| 1. |
- Bezerra Lima Verde, Isabel, et al.
(författare)
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Effect of freezing bull semen in two non-egg yolk extenders on post-thaw sperm quality
- 2018
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Ingår i: Reproduction in Domestic Animals. - : Wiley. - 0936-6768 .- 1439-0531. ; 53, s. 127-136
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Tidskriftsartikel (refereegranskat)abstract
- Traditionally, extenders for bull semen included egg yolk or milk, but recently there has been a move to avoid material of animal origin. The aim of this study was to evaluate the effects of two commercial extenders (based on soya lecithin and liposomes) on bull sperm quality after cryopreservation. Post-thaw sperm quality was evaluated by computer-assisted sperm analysis and flow cytometric assessment of membrane integrity, chromatin integrity, mitochondrial membrane potential, production of reactive oxygen species and tyrosine phosphorylation. Furthermore, an artificial insemination (AI) trial was conducted, and 56-day non-return rates were evaluated. Semen frozen in the liposome-based extender showed similar membrane integrity and higher mitochondrial membrane potential compared to those in the soya lecithin-based extender. Chromatin integrity and production of live H2O2+ reactive oxygen species were similar in both extenders. Less superoxide was produced in the samples extended with liposome-based extender, with or without menadione stimulation. Chromatin integrity and tyrosine phosphorylation were not affected by either type of extender. No differences in 56-day non-return rate between extenders containing soya lecithin and liposomes were observed in the AI trial (66%+/- 0.8 and 65%+/- 0.8, respectively). In conclusion, the sperm quality of bull semen frozen in the two extenders that do not contain material of animal origin was similar, although the semen frozen in the liposome-based extender had higher mitochondrial membrane potential. Either extender could be used in situations where extenders containing material of animal origin are to be avoided.
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| 2. |
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| 3. |
- Johannisson, Anders, et al.
(författare)
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Season does not have a deleterious effect on proportions of stallion seminal plasma proteins
- 2020
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Ingår i: Journal of reproduction and development. - : Japanese Society of Animal Reproduction. - 0916-8818 .- 1348-4400. ; 66:3, s. 215-221
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Tidskriftsartikel (refereegranskat)abstract
- The mechanism by which the content of the major groups of seminal plasma proteins in stallion semen changes between the breeding and non-breeding seasons remains unknown. Here, we investigated the proportions of non-heparin-binding, phosphorylcholine-binding, and heparin-binding proteins in seminal plasma with the aim of relating them to sperm quality and testosterone levels in good and bad freezer stallions. Only minor variations in the major protein groups were found between the breeding and non-breeding seasons. In the non-breeding season, a higher content of a subset of non-heparin binding proteins as well as of heparin-binding proteins was found. Analysis of semen characteristics revealed a somewhat contrasting picture. While only minor variations in sperm kinematics and sperm morphology were found between seasons, the flow-cytometric measurements of mitochondrial membrane potential and also, to some extent, reactive oxygen species production indicated lower sperm quality in the breeding season. Chromatin integrity and testosterone levels were unchanged between seasons. The results suggest that stallion ejaculates could be used year-round for freezing, since only minor differences in protein composition exist between the breeding and non-breeding seasons, as well as between good and bad freezers. In addition, sperm quality is not impaired during the non-breeding season.
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| 4. |
- Abraham, Maria Celina, et al.
(författare)
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Testicular length as an indicator of the onset of sperm production in alpacas under Swedish conditions
- 2016
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Ingår i: Acta Veterinaria Scandinavica. - : Springer Science and Business Media LLC. - 0044-605X .- 1751-0147. ; 58
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Tidskriftsartikel (refereegranskat)abstract
- Background The popularity of alpacas (Vicugna pacos) is increasing in Sweden as well as in other countries; however, knowledge about optimal management practices under Swedish conditions is still limited. The wide age range reported when the onset of puberty can occur, between 1 and 3years of age, makes management decisions difficult and may be influenced by the conditions under which the alpacas are kept. The aim of this study was to find out when Swedish alpacas can be expected to start producing sperm, by using testicular length and body condition score as a more precise indirect indicator than age. Results This study suggests that animals with a testicular length ≥3.8cm would be producing sperm; however, if it is crucial to know that there is no sperm production for management purposes, the threshold level for testicular length used to differentiate between sperm-producing and non-sperm producing animals should be ≤1.6cm instead. If only one variable is considered, testicular length appears to better than age alone to predict sperm production. Body condition score together with testicular length explains the individual onset of puberty and better guide management recommendations. Conclusions Using a combination of these parameters (testicular length, body condition score and age) as a tool for decision making for alpaca husbandry under Swedish conditions is suggested.
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| 5. |
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| 6. |
- Al-Essawe, Essraa M, et al.
(författare)
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Addition of seminal plasma to thawed stallion spermatozoa did not repair cryoinjuries
- 2018
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Ingår i: Animal Reproduction Science. - : Elsevier BV. - 0378-4320 .- 1873-2232. ; 196, s. 48-58
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Tidskriftsartikel (refereegranskat)abstract
- Freezing and thawing processes induce structural and functional damage to sperm plasma membranes and internal organelles. Adding seminal plasma (SP) has been found to minimize or repair the cryoinjuries in some species. The objective of this study was to investigate whether adding SP from stallions of known freezability after thawing could repair cryoinjuries. Semen was collected from warmblood stallions (n = 8, three ejaculates/stallion) and processed by Single Layer Centrifugation (SLC) to remove SP prior to freezing. Pooled SP (5%) from bad freezer (BF) or good freezer (GF) stallions was added after thawing. Post-thaw sperm quality was assessed by flow cytometry in terms of chromatin integrity (ßI), membrane integrity, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and MitoSOX. Sperm kinematics were also assessed by computer-assisted sperm analysis. The ßI was lower in SLC control (C) than in BF or GF (P < 0.0001, P < 0.0003 respectively). The proportion of viable spermatozoa with intact cell membranes was higher in C than in SP treated groups (C vs. BF, P = 0.02; C vs GF, P = 0.05). There were fewer spermatozoa with low MMP and more with high MMP for C than GF (P = 0.006). The spermatozoa treated with SP from good freezers produced more ROS than when treated with SP from bad freezers (P = 0.007). Motility parameters were not affected by adding SP. In conclusion, adding SP after thawing does not have a beneficial effect on sperm quality, suggesting an inability to repair stallion sperm cryoinjuries, regardless of whether the SP originated from stallions semen, which has good or bad quality after thawing.
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| 7. |
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| 8. |
- Al-Essawe, Essraa M
(författare)
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Equine seminal plasma: its role in protecting stallion spermatozoa during cryopreservation
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There is considerable variability in the ability of spermatozoa from different stallions to withstand the freezing process. As a result, stallions are usually categorized as good or bad freezers. In the equine industry, the demand for frozen semen for artificial insemination is increasing, resulting in a need for optimising cryopreservation techniques. Previously the removal of seminal plasma (SP) prior to cryopreservation was shown to improve post-thaw sperm quality, whereas the effect of adding SP on spermatozoa varied among studies. Single Layer Centrifugation (SLC) is a technique that has been used to select the most robust spermatozoa from the ejaculate and prolong their viability, as well as separating them from SP. The aims of this thesis were: 1) to study the effect of combining SLC with addition of SP from stallions of known freezability on sperm cryosurvival, including their ability to bind to heterologous oocytes; 2) To explore the differences in the major protein groups in SP between the breeding and non-breeding seasons in relation to sperm quality. Selecting robust spermatozoa using SLC prior to freezing improved post-thaw sperm quality, whereas addition of pooled SP from good or bad freezers to the selected sperm samples did not have an additional beneficial effect. Sperm quality was adversely impaired after restoring pooled SP to SLC-selected spermatozoa after thawing, independently of whether the SP came from a good or a bad freezer stallion, suggesting an inability of SP to repair stallion sperm cryoinjuries in the presence of an egg yolk-containing extender. Sperm binding affinity to the zona pellucida (ZP) of bovine oocytes was reduced after adding SP from good freezer stallions prior to cryopreservation. However, when SP was added after thawing, the mean number of bound spermatozoa was higher for the group treated with SP from good freezers than for the group treated with SP from bad freezers. Minor differences in protein composition were observed between seasons as well as between good and bad freezers. In the nonbreeding season there was a higher content of heparin-binding proteins and also of a subset of non-heparin binding proteins compared to the breeding season; these proteins may be linked to fertility. Sperm quality did not decline during the non-breeding season and SP-testosterone levels did not vary between seasons. Customization of the cryopreservation protocol for individual stallions, including studying the effect of adding SP from individual stallions, would be required to optimize the effect on sperm cryosurvival. Global proteome investigation of SP proteins could help to identify cryosurvival biomarkers for stallion spermatozoa.
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| 9. |
- Al-Essawe, Essraa M, et al.
(författare)
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Extenders for alpaca epididymal spermatozoa: Comparison of INRA96 and andromed
- 2020
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Ingår i: Animal Reproduction Science. - : Elsevier BV. - 0378-4320 .- 1873-2232. ; 223
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Tidskriftsartikel (refereegranskat)abstract
- Artificial insemination would be a useful technique for alpaca breeders to use as an aid to breeding to increase fleece quality. The technique, however, is not well developed in alpacas, partly because of the viscous nature of their seminal plasma. Castration conducted for husbandry purposes can provide a source of epididymal spermatozoa to test semen extenders or handling regimens, thus circumventing the problem of the viscous ejaculate. In this experiment, two semen extenders (Andromed and INRA96) developed for other species (bovine and equine, respectively) were tested with alpaca spermatozoa derived from the cauda epididymis. Sperm total motility (mean ± SEM A: 29.1 ± 4.8 % compared with I: 35.4 ± 4.8 %; NS), membrane integrity (A: 58 ± 9% compared with I: 56 ± 9%; NS) and acrosome integrity (A: 65 ± 7% compared with I: 54 ± 7%; NS) were not different between the two extenders. Progressive motility with use of INRA96 was greater after incubating for 30 min than after incubating for 10 min (35 ± 4% vs. 12 ± 4%, respectively; P = 0.03). In conclusion, viable epididymal spermatozoa could be extracted from the castrated organs after overnight transport. There were no differences in sperm quality between the two extenders; therefore, it appears that either extender could be used for alpaca spermatozoa. These results could help in the development of a technique for artificial insemination in alpacas.
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| 10. |
- Al-Essawe, Essraa M, et al.
(författare)
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Improved cryosurvival of stallion spermatozoa after colloid centrifugation is independent of the addition of seminal plasma
- 2018
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Ingår i: Cryobiology. - : Elsevier BV. - 0011-2240 .- 1090-2392. ; 81, s. 145-152
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Tidskriftsartikel (refereegranskat)abstract
- Addition of seminal plasma (SP) prior to cryopreservation may influence stallion sperm cryosurvival. The objective of this study was to investigate the addition of pooled SP from "good" or "bad" freezer stallions to spermatozoa selected by single layer centrifugation (SLC) prior to cryopreservation on post-thaw sperm quality. Semen from 12 stallions was collected; 5 mL was frozen as control (C) and the remainder was processed by SLC to remove SP and was divided into three aliquots: i) SLC sample without SP (SLC); ii) SLC plus pooled SP from "good freezer" stallions (SLC-GF); iii) SLC plus pooled SP from "bad freezer" stallions (SLC-BF). After thawing, the following parameters were evaluated: chromatin integrity (DNA fragmentation index; ßI), mitochondria) membrane potential (MMP), membrane integrity (MI), reactive oxygen species (ROS) and sperm kinematics. The ßI was reduced (P < 0.0001) in SLC samples compared to controls. The SLC group showed a lower proportion of spermatozoa with low MMP and a higher proportion of spermatozoa with high MMP than other groups (P < 0.0001), and had lower hydrogen peroxide content than control. Sperm kinematics were not different. In conclusion, selection by SLC prior to cryopreservation improved post-thaw sperm quality; inclusion of SP from "good" and "bad" freezer stallions did not have an additional beneficial effect.
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