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Green LE Wassink GJ Grogono-Thomas R Moore LJ Medley GF 《Preventive veterinary medicine》2007,78(2):172-178
A total of 160 ewes on one farm in England were studied for 18 months. The incidence of footrot and interdigital dermatitis in individually identified sheep and treatment and flock control measures were recorded. A binomial mixed effect model with the incidence of footrot or interdigital dermatitis as the outcome was used to investigate patterns of association between treatments, flock control measures and the incidence of footrot or interdigital dermatitis. In this one flock, the incidence of footrot and interdigital dermatitis was positively associated with the incidence of footrot and interdigital dermatitis and with trimming of feet and negatively associated with the use of parenteral antibiotics and topical antibiotic sprays in either the first and/or second 2-week period prior to the incidence of interest. These results provide two hypotheses: one that 'footrot and interdigital dermatitis are infectious diseases that can be controlled, in part, through the use of antibiotic therapy, which acts to reduce the infectious period of diseased sheep' and two, that 'routine trimming of diseased and healthy feet exacerbate disease, through environmental contamination and/or through increased susceptibility of sheep with recently trimmed feet'. 相似文献
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A W Mukhebi T Chamboko C J O'Callaghan T F Peter R L Kruska G F Medley S M Mahan B D Perry 《Preventive veterinary medicine》1999,39(3):173-189
Heartwater, caused by the rickettsial organism Cowdria ruminantium, is a serious constraint to livestock development in much of sub-Saharan Africa. Traditionally, the disease has been controlled by the use of chemical acaricides to control the vector tick. The University of Florida/USAID-supported heartwater research project (based in Zimbabwe) is developing a new inactivated vaccine to control the disease. In order that the vaccine is used effectively, the project has been studying the epidemiology of the disease in different livestock production systems of Zimbabwe, and evaluating the economic impact of the disease and of its future control using a vaccine such as the one under development. Initially, field studies were conducted to characterise the communal and commercial livestock-productions systems at risk from heartwater and to understand the epidemiology of the disease. The data from these studies were then applied to an infection-dynamics model of heartwater, which was used to provide estimates of disease incidence and impact under various scenarios over a period of 10 yr. Two principal outputs of the epidemiological model (cumulative annual heartwater incidence and infection-fatality proportion) were key inputs into an economics model. The estimated total annual national losses amount to Z$ 61.3 million (US$ 5.6 million) in discounted value terms over 10 yr. Annual economic losses per animal in the commercial production system (Z$ 56 discounted values) are 25 times greater than the losses in the communal system (Z$ 2.2). The greatest component of economic loss is acaricide cost (76%), followed by milk loss (18%) and treatment cost (5%). Losses in outputs other than milk (beef, traction and manure) appear to be minimal. A new vaccine has the promise of a benefit: cost ratio of about 2.4:1 in the communal and 7.6:1 in the commercial system. A control strategy based on a new vaccine would yield additional non-financial benefits to farmers and the government resulting from reductions in the use of chemical acaricides. 相似文献
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LY Hardefeldt HK Crabb KE Bailey T Johnstone JR Gilkerson H Billman‐Jacobe GF Browning 《Australian veterinary journal》2019,97(9):316-322
The Australian Veterinary Prescribing Guidelines for antimicrobial prophylaxis for surgery on dogs and cats are evidence‐based guidelines for veterinary practitioners. Validation of these guidelines is necessary to ensure quality and implementability. Two validated tools, used for medical guideline appraisal, were chosen to assess the guidelines. The terminology from the GuideLine Implementability Appraisal (GLIA) and the Appraisal of Guidelines for Research and Evaluation version 2 (AGREE II) were adapted for use by veterinarians. A two‐phase evaluation approach was conducted. In the first phase of the evaluation, the GLIA tool was used by two specialist veterinary surgeons in clinical practice. The results of this phase were then used to modify the guidelines. In the second phase, the AGREE II tool was used by 6 general practitioners and 6 specialists to appraise the guidelines. In phase 1, the specialist surgeons either agreed or strongly agreed that the guidelines were executable, decidable, valid and novel, and that the guidelines would fit within the process of care. The surgeons were neutral on flexibility and measurability. Additional clarity around one common surgical procedure was added to the guidelines, after which the surgeons agreed that the guidelines were sufficiently flexible. In phase 2, 12 veterinarians completed the assessment using the AGREE II tool. In all sections the scaled domain score was greater than 70%. The overall quality of the guidelines was given a global scaled score of 76%. This assessment has demonstrated that the guidelines for antimicrobial prophylaxis for companion animal surgery are valid and appear implementable. 相似文献
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Regulation of Anti‐Müllerian Hormone and Its Receptor Expression around Follicle Deviation in Cattle 
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下载免费PDF全文 GF Ilha MT Rovani BG Gasperin R Ferreira MP de Macedo OA Neto R Duggavathi V Bordignon PBD Gonçalves 《Reproduction in domestic animals》2016,51(2):188-194
The anti‐Müllerian hormone (AMH) is an important marker of ovarian reserve and for predicting the response to superovulatory treatments in several species. The objective of this study was to investigate whether AMH and its receptor (AMHR2) are regulated in bovine granulosa cells during follicular development. In the first experiment, granulosa cells were retrieved from the two largest follicles on days 2 (before), 3 (at the expected time) or 4 (after deviation) of follicular wave. In the second experiment, four doses of FSH (30, 30, 20 and 20 mg) or saline were administered twice a day starting on Day 2 of the first follicular wave of the cycle. Granulosa cells and follicular fluid were collected from the two largest follicles 12 h after the last injection of FSH or saline. AMH mRNA abundance was similar in granulosa cells of the two largest follicles (F1 and F2) before deviation (Day 2), but greater in dominant (DF) than subordinate follicles (SF) at the expected time (Day 3) and after (Day 4) deviation (p < 0.05). In experiment 1, AMH mRNA levels declined in both DF and SF near the expected time and after deviation when compared to before deviation. There was no difference in AMHR2 mRNA levels before and during follicular deviation (p > 0.05), but they tended to be greater in DFs than SFs (p < 0.1) after deviation. Experiment 2 showed that AMH and AMHR2 mRNA in granulosa cells and AMH protein abundance in follicular fluid were similar (p > 0.05) between both co‐dominant follicles collected from the FSH‐treated cows. These findings indicate the followings: AMH mRNA levels decrease in both DFs and SFs during follicular deviation; granulosa cells from heathy follicles express more AMH mRNA compared to subordinate follicles undergoing atresia and FSH stimulates AMH and AMHR2 mRNA expression in granulosa cells of co‐dominant follicles. 相似文献
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The haemolytic RTX toxins of 27 isolates of Actinobacillus pleuropneumoniae, representing all serovars that have been isolated in Australia, were characterised. The quantity of protein secreted by these isolates into the media was not significantly different between serovars, but haemolytic activity was detected only in the unconcentrated supernatants from cultures of serovar 1 and 5 isolates. Haemolytic activity in supernatants of serovar 2, 3 and 7 isolates was detected only after the supernatants were concentrated. On Southern hybridisation blots, genomic DNA of serovar 1 and 5 isolates contained regions that were similar to the cloned structural genes for Apxl (apxIA) and for ApxII (apxIIA). In contrast, genomic DNA of serovar 2,3 and 7 isolates only contained regions similar to, if not identical with, the cloned apxIIA gene. The haemolytic activity of the culture supernatant depends on the type or composition of media and adaptability of the bacteria to in-vitro cultivation. Low passage cultures of A pleuropneumoniae, which were characterised by waxy colonies, produced significantly weaker haemolytic activity than A pleuropneumoniae after several passages in vitro. 相似文献
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GF Mastromonaco E Semple C Robert GJ Rho DH Betts WA King 《Reproduction in domestic animals》2004,39(6):462-467
Important differences exist between in vitro fertilized (IVF) and nuclear transfer (NT) bovine embryos. Studies have shown that although in vitro development is comparable, post-implantation survival is greatly reduced in NT embryos. In this study, we compare serum and bovine serum albumin (BSA) supplementation during oocyte maturation and embryo culture of IVF and NT embryos. In experiment 1, oocytes and embryos were randomly distributed into different treatment groups consisting of synthetic oviductal fluid (SOF) medium supplemented with either serum, fatty acid-free BSA (FAF) or fraction V BSA during maturation and/or culture to assess IVF embryo development. In experiment 2, oocytes were matured in SOF + serum or SOF + FAF and reconstructed embryos were cultured in SOF + FAF to assess NT embryo development. Among the IVF treatment groups, a greater number of blastocysts were observed in the steer serum (SER) group (IVM and IVC in SOF + serum) on day 6; however, no significant differences were seen in blastocyst development from day 8 onwards. Hatching frequencies on days 8 and 9 were significantly greater in groups with serum, with the exception of FAF (IVM and IVC in SOF + FAF) on day 9. For the NT treatment groups, the presence of serum during IVM resulted in a higher proportion of MII oocytes and increased blastocyst development and hatching rates were compared with supplementation of FAF. These results indicate that both serum and FAF provide comparable embryo development for IVF but not for NT bovine embryos. 相似文献
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Martin J. Green Graham F. Medley Andrew J. Bradley William J. Browne 《Veterinary research》2010,41(2)
Knowledge of the efficacy of an intervention for disease control on an individual farm is essential to make good decisions on preventive healthcare, but the uncertainty in outcome associated with undertaking a specific control strategy has rarely been considered in veterinary medicine. The purpose of this research was to explore the uncertainty in change in disease incidence and financial benefit that could occur on different farms, when two effective farm management interventions are undertaken. Bovine mastitis was used as an example disease and the research was conducted using data from an intervention study as prior information within an integrated Bayesian simulation model. Predictions were made of the reduction in clinical mastitis within 30 days of calving on 52 farms, attributable to the application of two herd interventions previously reported as effective; rotation of dry cow pasture and differential dry cow therapy. Results indicated that there were important degrees of uncertainty in the predicted reduction in clinical mastitis for individual farms when either intervention was undertaken; the magnitude of the 95% credible intervals for reduced clinical mastitis incidence were substantial and of clinical relevance. The large uncertainty associated with the predicted reduction in clinical mastitis attributable to the interventions resulted in important variability in possible financial outcomes for each farm. The uncertainty in outcome associated with farm control measures illustrates the difficulty facing a veterinary clinician when making an on-farm decision and highlights the importance of iterative herd health procedures (continual evaluation, reassessment and adjusted interventions) to optimise health in an individual herd. 相似文献