The role of the environment in partial migration: food availability affects the adoption of a migratory tactic in brown trout Salmo trutta

Abstract –  Alternative reproductive tactics are commonly reported for salmonids (Pisces) and typically involve large migratory and small resident individuals. Variation in migratory tendency should reflect the different benefits and costs that the two different phenotypes face with regard to fitness. Therefore, the effect of food availability on the adoption of a migratory tactic in brown trout was investigated. Fifty trout were placed in each of 12 tanks and fed at three different levels. Growth-related variables were measured regularly, and at the end of the experiment, the proportion of migrants and residents was recorded. Low food availability led to increased numbers of migratory fish. The expected sex-bias was also present, with a lower percentage of resident females than resident males. As all fish originated from the same gene pool, the changing proportions of the migratory tactics can be classified as phenotypic plasticity. The study provides evidence that the different phenotypes reflect alternative tactics within a conditional strategy. Some differences in growth-related variables were present between the sexes, and a very pronounced difference in condition factor was found between resident and migratory males, but not in females. Thus, the results provide evidence that different selective forces may be acting on the sexes.     

Evaluation of Antioxidant,Lipid, and Protein Fractions of Accessions of Oryza Species

The genus Oryza has given rise to rice (Oryza sativa L.), a major source of food for much of the human population. The Oryza genus is small, including only 23 species, but it is remarkably diverse in terms of its ecological adaptation. This diversity may not be only restricted to ecological characteristics but also to kernel end‐use quality characteristics. This study was undertaken to evaluate Oryza species as a gene pool for improving the properties of rice bran for human consumption. Several accessions of 13 Oryza species were grown in a greenhouse, along with eight rice (Oryza sativa L.) accessions displaying low and high bran oil content, as well as low and high palmitic acid content. The total lipid content of the Oryza species was within the range found for Oryza sativa accessions. However, the level of palmitic acid in the O. species was as high as that reported for soybean high‐palmitic acid mutants. Oryza species also contained higher levels of the γ‐oryzanol and phenolic fractions compared to cultivated rice. Low or not significant phenotypic correlations between lipid, palmitic acid, and γ‐oryzanol suggest that these fractions in cultivated rice could be increased simultaneously using several of the Oryza species accessions identified in this study. A cultivar with enhanced levels of these fractions would be suitable for use in the production of high γ‐oryzanol margarine, shortening, and frying oils.     

Ectoparasitic dermatitis in free-ranging swamp wallabies (Wallabia bicolor) in New South Wales

We report extensive dermatological lesions in three, free-ranging, adult, male swamp wallabies ( Wallabia bicolor ), presented to Taronga Western Plains Zoo wildlife hospital. All three animals were moderately infested with the louse species Heterodoxus ualabati , and two were concurrently infested with a previously undescribed sarcoptiform mite of the genus Diabolicoptes . Histological changes included moderate to marked compact hyperkeratosis, focal deep pyoderma and superficial dermatophytosis. Mild to moderate hyperplastic perivascular and periadnexal dermatitis with marked superficial and follicular hyperkeratosis was evident in the skin of the inguinal region and lateral thigh of the two wallabies infested with the Diabolicoptes species. This is the first report of ectoparasitic dermatitis in free-ranging swamp wallabies and the first report of mites of the genus Diabolicoptes from a macropodid.     

Retrospective evaluation of toceranib phosphate (Palladia®) toxicity in cats

The purpose of this study was to describe the toxicity profile of toceranib phosphate in tumour bearing cats. Medical records were reviewed from seven institutions. Patients with incomplete medical records and those receiving concurrent chemotherapy or NSAIDs (non‐steroidal anti‐inflammatory) were excluded. Fifty‐five cats met the inclusion criteria. Carcinoma was diagnosed in 55% of cases. Median oral toceranib dose was 2.7 mg kg^?1 and was most commonly administered on Monday, Wednesday and Friday. Thrombocytopenia (16.3%) and neutropenia (9.1%) were the most common haematologic toxicities. Azotemia (14.5%) and alanine aminotransferase (ALT) elevations (7.2%) were the most frequently encountered biochemical alterations. Gastrointestinal (GI) toxicity was seen in 21.8% of cats, and was lower than previously reported in dogs. The results of this study showed that treatment of cats with toceranib is well‐tolerated and toxicity is uncommon. Additional studies to define a more structured dosing schedule and to evaluate the efficacy of toceranib in the treatment of feline cancers are needed.     

Leukotrienes Affect Secretory Function of Ovarian Cells In Vitro*

The aim of this study was to determine which cells are the source of production and target for leukotriene (LTs) action within the bovine ovary. Luteal (CL, days 14–16 of the oestrous cycle), steroidogenic cells (LSC) and endothelial cells (LEC) of the bovine corpus luteum (CL), and granulosa cells (GC) were isolated enzymatically, cultured in a monolayer and incubated with LTC₄, LTB₄, Azelastine (an antagonist of LTC₄) or Dapsone (an antagonist of LTB₄). Then cells were collected for determination of mRNA expression for LT receptors (LTRs) and 5‐lipoxygenase (5‐LO) by real time RT‐PCR, and media were collected for determination of prostaglandin (PG)E₂, F_2α, progesterone (P4; LSC only), endothelin‐1 (ET‐1; LEC only) and 17‐β oestradiol (E2; GC only). The greatest mRNA expression for LTR‐II and 5‐LO were found in LEC, whereas LTR‐I mRNA expression did not differ among cell types. The level of PGE₂ increased after LTs treatment in each type of ovarian cell, excluding LTC₄ treatment in LEC. The secretion of PGF_2α was also increased by LTs, but decreased after LTB₄ treatment of LSC. In GC cultures, both LTs stimulated E2 secretion; in LEC cultures, LTB₄ stimulated whereas LTC₄ inhibited P4 secretion; in LEC cultures, LTC₄ stimulated but LTB₄ inhibited ET‐1 secretion. The results show that LTs are produced locally and are involved in PGs production/secretion in all examined cells (LSC, LEC and GC) of bovine ovary. Leukotriene treatment modulate secretion of E2, by GC, P4 by LSC and ET‐1 by LEC, which indicates that LTs are involved in regulation of ovarian secretory functions.     

Expression and localization of BCRP,MRP1 and MRP2 in intestines,liver and kidney in horse

Tydén, E., Bj?rnstr?m, H., Tjälve, H., Larsson, P. Expression and localization of BCRP, MRP1 and MRP2 in intestines, liver and kidney in horse. J. vet. Pharmacol. Therap. doi: 10.1111/j.1365‐2885.2009.01140.x. The gene and protein expression and the cellular localization of the ABC transport proteins breast cancer resistance protein (BCRP), multidrug resistance‐associated protein 1 (MRP1) and multidrug resistance‐associated protein 2 (MRP2) have been examined in the intestines, liver and kidney in horse. High gene and protein expression of BCRP and MRP2 were found in the small intestines, with cellular localization in the apical membranes of the enterocytes. In the liver, MRP2 was present in the bile canalicular membranes of the hepatocytes, whereas BCRP was localized in the cytoplasm of hepatocytes in the peripheral parts of the liver lobuli. In the kidney both BCRP and MRP2 were predominantly present in the distal tubuli and in the loops of Henle. In most tissues, the gene and protein expression of MRP1 were much lower than for BCRP and MRP2. Immunostaining of MRP1 was detectable only in the intestines and with localization in the cytoplasm of enterocytes in the caecum and colon and in the cells of serous acini of Brunner’s glands in the duodenum and the upper jejunum. The latter cells were also stained for BCRP, but not for MRP2. Many drugs used in horse are substrates for one or more of the ABC transport proteins. These transporters may therefore have important functions for oral bioavailability, distribution and excretion of substrate compounds in horse.     

Computed tomographic morphology of the synovial invaginations of the distal sesamoid bone of the horse

The morphological features of the distal border synovial invaginations (SI) of the distal sesamoid bone (DSB) in horses were described by the use of computed tomography (CT). Transverse CT images were obtained on 50 cadaver forefeet from 25 Warmblood horses. Dorsal and sagittal planes were reformatted. The CT images allowed the evaluation of the number, shape, depth of penetration and direction of the SI into the bone. The total number of SI was 295 (mean 5.9). The number of invaginations in a particular DSB ranged from 3 (n = 3), 4 (n = 6), 5 (n = 11), 6 (n = 12), 7 (n = 13), 8 (n = 3), 9 (n = 1) to 11 (n = 1). The shape of the SI was 'conical' (n = 118), 'linear' (n = 109), 'lollipop' (n = 38) or 'branched' (n = 30). Penetration of the SI into the DSB was 'mild' in 195 cases, 'moderate' in 67 cases and 'deep' in 33 cases. The SI ran in a 'straight', 'dorsoproximal' and 'palmaroproximal' direction in 187, 28 and 80 cases, respectively. In only six DSBs, all SI ran in the same direction. The images obtained in this study may serve as reference for the radiographic evaluation of these SI.     

Introduction and elimination of Bovine Viral Diarrhoea Virus in a commercial beef herd: a case study

Routine Bovine Viral Diarrhoea Virus (BVDV) monitoring of a commercial beef herd in southern New South Wales over a 10-year period provided an opportunity to assess the impact of the introduction of BVDV on that herd. BVDV antibody testing provided strong evidence that the herd was initially free of BVDV (2009–2011). Testing from 2012 suggested BVDV had been introduced into the herd and this was confirmed in 2015 with the identification of persistently infected (PI) animals. Having become established in the herd, the owners then set out to eliminate BVDV from the herd. Antigen testing aimed at identifying PI animals revealed BVDV was already absent from the herd. Subsequent antibody testing confirmed that the herd was now free from BVDV. Despite the incursion of BVDV in this herd, there was little measurable impact on reproductive performance (pregnancy rates), although suspected increased calf losses from birth to calf marking were reported. This is the first time such self-clearance has been documented as part of a longitudinal study under Australian conditions.     

A Gas Chromatography Procedure for Determining Milled Rice Surface Lipid Content

Rice (Oryza sativa, L.) degree of milling (DM) is a quantification of the amount of bran that has been removed from kernels during the milling process. Historically it has been determined using a time-consuming continuous solvent extraction (CSE) procedure to measure the surface lipid content. The objective of this research was to develop a gas chromatography (GC) method for rice surface lipids. The GC procedure was highly correlated with several other methods for DM including a commonly used CSE procedure and it demonstrated repeatability within acceptable analytical limits. Other aspects in support of the utility of this procedure are that it requires a relatively small amount of sample, organic solvent, and technician time. Consequently, this GC method for rice surface lipids measurement is suitable for use in determining rice DM in cultivar development programs and studies that require the analysis of a large number of samples.     

Rice Milling Quality,Grain Dimensions,and Starch Branching as Affected by High Night Temperatures

Important rice grain quality characteristics such as percentage of chalky rice kernels are affected by both high and low night temperatures and by different day and day/night temperature combinations. High nighttime temperatures have also been suspected of reducing rice milling quality including head rice yields. Experiments to confirm or refute this have not been reported. A controlled climate experiment was conducted. Conditions in the chambers were identical except between 2400 and 0500 hours (midnight and 5 am). For those times, two temperature treatments were imposed: 1) 18°C (low temperature treatment) and 2) 24°C (high temperature treatment). Two cultivars were tested: LaGrue and Cypress. The high temperature treatment reduced head rice yields compared with the low temperature treatment. Grain widths were reduced for the high temperature treatment compared with the low temperature treatment. There was no effect of temperature on grain length or thickness. Amylopectin chain lengths 13–24 were increased by the high temperature treatment by ≈1%. Future research will focus on determining whether genetic variability exists among cultivars in their head rice yield response to high temperatures. After identifying a source of resistance to high temperature effects, this characteristic can be incorporated into rice cultivars. In addition, ways to reduce this effect, including biotechnological remedies, have the potential for increasing rice yield and quality.