Effectiveness of a non-surgical alternative to the Mules operation in sheep

Objective To measure changes to the perineal bare area, local tissue reaction and healing responses of young sheep, following intradermal administration of cetrimide and polyvinylpyrrolidone (PVP), with and without ethanol, to the breech and tail. Method A needle‐less injector was used to deposit formulations containing 40 g/L cetrimide and 30 g/L PVP (group 2) or 20 g/L cetrimide, 30 g/L PVP and 15 g/L ethanol (group 3), within the dermis of the tail and the region surrounding the perineal bare breech area of groups (N = 8) of Merino weaner sheep. The dimensions of the perineal bare area (length, width and diagonal distances left and right) and tail width were recorded before and at intervals after treatment for 60 days. Observations of swelling and bruising and scab formation at the treatment sites were recorded for up to 35 days after treatment. Rectal temperatures were monitored for up to 35 days after treatment and bodyweight for up to 60 days after treatment. An untreated control group (group 1) was included. Results Comparison of day ‐3 and day 35 measurement data showed that both treated groups had significantly (P < 0.05) wider breech bare areas compared to the untreated controls and that group 2 sheep had significantly (P < 0.05) longer breech bare areas compared to group 3 sheep or to the untreated controls, which were not significantly different. At this time scabs were still firmly in place on many treated sheep. At day 35 there was no increase in tail bare area caused by either treatment. By day 60 there was no significant difference between the treated and control groups in either the breech or tail regions indicating that the changes present at day 35, were not permanent. Mean weight gain in the groups throughout the 60‐day interval was unaffected by treatment. Intradermal treatment was associated with a significant elevation in body temperature. This effect lasted for 3 days and was associated with signs of discomfort and depressed appearance in at least some of the treated sheep. Bruising was mild to severe in all treated sheep within two days of treatment but was not evident in any sheep by day 21. Mild to moderate swelling was also associated with treatment but was not uniform across sheep in the groups. The tail of one sheep was severely swollen for several days. Swelling remained obvious in most treated sheep until day 14 but was not present at day 21. Conclusion Under the conditions of this study intradermal injection of cetrimide had no permanent effect on bare area measurements on the breech or the amount of wool‐bearing skin on the tail. It also caused signs of discomfort and pain that raise welfare concerns.     

Serum cobalamin concentrations in healthy cats and cats with non-alimentary tract illness in Australia

Objective   To determine a reference range for serum cobalamin concentration in healthy cats in Australia using a chemiluminescent enzyme immunoassay and to prospectively investigate the prevalence of hypocobalaminaemia in cats with non-alimentary tract disease.
Design   Prospective study measuring serum cobalamin concentrations in clinically healthy cats and cats with non-alimentary tract illness.
Procedure   Blood was collected from 50 clinically healthy cats that were owned by staff and associates of Veterinary Specialist Services or were owned animals presented to Creek Road Cat Clinic for routine vaccination. Blood was collected from 47 cats with non-alimentary tract illness presented at either clinic. Serum cobalamin concentration was determined for each group using a chemiluminescent enzyme immunoassay.
Results   A reference range for Australian cats calculated using the central 95th percentile in the 50 clinically healthy cats was 345 to 3668 pg/mL. Median serum cobalamin concentration in 47 cats with non-alimentary tract illness (1186 pg/mL; range 117–3480) was not significantly different to the median serum cobalamin of the 50 healthy cats (1213 pg/mL, range 311–3688). Using the calculated reference range one sick cat with non-alimentary tract illness had a markedly low serum cobalamin concentration.
Conclusion   Although hypocobalaminaemia is uncommon in sick cats with non-alimentary tract illness in Australia, its occurrence in this study warrants further investigation.     

Ameliorative Effects of Melatonin against Hydrogen Peroxide‐Induced Oxidative Stress on Boar Sperm Characteristics and Subsequent In Vitro Embryo Development

Melatonin, the major secretory product of the pineal gland, scavenges a variety of reactive oxygen and nitrogen species in vivo and in vitro, indicating that melatonin is a potent function as an antioxidant. The objective of this study was to investigate the effect of melatonin in the presence or absence of hydrogen peroxide (H₂O₂) on sperm characteristics (motility, viability, survival rate, membrane integrity, lipid peroxidation (LPO) and mitochondria activity) and also to examine the developmental rates to the blastocysts stage of porcine oocytes fertilized in vitro with semen treated with or without melatonin (100 nm ) in the presence or absence of H₂O₂ (250 μm ). The sperm were treated with melatonin in the presence or absence of H₂O₂ for 3, 6, 9 and 12 h at 37°C and then analysed for the sperm characteristics. The porcine embryos were produced by in vitro maturation and in vitro fertilization (IVM/IVF) using semen treated with or without melatonin (100 nm ) in the presence or absence of H₂O₂ (250 μm ) for 6 h. The semen characteristics, including motility, viability, survival rate, membrane integrity and mitochondria activity, were higher in the groups that were treated with melatonin in comparison to other groups, irrespective of incubation periods. Malondialdehyde levels in control, melatonin and melatonin + H₂O₂ groups were lower than H₂O₂ only group. A positive correlation was shown among motility, viability, survival rate and membrane integrity, but a negative correlation was observed between LPO and the other evaluation methods. The developmental rates to blastocysts of IVM/IVF porcine oocytes fertilized by semen treated with melatonin were significantly increased compared with any other groups, with the cell number of blastocysts shown to have a similar trend to the developmental rates. These results demonstrate that melatonin can improve the semen characteristics during in vitro storage and support the developmental ability of IVM/IVF embryos in pigs.     

Antioxidative Effects of Astaxanthin against Nitric Oxide‐Induced Oxidative Stress on Cell Viability and Gene Expression in Bovine Oviduct Epithelial Cell and the Developmental Competence of Bovine IVM/IVF Embryos

The aim of the present study was to elucidate the fundamental mechanism of bovine oviduct epithelial cell (BOEC) co‐culture on developmental capacity of bovine in vitro oocyte maturation/in vitro fertilization (IVM/IVF) embryos. We examined the effects of astaxanthin against nitric oxide‐induced oxidative stress on cell viability by MTT assay, lipid peroxidation (LPO) by using thiobarbituric acid (TBA) reaction for malondialdehyde (MDA) and the expression of antioxidant genes (CuZnSOD, MnSOD and Catalase) or apoptosis genes (Bcl‐2, Caspase‐3 and Bax) by RT‐PCR in BOEC. We also evaluated the developmental rates of bovine IVM/IVF embryos co‐cultured with BOEC pre‐treated with astaxanthin (500 μm ) in the presence or absence of sodium nitroprusside (SNP, 1000 μm ) for 24 h. Cell viability in BOEC treated with SNP (50–2000 μm ) lowered, while astaxanthin addition (50–500 μm ) increased it in a dose‐dependent manner. Cell viability in astaxanthin plus SNP (1000 μm ) gradually recovered according to the increase in astaxanthin additions (100–500 mm ). The LPO in astaxanthin group (50–500 μM) gradually decreased in a dose dependent manner and among SNP or astaxanthin plus SNP group, SNP alone and astaxanthin (50 μM) plus SNP shown a significant increase than other groups (p < 0.05). Expression of apoptosis or antioxidant genes was detected by RT‐PCR. Bcl‐2 and antioxidant genes were detected in astaxanthin or astaxanthin plus SNP group, and Caspase‐3 and Bax genes were only found in SNP group. When bovine IVM/IVF embryos were cultured for 6–7 days under co‐culture system such as BOEC treated with astaxanthin in the presence or absence of SNP, the developmental ability to blastocysts in 500 μm astaxanthin group was the highest of all groups. These results suggest that astaxanthin has a antioxidative effect on cell viability and LPO of BOEC, and development of bovine IVM/IVF embryos due to the induction of antioxidant genes and suppression of apoptosis genes.     

Brucellosis associated with stillbirth in a bottlenose dolphin in Australia

A captive adult female bottlenose dolphin presented with stillbirth. The placenta appeared oedematous. No other gross lesions were evident in the placenta or the stillborn calf. Histopathology revealed mild multifocal placentitis and foetal encephalitis. Brucella sp. was isolated from lung, liver, spleen and kidney. Sequence and phylogenetic analysis demonstrated this organism to be most similar to Brucella ceti sequence type (ST) 27. Brucella sp. DNA was detected in formalin-fixed paraffin-embedded placenta and brain by real-time PCR using primers targeting the IS711 gene. Immunohistochemical staining revealed Brucella sp. antigen in placental inflammation. This is the first report of isolation of Brucella sp. from a marine mammal in the Southern Hemisphere and the first report of marine Brucella-associated disease in Australia.     

Single species island biogeography and Montana mule deer

The theory of island biogeography supplemented with dynamic concepts from other areas of biology can be applied to a single species. Data series from mule deer Odocoileus hemonius hemonius populations inhabiting diverse mountain as well as prairie habitats were compared. The fawn-doe ratios obtained at 6 months of age were inversely correlated (r = ?0·97; p < 0·01) with ‘island’ size as indicated by the percentage of cover. Populations inhabiting small islands of cover in the prairie consistently had higher winter fawn-doe ratios than those of the relatively secure mountain habitats. Cover fragmentation and low security level of the prairi populations relates to a high annual turnover rate compared with that of the mountain populations. The impact of cover fragmentation is consistent with this interpretation of theory which pictures reproduction as annual recolonisation. This approach may be useful in predicting hunting and ecological impact effects.     

Isolation of very virulent Marek''s disease viruses from vaccinated chickens in Australia

Very virulent Marek's disease viruses (vvMDV), defined as isolates against which the herpesvirus of turkey (HVT) vaccine provide poor protection, have been isolated from poultry flocks in both the United States and Europe. Twenty-one samples from vaccinated Australian flocks, experiencing problems with excessive Marek's disease (MD), were tested for the presence of transmissible MD viruses (MDV). Of the 16 samples which contained a transmissible agent, 14 were pathogenic in chickens, based on the development of MD lesions or depression of the bursa/body weight ratio. Of the pathogenic isolates which have been successfully typed 10 were serotype 1, and one was serotype 2 MDV. Pathogenicity of isolates varied. Several isolates caused tumours in 20-30% of both vaccinated and unvaccinated chickens. Two isolates, MPF6 and MPF23, caused tumours in more than 50% of chickens. When MPF6 and MPF23 were tested in vaccine trials bivalent vaccine gave no better protection against development of MD lesions than a monovalent vaccine. Isolate MPF23 was so pathogenic that lesions were produced in all chickens, regardless of the vaccine protocol used. Therefore vvMDV have been isolated in Australia, and unlike the vaccines tested overseas, bivalent Australian vaccines do not appear to provide greater protection against these vvMDV.