Genital pathology of feral male goats

Genitalia from 1000 feral male goats derived from western Queensland and New South Wales were examined after slaughter at an abattoir and the prevalence of abnormalities determined. Ulcerative balanoposthitis, considered due to caprine herpesvirus infection, was observed in 11 animals (1.1%); acidophilic intranuclear inclusions were found in 7 of these. Other conditions included focal hypoplasia of seminiferous tubules in 2 bucks (0.2%), segmental aplasia of the epididymis (one buck, 0.1%), bulbourethral gland cysts with contained aggregations (33 bucks, 3.3%) and haemangiosarcoma of the bulbourethral gland in one animal. The low prevalence of several conditions such as spermatic granuloma, cryptorchidism, and testicular hypoplasia, was attributed largely to the fact that the bucks examined were horned so that the recognised association between genital abnormalities and polledness did not apply.     

Association of key foods and beverages with obesity in Australian schoolchildren

OBJECTIVE: To examine the pattern of intake of key foods and beverages of children aged 4-12 years and the association with weight status. DESIGN AND SETTING: A computer-assisted telephone interview was used to determine the intake of fruit, vegetables, packaged snacks, fast foods and sweetened drinks 'yesterday' and 'usually' as reported by parents/guardians of a representative sample of 2184 children from the Barwon South-Western region of Victoria, Australia. RESULTS: Children who consumed >2-3, >3-4 and >4 servings of fruit juice/drinks 'yesterday' were, respectively, 1.7 (95% confidence interval (CI) 1.2-2.2), 1.7 (95% CI 1.2-2.5) and 2.1 (95% CI 1.5-2.9) times more likely to be overweight/obese compared with those who had no servings of fruit juice/drink 'yesterday', adjusted for age, gender and socio-economic status (SES). Further, children who had > or = 3 servings of soft drink 'yesterday' were 2.2 (95% CI 1.3-3.9) times more likely to be overweight/obese compared with those who had no servings of soft drink 'yesterday', adjusted for age, gender and SES. In addition, children who 'usually' drank fruit juice/drinks twice or more per day were 1.7 (95% CI 1.2-2.4) times more likely to be overweight/obese compared with those who drank these beverages once or less per week, adjusted for age, gender and SES. Although fast foods and packaged snacks were regularly eaten, there were no associations between weight status and consumption of these foods. CONCLUSIONS: Intake of sweetened beverages was associated with overweight and obesity in this population of Australian schoolchildren and should be a target for intervention programmes aimed at preventing unhealthy weight gain in children.     

IHHN virus: Infectivity and pathogenicity studies in Penaeus stylirostris and Penaeus vannamei

Infectivity studies of infectious hypodermal and hematopoietic necrosis virus (IHHNV) were conducted on Penaeus stylirostris and P. vannamei (representing species highly susceptible and highly refractory to the disease) via intramuscular injections of the virus. Distinctive histological lesion patterns were observed between species. Six target organ systems were compared interspecifically. The gills and nerve cord/ganglia were shown to undergo significantly higher degrees of tissue damage in infected P. stylirostris compared with infected P. vannamei. Pathogenetic differences correlated well with observed differences in epizootiology between the two species.The infectivity study confirmed that IHHN disease is virus-caused. Cell-free extracts from IHHNV-infected shrimp, when injected into healthy, susceptible shrimp, produced mortalities and Cowdry type A intranuclear eosinophilic inclusion bodies presently considered pathognomonic for the disease.     

A hyperparasitic microsporidian infecting the salmon louse, Lepeophtheirus salmonis: an rDNA-based molecular phylogenetic study

The sea louse, Lepeophtheirus salmonis, is an obligate ectoparasitic copepod that lives on the external surface of salmonid fish. It is the most common ectoparasite of marine cage-reared salmonids, causing major economic loss to the aquaculture industry. During a sea louse monitoring programme, samples of L. salmonis were found to harbour an unreported microsporidian parasite. The microsporidian was observed in pre-adult and adult stages of both male and female copepods, with a prevalence of up to 5%. Unfixed spores were slightly pyriform in shape measuring 2.34 microm by 1.83 microm (+/- 0.01 microm) and were not observed to be enclosed by a sporophorous vesicle. The microsporidian infection was observed in all areas of the copepods' body, xenoma-like cysts forming directly under the cuticle in the epidermal tissue layer. In the present study, rDNA (530f-580r) sequence data gathered from the unidentified microsporidian parasite isolated from infected sea lice were compared with equivalents available in the databases in an attempt to identify its systematic position. The microsporidian was found to group within the phylogenetic clade containing the family Enterocytozoonidae, being most similar to members of the intranuclear genus Nucleospora. This is the first report of a hyperparasitic microsporidian infecting a caligid copepod.     

Grow-out of sandfish Holothuria scabra in ponds shows that co-culture with shrimp Litopenaeus stylirostris is not viable

We examined the potential for producing the large numbers of sandfish (Holothuria scabra) needed for restocking programmes by co-culturing juveniles with the shrimp Litopenaeus stylirostris in earthen ponds. Our experiments in hapas within shrimp ponds were designed to detect any deleterious effects of sandfish on shrimp, and vice versa. These experiments showed that a high stocking density of juvenile sandfish had no significant effects on growth and survival of shrimp. However, survival and growth of sandfish reared with shrimp for 3 weeks were significantly lower than for sandfish reared alone. Increased stocking density of shrimp also had a significant negative effect on survival and/or growth of sandfish. A grow-out trial of juvenile sandfish in 0.2-ha earthen ponds stocked with 20 shrimp post-larvae m^− 2, and densities of sandfish between 0.8 and 1.6 individuals m^− 2, confirmed that co-culture is not viable. All sandfish reared in co-culture were dead or moribund after a month. However, sandfish stocked alone into 0.2-ha earthen ponds survived well and grew to mean weights of ∼ 400 g within 12 months without addition of food. The grow-out trial demonstrated that there is potential for profitable pond farming of sandfish in monoculture. Further research is now needed to identify the optimal size of juveniles, stocking densities and pond management regimes.     

Effects of dietary lipid level and vegetable oil on fatty acid metabolism in Atlantic salmon (Salmo salar L.) over the whole production cycle

Changes in fatty acid metabolism in Atlantic salmon (Salmo salar) induced by vegetable oil (VO) replacement of fish oil (FO) and high dietary oil in aquaculture diets can have negative impacts on the nutritional quality of the product for the human consumer, including altered flesh fatty acid composition and lipid content. A dietary trial was designed to investigate the twin problems of FO replacement and high energy diets in salmon throughout the entire production cycle. Salmon were grown from first feeding to around 2 kg on diets in which FO was completely replaced by a 1:1 blend of linseed and rapeseed oils at low (14–17%) and high (25–35%) dietary oil levels. This paper reports specifically on the influence of diet on various aspects of fatty acid metabolism. Fatty acid compositions of liver, intestinal tissue and gill were altered by the diets with increased proportions of C₁₈ polyunsaturated fatty acids and decreased proportions of n-3 highly unsaturated fatty acids (HUFA) in fish fed VO compared to fish fed FO. HUFA synthesis in hepatocytes and enterocytes was significantly higher in fish fed VO, whereas β-oxidation was unaltered by either dietary oil content or type. Over the entire production cycle, HUFA synthesis in hepatocytes showed a decreasing trend with age interrupted by a large peak in activity at seawater transfer. Gill cell prostaglandin (PG) production showed a possible seasonal trend, with peak activities in winter and low activities in summer and at seawater transfer. PG production in seawater was lower in fish fed the high oil diets with the lowest PG production generally observed in fish fed high VO. The changes in fatty acid metabolism induced by high dietary oil and VO replacement contribute to altered flesh lipid content and fatty acid compositions, and so merit continued investigation to minimize any negative impacts that sustainable, environmentally-friendly and cost-effective aquaculture diets could have in the future. Abbreviations: FO - fish oil; HUFA - highly unsaturated fatty acids acids (carbon chain length ≥C ₂₀ with ≥3 double bonds); LO - linseed oil; RO - rapeseed oil; VO - vegetable oil. This revised version was published online in July 2006 with corrections to the Cover Date.