| 1. |
- Ballester, J., et al.
(författare)
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Post-thaw viability of bull AI-doses with low-sperm numbers
- 2007
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Ingår i: Theriogenology. - : Elsevier. - 0093-691X .- 1879-3231. ; 68:6, s. 934-943
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Tidskriftsartikel (refereegranskat)abstract
- Use of AI-doses containing low-sperm numbers are increasingly been used to optimise use of elite bulls as well as to accommodate an eventual wider application of sex-sorted semen. Since spermatozoa might, however, suffer from high extension rates, thus compromising fertility, this study evaluated the post-thaw sperm quality of semen from commercial progeny-tested, high-ranked AI-sires whose semen was within acceptable limits of normality, frozen in a split-design to 15 (control, 15M) or 2 x 106 total spermatozoa (treatment, 2M) per straw. Assessment post-thaw included computer-evaluated sperm motility (CASA), membrane integrity (SYBR-14/PI), membrane stability (Annexin-V/Pl), acrosome integrity (Carboxy-SNARF-1/PI/ FITC-PSA), and chromatin integrity (AO of in situ acid-induced DNA denaturation). High extension did not affect the proportions of linearly motile spermatozoa, of membrane integrity or stability nor chromatin integrity, immediately post-thaw. However, high extension clearly affected linear sperm motility following incubation at 38 degrees C for 30 min, sperm viability when assessed by SNARF and, particularly, acrosome integrity of the otherwise viable spermatozoa. Individual sire variation was evident. Fertility was preliminarily evaluated for one of the less affected bulls in a blind field trial. A total of 109 dairy cows were randomly inseminated with 15M or 2M-straws without differences in pregnancy rate between them (47% versus 43%). This similarity in fertility rates, confirmed the in vitro methods used were appropriate for identifying cryosurvival and further suggested the site of sperm deposition was not crucial for the fertility of low-sperm AI-numbers for this particular sire. However, the inter-bull variation seen calls for caution when cryopreserving low concentrations of bull spermatozoa with conventional freezing protocols. (C) 2007 Elsevier Inc. All rights reserved.
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| 2. |
- Bergqvist, A.-S., et al.
(författare)
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Heparin and dermatan sulphate induced capacitation of frozen-thawed bull spermatozoa measured by merocyanine-540
- 2007
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Ingår i: Zygote (Cambridge. Print). - : Cambridge University Press (CUP). - 0967-1994 .- 1469-8730. ; 15:3, s. 225-232
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Tidskriftsartikel (refereegranskat)abstract
- Glycosaminoglycans (GAGs) are present in the oviduct in which the major part of sperm capacitation occurs. In this study we have tested how capacitation of frozen-thawed bull spermatozoa is effected by exposure to different GAGs detectable or possibly present in oviductal fluid; i.e. heparin, hyaluronan, heparan sulphate, dermatan sulphate and chondroitin sulphate. Following exposure of different duration, the spermatozoa were stained with either Chlortetracycline (CTC) or merocyanine-540 and evaluated with epifluorescent light microscopy or flow cytometry, respectively. Heparin elicited a significant increase in the number of alive, capacitated spermatozoa, either expressed as higher merocyanine-540 fluorescence (p less than 0.0001) or as B-pattern (p = 0.0021) in the CTC assay, during 4 h of incubation. When comparing the different GAG treatments one by one to the negative control in the flow cytometric study, only heparin and dermatan sulphate were significant (p less than 0.0001) higher than the control at 0-30 min of incubation. Duration of incubation did not affect the proportion of capacitated spermatozoa when measured as merocyanine-540 fluorescence or CTC B-pattern, but the length of the incubation did affect the number of dead (Yo-PRO 1 positive) spermatozoa (p less than 0.0001). Exposure to zona pellucida proteins significantly increased the proportion of acrosome reacted spermatozoa (p = 0.016). Both heparin and dermatan sulphate induce capacitation of frozen-thawed bull spermatozoa in vitro.
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| 3. |
- Bierla, Joanna B., et al.
(författare)
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Sperm morphology of the Eurasian beaver, Castor fiber: An example of a species of rodent with highly derived and pleiomorphic sperm populations
- 2007
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Ingår i: Journal of morphology. - : Wiley-Blackwell. - 0362-2525 .- 1097-4687. ; 268:8, s. 683-689
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Tidskriftsartikel (refereegranskat)abstract
- The structural organization of the spermatozoon from the Eurasian beaver, Castor fiber (Family: Castoridae), was determined and compared to that of other sciuromorph rodents. The beaver spermatozoon has a head, which is variable in form but usually paddle-shaped, with a small nucleus and very large acrosome, and a tail that is relatively short compared to that of most other rodents. Transmission electron microscopy indicates that in most testicular spermatozoa the acrosome projects apically, although in a few it becomes partly flexed. During the final stages of maturation, however, the acrosome becomes highly folded so that the apical segment comes to lie alongside part of the acrosome that occurs lateral to the nucleus, with, in some cases, fusion taking place between the outer acrosomal membranes. The sperm nucleus is wedge-shaped, being broader basally and narrowing apically with an occasional large nuclear vacuole occurring. This spermatozoon structure is markedly different from that found in the other species of Geomyoidea, which is the sister group of the Castoridae. The findings thus emphasize the highly divergent nature of the beaver spermatozoon and demonstrate that, within the proposed Infraorder Castorimorpha, very large differences in sperm structure have evolved.
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| 4. |
- Brandt, Y., et al.
(författare)
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Effects of ACTH injections during estrus on concentrations and patterns of progesterone, estradiol, LH, and inhibin alpha and time of ovulation in the sow
- 2007
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Ingår i: Domestic Animal Endocrinology. - : Elsevier. - 0739-7240 .- 1879-0054. ; 32:2, s. 122-137
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated whether injections of ACTH for 48 h, from the onset of the second standing estrus after weaning, had any impact on time of ovulation and patterns of progesterone, estradiol, luteinizing hormone (LH), and inhibin a. The studied sows (n = 15) were fitted with jugular vein catheters and randomly divided into a control (C group) and an ACTH group. From the onset of standing estrus, the sows were injected (NaCl or synthetic ACTH, 5 mu g/kg) every 4 h; blood samples were collected immediately before and 45 min after each injection. Ovulation was monitored using ultrasonography. The ACTH-group sows stopped displaying signs of standing estrus sooner after ovulation in their second estrus, but no impact was found on time of ovulation. There were no significant differences in the intervals between LH peak, estradiol peak, and the onset of standing estrus between the C and ACTH groups. The cortisol and progesterone concentrations were significantly elevated (p less than 0.001) in samples taken 45 min after ACTH injection. There were minor differences in estradiol and LH concentrations between the groups. Overall inhibin a concentrations were significantly higher during the treatment period in the ACTH than in the C group, but there were no significant differences between samples taken either 45 min or 4h after injection. In conclusion, injections of synthetic ACTH during estrus in the sow apparently disturb the duration of signs of standing estrus and the hormonal pattern of progesterone, and possibly of inhibin ot, estradiol and LH. (c) 2006 Elsevier Inc. All rights reserved.
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| 5. |
- Brandt, Y., et al.
(författare)
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Effects of exogenous ACTH during oestrus on early embryo development and oviductal transport in the sow
- 2007
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Ingår i: Reproduction in domestic animals. - : Wiley-Blackwell. - 0936-6768 .- 1439-0531. ; 42:2, s. 118-125
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Tidskriftsartikel (refereegranskat)abstract
- This study was conducted to assess the effects of ACTH injections on the early development of embryos and their transportation to the uterus. Fifteen sows were monitored for ovulation using transrectal ultrasonography during the first two oestrous periods after weaning. The sows were randomly divided into a control group (C group, n = 8) and an ACTH-treated group (ACTH group, n = 7), and were all surgically fitted with intra-jugular catheters. From the onset of the second standing oestrus after weaning, the sows were injected (NaCl/synthetic ACTH) every 4 h. Blood samples were collected immediately before and 45 min after each injection. All sows were inseminated once 10-33 h before ovulation in their second oestrus after weaning. At 48 (n = 4) or 60 (n = 11) h after ovulation during their second oestrus, the sows were killed and the embryos retrieved from the oviduct and uterus. The embryos were counted and compared with the number of corpora lutea, cleavage rate was noted and, finally, the embryos were prepared for confocal laser scanning microscopy and transmission electron microscopy. There was no difference between the groups regarding cleavage rate, the cytoskeleton, or the number of active nucleoli. However, the ACTH group had significantly (p less than 0.05) fewer ova/embryos retrieved (51%) than the C group (81%), and there was a tendency towards faster transportation to the uterus in the ACTH group, possibly because of high progesterone concentrations during treatment. To conclude, administration of ACTH every 4 h from onset of oestrus to 48 h caused significant loss of oocytes or embryos, and possibly faster transportation through the oviduct.
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| 6. |
- Cuello, C., et al.
(författare)
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Vitrification of in vitro cultured porcine two-to-four cell embryos
- 2007
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Ingår i: Theriogenology. - : Elsevier. - 0093-691X .- 1879-3231. ; 68:2, s. 258-264
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this experiment was to evaluate the effect of a 5-day period of in vitro culture of two-to-four cell porcine embryos up to the blastocyst stage on their ability to survive vitrification and warming. In order to increase the cooling rate, superfine open pulled straws and Vit-Master (R) technology were used for vitrification. Two-to-four cell embryos were collected from weaned sows (n = 11) on day 2 (DO = onset of estrus). Some embryos (N = 63) were vitrified within 3 It after collection, warmed and cultured for 120 h (Group V2). Additionally, 81 two-to-four cell embryos were cultured for 96 It in order to obtain blastocysts; these were then vitrified, warmed and cultured for 24 h (Group VB; N = 65). The remaining two-to-four cell embryos were used as controls and thus not vitrified (control embryos; N = 70) but were cultured in vitro for 120 h. The V2, VB and control embryos were evaluated for their developmental progression and morphology during culture. All embryos (V2, VB and controls) were fixed on the same day of development in order to assess the total number of blastomeres. The survival and blastocyst formation rates obtained from V2 embryos were very poor (9.6 +/- 0.7% and 3.2 +/- 0.5%, respectively). The survival and hatching rates of VB embryos (75.0 +/- 0.69% and 33.6 +/- 0.13%) were lower (p less than 0.001) than those obtained with control embryos (89.1 +/- 0.8% and 47.5 +/- 0.12%). Hatched VB embryos had a lower (p less than 0.01) total cell number than hatched control embryos (70.3 +/- 4.5 versus 90.6 +/- 3.2, respectively). There was no difference between expanded VB and control blastocysts. In conclusion, blastocysts derived from in vitro culture of two-to-four cell pig embryos could be successfully vitrified using SOPS straws and Vit-Master (R). (c) 2007 Elsevier Inc. All rights reserved.
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| 7. |
- Ekwall, Hans, et al.
(författare)
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Cryo-scanning electron microscopy (Cryo-SEM) of boar semen frozen in medium-straws and MiniFlatPacks
- 2007
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Ingår i: Theriogenology. - : Elsevier. - 0093-691X .- 1879-3231. ; 67:9, s. 1463-1472
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Tidskriftsartikel (refereegranskat)abstract
- In this study we demonstrate, in the frozen state, the architecture of frozen boar spermatozoa collected from the sperm-rich fraction of ejaculates (n = 13) from four fertile boars packed and split-frozen in medium-straws (MS) and MiniFlatPacks (MFP), cross-sectioned in the frozen state and evaluated by image analysis on images obtained by use of cryo-scanning electron microscopy (Cryo-SEM). The tested hypothesis was that the degree of in situ dehydration and levels of homogeneity of boar semen either frozen in MSs or MFPs packages differ between them, with MFPs allowing for a more uniform dehydration of the spermatozoa and a higher cryosurvival, monitored by computer assisted sperm analysis (CASA) as proportion of linearly motile spermatozoa, compared to semen packaged and processed in MSs. The organization and relative surface of biological material (veins; e.g., frozen extender, bound water, solutes and spermatozoa) as well as free water (lakes) was measured as the degree of dehydration of the samples. The apparent organization of lakes and veins differed between packages, with the MFPs depicting larger lakes than the MSs. The sizes of the lakes in the latter appeared, moreover, highly asymmetrical depending on their position of the section. The relative surface of these lakes per section, respectively veins differed between packages (P less than 0.05), indicating a larger amount of free-water (lakes; 81.73 +/- 2.07% vs. 77.91 +/- 1.57%) in the MFPs and, consequently, thinner veins than in MSs. In conclusion, MFPs seem to allow for a more homogenous dehydration of the spermatozoa/frozen extender compared to MSs, which might account for their somewhat better sperm quality post-thaw. (C) 2007 Elsevier Inc. All rights reserved.
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| 8. |
- Hernandez, Marta, et al.
(författare)
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Cryo-scanning electron microscopy (Cryo-SEM) of semen frozen in medium-straws from good and sub-standard freezer AI-boars
- 2007
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Ingår i: Cryobiology. - : Elsevier. - 0011-2240 .- 1090-2392. ; 54:1, s. 63-70
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Tidskriftsartikel (refereegranskat)abstract
- A major limiting factor for commercial cryopreservation of boar semen for artificial insemination (AI) is the large individual variation to cooling, where the degree of cell dehydration during ice (re)shaping seems to play a major role. This study investigated, in the frozen state, the degree of dehydration and ice crystal distribution in boar semen doses whose spermatozoa displayed different viability after thawing. Cross-sectioned medium-straws (0.5 mL, n = 10) from a total of 10 stud boars classified as "good" (n = 5) or sub-standard (e.g., "bad" freezers, n = 5) by conventional analyses (computer assisted motility and sperm viability) were examined by Cryo-scanning electron microscopy (Cryo-SEM) to determine whether differences between groups could be already distinguishable prior to thawing. The degree of hydration was monitored in relation to the areas of ice crystal formed extracellularly (lakes), the areas of frozen, concentrated extender (veins) where spermatozoa were located and the degree of compartmentalization (number of lakes) present. Irrespectively of the region studied, the gradient of main dehydration (as lakes) observed along the cross-section area of the straws was very irregular. Most spermatozoa were enclosed in the freezing extender matrix and no obvious signs of external membrane damage were observed. None of the Cryo-SEM variables significantly correlated with post-thaw sperm parameters (p greater than 0.05). However, we identified significant differences (p less than 0.0001) among boars for all ultrastructure variables studied, including the size of the veins, where differences in solute concentration is expected. We concluded that despite the large variability in ice crystal formation during the conventional freezing process among boars, this is unrelated to inter-boar post-thaw sperm differences. (c) 2007 Elsevier Inc. All rights reserved.
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| 9. |
- Koonjaenak, S., et al.
(författare)
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Assessment of semen quality in Swamp Buffalo AI Bulls in Thailand
- 2007
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Ingår i: Italian Journal of Animal Science. - : PAGEpress / PAGEPress Publications. - 1594-4077 .- 1828-051X. ; 6, s. 701-704
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Tidskriftsartikel (refereegranskat)abstract
- Characteristic of Thai swamp buffalo bulls semen used for artificial insemination (AI) in Thailand, aspects relevance in freezing and thawing of semen are review. Semen and sperm characteristics were evaluated included sperm count, motility (assessed subjectively and by CASA), morphology (using phase-contrast light microscopy and SEM), plasma membrane integrity (PMI) (using a hypo-osmotic swelling test [HOST]) and SYBR-14/propidium iodide [PI]), plasma membrane stability (PMS) (using Annexin-V/PI) and deoxyribonucleic acid (DNA) integrity (using SCSA and flow cytometry [FCM]). The average ejaculate volume was about 3.0-4.0 mL, with good viability (PMI measured by the HOST) and motility (greater than65% and greater than70%, respectively). Sperm concentration ranged from 1.1 to 1.2 billion/mL, being also affected by bull age. Whereas semen quality (including sperm output, pH and initial sperm motility) did not differ between the seasons. Few spermatozoa (less than15%/ejaculate) had abnormal morphology with abnormalities resembling those in other bovidae. In FT semen, PMI (using SYBR-14/PI) and PMS were highest in winter. Across seasons, similar to 50% of post-thaw spermatozoa depicted linear motility, a proportion that decreased to similar to 35% during incubation (38 degrees C for 60 minutes), without marking any seasonal difference. The sperm DNA was hardly damaged (with less than3% fragmentation, expressed as DNA fragmentation index [DFI]), among seasons.
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| 10. |
- Koonjaenak, S., et al.
(författare)
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Morphological features of spermatozoa of swamp buffalo ai bulls, inThailand
- 2007
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Ingår i: Journal of Veterinary Medicine A. - : Wiley-Blackwell. - 0931-184X .- 1439-0442. ; 54:4, s. 169-178
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Tidskriftsartikel (refereegranskat)abstract
- The appearance and incidence of sperm abnormalities was studied in 115 ejaculates, collected periodically over I year covering all seasons from five mature, healthy swamp buffalo (Bubalus bubalis) bulls reared under tropical conditions and serving as the current source of semen for artificial insemination (Al) in Thailand. Light microscopy of stained smears was used to investigate sperm head shape morphology, while unstained wet smears were used to examine other sperm abnormalities. The most commonly found morphological aberrations were pear-shaped spermatozoa, knobbed acrosomes, proximal cytoplasmic droplets, simple bent tails and coiled tails under the head, whose ultrastructure (scanning electron microscopy) corresponded to what has been found in other species of bovidae, including varieties of buffalo. The mean prevalence (as least squares mean SEM) of sperm abnormalities was low (below 15%), corresponding to healthy spermiograms. The younger bulls (less than 10 years old, n = 3) had less abnormalities than the older ones (10.1 +/- 0.6% versus 14.1 +/- 0.8%, P less than 0.001, n = 2), including abnormalities of sperm head shape (1.1 +/- 0.3% versus 3.6 +/- 0.3, P less than 0.001), acrosome defects with knobbed acrosomes (1.1 +/- 0.2% versus 1.2 +/- 0.3%, P less than 0.001), spermatozoa with proximal cytoplasmic droplets (2.7 +/- 0.1 % versus 1.4 +/- 0.2%, P less than 0.00 1), defective mid-pieces (0.2 +/- 0.1% versus 0.3 +/- 0.1%) and abnormal sperm tails (3.1 +/- 0.3% versus 5.7 +/- 0.4%, P less than 0.001). The within-bull effect of the year solely affected the incidence of pear-shaped spermatozoa while the incidences of abnormal contour, variable size of sperm head shapes, abnormal mid-piece and simple bent tail among bulls were affected by ejaculate (week of collection). Interaction between age and ejaculate affected only the prevalence of spermatozoa with proximal cytoplasmic droplets. In conclusion, the types of defects encountered were similar to those found in other bovidae, with a very low prevalence over the year the Al sires were followed through.
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