Scarring patterns of whale sharks,Rhincodon typus,at a provisioning site in the Philippines

1. Shark-based tourism continues to be a rapidly growing industry, and thus understanding the impacts of such activities is essential to mitigate the potential negative effects on the target species. The consequences of provisioning on whale sharks (Rhincodon typus) are not fully understood, although changes to the local environment, ecology, behaviour, and site visitation patterns have been highlighted. Here, the scarring patterns of whale sharks were investigated at a provisioning site in Oslob, Cebu, Philippines, as an indicator of the physical impacts of tourism activities on individual sharks. Photographic identification was used to attribute scars to individual animals (n = 152) between March 31, 2012 and January 31, 2015.
2. Scars were categorized by type and body location, and were compared with non-provisioned aggregations in Australia, Mozambique, and Seychelles. Oslob whale sharks were more scarred than other studied populations, with 94.7% (n = 144) having at least one scar, and with 90.8% (n = 138) having more than one scar. Scarring incidence was found to be significantly higher in sharks that regularly visited the provisioning site, and analysis of scarring over time in highly resident sharks showed that all individuals gained scars through periods of consistent re-sightings. A significantly higher incidence of minor scar types was found, most commonly on the dorsal side of the animal, probably resulting from sustained proximity to boats and ropes throughout the provisioning activities. The consequences of interactions with propeller boats were observed, despite a ban on their use in the provisioning site, highlighting the risk to the species beyond the study site.
3. We recommend the strict enforcement of a minimum distance between boats and sharks, a zero-contact policy during interactions, the expansion of the provisioning site, and the implementation of a no-boat-access zone around the perimeter of the provisioning site to mitigate potential collisions.

     

ELASTOGRAPHY OF THE NORMAL CANINE LIVER,SPLEEN AND KIDNEYS

Elastography is a simple, expedient and noninvasive technique that may be used to assess the elasticity or stiffness of a tissue, in conjunction with traditional B‐mode ultrasonography. Quantitative assessment of tissue stiffness can be made which involves measurement of the shear wave velocity within the tissue of interest. The goal of this study was to assess the feasibility of elastography for clinical use in the abdomen of conscious small animals and to investigate factors that affect shear wave velocity measurement. Elastography was performed on the liver, spleen, and kidneys of 15 dogs at predefined depths within the parenchyma. Breed, age, gender, neuter status, and weight were documented for each animal. Depth at which measurements were taken had a significant negative relationship with the shear wave velocity value obtained. Individual dog effects, such as weight and gender, also appeared to have a significant effect on the shear wave velocity measurement for specific organs; weight had a significant positive effect on the shear wave velocity for each of the organs examined, whereas the effect of gender was inconsistent between organs (having a positive effect for the liver and a negative effect for the spleen). It is hoped that these results may act as a baseline to guide further work into the field of elastography in companion animals.     

Understory vegetation response after 30 years of interval prescribed burning in two ponderosa pine sites in northern Arizona,USA

Southwestern USA ponderosa pine (Pinus ponderosa C. Lawson var. scopulorum Engelm.) forests evolved with frequent surface fires and have changed dramatically over the last century. Overstory tree density has sharply increased while abundance of understory vegetation has declined primarily due to the near cessation of fires. We examined effects of varying prescribed fire-return intervals (1, 2, 4, 6, 8, and 10 years, plus unburned) on the abundance and composition of understory vegetation in 2007 and 2008 after 30+ years of fall prescribed burning at two ponderosa pine sites. We found that after 30 years, overstory canopy cover remained high, while understory plant canopy cover was low, averaging <12% on all burn intervals. We attributed the weak understory response to a few factors – the most important of which was the high overstory cover at both sites. Graminoid cover and cover of the major grass species, Elymus elymoides (squirreltail), increased on shorter fire-return intervals compared to unburned plots, but only at one site. Community composition differed significantly between shorter fire-return intervals and unburned plots at one site, but not the other. For several response variables, precipitation levels appeared to have a stronger effect than treatments. Our findings suggest that low-severity burn treatments in southwestern ponderosa pine forests, especially those that do not decrease overstory cover, are minimally effective in increasing understory plant cover. Thinning of these dense forests along with prescribed burning is necessary to increase cover of understory vegetation.     

The interaction of infectious salmon anaemia virus (ISAV) with the blue mussel,Mytilus edulis

Integrated multi‐trophic aquaculture (IMTA) is an alternative approach to mono‐culture aquaculture that reduces environmental impacts of commercial aquaculture systems by combining the cultivation of fed species with extractive species. Shellfish play a critical role in IMTA systems by filter‐feeding particulate‐bound organic nutrients. They may also increase or decrease disease risk on farms by serving as reservoirs or barriers for important finfish pathogens such as infectious salmon anaemia virus (ISAV). This study aimed to optimize culture and molecular assays in shellfish tissues and to determine the fate of ISAV in mussels, Mytilus edulis. To determine detection limits, qRT‐PCR and culture assays in both CHSE‐ and ASK cells were optimized in ISAV‐inoculated mussel tissue homogenates. Both qRT‐PCR and culture assays performed in ASK cells had comparable detection limits of 10^2.8 TCID₅₀ mL^?1. The ISAV RNA genome was consistently detected in digestive gland tissue of ISAV‐exposed mussels. Viable ISAV was not detected in mussel tissues by culture analysis in CHSE‐ and ASK cells. The fact that qRT‐PCR analysis resulted in positive cycle threshold (CT) values that corresponded to the detectable range of ISAV in ASK culture assays suggests that little to no viable ISAV particles are present in the mussel tissues.     

Bovine γδ T cells: cells with multiple functions and important roles in immunity

The γδ T-cell receptor (TCR)-positive lymphocytes are a major circulating lymphocyte population in cattle, especially in young calves. In contrast, human and mice have low levels of circulating γδ TCR(+) T cells (γδ T cells). The majority of the circulating γδ T cells in ruminants express the workshop cluster 1 (WC1) molecule and are of the phenotype WC1(+) CD2(-) CD4(-) CD8(-). WC1 is a 220000 molecular weight glycoprotein with homology to the scavenger receptor cysteine-rich (SRCR) family, closely related to CD163. The existence of 13 members in the bovine WC1 gene family has recently been demonstrated and although murine and human orthologues to WC1 genes exist, functional gene products have not been identified in species other than ruminants and pigs. Highly diverse TCRδ usage has been reported, with expanded variable genes in cattle compared to humans and mice. Differential γ chain usage is evident between populations of bovine γδ T cells, this may have implications for functionality. There is a growing body of evidence that WC1(+) γδ T cells are important in immune responses to mycobacteria and may have important roles in T cell regulation and antigen presentation. In this review, we will summarize recent observations in γδ T cell biology and the importance of γδ T cells in immune responses to mycobacterial infections in cattle.     

ASVCP quality assurance guidelines: control of preanalytical and analytical factors for hematology for mammalian and nonmammalian species, hemostasis, and crossmatching in veterinary laboratories

In December 2009, the American Society for Veterinary Clinical Pathology (ASVCP) Quality Assurance and Laboratory Standards committee published the updated and peer-reviewed ASVCP Quality Assurance Guidelines on the Society's website. These guidelines are intended for use by veterinary diagnostic laboratories and veterinary research laboratories that are not covered by the US Food and Drug Administration Good Laboratory Practice standards (Code of Federal Regulations Title 21, Chapter 58). The guidelines have been divided into 3 reports: (1) general analytical factors for veterinary laboratory performance and comparisons; (2) hematology, hemostasis, and crossmatching; and (3) clinical chemistry, cytology, and urinalysis. This particular report is one of 3 reports and provides recommendations for control of preanalytical and analytical factors related to hematology for mammalian and nonmammalian species, hemostasis testing, and crossmatching and is adapted from sections 1.1 and 2.3 (mammalian hematology), 1.2 and 2.4 (nonmammalian hematology), 1.5 and 2.7 (hemostasis testing), and 1.6 and 2.8 (crossmatching) of the complete guidelines. These guidelines are not intended to be all-inclusive; rather, they provide minimal guidelines for quality assurance and quality control for veterinary laboratory testing and a basis for laboratories to assess their current practices, determine areas for improvement, and guide continuing professional development and education efforts.     

A comparison of the performance of three sward mixtures sown under trees in a silvopoultry system in the UK

Establishment of trees in the range as part of a silvopoultry system is considered to improve poultry welfare as well as provide wider environmental benefits. However one issue with these systems is a lack of understorey vegetation. This paper outlines the results of a trial on an organic poultry unit in southern England. The trial aimed to identify an understorey sward mixture able to establish and persist in a commercial poultry unit. Three sward mixtures (a standard grass and legume mix, a grass only mix, and a diverse sward mix) were sown in replicated 15 year old mixed broadleaf plots and compared with a natural regeneration control. Chickens were excluded for the first 3 months to allow sward establishment and then introduced for a 6 week period at two densities. Growth and establishment of the sward mixes along with the presence and abundance of unsown plants and unpalatable weeds was assessed. All mixtures established well under trees and didn’t show significant differences in cover after 6 weeks. Sward cover increased after 4 weeks suggesting minimum establishment period and higher weed suppression potential after this. Sowing any of the sward mixtures reduced the abundance of unpalatable weeds compared to the control. The commercially available standard sward mixture performed well compared to the other mixes, showing significantly higher biomass production by week six. Following the introduction of chickens, the sward mixtures survived only in the block with lower chicken pressure, measured by distance from house. Results from this trial demonstrate that establishing a sward under trees is possible but that the challenge is to maintain the sward in the presence of chickens. Excluding chickens initially to aid establishment and then optimising chicken pressure appears to be the key to maintaining a sward.     

Effect of mycobacterial cell wall fractions on dairy cow health and fertility

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Management of the transition dairy cow is key to future reproductive success, reduction of disease and lessening the incidence of metabolic disorders (Horst et al., 2021). Stimulation of the immune system during late gestation with choline, synthetic zeolites or other nutraceutical approaches may help prevent unwanted health consequences during the early lactation period (Riboni et al., 2019; Crookenden et al., 2020; Zenobi et al., 2020). A recent study demonstrates that injection of non-pathogenic mycobacterium cell wall fractions as an immunostimulant improves subsequent fertility rates in dairy cows and may offer another method for improving periparturient cow health (Solano-Suarez et al., 2021).     

The eye and orbit

Computed tomography (CT) and magnetic resonance imaging (MRI) provide excellent morphological detail of the eye and its associated structures. In veterinary medicine, these imaging modalities are most often used to diagnose and determine the extent of ocular or periocular tumors. They may also be used to diagnose inflammatory conditions of the orbital region and to determine the severity and extent of ocular trauma. This article reviews the applications of CT and MRI for ocular and orbital diseases, discusses normal findings, and presents representative case examples.