Color stability of semitendinosus,semimembranosus, and biceps femoris steaks packaged in a high-oxygen modified atmosphere

The objectives of this study were to evaluate visual and chemical attributes of beefsteaks from various USDA quality grades and muscles packaged in high-oxygen (80% O2/20% CO2) modified-atmosphere packaging (MAP). A total of nine carcasses were selected to represent Select (n = 3), low Choice (n = 3), and high Choice (n = 3) USDA quality grades. The semimembranosus (SM), semitendinosus (ST), and biceps femoris (BF) muscles were removed from each carcass and allotted to two packaging types (MAP or polyvinyl chloride over-wrap) and were displayed for up to 10 d, with evaluation on d 1, 3, 5, 7, and 10. Fifty-four steaks were evaluated on each day by a five-member trained panel for visual color (lean color and discoloration) and were also analyzed with a Minolta Chroma Meter CR-310 for L* and a* values (lightness and redness, respectively). Chemical properties measured included percentage of metmyoglobin formation and fat content. Visual color scores did not differ (P > 0.05) at d 1 and 3 with respect to all quality grades, but decreased after d 3, with a greater reduction (P < 0.05) in high Choice steaks for both lean color and discoloration. The low Choice steaks packaged in MAP displayedhigher (P < 0.05) lean color scores and less (P < 0.05) discoloration at d 7 and 10 than did Select and high Choice steaks. Redness (a*) values also decreased (P < 0.05) after d 3, whereas (lightness) L* values declined (P < 0.05) from d 1 to 5. The high Choice steaks had higher (P < 0.05) metmyoglobin content than low Choice and Select steaks, but packaging had no effect (P > 0.05) on metmyoglobin content. Muscle type did affect metmyoglobin content; however, the metmyoglobin content of the SM was greatest (P < 0.05), followed by the BF, with the ST having the lowest (P < 0.05) metmyoglobin formation. Results indicate that low Choice steaks react the best in MAP, and the ST maintained greater storage characteristics regardless of quality grade or packaging.     

Occupational health and safety in small animal veterinary practice: Part I--nonparasitic zoonotic diseases

Zoonotic diseases are an ever-present concern in small animal veterinary practice and are often overlooked. A variety of nonparasitic zoonotic diseases may be encountered in small animal practice, including cat scratch disease (bartonellosis), cat bite abscesses, rabies, leptospirosis, methicillin-resistant Staphylococcus aureus, Clostridium difficile-associated diarrhea, salmonellosis, avian chlamydiosis, campylobacteriosis, dermatophytosis, and blastomycosis. These may cause human disease ranging from mild and self-limiting to fatal. The risk of development of a zoonotic disease can be lessened by early recognition of infected animals, proper animal handling, basic biosecurity precautions, and, most importantly, personal hygiene.     

Dilated cardiomyopathy in juvenile Portuguese Water Dogs

Dilated cardiomyopathy recently has been recognized in juvenile Portuguese Water Dogs. The purpose of this study was to evaluate unaffected and affected puppies by physical examination, electrocardiogram (ECG), echocardiogram, specific biochemical assays, and ultrastructure to document disease progression and to develop a method of early detection. Results of segregation analysis were consistent with autosomal recessive inheritance. Of 124 puppies evaluated clinically and echocardiographically, 10 were affected. No significant differences were found between unaffected and affected puppies for blood and myocardial carnitine or taurine concentrations, serum chemical variables, results of ophthalmological examinations, ECGs, or measurement of urine metabolites. Ultrastructural examination of myocardium from affected dogs revealed myofibrillar atrophy and small regions of myofibrillar degeneration, most prominently at the region of the intercalated discs. Only echocardiography allowed detection of affected puppies before clinical signs became evident. Echocardiography revealed a significant difference in the shortening fraction, E point to septal separation, and the end systolic and diastolic left ventricular internal diameters. Affected puppies were detected 1-4 weeks before the development of acute congestive heart failure.     

Chronic copper toxicity in a dairy cow

A three year old Holstein dairy cow fed a ration containing a copper supplement died of chronic copper poisoning. The concentration of copper in the liver was 331 ppm (wet weight). The typical lesions of chronic copper toxicity including icterus, hepatic fibrosis and hemoglobinemic nephrosis were found at necropsy. The chronic copper toxicity was not considered to be a herd problem since the liver copper concentration in a slaughtered cull animal and blood samples taken from five animals in the same herd were within normal limits.     

Measuring forest damage of ungulates: what should be considered

Principles and criteria for the objective assessment of ‘damage' are presented as a basis for objective discussion and to promote targeted research. The topic will be considered from three different viewpoints – theoretical background, silviculture, and nature conservation. Examples of methods to assess ‘damage' are given, as are the criteria and indicators for target values for growing stock.

The objective existence of damage must be established by comparing the current status against a target. Only if the present status no longer permits achievement of the desired target can damage be claimed. The same is true for verification of ‘benefit' resulting from an impact leading to a favorable status. Establishing the degree of browsing damage on forest regeneration allows forecasts of damage to be made, but the actual damage can only be determined at a future time, for example when the timber is harvested or when the function of the forest is seen to have been compromised. The earlier the forecast is made the more uncertain it is, because the compensatory responses of the forest can only be forecast to a limited extent. Silvicultural targets depend on the requirements of both, the forest owner and the public. Main indicators for assessing ungulate damage on forest regeneration are total tree density, species composition, and height structure. From the viewpoint of nature conservation the determination of target values is particularly difficult. The measurement of damage involves choosing the most relevant indicators of favorable condition of woodland habitats and assessing these in the field. With adequate resources this can be done quantitatively using a wide range of standard field measurement techniques. Alternatively, where resources are limited, it can be done qualitatively by scoring different areas for a range of indicators. As yet, such qualitative methods are in their infancy. Specific research is now being undertaken in some European countries.     

Trace Metal Levels and Partitioning in Wisconsin Rivers

Trace metal clean-techniques were applied in the determination of the levels and particle partitioning of Al, Cd, Cu, Pb, Zn in 14 rivers in Wisconsin. Nine headwater and five receiving water sites, representing both major river systems and diverse physiographic regions were sampled in the fall of 1991 and 1992, and spring of 1993. Mean filterable concentrations (range) of Cd 9.5 (4.6–26), Cu 620 (110–1800), Pb 76 (20–200), and Zn 460 (160–930) ng L-1 are comparable with recent data from oceanic, Great Lakes, and other river systems determined by researchers using modern ‘clean’ methods. Metal partition coefficients at each site generally followed the trend (pooled mean log Kd): Pb (5.84) > Zn (5.54) > Cd (4.92) > Cu (4.94). Order-of-magnitude differences in Kds were observed between sites, however, a large fraction of this variance could be explained by dissolved organic carbon (DOC) levels and degree of anthropogenic perturbation. Watershed yields of Cd, Pb, and Zn, under baseflow conditions were a very small fraction, typically 1–2%, of atmospheric loading. Copper yields represented a much higher fraction, particularly during spring high flow conditions. Filterable levels and yields of Al, Pb, and Zn are significantly higher in non-calcareous systems than in calcareous ones, which correlates with the higher levels of DOC in non-calcareous, forested systems.     

Expert opinion on the status and stressors of brook trout,Salvelinus fontinalis,in Ontario

Ontario supports a vast fisheries resource with an abundance of lakes, rivers and streams. A landscape approach to management informed by a broad‐scale monitoring programme has been initiated to assess the status of fisheries within lakes. However, not all species are assessed by this programme, and there is no provincial monitoring of species inhabiting rivers and streams. As such, changes in the status of a species such as brook trout, Salvelinus fontinalis (Mitchill), could be entirely missed. Brook trout is a highly valued and sought after species by anglers within the province, but there are concerns the species is declining. Given the paucity of broad, empirical data, the status and trends of brook trout across the province have been based on expert opinion at multiple local scales. In 2016, a online questionnaire was sent to brook trout experts to determine status, stressors, management approaches and assess risks (magnitude and probability) to lake and river/stream populations in different geographic areas of Ontario. A Bayesian network was used to analyse responses and develop a risk assessment based on expert opinion for brook trout at multiple scales within the province.     

Fate and legacy of an invasion: extinct and extant populations of the soft‐shell clam (Mya arenaria) in Grays Harbor (Washington)

1. The soft‐shell clam, Mya arenaria, was intentionally introduced to Washington State during the mid‐1870s. Presently, extensive shell deposits cover parts of the intertidal flats of Grays Harbor, an estuarine ecosystem that has received much attention because of its role as nursery ground for Dungeness crab (Cancer magister), a commercially significant species. 2. Preliminary observations revealed that shells in the deposits belonged to clams that were much larger than extant conspecifics. Shell deposits and extant populations have spatially disjoint distributions; few individuals are found living within the deposits. The purpose of our study was to determine the cause of the different size characteristics between extinct and extant clams, when and how the deposits originated, and why the extant population does not prosper in what appears to be prime habitat. 3. We (i) surveyed extant populations and shell deposits, (ii) followed the extant population through periodic sampling over a 3‐year period, (iii) investigated growth and survival in extant and extinct populations, (iv) experimentally manipulated growth conditions, and (v) searched archival sources for information about the origin of the deposits. 4. We conclude that extinct clams grew faster and lived longer, apparently because they occupied the best habitats available. Archival records suggest that the population expanded rapidly during the period around 20 years after its introduction, but was decimated between 1895 and 1897 by a mass‐mortality episode that resulted in the formation of the deposits. The population since then has never rebounded in its prime habitat, in spite of potential settlers being regularly available. 5. Dungeness crab larvae settle preferentially in the shell deposits, where the abundance of 0+ age juveniles is orders of magnitude higher than in the adjacent flats. We hypothesize that predation by juvenile crabs limits clam recruitment. 6. The introduction of Mya to Grays Harbor during the 1870s has had long‐lasting effects, which persist a century after their once large populations were decimated by a mass‐mortality event. Copyright © 2000 John Wiley & Sons, Ltd.     

Detection and spread of Phytophthora austrocedri within infected Juniperus communis woodland and diversity of co‐associated Phytophthoras as revealed by metabarcoding

Phytophthora austrocedri is a recently invasive soilborne pathogen which is causing widespread mortality of Juniperus communis in northern Britain. The pathways by which a single genotype of P. austrocedri has spread to infect such a geographically dispersed range of woodland sites within a relatively short timeframe are unknown. This study examined the detectability of P. austrocedri in soil and water within infected J. communis woodland using qPCR to gain a better understanding of the pathogen's key mechanisms of spread. A Phytophthora metabarcoding method was also applied to investigate the wider diversity of Phytophthora species present in water at one of the sites. qPCR analyses of P. austrocedri in soil samples at a J. communis woodland exhibiting low‐to‐moderate levels of disease suggested a slow natural spread of the pathogen in soil, requiring high moisture conditions. However, the ubiquity of P. austrocedri DNA in soil samples collected across a heavily infected J. communis site suggests that once established at a site the pathogen can be spread readily in soil locally, most likely vectored by animal movements and/or human activities. The hypothesis that P. austrocedri is aerially transmitted in rainwater was not adequately proven, and an alternative hypothesis for the widespread distribution of the pathogen on J. communis in northern Britain is presented. Metabarcoding identified DNA from a diverse range of Phytophthora species in river and rainwater samples although the main target pathogen, P. austrocedri, was not amplified which disagreed with some of the qPCR findings. Possible reasons for this are discussed.