Variable selection in near infrared spectra for the biological characterization of soil and earthworm casts

Near infrared reflectance spectroscopy (NIRS) was used to predict six biological properties of soil and earthworm casts including extracellular soil enzymes, microbial carbon, potential nitrification and denitrification. Partial least squares regression (PLSR) models were developed with a selection of the most important near infrared wavelengths. They reached coefficients of determination ranging from 0.81 to 0.91 and ratios of performance-to-deviation above 2.3. Variable selection with the variable importance in the projection (VIP) method increased dramatically the prediction performance of all models with an important contribution from the 1750–2500 nm region. We discuss whether selected wavelengths can be attributed to macronutrient availability or to microbial biomass. Wavelength selection in NIR spectra is recommended for improving PLSR models in soil research.     

Treatment of leiomyosarcoma in a tiger (Panthera tigris) with stereotactic radiotherapy

A 10‐year‐old male captive tiger (Panthera tigris) developed right‐sided facial asymmetry and enlargement. Computed tomography revealed a destructive mass of the right maxillary bone with right nasal cavity involvement. Histopathology indicated a spindle cell sarcoma. A single fraction of 22 Gy using stereotactic radiotherapy was prescribed. After treatment, the facial conformation returned to normal and the tiger resumed normal behavior. Diagnostics 4 months later indicated severe metastatic disease. Humane euthanasia and necropsy were performed. This is the first case utilizing stereotactic radiotherapy for the treatment of cancer in a tiger.     

The oxidant/antioxidant equilibrium in horses

Since "free radical research" started in 1954, understanding the role of oxidants and antioxidants in physiological and pathological conditions has increased continuously. Oxidants are essentially generated by metabolic enzymes, inflammatory cells and mitochondrial electron leakage; they are indispensable for the cellular redox regulation and may, under certain conditions, have a pro-inflammatory stimulatory role. Endogenous and exogenous antioxidants counterbalance the oxidative processes and so maintain the oxidant/antioxidant equilibrium. Excessive oxidant generation or antioxidant insufficiency can lead to oxidative stress. The aims of this review are: (1) to provide an insight into the concept of the oxidant/antioxidant equilibrium by briefly introducing the oxidant and the antioxidant systems; (2) to describe how the oxidant/antioxidant equilibrium or oxidative stress can be evaluated in horses, and (3) to summarise current knowledge about oxidative stress in equine medicine and equine exercise physiology.     

Evaluation of targeted drenching using Famacha method in Creole goat: reduction of anthelmintic use, and effects on kid production and pasture contamination

Haemonchus infection was monitored for 2 years (six kidding periods) in a Creole goat flock grazing under oceanic-tropical climate. Two hundred and thirty individual does were involved from late pregnancy to weaning. Anaemia diagnoses using Famacha method and packed cell volume (PCV) were compared. The best agreement (Kappa=0.33) was found if anaemia was declared when PCV values fell to 16 or below and Famacha score was 4 or 5. Drenching policy according to Famacha method was compared to systematic drenching policy. Using the Famacha method allowed a dramatic decrease in anthelmintic use during the periparturient period (0.57 individual dose instead of three doses for the control). The proportion of the nematode population on the pasture not derived from previously-treated goats (in refugia) was estimated to about 79% (65-90%) of the pasture contamination derived from the Famacha group. On the average, goats which needed to be drenched produced less than the control or undrenched goats (kid average daily gain was decreased by about 15%). The repeatability of the need for drenching individual does was estimated to 0.41. The older goats or the goats in poorer body condition at kidding needed more drenching than the younger animals and the animals in good body condition. Consequently the Famacha method may be used as an additional tool for the culling management.     

Collection of exhaled breath condensate and analysis of hydrogen peroxide as a potential marker of lower airway inflammation in cats

The objective of this study was to describe a standardised and non-invasive method for exhaled breath condensate (EBC) collection in cats and to test whether determination of hydrogen peroxide (H(2)O(2)) in EBC might be used as marker of lower airway inflammation. The technique of barometric whole body plethysmography for cats was combined with a system to condense the effluent air from the plethysmograph, allowing simultaneous EBC collection and respiratory pattern measurement. H(2)O(2) was determined spectrophotometrically. Eighteen experimental cats were used to investigate the impact on EBC volume and EBC H(2)O(2) of plethysmograph ventilation rate, collection duration, sample stability, within-day and day-to-day variability. After determination of a standardised EBC collection procedure, correlation analyses between EBC H(2)O(2) and bronchoalveolar lavage (BAL) cytology of healthy and allergen-challenged Ascaris suum (AS)-sensitised cats were performed. A significant and positive correlation between EBC H(2)O(2) and bronchoalveolar lavage (BAL) neutrophil% was found in healthy cats (P < 0.001, r = 0.55), whereas in AS-sensitised cats, correlation with BAL eosinophil% was significant (P < 0.005, r = 0.61). H(2)O(2) was increased after an allergen challenge in AS-sensitised cats (n = 6, 0.56+/-0.12 versus 1.08+/-0.35 micromol/L, P < 0.05). This study proposes a non-invasive, well tolerated and repeatable method of EBC collection for cats and suggests that EBC H(2)O(2) might be used as non-invasive biomarker for monitoring lower airway inflammation.     

Geosmin causes off‐flavour in arctic charr in recirculating aquaculture systems

The ‘earthy’ and ‘muddy’ off‐flavours in pond‐reared fish are due to the presence of geosmin or 2‐methylisoborneol in the flesh of the fish. Similar off‐flavours have been reported in fish raised in recirculating aquaculture systems (RAS); however, little information is available regarding the cause of these off‐flavours. Our hypothesis was that earthy and muddy off‐flavour compounds, found previously in pond‐raised fish, are also responsible for off‐flavours in fish raised in RAS. In this preliminary study, we examined water, biofilms in RAS and fillets from cultured arctic charr known to have off‐flavours and requiring depuration using instrumental [solid‐phase microextraction procedure and gas chromatograph‐mass spectrometry (GC‐MS)] and human sensory analyses. Geosmin was present in the samples taken from the biofilter and on the side walls of the tanks. Two‐methylisoborneol was only found in low levels in the samples. The GC‐MS results indicated the presence of geosmin in the fillets (705 ng kg^?1), but lower levels were found in the water (30.5 ng L^?1). Sensory analyses also detected an earthy flavour (i.e., geosmin presence) in the fillets, and, therefore, it appears that geosmin is the main compound responsible for the off‐flavour in RAS. Further studies are being performed to identify the microorganisms responsible for geosmin production in RAS.     

Effect of an inactivated bluetongue serotype 8 vaccine on semen quality in rams

The aim of this study was to determine whether a single dose of an inactivated bluetongue virus serotype 8 (BTV-8) vaccine altered semen quality in rams. Twenty sexually mature rams were assigned to three experimental groups: two groups of four animals were vaccinated and a third group of four animals was unvaccinated. The first group included rams with a history of natural BTV-8 infection in 2007 and the second and third groups included BTV-8 na?ve rams. Semen was collected prior to vaccination and for 4months post-vaccination. There were no significant differences in semen quality traits, including motility and concentration of spermatozoa, and percentages of living, normal dead and abnormal dead spermatozoa, between vaccinated and unvaccinated groups, or over time (P>0.05). The BTV-8 vaccine tested in this study did not appear to have any adverse effect on semen quality in rams.