Preliminary investigation into the prevalence of mucormycosis in the platypus (Ornithorhynchus anatinus) in three catchments in north-west Tasmania

Objective To investigate the distribution and prevalence of mucormycosis in platypus (Ornithorhynchus anatinus) from the Inglis, Emu and Black-Detention catchment areas in north-west Tasmania. Procedure A field study was performed and resulted in the examination of 44 wild platypuses; in addition, one dead platypus and two live platypuses were examined after they were independently submitted to a local veterinary clinic. Results No cases of mucormycosis were conclusively diagnosed. One platypus with signs consistent with those previously described in cases of mucormycosis was captured in the Emu River catchment. However, laboratory tests did not provide a definitive diagnosis for the lesion. Two platypuses from the Inglis catchment area had signs very similar to those previously described in cases of mucormycosis, but laboratory tests found Corynebacterium ulcerans to be the likely cause of the cutaneous ulcers on one of these platypuses and an unidentified fungal agent to be the cause of a cutaneous nodule in the other. Conclusions These findings do not prove that mucormycosis is absent from the populations studied. However, they may indicate that the prevalence of disease is low. The possibility that Mucor amphibiorum is present in a subclinical form in platypuses, or infecting another reservoir, is not excluded. The findings also suggest that caution should be exercised when diagnosing mucormycosis based on clinical findings alone and raise the possibility that some cases may have been incorrectly diagnosed.     

Evaluation of procedures to predict fat-free lean in swine carcasses

The objectives were to develop equations for predicting fat-free lean in swine carcasses and to estimate the prediction bias that was due to genetic group, sex, and dietary lysine level. Barrows and gilts (n = 1,024) from four projects conducted by the National Pork Board were evaluated by six procedures, and their carcass fat-free lean was determined. Pigs of 16 genetic groups were fed within weight groups one of four dietary regimens that differed by 0.45% in lysine content and slaughtered at weights between 89 and 163 kg. Variables in equations included carcass weight and measures of backfat depth and LM. Fat-free lean was predicted from measures of fat and muscle depth measured with the Fat-O-Meater (FOM), Automated Ultrasonic System (AUS), and Ultrafom (UFOM) instruments, carcass 10th-rib backfat and LM area (C10R), carcass last-rib backfat (CLR), and live animal scan of backfat depth and LM area with an Aloka 500 instrument (SCAN). Equations for C10R (residual standard deviation, RSD = 2.93 kg) and SCAN (RSD = 3.06 kg) were the most precise. The RSD for AUS, FOM, and UFOM equations were 3.46, 3.57, and 3.62 kg, respectively. The least precise equation was CLR, for which the RSD was 4.04 kg. All procedures produced biased predictions for some genetic groups (P < 0.01). Fat-free lean tended to be overestimated in fatter groups and underestimated in leaner ones. The CLR, FOM, and AUS procedures overestimated fat-free lean in barrows and underestimated it in gilts (P < 0.01), but other procedures were not biased by sex. Bias due to dietary lysine level was assessed for the C10R, CLR, FOM, and SCAN procedures, and fat-free lean in pigs fed the lowlysine dietary regimen was overestimated by CLR, FOM, and SCAN (P < 0.05). Positive regressions of residuals (measured fat-free lean minus predicted fat-free lean) on measured fat-free lean were found for each procedure, ranging from 0.204+/-0.013 kg/kg for C10R to 0.605+/-0.049 kg/kg for UFOM, indicating that all procedures overestimated fat-free lean in fat pigs and underestimated it in lean pigs. The pigs evaluated represent the range of variation in pigs delivered to packing plants, and thus the prediction equations should have broad application within the industry. Buying systems that base fat-free lean predictions on measures of carcass fat depth and muscle depth or area will overvalue fat pigs and undervalue lean pigs.     

Designing superoleophobic surfaces

Understanding the complementary roles of surface energy and roughness on natural nonwetting surfaces has led to the development of a number of biomimetic superhydrophobic surfaces, which exhibit apparent contact angles with water greater than 150 degrees and low contact angle hysteresis. However, superoleophobic surfaces-those that display contact angles greater than 150 degrees with organic liquids having appreciably lower surface tensions than that of water-are extremely rare. Calculations suggest that creating such a surface would require a surface energy lower than that of any known material. We show how a third factor, re-entrant surface curvature, in conjunction with chemical composition and roughened texture, can be used to design surfaces that display extreme resistance to wetting from a number of liquids with low surface tension, including alkanes such as decane and octane.     

The efficacy of a controlled-release albendazole capsule in suppressing nematode burdens in sheep

An experiment was undertaken between July and November 1985 in East Gippsland, Victoria, to determine the efficacy of an intra-ruminal controlled-release albendazole capsule against naturally acquired worm burdens and larval challenge in Merino hoggets. Two groups of 20 sheep, one group untreated, the other dosed with a capsule were grazed together; 5 sheep from each group were slaughtered for total worm counts 30 and 101 d after capsules were administered. Serum anthelmintic concentrations, faecal egg counts and body weights were monitored. Most capsules were exhausted within 91 d of administration. During the estimated 80 d for which they remained active the capsules were highly effective against the benzimidazole-susceptible worm populations. Faecal egg counts were reduced to zero and total worm populations were reduced by over 97% 30 d after administration. By 101 d egg counts were increasing and worm counts indicated that sheep were becoming reinfected. Sheep treated with the capsules grew faster than those not treated.     

Constant rate infusion of ketamine reduces minimal alveolar concentration of isoflurane in alpacas

Ketamine is a rapid acting, potent, nonspecific, noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist commonly used for inducing general anesthesia and for providing post-operative pain management and may possibly lessen the need for other potentially harmful or contraindicated analgesics in camelids, such as nonsteroidal anti-inflammatory drugs. Prior to determining the effectiveness of CRI ketamine for analgesia, a safe, sub-anesthetic dose was established that did not produce untoward side effects, sedation or alter normal behavior. Six healthy male alpacas (40–90 kg) were used for the trial and each acted as its own control. Each alpaca was randomly assigned to receive ketamine at 20 and 40 μg kg^–1 minute^–1 in 500 mL saline. A blinded observer recorded heart rate, respiratory rate, and body temperature hourly, and behavior for 8 hours. There was a 72-hour washout period between each dosing regime. An equal volume saline CRI without ketamine was used as a control. Each alpaca was allowed a one-week washout prior to being anesthetized with isoflurane using mask induction. After achieving a stable plane of anesthesia, the MAC value for isoflurane was determined. Ketamine was infused at 40 μg kg^–1pre-existing pain is unknown, but for elective procedures, preemptive analgesia using ketamine CRI in alpacas may be beneficial.     

Relationship between litters per sow per year sire breeding values and sire progeny means for farrowing rate,removal parity and lifetime born alive

The objective of this study was to determine the relationship between individual sire estimated breeding values (EBV) for litters/sow/year (LSY) and sire progeny means for farrowing rate (FR), removal parity and lifetime born alive (LTBA). Genetic parameters and breeding values were estimated using ASREML. The heritability estimate for LSY was 0.11. When all sires with 10 or more daughters with records were included in the analysis, Spearman rank correlations between the sire's LSY EBV and the sires' daughter means for FR, removal parity and LTBA were 0.49, 0.23 and 0.25 (p < 0.01). The sire EBV for LSY was favourably correlated with sires' daughter means for all three traits. This provides evidence that selecting sires with high EBV for LSY could improve herd FR, removal parity and LTBA. By including LSY as part of the selection criterion, the LTBA may be indirectly improved. The positive genetic correlation between LTBA and LSY may be a result of the improved longevity of sows with greater LSY compared with sows with lower LSY. The relationships between LSY and FR, removal parity and LTBA are strongly supported by the correlations between the sire progeny means for each trait and the sire LSY EBV.     

Progressive ataxia associated with degenerative thoracic myelopathy in Merino sheep

A neurological disorder in Merino sheep, characterised clinically by progressive posterior ataxia and microscopically by Wallerian degeneration in thoracic segments of the spinal cord, is described. Animals of both sexes were affected, with the earliest onset of disease being at 5 months of age. Most affected animals died before 2 years of age. The clinical, pathological and epidemiological features suggest that this degenerative thoracic myelopathy is a previously unrecognised entity differing from other reported causes of ataxia in sheep in Australia.     

Influence of Elemental Sulfur on Sugarcane Yield on Histosols with Near-Neutral pH

Soil subsidence of Florida Histosols caused by microbial oxidation following drainage of these soils has resulted in decreased depth. Soil pH has increased from tillage operations and vertical movement of carbonates from underlying limestone bedrock through evapotranspiration and seepage irrigation. This study was conducted to determine sugarcane (Saccharum spp.) yield response to banded elemental sulfur (S) (granular 90% S and granular 80% S with 5% manganese (Mn)) in soils with unamended pH ranging from 6.5 to 7.2. Four field experiments were established as small-plots on Histosols in the Everglades Agricultural Area (EAA). Each experiment was a randomized complete block design with six replications and elemental S rates of 0, 90, 224, and 448 kg S ha^?1. Less than optimum leaf Mn at two locations were associated with Mehlich 3-extractable Mn<5 g m^?3. There were no sugarcane yield responses to elemental S with unamended pH<7.2, although S significantly reduced in-row pH.

Abbreviations: EAA, Everglades Agricultural Area; ICP, inductively coupled argon plasma; KSM, kg sucrose Mg^?1 cane; MAP, monoammonium phosphate; M3-Mn, Mehlich 3-extractable Mn; RCB, randomized complete block; STM5, granular 80% S with 5% Mn; MCH, Mg cane ha^?1; MSH, Mg sucrose ha^?1