A bioeconomic model was developed to estimate effects of change in production and functional traits on profit of dairy or dual-purpose milked sheep under alternative management systems. The flock structure was described in terms of animal categories and probabilities of transitions among them, and a Markov chain approach was used to calculate the stationary state of the resultant ewe flock. The model included both deterministic and stochastic components. Performance for most traits was simulated as the population average, but variation in several traits was taken into account. Management options included lambing intervals, mating system, and culling strategy for ewes, weaning and marketing strategy for progeny, and feeding system. The present value of profit computed as the difference between total revenues and total costs per ewe per year, both discounted to the birth date of the animals, was used as the criterion for economic efficiency of the production system in the stationary state. Economic values (change in system profit per unit change in the trait) of up to 35 milk production, growth, carcass, wool, and functional traits may be estimated.

• MeSH
• biologické modely * MeSH
• mlékárenství * ekonomika   MeSH
• ovce genetika   fyziologie   MeSH
• těhotenství MeSH
• zvířata MeSH
• Check Tag
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A mitral allograft is used exceptionally in the mitral, as well as in the tricuspid position, mostly as an experimental surgical procedure. The authors decided to evaluate the possibility of inserting a cryopreserved mitral allograft into the tricuspid position in a sheep experimental model. Within the framework of this experimental project the mechanical properties of the cryopreserved mitral allograft were tested. A novel methodology studying the functional unit composed of mitral annulus, leaflet, chordae tendinaea, and papillary muscle is presented. A five-parameter Maxwell model was applied to characterize the viscoelastic behavior of sheep mitral valves. A control group of 39 fresh mitral specimens and a test group of 13 cryopreserved mitral allografts from tissue bank were tested. The testing protocol consisted of six loading cycles with 1 mm elongation every 5 min. There was no significant difference in the mean values of the determined parameters (p>0.05) which confirms the main hypothesis that cryopreservation does not influence significantly material parameters characterizing the tissue mechanics. Slight discrepancy is observed in variances of viscous parameters suggesting that the values of the test group may be spread over larger interval due to the treatment.

• MeSH
• kryoprezervace * MeSH
• mechanický stres MeSH
• mitrální chlopeň * MeSH
• modely u zvířat MeSH
• ovce MeSH
• povrchové vlastnosti MeSH
• srdeční chlopně umělé * MeSH
• trikuspidální chlopeň chirurgie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

OBJECTIVE: A short literature review of ewe as an experimental model in research of effects of pregnancy, delivery and urogynecological surgical procedures on the pelvic floor. DESIGN: Literature overview. SETTING: Institute for the Care of Mother and Child, Third Faculty of Medicine, Prague. METHODS: This is an overview of recent literature on experiments using ewes as a model for biomechanical and morphological changes of the vagina induced by pregnancy, delivery and transvaginal graft implantation. RESULTS AND CONCLUSION: The ovine pelvic floor and vagina have comparable morphology to human. Its biomechanical and biochemical properties get changed during the pregnancy and postpartum similarly to clinical findings. Sheep could be used for testing of urogynaecological implants vaginally and simultaneously implanted in the abdominal wall to provide better understanding of anatomical environment differences. The size of the ovine vagina gives the opportunity to perform comprehensive biomechanical, histological and biochemical testing. Experiments and observation may improve our understanding of pathology and physiology of vaginal wall changes induced by hormones, prolapse or surgery.

• Klíčová slova
• pelvic floor, sheep effects of pregnancy and delivery.,
• MeSH
• gynekologické chirurgické výkony MeSH
• modely u zvířat * MeSH
• ovce * MeSH
• pánevní dno chirurgie   MeSH
• poporodní období MeSH
• těhotenství * MeSH
• urologické chirurgické výkony MeSH
• vagina chirurgie   MeSH
• vedení porodu * MeSH
• zvířata MeSH
• Check Tag
• těhotenství * MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The anaerobic bacterium Cutibacterium acnes has been increasingly linked to the development of degenerative disc disease (DDD), although causality is yet to be conclusively proven. To better study how this organism could contribute to the aetiology of DDD, improved animal models that are more reflective of human disc anatomy, biology and mechanical properties are required. Against this background, our proof-of concept study aimed to be the first demonstration that C. acnes could be safely administered percutaneously into sheep intervertebral discs (IVDs) for in vivo study. Following our protocol, two sheep were successfully injected with a strain of C. acnes (8.3 × 106 CFU/disc) previously recovered from a human degenerative disc. No adverse reactions were noted, and at one-month post inoculation all triplicate infected discs in our first animal grew C. acnes, albeit at a reduced load (5.12 × 104 to 6.67 × 104 CFU/disc). At six months, no growth was detected in discs from our second animal indicating bacterial clearance. This pilot study has demonstrated the feasibility of safe percutaneous injection of C. acnes into sheep IVDs under fluoroscopic guidance. The design of follow-up sheep studies to investigate the potential of C. acnes to drive pathological changes within infected discs should now be pursued.

• Klíčová slova
• Cutibacterium acnes, bacterial discitis, percutaneous injections, sheep model, spinal intervertebral discs,
• Publikační typ
• časopisecké články MeSH

Mitral allografts are still used only exceptionally in the mitral or tricuspid position. The main indication remains infectious endocarditis of atrioventricular valves for its flexibility and low risk of infection. The aim of our study was to evaluate 1-year results of mitral allografts transplantation into the tricuspid position in a sheep model. Mitral allografts were processed, cryopreserved, and transplanted into the tricuspid position anatomically (Group I - 11 animals) or antianatomically (Group II - 8 animals). All survivors (4 from Group I, and 3 from Group II) were checked at 3, 6, and 12 months by echocardiography with the exception of one survivor from Group II (which was examinated only visually). Examination throughout follow-up included for mitral allograft regurgitation and annuli dilatation. At postmortem, the papillary muscles were healed and firmly anchored to the right ventricular wall in all subjects. Transventricular fixation of the papillary muscles with buttressed sutures was proven to be a stable, reproducible, and safe method for anchoring mitral allograft leaflets. There were no significant differences between the two implantation methods. Annulus support of mitral allografts might be very useful in this type of operation and could prevent annular dilatation.

• MeSH
• alografty MeSH
• kryoprezervace MeSH
• mitrální chlopeň transplantace   MeSH
• modely u zvířat MeSH
• ovce MeSH
• trikuspidální chlopeň chirurgie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: There is an urgent need to develop better materials to provide anatomical support to the pelvic floor without compromising its function. OBJECTIVE: Our aim was to assess outcomes after simulated vaginal prolapse repair in a sheep model using three different materials: (1) ultra-lightweight polypropylene (PP) non-degradable textile (Restorelle) mesh, (2) electrospun biodegradable ureidopyrimidinone-polycarbonate (UPy-PC), and (3) electrospun non-degradable polyurethane (PU) mesh in comparison with simulated native tissue repair (NTR). These implants may reduce implant-related complications and avoid vaginal function loss. DESIGN, SETTING, AND PARTICIPANTS: A controlled trial was performed involving 48 ewes that underwent NTR or mesh repair with PP, UPy-PC, or PU meshes (n=12/group). Explants were examined 60 and 180 d (six per group) post-implantation. INTERVENTION: Posterior rectovaginal dissection, NTR, or mesh repair. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Implant-related complications, vaginal contractility, compliance, and host response were assessed. Power calculation and analysis of variance testing were used to enable comparison between the four groups. RESULTS: There were no visible implant-related complications. None of the implants compromised vaginal wall contractility, and passive biomechanical properties were similar to those after NTR. Shrinkage over the surgery area was around 35% for NTR and all mesh-augmented repairs. All materials were integrated well with similar connective tissue composition, vascularization, and innervation. The inflammatory response was mild with electrospun implants, inducing both more macrophages yet with relatively more type 2 macrophages present at an early stage than the PP mesh. CONCLUSIONS: Three very different materials were all well tolerated in the sheep vagina. Biomechanical findings were similar for all mesh-augmented repair and NTR. Constructs induced slightly different mid-term inflammatory profiles. PATIENT SUMMARY: Product innovation is needed to reduce implant-related complications. We tested two novel implants, electrospun and an ultra-lightweight polypropylene textile mesh, in a physiologically relevant model for vaginal surgery. All gave encouraging outcomes.

• Klíčová slova
• Biocompatibility, Biomaterials, Biomechanics, Pelvic organ prolapse, Vaginal surgery,
• MeSH
• biokompatibilní materiály MeSH
• chirurgické síťky * MeSH
• gynekologické chirurgické výkony MeSH
• modely nemocí na zvířatech MeSH
• modely u zvířat MeSH
• ovce MeSH
• polypropyleny * MeSH
• prolaps dělohy chirurgie   MeSH
• protézy - design MeSH
• pyrimidinony MeSH
• testování materiálů MeSH
• textilie MeSH
• výsledek terapie MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biokompatibilní materiály MeSH
• polypropyleny * MeSH
• pyrimidinony MeSH
• ureidopyrimidinone MeSH Prohlížeč

A bioeconomic model for dairy sheep was applied to a production system with one lambing per year. The classical extensive Carpathian system with indoor winter lambing, traditional weaning, sale of surplus lambs before Easter, and a summer milking period with ewes on pasture was modeled. The economic values of 15 performance and functional traits were calculated for the Slovakian Improved Walachian multi-purpose breed. The economic values per unit increase in the traits were 0.32 euro/kg of milk yield during the standardized milking period of 150 d, 0.29 euro/0.1% milk fat, 0.42 euro/0.1% milk protein, 0.28 euro/% and 0.56 euro/% for conception rates of female lambs and ewes, respectively, 0.20 euro/0.01 lamb born, 0.0036 euro/% and 0.0040 euro/% for lamb survival at birth and until weaning, respectively, 0.65 euro/kg of birth weight, 0.032 euro/g per d daily gain from birth until weaning, -0.030 euro/kg of mature weight, -0.38 euro/0.1 and -0.21 euro/0.1 conformation quality grade for weaned lambs and adult sheep, respectively, 0.42 euro/kg of fleece weight and 11.10 euro/year of productive lifetime for ewes.

• MeSH
• biologické modely * MeSH
• časové faktory MeSH
• krmivo pro zvířata analýza   ekonomika   MeSH
• mlékárenství ekonomika   MeSH
• náklady a analýza nákladů MeSH
• odstavení MeSH
• ovce růst a vývoj   fyziologie   MeSH
• porod MeSH
• reprodukovatelnost výsledků MeSH
• software normy   MeSH
• těhotenství MeSH
• zvířata MeSH
• Check Tag
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A bio-economic model including a computer program was developed where a large number of parameters can be modified to describe a great variety of production systems. Economic values for up to 27 traits can be calculated. Seasonal feeding is considered and protein requirement in addition to net energy may be taken into account when calculating feed requirement. Furthermore, the model allows for the evaluation of individual parts of the growth curve. The model was applied to the Czech Suffolk breed used in pure-breeding. An extensive pasture system with spring lambing and sale of surplus progeny for slaughter after weaning or after a finishing period was assumed. The economic values (in Euro cent per ewe, per year and per genetic standard deviation of the trait) were as follows: 9.9 for birth weight, -72.6 for mature weight, 142, 32.1 and 16.9 for growth rates till weaning, in rearing of breeding animals and in fattening, respectively, 19.9 and 101 for conception rate of female lambs and ewes, respectively, 690 for litter size per ewe lambing, 172 for productive lifetime of ewes, 402 and 503 for survival rate of lambs at lambing and till weaning, respectively, and 16.5 for fleece weight.

• MeSH
• biologické modely MeSH
• chov zvířat MeSH
• dlouhověkost MeSH
• ekonomické modely MeSH
• odstavení MeSH
• ovce genetika   růst a vývoj   MeSH
• rozmnožování genetika   MeSH
• těhotenství MeSH
• velikost vrhu MeSH
• zemědělství ekonomika   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Mediterranean pastures are experiencing strong changes in management, involving shifts from sheep to cattle-based livestock systems. The impacts of such shifts on biodiversity are still poorly understood. Here, we sought to contrast the grazing regime, vegetation structure, bird species richness and abundance, between sheep and cattle grazed parcels, to understand the mechanisms through which management decisions impact farmland birds. During spring 2019, we characterized livestock management, bird populations and sward structure in 23 cattle and 27 sheep grazed parcels. We used a Structural Equation Model to infer the direct and indirect effects of sheep and cattle grazing on birds. Although no effects were found on overall species richness, there were species-specific responses to sheep and cattle grazed systems. Grazing pressure (variable integrating stocking rate and the number of days in the parcel) had negative impacts on the prevalence/abundance of Zitting Cisticola, Corn Bunting and Little Bustard, either directly or indirectly, through the effects of grazing pressure on vegetation height. Animal density and vegetation cover had direct positive effects in Galerida spp. and Common Quail, respectively. Zitting Cisticola and Little Bustard also showed a direct response to livestock type. Our study emphasizes the importance of grazing pressure as a driver of negative impacts for bird populations in Mediterranean grasslands. Since the ongoing transition from sheep to cattle-based systems involves increases in stocking rate, and therefore potentially higher grazing pressure, we propose a policy change to cap the maximum allowed grazing pressure. At the landscape scale, a mix of sheep and cattle grazed fields would be beneficial for maintaining bird diversity.

• MeSH
• biodiverzita MeSH
• býložravci MeSH
• dobytek klasifikace   růst a vývoj   MeSH
• ovce MeSH
• pastviny MeSH
• ptáci klasifikace   růst a vývoj   MeSH
• skot MeSH
• teoretické modely MeSH
• zachování přírodních zdrojů MeSH
• zemědělství metody   MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Středomoří MeSH

The objective of this paper was to adapt gene-flow methodology for the calculation of economic weights (EW) for direct and maternal traits and trait components in sheep and to apply this methodology to the Suffolk breed in the Czech Republic. Computer programs were developed in which annual-lambing sheep production systems with purebreeding or partial terminal crossing were simulated. Using these programs, the EW for 12 production and functional traits were estimated for i) Suffolk sires whose sons were used both in purebreeding and in terminal crossing with the 4 dual-purpose breeds, Romanov, Sumavska, Romney, and Merinolandschaf; and ii) Suffolk sires used only for terminal crossing. For case (i), the EW were at first calculated separately for the purebreeding system and for the crossing systems with the 4 dual-purpose breeds in dam position. Compound EW for the general breeding goal for Suffolk were then estimated as weighted averages from the EW in the 5 subsystems. Standardized EW were calculated by multiplying the marginal EW with the genetic SD of the trait, and relative EW were defined as absolute values of the standardized EW expressed as percentage of the sum of the absolute values of the standardized EW over all traits. The 5 most important trait components for Suffolk sires whose sons were used both in purebreeding and in terminal crossing were (relative EW given in parentheses): the direct components of survival rate until weaning (21.0%), daily BW gain until weaning (14.1%), survival rate at birth (14.0%), the maternal component of survival rate until weaning (10.7%), and litter size at lambing (7.6%). There were only small differences between the relative EW calculated for the whole system with pure- and crossbreeding and the relative EW for the purebred system within the Suffolk breed. Therefore, selection of Suffolk rams using a selection index based on the compound EW is expected to be of high efficiency in all of the simulated breeding systems. Only direct traits were relevant for Suffolk sires used only for terminal crossing; the most important (range of relative EW calculated for the 4 crossing systems given in parentheses) were survival rate until weaning (35.2 to 36.5%), daily BW gain until weaning (24.2 to 26.3%), and survival rate at birth (23.7 to 24.8%).

• MeSH
• biologické modely MeSH
• chov ekonomika   MeSH
• genetická variace MeSH
• hmotnostní přírůstek MeSH
• ovce genetika   MeSH
• rozmnožování genetika   fyziologie   MeSH
• tok genů MeSH
• vlna MeSH
• zemědělství ekonomika   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH