Flow Cytometry Identification of X- and Y-Chromosome-Bearing Goat Spermatozoa

Flow cytometric sorting technology was used to measure the difference in DNA content between X- and Y-chromosome-bearing spermatozoa in bucks. Spermatozoa were analysed by flow cytometry to characterize X- and Y-chromosome-bearing sperm populations and to quantify the DNA difference between them. Two symmetrical, overlapping and clearly separated peaks, corresponding to X- and Y-bearing spermatozoa, were detected. The difference in fluorescence intensity between the peaks was 4.4 +/- 0.03% without any significant inter- or intra-animal variations. Therefore, the identification and selection of high-purity samples of sperm populations for sex sorting is easier in bucks compared with other domestic species.     

Review: The strobilurin fungicides

The original article to which this Correction refers was published in Pest Management Science 58 (7): 649–662 (2002).Copyright © 2004 Society of Chemical Industry     

Equine pituitary pars intermedia dysfunction: current understanding and recommendations from the Australian and New Zealand Equine Endocrine Group

The purpose of this article is to provide a review of the current knowledge and opinions about the epidemiology, clinical findings (including sequelae), diagnosis, treatment and monitoring of equine pituitary pars intermedia dysfunction, particularly in the Australian context. This information and the recommendations provided will assist practitioners in making informed decisions regarding the diagnosis and management of this disorder.     

Effect of bovine seminal plasma on bovine endometrial epithelial cells in culture

The purpose of this study was to investigate the effect of seminal plasma (SP) from bulls of known fertility on bovine endometrial epithelial cells (bEEC) in culture. The bEEC from passage 5, approximately 5.0–13 × 10⁵ cells per flask, were challenged with SP from bulls of high or low fertility (n = 3 and 2, respectively) or PBS (control), at 1% (75 μl) or 4% (300 μl) and were incubated for 72 hr (n = 13 per challenge). Total cell number and viability of bEEC after challenge with 1% SP from either high‐ or low‐fertility bulls (75H or 75L, respectively) did not differ from controls. In contrast, challenge with 4% of SP from high‐ or low‐fertility bulls (300H or 300L) negatively affected bEEC cell number and viability. Challenge with 300 L had a greater adverse effect than 300H. These results suggest that the negative effect of bovine SP on bEEC is both dose‐dependent and fertility‐dependent.     

A framework for evaluation of on-farm mastitis diagnostics in Australia

Numerous culture-based diagnostics are available on the Australian and international markets for on-farm detection of bacterial pathogens in milk. Use of such diagnostics may provide an opportunity to improve the prudent use of antimicrobials in udder health management. Farms are low-resource settings in terms of diagnostic microbiology capacity. The World Health Organisation has identified criteria for the evaluation of diagnostic tests in low resource settings based on Accuracy, Sensitivity, Specificity, User-friendliness, being Rapid or Robust, Equipment-free and being Deliverable (ASSURED). Here, we review how those criteria can be interpreted in the context of microbiological diagnosis of mastitis pathogens, and how on-farm diagnostics that are currently available in Australia perform relative to ASSURED criteria. This evaluation identifies multiple trade-offs, both with regard to scientific criteria and with regards to convenience criteria. More importantly, the purpose of testing may differ between farms, and test performance should be evaluated relative to its intended use. The ability of on-farm mastitis diagnostics to inform mastitis treatment decision-making in a timely and cost-effective manner depends not just on test characteristics but also on farm-specific pathogen prevalence, and on the farm enterprise's priorities and the farm manager's potential courses of action. With most assay evaluations to date conducted in professional laboratories, there is a surprising dearth of information on how well any of the diagnostic tests perform on-farm and, indeed, of the on-farm decision-making processes that they aim to inform.     

The effects of sodium chloride on ornamental shrubs

The use of saline waters is an option for the irrigation of salt tolerant ornamentals as competition for high quality water increases. However, despite the importance of ornamental shrubs in Mediterranean areas, salt tolerance of such species has received little attention. The aims of our investigation were to quantify the growth response and any injury symptom of 12 widely cultivated ornamental shrubs to irrigation with saline water and to investigate any possible relation with the concentration of Na⁺ and Cl⁻ in the plants. Species were irrigated with different salinities (10, 40, and 70 mM NaCl) for a 120-day period. At the end of salt treatment, plants were sampled and dry biomass recorded; the relative growth rate (RGR) was also calculated. Root and leaf samples from each species were used to evaluate Na⁺, K⁺ and Cl⁻ concentrations. Growth rates were significantly reduced in Cotoneaster lacteus, Grevillea juniperina and Pyracantha ‘Harlequin’, which also showed the highest percentage of necrotic leaves. The increasing external NaCl lead to an increase of Na⁺ and Cl⁻ in roots and leaves of the different species, although less Na⁺ was accumulated than Cl⁻: growth reduction well correlated with the concentration of Cl⁻ and/or Na⁺ in the leaves. The most sensitive species (i.e. C. lacteus, G. juniperina and Pyracantha ‘Harlequin’) had high concentrations of Na⁺ and/or Cl⁻ in their leaves and also showed a decrease in their leaf K⁺/Na⁺ ratios. Even though other species (i.e. Bougainvillea glabra, Ceanothus thyrsiflorus, Leptospermum scoparium, Leucophyllum frutescens and Ruttya fruticosa) demonstrated a high ion concentration in their leaves, they could be considered relatively salt tolerant as there was little growth reduction and few symptoms of injury in the leaves. In some other cases (i.e. Cestrum fasciculatum, Escallonia rubra and Viburnum lucidum) the observed tolerance was related to higher ion concentration in the roots compared to the leaves, probably indicative of a limited transport to the shoots. Only in Eugenia myrtifolia was the absence of symptoms associated with a limited Na⁺ and Cl⁻ uptake from the rhizosphere.     

Fluorescent enzyme immunoassay for rapid screening of Salmonella in foods: collaborative study

A collaborative study was performed in 13 laboratories to validate an enzyme immunoassay (EIA) procedure for rapid detection of Salmonella in foods. The EIA was compared with the standard culture procedure for detection of Salmonella in 6 food types: ground black pepper, soy flour, dried whole eggs, milk chocolate, nonfat dry milk, and raw deboned turkey. Uninoculated and inoculated samples were included in each food group analyzed. There was no significant difference in the proportion of samples positive by the EIA and culture procedures at the 5% level for any of the 6 foods. The enzyme immunoassay screening method has been adopted official first action as a rapid screening method for detection of Salmonella.     

Management of drug-resistant cyathostominosis on a breeding farm in central North Carolina

REASONS FOR PERFORMING STUDY: Possible anthelmintic resistance on a breeding farm where a rapid rotation anthelmintic programme had been implemented for 9 years was investigated. Cyathostomins resistant to fenbendazole and pyrantel were documented by faecal worm egg count reduction test (FWECRT). OBJECTIVES: To 1) manage small strongyle transmission in a herd of horses in which resistance to both pyrantel pamoate and fenbendazole was identified and thereby reduce the risk of clinical disease in the individual animal, 2) monitor the change in resistance patterns over time and 3) monitor the efficacy of ivermectin over the study period. METHODS: Targeted ivermectin treatment of horses on the farm was instituted for mature horses with faecal worm egg counts (FWEC) > 200 eggs/g (epg) and for horses < age 2 years with FWEC > 100 epg. RESULTS: Over a 30 month period, targeted ivermectin treatment achieved acceptable control in mares, as judged by FWEC, and improved control of patent cyathostome infection in consecutive foal crops. Egg reappearance time (ERT) after treatment with ivermectin was < 8 weeks in mares and foals more frequently in the second year of the study than in the first year. Numbers of anthelmintic treatments were reduced by 77.6 and 533% in the mare and foal group, respectively. CONCLUSIONS: Targeted ivermectin treatment may be an economically viable method of managing multiple drug resistant cyathostominosis. POTENTIAL RELEVANCE: Use of ivermectin should be monitored closely for development of resistance.