| 1. |
- Einarsson, S., et al.
(författare)
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Short- and long-term effects of immunization against gonadotropin-releasing hormone, using Improvac (TM), on sexual maturity, reproductive organs and sperm morphology in male pigs
- 2009
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Ingår i: Theriogenology. - : Elsevier. - 0093-691X .- 1879-3231. ; 71:2, s. 302-310
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to determine the short and long term effects of a gonadotropin-releasing hormone (GnRH) vaccine (Improvac (TM) Pfizer Ltd.), on sexual maturity, development of the reproductive organs, and the morphology of caudal epididymal spermatozoa in non-castrated male pigs. The pigs were slaughtered 4, 16 or 22 weeks after the second Improvac (TM) vaccination. A total of 80 crossbred non-castrated male pigs were included in this study comprising two experiments, a short-effect (Experiment 1) and a long-effect (Experiment 2). The first experiment included 56 pigs, 24 of them were maintained as controls and 32 were vaccinated twice, and slaughtered 4 weeks after the second vaccination. The second experiment included 24 pigs, 12 controls and 12 vaccinated twice, and slaughtered either 16 weeks (n = 6) or 22 weeks (n = 6) after the second vaccination. None of the immunized pigs was sexually mature at slaughter, i.e. 4, 16 or 22 weeks after second vaccination. Corresponding results of the control pigs showed that 50% had reached sexual maturity at the age corresponding to 4 weeks after the second vaccination. and 100% at slaughter 16, respectively, 22 weeks after vaccination. At 4, 16 and 22 weeks after second vaccination both testes weight and bulbourethral length were significantly reduced (p less than 0.001). The percentages of proximal droplets and abnormal heads were significantly lower in the control pigs than in the immunized pigs at slaughter 4 weeks after vaccination, whereas distal droplets were higher. For the other morphological parameters no significant differences were seen, but all mean values except for acrosome defects were numerically lower in the control pigs compared with the immunized pigs. For pigs slaughtered 16 or 22 weeks after vaccination, the vaccination effect was significant for percentages of proximal droplets, distal droplets, acrosome defects, acrosome abnormality and abnormal heads (p = 0.017-0.001). The immunization clearly disrupted the number and morphology of the interstitial Leydig cells, lasting throughout the study period (4-22 weeks after vaccination). Spermatogenesis was also clearly affected in the immunized pigs, to various degrees, from mild disruption (spermatocyte loss, decrease of the normal number of layers of germ cells) to severe loss of germ cells including tubuli with Sertoli cells-only (complete disappearance of germ cells), also covering the entire study period. The results indicated that the effect of immunization persisted for at least 22 weeks after the second vaccination. (c) 2009 Elsevier Inc. All rights reserved.
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| 2. |
- Macias Garcia, B., et al.
(författare)
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Single-Layer Centrifugation Through Colloid Positively Modifies the Sperm Subpopulation Structure of Frozen-Thawed Stallion Spermatozoa
- 2009
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Ingår i: Reproduction in domestic animals. - : Wiley-Blackwell. - 0936-6768 .- 1439-0531. ; 44:3, s. 523-526
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Tidskriftsartikel (refereegranskat)abstract
- The present study attempted to select the subpopulation of stallion spermatozoa that best survived a conventional freezing and thawing procedure, using centrifugation of post-thawed semen samples through a single layer of a glycidoxypropyltrimethoxysilane-coated silica colloid with a species-specific formulation (Androcoll-E (TM)). After freezing and thawing, four sperm subpopulations were identified, listed as FT1 to FT4. While subpopulations FT1 and FT2 were characterized by low sperm velocity, high velocities characterized the ones called FT3 and FT4. The single-layer centrifugation (SLC)-handled sperm sample was enriched in subpopulation FT3, reaching a proportion of 82.6% of the present spermatozoa, in contrast with the non-filtered control post-thawed semen, where this sperm subpopulation only accounted for 16.3% of the total. It is concluded that in the equine industry, the SLC is a practical, easy-to-perform approach to improve the quality of equine frozen-thawed semen samples.
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| 3. |
- Thys, M., et al.
(författare)
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In vitro Fertilizing Capacity of Frozen-thawed Bull Spermatozoa Selected by Single-layer (Glycidoxypropyltrimethoxysilane) Silane-coated Silica Colloidal Centrifugation
- 2009
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Ingår i: Reproduction in domestic animals. - : Wiley-Blackwell. - 0936-6768 .- 1439-0531. ; 44:3, s. 390-394
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Tidskriftsartikel (refereegranskat)abstract
- Barriers to the use of density gradient centrifugation for preparing animal spermatozoa for artificial insemination (AI) include the scarcity of animal-specific formulations and the daunting prospect of processing large volumes of ejaculate in small aliquots (1.5 ml extended semen). Recently, new colloid formulations have been tested in vitro in a modified procedure, centrifugation on a single layer of colloid. The present study investigated the fertilizing ability during in vitro fertilization (IVF) of frozen-thawed bovine spermatozoa following centrifugation through a single layer of glycerolpropylsilane (GS)-coated silica colloid with a species-specific formulation (patent applied for; treatment, T). Controls (C) included centrifugation through gradients of either the same colloid (C1) or Percoll (TM) (C2). Sperm recovery surpassed 50% for both C1-C2 and T (n.s.). Mean values of various parameters of computerized analysis of sperm motility did not differ between T and C1 (n.s.), and only the proportions of path straightness and linearity were lower in T vs C2 (p less than 0.05). In T, the mean (+/- SD) percentages of fertilization rate, blastocyst development rate and the total number of blastomeres were 58.1 +/- 23.3%, 24.5 +/- 14.3% and 94.6 +/- 23.4%, respectively. The proportions did not differ significantly from controls (C1/C2). Therefore, centrifugation through a single layer of colloid offers an alternative method to density gradient centrifugation for selection of viable, potentially fertile frozen-thawed bull spermatozoa. This single-layer technique is gentle, versatile and convenient because it facilitates scaling-up the process of sperm preparation to allow larger numbers of spermatozoa (for instance, whole ejaculates) to be processed for AI.
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| 4. |
- Awasthi, H., et al.
(författare)
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Do Cytoplasmic Lipid Droplets Accumulate in Immature Oocytes from Over-Conditioned Repeat Breeder Dairy Heifers?
- 2010
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Ingår i: Reproduction in domestic animals. - : Wiley-Blackwell. - 0936-6768 .- 1439-0531. ; 45:5, s. E194-E198
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Tidskriftsartikel (refereegranskat)abstract
- One of the main sources of repeat breeding in dairy cattle, caused by fertilization failure or early embryonic death, is metabolic stress during lactation. Nutrition seems also to play a role when the condition is seen in heifers, where oocyte cytoplasmic maturation is impaired. To determine whether over conditioning affects oocyte morphology, immature oocytes were collected by ovum pick-up (OPU) twice weekly during 5 weeks from three over-conditioned repeat breeder dairy heifers (RBH) and two normal virgin heifers (VH, controls) of the Swedish Red breed, monitored by body weight and condition. Oocyte quality was assessed under stereomicroscope and further examined by transmission electron microscope for accumulation of cytoplasmic lipid deposits. After OPU, the RBH yielded more low quality oocytes (60% vs 52% for VH, p = 0.14). The relative occupancy of osmophilic lipid droplets in the cytoplasm was higher in oocytes of bad quality compared with good ones, especially in RBH (p = 0.08) but also in VH (p = 0.11). Moreover, the oocytes from over-conditioned RBH showed higher amounts of cytoplasmic lipid deposits both in good (p = 0.14) and, even more prominent, in bad quality oocytes (p = 0.06). Such accumulation of lipid droplets may imply increased sensitivity to oxidative stress, hinder cytoplasmic maturation and lead to subfertility, as accounted in over-conditioned repeat breeders of the Swedish Red breed.
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| 5. |
- Bolarin, A., et al.
(författare)
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Use of frozen-thawed semen aggravates the summer-autumn infertility of artificially inseminated weaned sows in the Mediterranean region
- 2009
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Ingår i: Journal of Animal Science. - : American Society of Animal Science. - 0021-8812 .- 1525-3163. ; 87:12, s. 3967-3975
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Tidskriftsartikel (refereegranskat)abstract
- Improvement of farrowing rate (FR) and litter size (LS) of sows that are AI with frozen-thawed (FT) semen can hardly be reached without identification of the factors behind the high variability seen among trials. Three experiments using weaned (4-d wean-to-estrus interval) multiparous (parity 2 to 7) sows were conducted to evaluate the effect of period of the year on FR and LS of FT-inseminated sows in southern Spain. Sows were grouped into 2 periods of the year: winter-spring (November to April; WS) and summer-autumn (May to October; SA). Ovarian status was monitored by transrectal ultrasonography to record how long before or after ovulation AI was performed (pre-, peri-, or postovulatory AI) and to determine the onset of estrus-to-ovulation interval (EOI). Inseminations were performed using deep intrauterine AI with 1.5 x 109 FT sperm per dose. The first experiment was designed to determine the influence of the period of the year on FR and LS of FT semen. Sows (116 in WS and 100 in SA) were AI at 33 and 39 h after the onset of estrus. The period of the year influenced the FR and LS (P less than 0.01). Farrowing rate and LS were least in SA (P less than 0.05). This pattern of annual variation was similar to that shown by sows on the same farm currently undergoing AI with liquid semen (cervical AI at 12 and 36 h after the onset of estrus with 3 x 109 sperm per dose). However, the FR reduction in SA respect to WS was more substantial in sows artificially inseminated with FT (77.6 vs. 50%, P less than 0.001) than those artificially inseminated with liquid semen (83.9 vs. 71.8%, P less than 0.05). More pre- and less periovulatory AI were performed in SA sows than in WS sows (P = 0.05). Experiment 2 was designed to evaluate whether the period of the year influenced EOI. Ovarian status was transrectal ultrasonography scanned every 6 h after the onset of estrus until the end of ovulation (WS: 30; SA: 31 sows). There were more sows with long EOI (greater than48 h) in SA than in WS (P = 0.05). Experiment 3 aimed to improve the reduced FR and LS recorded in SA sows when using FT semen (Exp. 1) by inducing ovulation with eCG + hCG. A single AI with FT semen was performed 5 h before the expected ovulation (55 sows). As a control, spontaneously ovulating sows (n = 53) were FT-inseminated as in Exp. 1. Hormonal induction of ovulation did not improve FR and LS (P greater than 0.05). In the Spanish Mediterranean area, a longer EOI during SA negatively influenced the FR and LS of weaned sows after AI. This effect was particularly evident when FT semen was used. These findings were not ameliorated by hormonal induction of ovulation.
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| 6. |
- Brandt, Y., et al.
(författare)
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Effects of continuous elevated cortisol concentrations during oestrus on concentrations and patterns of progesterone, oestradiol and LH in the sow
- 2009
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Ingår i: Animal Reproduction Science. - : Elsevier Masson. - 0378-4320 .- 1873-2232. ; 110:1-2, s. 172-185
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the effect of continuous elevated cortisol concentrations during standing oestrus on time of ovulation and patterns Of progesterone. oestradiol and luteinising, hormone (LH) in sows. The elevation of cortisol concentrations was achieved through repeated intravenous injections of synthetic adrenocorticotropic hormone (ACTH) every 2 It for approximately 48 h, from the onset of the second standing oestrus alter weaning. Treatment was terminated when ovulation was detected (monitored by transrectal ultrasonography every 4h) or when (lie sow had received a maximum of 24 injections. The close of ACTH (2.5 mu g/kg) was chosen to mimic the cortisol concentrations seen during mixing of unfamiliar SOWS. The sows (n = 14) Were surgically fitted with jugular vein catheters and randomly divided into a control (C group) where only NaCl solution were injected) or an ACTH group. Blood samples were collected every 2 h. In parallel with the blood sampling, saliva samples for cortisol analyses were taken from eight sows before onset of treatment and from four of the sows during treatment. There was no difference in time from onset of standing, oestrus to ovulation between the two groups. The interval between the peaks of oestradiol and LH to ovulation was prolonged in the ACTH group compared to the C group (p less than 0.05). with a tendency towards all earlier decline of oestradiol in the ACTH group. Cortisol and progesterone Concentrations were significantly elevated during treatment in the ACTH group (p less than 0.001). with cortisol peak concentrations occurring between 40 and 80 min after each ACTH injection. Cortisol concentrations in saliva and Plasma were highly correlated (p less than 0.001). In conclusion, elevated cortisol concentrations from the onset of standing oestrus increase progesterone concentrations and prolong the interval between oestradiol and LH peaks to ovulation, the latter possible due to an early decline in oestradiol concentrations and a change of the LH peak outline. the effect these hormonal changes have on reproductive performance need to be further investigated. (C) 2008 Elsevier B.V. All rights reserved.
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| 7. |
- Buranaamnuay, K., et al.
(författare)
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Effects of Straw Volume and Equex-STM (R) on Boar Sperm Quality after Cryopreservation
- 2009
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Ingår i: Reproduction in domestic animals. - : Wiley-Blackwell. - 0936-6768 .- 1439-0531. ; 44:1, s. 69-73
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Tidskriftsartikel (refereegranskat)abstract
- The present experiments were designed to study the effect of adding the detergent Equex-STM (R) to freezing extender, and of straw volume (0.25 ml vs 0.5 ml), on boar sperm quality after cryopreservation. Three ejaculates from each of four purebred boars (three Landrace and one Yorkshire) were collected and frozen with a lactose-egg yolk extender containing glycerol with or without 1.5% Equex-STM (R). The extended semen was loaded into either 0.25- or 0.5-ml straws. The straws were placed in liquid nitrogen (LN2) vapour approximately 3 cm above the level of LN2 for 20 min and then were plunged into LN2. Thawing was achieved in warm water at 50 degrees C for 12 s and then was incubated in a 38 degrees C water-bath for 30 min before evaluating sperm quality. Results showed that the individual motility, viability and acrosomal normal apical ridge (NAR) were improved (p less than 0.001) when Equex-STM (R) was added to the freezing extender. There was no difference (p = 0.48) in sperm motility between 0.25- and 0.5-ml straws when Equex-STM (R) was added. The percentages of viable and of NAR sperm in 0.5-ml straws were higher than those in 0.25-ml straws (p = 0.02, p = 0.0003 respectively). The percentages of membrane intact sperm evaluated using the short hypo-osmotic swelling test were not affected by straw volume or the adding of Equex-STM (R) (p greater than 0.05). The results of these investigations suggested that Equex-STM (R) exerts a beneficial effect on the quality of cryopreserved boar semen and this cryopreservation protocol was favourable for a 0.5-ml straw.
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| 8. |
- Cuello, C., et al.
(författare)
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Superfine open pulled straws vitrification of porcine blastocysts does not require pretreatment with cytochalasin B and/or centrifugation
- 2010
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Ingår i: Reproduction, Fertility and Development. - : CSIRO Publishing. - 1031-3613 .- 1448-5990. ; 22:5, s. 808-817
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigated the in vitro development of and cytoskeletal disruption suffered by in vivo-derived porcine blastocysts subjected to superfine open pulled straws (SOPS) vitrification. Blastocysts were either untreated prior to SOPS vitrification or were subjected to one of the following three pretreatment protocols: (1) centrifugation (12 min, 13 000g); (2) 25 min equilibration with 7.5 mu g mL(-1) cytochalasin B; or (3) equilibration with cytochalasin B followed by centrifugation. After 24 h culture, fresh (n = 32) and vitrified-warmed (n = 188) blastocysts were evaluated by stereomicroscopy, with survival and hatching rates recorded. Some blastocysts were stained with 4,6-diamidino2- phenylindole and processed for cytoskeletal evaluation. Three cytoskeletal patterns were identified: Grade I, intact cytoskeleton; Grade II, gross maintenance of integrity, but with some clumps of actin within the cytoplasm; and Grade III, a highly disrupted cytoskeleton. There were no differences in the survival, hatching and cell death rats, total cell number or cytoskeletal integrity between the different vitrification groups. Cell death was greater for vitrified blastocysts than for fresh blastocysts (3.6 +/- 0.4% v. 0.4 +/- 0.7%, respectively; P less than 0.05) and the percentage of blastocysts with a Grade I cytoskeletal pattern was lower for vitrified compared with fresh blastocysts (60.8% v. 92%, respectively; P less than 0.05). The vitrified-warmed blastocysts that hatched during culture exhibited a Grade I cytoskeletal pattern. In conclusion, successful SOPS vitrification of porcine blastocysts does not require pretreatment with cytochalasin B and/or centrifugation.
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| 9. |
- Johannisson, Anders, et al.
(författare)
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Colloidal centrifugation with Androcoll-E (TM) prolongs stallion sperm motility, viability and chromatin integrity
- 2009
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Ingår i: Animal Reproduction Science. - : Elsevier Masson. - 0378-4320 .- 1873-2232. ; 116:1-2, s. 119-128
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Forskningsöversikt (refereegranskat)abstract
- The objective was to investigate the changes in stallion sperm quality (sperm motility, viability, membrane integrity and chromatin integrity) occurring during cool storage, and to study the effect of sperm selection by single layer colloidal centrifugation on these parameters of sperm quality. Spermatozoa from 3 stallions (10 ejaculates, 3-4 per stallion) were selected by centrifugation through a single layer of colloid (SLC). The resulting sperm preparations and the control samples (extended but unselected semen samples) were stored at 5 degrees C for 48 h. Assessments of sperm quality, such as sperm motility, viability (SYBR-14/PI staining), membrane stability (Annexin-V/PI staining) and chromatin integrity, were performed on aliquots of the selected sperm preparations and unselected samples on the day of collection (3 h) and after 24 and 48 h of storage. In the SLC-selected sperm samples, sperm motility, sperm viability, proportions of spermatozoa with normal morphology and with intact chromatin were significantly better than in unselected samples (motility: 77 +/- 4% vs. 64 +/- 8% at 3 h; P less than 0.001; viability: 79.5 +/- 9% vs. 64.7 +/- 9%, P less than 0.001: normal morphology 89 +/- 6% vs. 69 9%; chromatin integrity DFI 11.3 +/- 5% vs. 22.1 +/- 10%). Membrane stability, however, was not different in the SLC-selected and unselected samples (74.6 +/- 8% vs. 69.3 +/- 8%). The deterioration seen in sperm quality in the unselected samples was prevented by SLC, so that sperm viability, membrane stability and chromatin integrity were unchanged in the selected samples by 48 h compared to 3 h (Pless than0.001), whereas the unselected samples were significantly worse by 48 h (Pless than0.001). Furthermore, it should be possible to send an aliquot of a normal insemination dose (i.e. unselected spermatozoa) overnight to a reference laboratory for analysis of both plasma membrane and chromatin integrity. In conclusion, centrifugation of stallion spermatozoa through a single layer of colloid is a useful technique for selecting the best spermatozoa from an ejaculate and, moreover, sperm quality is maintained during storage. (C) 2009 Elsevier B.V. All rights reserved.
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| 10. |
- Ljungvall, Ingrid, et al.
(författare)
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Use of signal analysis of heart sounds and murmurs to assess severity of mitral valve regurgitation attributable to myxomatous mitral valve disease in dogs
- 2009
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Ingår i: AMERICAN JOURNAL OF VETERINARY RESEARCH. - : American Veterinary Medical Association (AVMA). - 0002-9645. ; 70:5, s. 604-613
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Tidskriftsartikel (refereegranskat)abstract
- Objective-To investigate use of signal analysis of heart sounds and murmurs in assessing severity of mitral valve regurgitation (mitral regurgitation [MR]) in dogs with myxomatous mitral valve disease (MMVD). Animals-77 client-owned dogs. Procedures-Cardiac sounds were recorded from dogs evaluated by use of auscultatory and echocardiographic classification systems. Signal analysis techniques were developed to extract 7 sound variables (first frequency peak, murmur energy ratio, murmur duration > 200 Hz, sample entropy and first minimum of the auto mutual information function of the murmurs, and energy ratios of the first heart sound [S1] and second heart sound [S2]). Results-Significant associations were detected between severity of MR and all sound variables, except the energy ratio of S1. An increase in severity of MR resulted in greater contribution of higher frequencies, increased signal irregularity, and decreased energy ratio of S2. The optimal combination of variables for distinguishing dogs with high-intensity murmurs from other dogs was energy ratio of S2 and murmur duration > 200 Hz (sensitivity, 79%; specificity, 71%) by use of the auscultatory classification. By use of the echocardiographic classification, corresponding variables were auto mutual information, first frequency peak, and energy ratio of S2 (sensitivity, 88%; specificity, 82%). Conclusions and Clinical Relevance-Most of the investigated sound variables were significantly associated with severity of MR, which indicated a powerful diagnostic potential for monitoring MMVD. Signal analysis techniques could be valuable for clinicians when performing risk assessment or determining whether special care and more extensive examinations are required.
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