conditions which lead to oxidative stress—the imbalance between pro-oxidants and antioxidants (AO), following overproduction of reactive oxygen species (ROS)—resulting in ultrastructural, biochemical and functional damages of spermatozoa. Especially, viability, motility, mitochondrial activity, membrane integrity, and acrosome integrity are reduced while morphological abnormalities, DNA fragmentation, and lipid peroxidation (LPO) are increased, affecting the fertilizing ability and subsequent early embryonic development when using standard extenders. Indeed, an optimal semen extender must not only regulate and support an environment of adequate pH and buffering capacity to protect spermatozoa from osmotic and cooling stresses, but, also prevent the generation and/or scavenge excess ROS. To improve ram semen liquid storage, several methods have been developed with the supplementation of extenders with antioxidants or antioxidant like-compounds (enzymes, amino-acids, vitamins, plant extracts), seminal plasma, sugars, fatty acids, and nanoparticles being a relevant approach. Promising results have been registered with the supplementation of extenders with these compounds, confirming they can be used to preserve ram semen quality and fertility. Therefore, the present review provides an updated overview of the damages and associated mechanisms that ram spermatozoa undergo during liquid storage. Moreover, the supplementation of extenders with different compounds as a tool to improve semen storage is also discussed as well as their efficiency to reduce and/or prevent sperm damages during storage.
Highlights
In sheep farming, high feed price can be seen as an advantage for ovine since they have a better ability to convert fibrous, low quality feedstuffs into meat and other products than cattle
During the liquid storage process, sperm cells are exposed to artificial conditions which lead to oxidative stress—the imbalance between pro-oxidants and antioxidants (AO), following overproduction of reactive oxygen species (ROS)—resulting in ultrastructural, biochemical and functional damages of spermatozoa
As for freeze-thawing, semen liquid storage which consists of decreasing the metabolism rate of sperm cells so that the lifespan of spermatozoa is prolonged, reduces sperm quality and fertility, [1] [2] [3] and this trend is accentuated as the storage time increases [4] [5]
Summary
High feed price can be seen as an advantage for ovine since they have a better ability to convert fibrous, low quality feedstuffs into meat and other products than cattle In this field, the optimization of reproduction is achieved by the means of assisted reproductive techniques (ARTs) which include semen collection and storage, estrus synchronization, artificial insemination (AI), in vitro fertilization (IVF), intra-cytoplasmic sperm injection, embryo transfer, multiple ovulation embryo transfer, and juvenile in vitro embryo technology. To minimize the deleterious effects associated to storage, an optimal semen extender must regulate and support an environment of adequate pH and buffering capacity to protect spermatozoa from osmotic and cooling stresses, but, prevent the generation and/or scavenge excess ROS In this regard, several investigations have focused on the ability of different compounds used as additives to semen extenders, to maintain sperm viability, motility, membrane integrity and fertility. This article reviews the liquid storage-associated damages to ram sperm cells and the supplementation of extenders with different compounds, especially plant extracts to preserve ram sperm quality and fertility
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
