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- Abraham, Maria Celina, et al.
(författare)
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Breed influences on in vitro development of abattoir-derived bovine oocytes
- 2012
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Ingår i: Acta Veterinaria Scandinavica. - : Springer Science and Business Media LLC. - 0044-605X .- 1751-0147. ; 54
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is a discrepancy in the reproductive performance between different cattle breeds. Using abattoir-derived ovaries and data base information we studied the effects of breed on in vitro fertilization and early embryo development. Methods: The in vitro developmental competence of oocytes from cattle (n = 202) of Swedish Red (SR), Swedish Holstein (SH) and mixed beef breeds was compared, retrospectively tracing donors of abattoir-derived ovaries using a combination of the national animal databases and abattoir information. Age was significantly lower and carcass conformation score was higher in the beef breeds than in the dairy breeds. Cumulus oocyte complexes (n = 1351) were aspirated from abattoir-derived ovaries from animals of known breed (visual inspection confirmed through databases), age (databases), and abattoir information. Oocytes were matured, fertilized (frozen semen from two dairy bulls) and cultured according to conventional protocols. On day 8, blastocysts were graded and the number of nuclei determined. Results: Cleavage rate was not different between the breeds but was significantly different between bulls. The percentage of blastocysts on day 8 was significantly higher when the oocyte donor's breed was beef or SR than SH. There was no significant difference in blastocyst grades or stages between the breeds, but the number of nuclei in day 8 blastocysts was significantly lower in SH compared to the beef. Conclusions: The use of abattoir-derived ovaries from animals whose background is traceable can be a valuable tool for research. Using this approach in the present study, oocyte donor breed was seen to affect early embryo development during in vitro embryo production, which may be a contributing factor to the declining fertility in some dairy breeds seen today.
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| 3. |
- Einarsson, Stig, et al.
(författare)
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A 25 years experience of group-housed sows-reproduction in animal welfare-friendly systems
- 2014
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Ingår i: Acta Veterinaria Scandinavica. - : Springer Science and Business Media LLC. - 0044-605X .- 1751-0147. ; 56
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Forskningsöversikt (refereegranskat)abstract
- Since January 1 2013, group housing of sows has been compulsory within the European Union (EU) in all pig holdings with more than ten sows. Sows and gilts need to be kept in groups from 4 weeks after service to 1 week before the expected time of farrowing (Article 3(4) of Directive 2008/120/EC on the protection of pigs). The legislation regarding group housing was adopted already in 2001 and a long transitional period was allowed to give member states and producers enough time for adaptation. Even so, group housing of sows still seems to be uncommon in the EU, and is also uncommon in commercial pig farming systems in the rest of the world. In this review we share our experience of the Swedish 25 years of animal welfare legislation stipulating that sows must be loose-housed which de facto means group housed. The two most important concerns related to reproductive function among group-housed sows are the occurrence of lactational oestrus when sows are group-housed during lactation, and the stress that is associated with group housing during mating and gestation. Field and clinical observations in non-lactating, group-housed sows in Sweden suggest that by making basic facts known about the pig reproductive physiology related to mating, we might achieve application of efficient batch-wise breeding without pharmacological interventions. Group housing of lactating sows has some production disadvantages and somewhat lower productivity would likely have to be expected. Recordings of behavioural indicators in different housing systems suggest a lower welfare level in stalled animals compared with group-housed ones. However, there are no consistent effects on the reproductive performance associated with different housing systems. Experimental studies suggest that the most sensitive period, regarding disturbance of reproductive functions by external stressors, is the time around oestrus. We conclude that by keeping sows according to the pig welfare-friendly Directive 2008/120/EC, it is possible to combine group-housing of sows with good reproductive performance and productivity. However, substantially increased research and development is needed to optimize these systems.
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| 5. |
- Gonzalez Herrero, Raquel, et al.
(författare)
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Characterization of Mitochondrial and Actin Patterns in Cat Oocytes and Blastocysts
- 2012
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Ingår i: Reproduction in Domestic Animals. - : Wiley. - 0936-6768 .- 1439-0531. ; 47, s. 118-120
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Tidskriftsartikel (refereegranskat)abstract
- Contents Actin microfilaments and mitochondria distribution are considered useful markers of cytoplasmic maturation, but no information is available regarding their distribution in cat oocytes and embryos. Thus, the purpose of this study was to (i) assess cytoplasmic characteristics of the oocyte by mitochondria and actin staining in immature and in vitro/in vivo matured cat oocytes and (ii) characterize mitochondria and actin distribution in in vitro produced blastocysts by confocal laser scanning microscopy. Additionally, in vivo matured oocytes were collected to assess mitochondria and actin. Transzonal cumulus cell projections were more abundant in immature oocytes than in matured oocytes. A relocation of mitochondria throughout meiosis was not clearly observed. However, most in vitro produced blastocysts were of good quality, according to their actin cytoskeleton integrity and mitochondria distribution. The functional significance of mitochondria distribution in cat oocytes in relation to their developmental competence requires further research. This study represents the original description of actin and mitochondrial patterns in cat oocytes and embryos.
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| 6. |
- Gonzalez Herrero, Raquel, et al.
(författare)
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Effect of blood plasma collected after adrenocorticotropic hormone administration during the preovulatory period in the sow on oocyte in vitro maturation
- 2013
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Ingår i: Theriogenology. - : Elsevier BV. - 0093-691X .- 1879-3231. ; 80, s. 673-683
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Tidskriftsartikel (refereegranskat)abstract
- Reproduction may be affected by stressful events changing the female endocrine or metabolic profile. An altered environment during oocyte development could influence the delicate process of oocyte maturation. Here, the effect of simulated stress by media supplementation with blood plasma from sows after adrenocorticotropic hormone (ACTH) administration during the preovulatory period was assessed. Oocytes were matured for 46 hours in the presence of plasma from ACTH-treated sows, or plasma from NaCl-treated control sows, or medium without plasma (BSA group). The plasma used had been collected at 36 and 12 hours (+/- 2 hours) before ovulation (for the first 24 hours + last 22 hours of maturation, respectively). Subsequent fertilization and embryo development were evaluated. Actin cytoskeleton and mitochondrial patterns were studied by confocal microscopy both in the oocytes and the resulting blastocysts. Nuclear maturation did not differ between treatments. Subtle differences were observed in the actin microfilaments in oocytes; however, mitochondrial patterns were associated with the treatment (P < 0.001). These differences in mitochondrial patterns were not reflected by in vitro outcomes, which were similar in all groups. In conclusion, an altered hormonal environment provided by a brief exposure to plasma from ACTH-treated sows during in vitro oocyte maturation could induce alterations in actin cytoskeleton and mitochondria( patterns in oocytes. However, these changes might not hamper the subsequent in vitro embryo development. (C) 2013 Elsevier Inc. All rights reserved.
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