Charakterisierung der Virulenz einer Braunrost-Feldpopulation (Puccinia triticina f. sp. tritici) und Nachweis effektiver Braun-rost-resistenz-gene in Weizen (Triticum aestivum)

Puccinia triticina f. sp. tritici, the causal agent of leaf rust causes yield losses in wheat up to 60%. In order to avoid such losses, leaf rust resistance (Lr-) genes have been incorporated into wheat cultivars. The Lr- genes confer mostly vertical resistance, i.e. they are race specific. Therefore, knowledge of still effective resistance genes is required for efficient breeding of resistant cultivars. To get information on these virulences, a leaf rust population was monitored in field experiments in 2010. For this purpose naturally infection at three different timepoints of wheat development was monitored on Thatcher near isogenic lines (NILs) carrying 37 and accessions carrying 6 additional Lr-genes. Thatcher-NILs carrying Lr2a, Lr9, Lr19, Lr22a, Lr23, Lr24, Lr35, Lr38 and Lr49 showed a significantly lower infection with Puccinia triticina than the susceptible cultivar Thatcher. Thatcher-NILs carrying Lr13, Lr16, Lr37 and Lr46 showed no significant differences in comparison to Thatcher. In order to get information on the effectiveness of resistance genes, P. triticina isolates were collected from the NILs analysed in field trials and a leaf segment test was conducted followed by microscopic analyses. In the field and in the leaf segment test Lr9, Lr19, Lr24 and Lr38 and to some extent Lr3a turned out to be the most effective genes. By microscopic analyses, the infection process as well defense reactions activated before macroscopic symptoms are visible were monitored. By counting haustorial mother cells, it could be demonstrated which Lr-genes provide resistance, which were overcame and whether P. triticina isolates exist already at a low frequency, which may overcome a certain Lr-gene in the future. Thus microscopy offers a timesaving and effective method to detect susceptible or resistant plants and the upcoming of virulent races prior to typical symptom expression.     

Carbon monoxide toxicity: a case series

Objective: To describe diagnostics, therapy, and sequelae of acute carbon monoxide (CO) toxicity because of a motor vehicle generator in 4 dogs and 2 cats. Series summary: Four dogs and 2 cats presented for recumbency, disorientation, dyspnea, and stiffness after an estimated 6–8 hour exposure to exhaust from a generator. Diagnostics included a serum carboxyhemoglobin levels evaluation, arterial blood gas analysis, pulse oximetry readings, and blood pressure measurements. Initial therapy included oxygen (O₂) administration, intravenous bronchodilators, fluids, and a hemoglobin‐based O₂ carrying (HBOC) molecule. Following administration of the HBOC, 4 of the 6 animals showed dramatic clinical improvement. Two weeks after hospital discharge, the owner reported potential hearing deficits in all animals. Brain auditory evoked response (BAER) tests were conducted in all surviving animals and some degree of hearing impairment was documented in all cases, with complete clinical resolution noted 6 weeks later. Unique information provided: This report describes the therapeutic use of an HBOC in acute isolated CO toxicity (i.e. without the complications of smoke inhalation). In addition, delayed nervous system dysfunction was documented in all surviving animals.     

M-MODE AND DOPPLER ECHOCARDIOGRAPHIC FINDINGS IN NORMAL FERRETS SEDATED WITH KETAMINE HYDROCHLORIDE AND MIDAZOLAM

M-mode and Doppler echocardiographic values were obtained from 30 normal adult ferrets (14 neutered females, 13 neutered males, 3 intact males) sedated with an intramuscular combination of ketamine hydrochloride and midazolam. Routine M-mode measurements of the left and right ventricle, left atrium (LA) and aorta (AO) and Doppler measurements of aortic and pulmonic outflow, and mitral inflow were recorded. The following values were calculated: LA:AO diameter, ratio of peak E: peak A wave velocity (E:A ratio) for mitral inflow, and stroke volume (SV), cardiac output (CO) and cardiac index (CI) for both pulmonary and aortic outflow tracts. Maximal aortic velocities (AOmax) and velocity-time integral values (AO VTI) were significantly less than corresponding pulmonary outflow tract values (PAmax, PA VTI) but there was no difference in calculated values for SV, CO or CI. Calculated CO values were in the range expected based on the size of the species. Difficulties in aligning the aortic outflow tract for Doppler imaging may make pulmonary outflow Doppler values more consistent for use in estimating volume flow in ferrets.     

Extrapituitary and Pituitary Pathological Findings in Horses with Pituitary Pars Intermedia Dysfunction: A Retrospective Study

The objective of this study was to describe the histopathologic changes observed in extrapituitary organs as well as the pituitary glands of horses with pituitary pars intermedia dysfunction (PPID). Adrenal gland, thyroid gland, liver, lung, kidney, heart, and pituitary gland from 32 horses with clinical and histologic evidence of PPID and 20 control horses were reviewed histologically. Ten of the control horses were aged animals (≥15 years), allowing those changes attributed to age to be identified. In addition to previously reported changes in adrenal gland and liver, an association was established between PPID and several extrapituitary histopathologic changes, namely bronchiolitis, proliferative glomerulopathy, and myocardial lipofuscinosis and fibrosis. The potential biologic significance of these changes is discussed and, although the retrospective design of the current study precludes establishment of causal relationships between the observed extrapituitary changes and PPID, these findings suggest that further investigations are warranted.     

Fatty acid patterns of dog erythrocyte membranes after feeding of a fish-oil based DHA-rich supplement with a base diet low in n-3 fatty acids versus a diet containing added n-3 fatty acids

Background

In dogs, increasing the tissue n-3 fatty acid (FA) content is associated with potential benefit in some medical conditions, e.g. atopic dermatitis, cancer or heart disease. Therefore effectively and conveniently increasing tissue n-3 FA levels in dogs is of interest. Incorporation of dietary n-3 FA into cell membranes may be studied by FA analysis of erythrocyte membranes (EM), because of the correlation of its FA composition with the FA composition of other cells. Aim of the study was to determine whether an n-3 FA additive added to a control diet is as effective in increasing EM n-3 FA content as feeding an n-3 FA enriched diet. Furthermore the time course of the incorporation of dietary n-3 FA into canine EM was investigated.

Methods

Thirty dogs were randomly divided into three dietary groups with ten dogs per group. CONT got a dry dog food diet which did not contain EPA or DHA. FO got a dry dog food diet with a high EPA and DHA content. ADD got the CONT diet combined with an n-3 FA additive rich in DHA and EPA. After a feeding period of 12 weeks the additive was discontinued in ADD and these dogs were fed CONT diet for another four weeks to observe washout effects. Erythrocyte lipids were extracted from venous blood samples and their FA composition was determined by gas chromatography. The Mann-Whitney-U-test was used to detect significant differences between the different groups and time points.

Results

After one week the proportions of n-3 FA, DHA and EPA were already significantly increased in ADD and FO, apparently reaching a plateau within eight weeks. In our study DHA and not EPA was preferably incorporated into the EM. After discontinuing the administration of the additive in ADD, the n-3 FA values declined slowly without reaching baseline levels within four weeks.

Conclusions

In dogs, an increase of dietary n-3 FA content leads to a rapid inclusion of n-3 FA into EM, regardless of whether the n-3 FA are offered as an enriched diet or as a normal diet supplemented with an n-3 FA additive.     

Confidence as a barrier to the use of problem-based learning in veterinary undergraduate students

Problem-based or case-based learning is a popular method of instruction in clinical degrees such as veterinary science, nursing, and medicine. It is difficult, however, for students to adapt to this learning method, and this difficulty has been well described. The present study surveyed first-year undergraduate veterinary students at the University of Nottingham about the challenges they faced upon beginning problem-based learning sessions. A surprisingly large percentage of students (36% of females and 38% of males) reported a lack of confidence in speaking in front of the other students as a concern they experienced during their first term. Conversely, only 10% of the female students (and none of the male students) reported overconfidence as a problem. This is in contrast to the perceptions of the staff members who facilitated the sessions who reported that 14% of the students exhibited underconfidence and 14% exhibited overconfidence. The difference between the female and male students' responses as well as the difference between the perceptions of students and those of facilitators is statistically significant (G-test p<.05).     

Evaluation of age,weaning weight,body condition score,and reproductive tract score in pre-selected beef heifers relative to reproductive potential

Background: Artificial insemination is a preferred breeding method for beef heifers as it advances the genetic background, produces a predictive and profitable calving season, and extends the heifer's reproductive life span.As reproductive efficiency in heifers is key for the success of beef cattle production systems, following artificial insemination, heifers are exposed to a bull for the remainder of the breeding season. Altogether, up to 95% of heifers might become pregnant in their first breeding season. Heifers that do not become pregnant at the end of the breeding season represent an irreparable economical loss. Additionally, heifers conceiving late in the breeding season to natural service, although acceptable, poses serious losses to producers. To minimize losses due to reproductive failure, different phenotypic parameters can be assessed and utilized as selection tools. Here, we tested the hypothesis that in a group of pre-selected heifers, records of weaning weight, age at weaning, age at artificial insemination, and age of dam differ among heifers of varied reproductive outcomes during the first breeding season.Results: None of the parameters tested presented predictive ability to discriminate the heifers based on the response variable(‘pregnant to artificial insemination', ‘pregnant to natural service', ‘not pregnant'). Heifers categorized with body condition score = 6 and reproductive tract score ≥ 4 had the greatest proportion of pregnancy to artificial insemination(49% and 44%, respectively). Furthermore, it was notable that heifers presenting body condition score = 6 and reproductive tract score = 5 presented the greatest pregnancy rate at end of the breeding season(89%). Heifers younger than 368 d at the start of the breeding season did not become pregnant to artificial insemination. Those young heifers had 12.5% chance to become pregnant in their first breeding season,compared to 87.5% if the heifers were older than 368 days.Conclusion: Our results suggest that beef heifers with body condition score = 6 and reproductive tract score ≥ 4 are more likely to become pregnant to artificial insemination. Careful assessment should be undertaken when developing replacement heifers that will not reach 12 months of age by the beginning of the breeding season.