排序方式： 共有93条查询结果，搜索用时 31 毫秒
61.
YQ Lv S Ji X Chen D Xu XT Luo MM Cheng YY Zhang XL Qu Y Jin 《Reproduction in domestic animals》2020,55(8):1011-1020
Glycerol is used as a bovine semen osmotic cryoprotectant that greatly improves the quality of frozen and thawed bovine sperm. However, high glycerol concentrations can have a toxic effect on frozen and thawed bovine sperm. Therefore, this experiment investigated the effect of replacing a portion of the glycerol in a cryoprotectant solution with crocin on the sperm apoptosis, protamine deficiency and membrane lipid oxidation of frozen and thawed Yanbian yellow cattle sperm. The experiment included a control group (6% glycerol) and four treatment groups: I (3% glycerol), II (3% glycerol +0.5 mM crocin), III (3% glycerol + 1 mM crocin) and IV (3% glycerol + 2 mM crocin). Computer assisted semen analysis was used to detect sperm motility, Hoechst 33,342, propidium iodide, and JC-1 staining were used to analyse sperm viability and mitochondrial membrane potential, chromomycin A3 staining was used to detect protamine deficiency and DNA damage, flow cytometry was used for sperm membrane lipid disorder detection and analysis, and real-time quantitative RT-qPCR was used to detect the mRNA expression levels of protamine-related genes (PRM2, PRM3), sperm acrosome-associated genes (SPACA3), oxidative stress-related genes (ROMO1) and apoptosis-related genes (BCL2, BAX). Compared to the control group, replacing a portion of glycerol with 1 mM crocin significantly improved sperm motility, plasma membrane integrity, membrane lipid disorders (p < .05) and viability, mitochondrial membrane potential, protamine deficiency (p < .01). The expression level of PRM2, PRM3, SPACA3 and BCL2 significantly increased (p < .05), while the expression levels of ROMO1 and BAX significantly decreased (p < .05). Accordingly, the BCL2/BAX ratio significantly increased (p < .05). In summary, the substitution of a portion of glycerol with crocin in cryoprotective solution improved the quality of Yanbian yellow cattle sperm after freezing and thawing. 相似文献
62.
Experiments in Serengeti National Park, Tanzania, provide direct evidence that large, free-ranging mammalian grazers accelerate nutrient cycling in a natural ecosystem in a way that enhances their own carrying capacity. Both nitrogen and sodium were at considerably higher plant-available levels in soils of highly grazed sites than in soils of nearby areas where animal density is sparse. Fencing that uncoupled grazers and soils indicated that the animals promote nitrogen availability on soils of inherently similar fertility and select sites of higher sodium availability as well as enhancing that availability. 相似文献
63.
64.
Assaf Lerer Heather J. Chalmers Noel MM Moens Shawn D. Mackenzie Kristin Kry 《Veterinary radiology & ultrasound》2014,55(5):547-551
A 5‐month‐old intact male Basset Hound presented for evaluation of pain and crepitation during manipulation of the temporomandibular joint, worse on the right side. A computed tomography (CT) scan of the head was performed. The CT images demonstrated the osseous features of temporomandibular joint dysplasia and facilitated a 3D reconstruction, which allowed better visualization of the dysplastic features. The patient responded to conservative management with a tape muzzle with no recurrence reported by the owner 6 months after presentation. 相似文献
65.
CASE HISTORY: A 6-year-old, spayed, female, domestic short-haired cat presented with severe erythroderma and scaling skin. She showed disturbed gait and mild behavioural changes. CLINICAL FINDINGS: The cat had a generalised, erythematous, scurfy dermatitis with marked, multifocal crusting and skin thickening. The skin was painful and contracted, which appeared to prevent normal freedom of movement. DIAGNOSIS: The cat was suspected to have a paraneoplastic syndrome. A mediastinal mass was located and histologically confirmed as thymoma. The cat was diagnosed with a thymoma-associated cutaneous paraneoplastic syndrome. CLINICAL RELEVANCE: This is a rare condition with few reports in the literature. The skin changes, both grossly and histologically, were considered to be different from those described in cases of paraneoplastic dermatosis associated with pancreatic neoplasia. The clinical presentation was characteristic and more cases may occur in practice than are recognised. In this case, as in previous reports, the tumour was grossly resectable, which could lead to cure of the clinical condition. 相似文献
66.
Loneragan GH Brashears MM 《Journal of the American Veterinary Medical Association》2005,226(8):1378-1383
OBJECTIVE: To evaluate the effects of using retention-pond water for dust abatement on performance of feedlot steers and carriage of Escherichia coli O157 and Salmonella spp. DESIGN: Matched cohort studies. ANIMALS: 2 groups of feedlot steers comprising 3,510 (pathogen carriage) and 3,737 (performance) animals housed in a large commercial feedlot in the Texas Panhandle. PROCEDURE: Steers were systematically allocated to treatment pens approximately 60 days after arrival (pathogen carriage) or at arrival (performance). For evaluation of pathogen carriage, feces and hide swab specimens were collected from 25 animals in each pen within 10 days of slaughter. Samples were submitted for bacterial culture for E. coli O157 and were tested with a polymerase chain reaction-based assay for Salmonella spp. For evaluation of performance, pen weights of animals were obtained at arrival and slaughter and feed delivered to each pen was recorded. The exposure of interest for both studies was application of retention-pond water through fixed high-pressure sprinklers. RESULTS: Carriage of E. coli O157 and Salmonella spp and animal performance were not adversely affected by exposure to retention-pond water. Prevalences of E. coli O157 in feces, on hides, and either in feces or on hides for those exposed to retention-pond water were 8.3%, 8.9%, and 15.4%, respectively; prevalences for those unexposed to retention-pond water were 11.4%, 15.4%, and 22.6%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that use of retention-pond water for dust abatement in feedlot pens does not adversely affect pathogen carriage or animal performance. 相似文献
67.
F Garcia Pereira SA Greene R Keegan A Tibary MM McEwen 《Veterinary anaesthesia and analgesia》2005,32(4):8-9
Butorphanol has been used clinically to provide analgesia in alpacas, but cardiovascular effects have not been reported. Using a randomized cross‐over design, eight healthy, young adult female alpacas (3 ± 1 SD years) weighing 64 ± 9 SD kg were anesthetized with isoflurane by mask followed by tracheal intubation and maintenance of anesthesia with 1.75% et (isoflurane) in oxygen. Two treatments, butorphanol (0.1 mg kg–1 IV) and control (saline, IV) were assigned to the animals in a randomized manner allowing a minimum of two weeks between treatments. While anesthetized, animals were instrumented for measurement of cardiovascular variables including systolic, diastolic, and mean arterial blood pressure, pulmonary arterial pressure, pulmonary capillary wedge pressure, central venous pressure, cardiac output (CO) and pulmonary temperature (TEMP). CO was measured via thermodilution using 5 mL of iced 5% dextrose and recording the average of three replicate measurements. Cardiac index, systemic vascular resistance (SVR) and pulmonary vascular resistance were also calculated. Arterial and mixed venous blood samples were collected for blood gas analysis [pH, pO2, pCO2, (HCO3?), BE, Hbsat]. Variables were collected at baseline (time 0) and at 5, 10, 15, 30, 45, and 60 minutes following injection. Variables were analyzed by anova for repeated measures with post‐hoc differences between means identified using the Bonferroni comparison (p < 0.05). SVR decreased five minutes after administration of butorphanol (Huynh Feldt corrected p = 0.045) and remained decreased for 60 minutes. TEMP decreased with time in both groups (Huynh Feldt corrected p = 0.000027), but groups were not different between each other. Other cardiovascular and blood gas variables were not different between groups. We conclude that butorphanol (0.1 mg kg–1 IV) had minimal effects on the cardiovascular system of these alpacas, causing a mild decrease in SVR. 相似文献
68.
AJ Korzekwa JJ Jaroszewski I Woclawek-Potocka MM Bah DJ Skarzynski 《Reproduction in domestic animals》2008,43(4):464-472
Prostaglandin F2α (PGF2α) is a main luteolytic factor in vivo; however, its direct luteolytic influence on steroidogenic cells of bovine corpus luteum (CL) is controversial and not fully understood. The aim of the study was to clarify PGF2α action on bovine CL in different in vivo and in vitro conditions and to examine whether the contact among all main types of CL cells is necessary for luteolytic PGF2α action. In experiment 1, the bovine CL (day 15 of the oestrous cycle) was perfused using in vivo microdialysis system with dinoprost (an analogue of PGF2α) for 0.5 h. Dinoprost caused a short‐time increase in progesterone (P4), whose concentration decreased thereafter (at 6‐, 10‐, 12‐ and 24‐h after treatment). In experiment 2, the direct effect of PGF2α on P4 accumulation in CL steroidogenic cells cultured in monolayer (day 15 of the cycle) was determined. PGF2α after 24 h of incubation increased P4 accumulation in steroidogenic CL cells. In experiment 3 steroidogenic, endothelial CL and immune cells (day 15 of the cycle) were incubated with PGF2α in cocultures for 24 h in glass tubes and the levels of P4, stable metabolites of nitric oxide (NO) and leukotriene (LT) C4 were determined. Although PGF2α treatment increased P4 secretion in homogeneous steroidogenic CL cell culture, the decrease in P4 secretion in cocultures of all types of CL cells was observed. The secretion of NO and LTC4 increased after the treatment of PGF2α both in pure cultures of CL cells and in cocultures. The interactions between endothelial and immune cells with steroidogenic CL cells are needed for luteolytic PGF2α action within the bovine CL. Our results indicate that the cell coculture model, including the main types of CL cells, is the most approximate to study PGF2α role in vitro. 相似文献
69.
Platt TM Loneragan GH Scott HM Norby B Thomson DU Brown MS Brown MS Ives SE Brashears MM 《American journal of veterinary research》2008,69(8):988-996
OBJECTIVE: To evaluate administration of chlortetracycline in feed of cattle as a method to select for tetracycline resistance among enteric bacteria in feedlot settings. ANIMALS: 20 steers. PROCEDURES: Steers were randomly assigned to an exposed cohort (n = 10) or an unexposed cohort (control cohort; 10). Chlortetracycline (22 mg/kg) in cottonseed meal was administered to the exposed cohort on days 0 through 4, 6 through 10, and 12 through 16. The control cohort was administered only cottonseed meal. Fecal samples were collected from 16 steers on days -7, 0, 2, 6, 8, 12, 14, 19, 22, 26, and 33, and Escherichia coli and Enterococcus spp were isolated. Minimum inhibitory concentration (MIC) of selected antimicrobials was estimated. RESULTS: Overall, 56.0% and 31.4% of E coli and Enterococcus isolates, respectively, were resistant to tetracycline. Exposure to chlortetracycline was associated with a significant temporary increase in log(2) MIC for both genera but returned to preexposure values by day 33. Averaged across time, the proportion of tetracycline-resistant E coli and Enterococcus isolates was significantly greater in exposed than in unexposed steers. Although all ceftiofur-resistant E coli isolates were coresistant to tetracycline, exposure to chlortetracycline led to a significant decrease in the proportion of E coli resistant to ceftiofur during exposure. CONCLUSIONS AND CLINICAL RELEVANCE: Exposure to chlortetracycline was associated with a temporary increase in the likelihood of recovering resistant bacteria. Exposure to chlortetracycline decreased the likelihood of recovering ceftiofur-resistant E coli isolates, even though isolates were coresistant to tetracycline. These findings warrant further investigation. 相似文献
70.
MM WILLIAMSON PT HOOPER PW SELLECK LJ GLEESON PW DANIELS HA WESTBURY PK MURRAY 《Australian veterinary journal》1998,76(12):813-818
Objective To determine the infectivity and transmissibility of Hendra virus (HeV). Design A disease transmission study using fruit bats, horses and cats. Procedure Eight grey-headed fruit bats (Pteropus poliocephalus) were inoculated and housed in contact with three uninfected bats and two uninfected horses. In a second exper iment, four horses were inoculated by subcutaneous injection and intranasal inoculation and housed in contact with three uninfected horses and six uninfected cats. In a third experi ment, 12 cats were inoculated and housed in contact with three uninfected horses. Two surviving horses were inoculated at the conclusion of the third experiment: the first orally and the second by nasal swabbing. All animals were necropsied and examined by gross and microscopic pathological methods, immunoperoxidase to detect viral antigen in formalin-fixed tissues, virus isolation was attempted on tissues and SNT and ELISA methods were used to detect HeV-specific antibody. Results Clinical disease was not observed in the fruit bats, although six of eight inoculated bats developed antibody against HeV, and two of six developed vascular lesions which contained viral antigen. The in-contact bats and horses did not seroconvert. Three of four horses that were inoculated devel oped acute disease, but in-contact horses and cats were not infected. In the third experiment, one of three in-contact horses contracted disease. At the time of necropsy, high titres of HeV were detected in the kidneys of six acutely infected horses, in the urine of four horses and the mouth of two, but not in the nasal cavities or tracheas. Conclusions Grey-headed fruit bats seroconvert and develop subclinical disease when inoculated with HeV. Horses can be infected by oronasal routes and can excrete HeV in urine and saliva. It is possible to transmit HeV from cats to horses. Transmission from P poliocephalus t o horses could not be proven and neither could transmission from horses to horses or horses to cats. Under the experimental conditions of the study the virus is not highly contagious. 相似文献