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.     

Domoic acid toxicity in Californian sea lions (Zalophus californianus): clinical signs, treatment and survival

Eighty-one Californian sea lions (Zalophus californianus) with signs of domoic acid toxicity stranded along the coast of California in 1998 when there were blooms of the domoic acid-producing alga Pseudonitzschia australis off-shore. In 2000, a further 184 sea lions stranded with similar clinical signs, but the strandings occurred both during detectable algal blooms and after the blooms had subsided. The clinical signs in these 265 Californian sea lions included seizures, ataxia, head weaving, decreased responsiveness to stimuli and scratching behaviour. Affected animals had high haematocrits, and eosinophil counts, and high activities of serum creatine kinase. They were treated supportively by using fluid therapy, diazepam, lorazepam and phenobarbitone. Fifty-five of the 81 sea lions (68 per cent) affected in 1998 and 81 of the 184 (44 per cent) affected in 2000 died despite the treatment. Three of the 23 sea lions which survived in 1998 were tracked with satellite and radiotransmitters; they travelled as far south as San Miguel Island, California, and survived for at least three months. Eleven of the 129 animals which were released stranded within four months of being released.     

Annual, career or single race records for breeding value estimation in race horses

The racing careers of 2, 3, 4, and 5-year-old Thoroughbreds and French trotters born in France between 1995 and 1999 were analysed. The horses were evaluated on a set of traits, with particular attention to annual or career earnings and number of starts.

As expected, the distributions of earnings corrected for year, age and sex are very skew and thus inappropriate for breeding value estimations. However, Log transformation results in near normal distributions more suitable for this purpose.

Another problem of annual or career earnings required a more complex approach. As most horses did not win any money in France (67% of the trotters and 41% of the Thoroughbreds), it is difficult to correctly evaluate these horses. On the other hand, a linear adjustment of the Log of earnings by the Log of the number of starts (exponential adjustment of the earning index) leads to regression coefficients close to 1. It justified the use of the Log of earnings per start and explained its higher heritability in literature. A quadratic adjustment of the Log of earnings by the Log of the number of starts (sigmoid adjustment of the earning index) improves the adjustment for the Thoroughbred only and should be implemented for these horses.

The probability of a horse to be placed according to the number of starts was also studied. It is shown that the observed percentage of non-placed horses p_s according to the number of starts, s, is in all cases inferior to the expected percentage (p_s < p₁^s). Therefore, races of the same horse cannot be considered as independent events. The percentage of horses placed and the mean earnings for each age can be combined in order to estimate the economical weights for each age class. Economical weights for the French trotter were 0.00, 0.21, 0.40, and 0.39 for 2, 3, 4, and 5-year olds respectively. They were 0.11, 0.45, 0.26 and 0.18 respectively for Thoroughbreds of the same age categories. The current tendency to move from annual or career criteria towards criteria at the race level is discussed. However, the question on how to evaluate the important proportion of horses born that never appeared in a race still remains open and should focus future research.     

Acute cortisol responses of calves to scoop dehorning using local anaesthesia and/or cautery of the wound

Objective To measure plasma cortisol responses in calves dehorned using a scoop after administration of local anaesthesia and/or cautery of the wounds.
Design A physiological study with controls.
Procedure There were six treatments: control handling with and without local anaesthesia, dehorning, dehorning after local anaesthesia, dehorning followed by wound cautery, and dehorning after local anaesthesia followed by wound cautery. Blood samples were taken before and after dehorning.
Results Dehorning caused an increase in plasma cortisol concentrations, which decreased a little to plateau values and then declined to pretreatment values 3 to 4 h after dehorning. The peak was smaller after local anaesthesia was administered but when its effects wore off, cortisol concentrations increased and thereafter were similar to those in the dehorned animals. The combination of local anaesthesia and cautery resulted in a plasma cortisol response similar to those in control calves with or without local anaesthesia.
Conclusions If plasma cortisol concentrations reflect the distress being experienced by the calves, then local anaesthesia reduces the acute distress for about 3 h after dehorning but not during the subsequent 3 to 4 h. Combining local anaesthetic and cautery prevented the significant increase in plasma cortisol following dehorning and may eliminate the acute distress caused by scoop dehorning.     

Transient diabetes mellitus in a domestic ferret (Mustela putorius furo)

A 3.5-year-old spayed female ferret, fed a diet high in refined sugar, was referred for lethargy, polyuria, polydipsia, and polyphagia. Diabetic ketoacidosis was diagnosed. Treatment included insulin therapy and a low carbohydrate diet. Diabetes mellitus resolved 54 d later, and insulin therapy was discontinued. There has been no recurrence of the diabetes mellitus.     

Expression of Perilipin 2 (PLIN2) in Porcine Oocytes During Maturation

Perilipins have been reported to limit the interaction of lipases with neutral lipids within the droplets, thereby regulating neutral lipid accumulation and utilization. This study aimed to identify the location and expression of PLIN1 and PLIN2 in porcine oocytes during maturation. Quantitative real‐time polymerase chain reaction (qRT‐PCR), immunostaining and Western blot methods were used to characterize the expression and distribution patterns of PLIN1 and PLIN2 in porcine oocytes. The results showed that PLIN1 was not detectable in porcine oocytes. PLIN2 and BODIPY 493/503‐detected neutral lipid droplets appeared identical distribution patterns and extensive colocalization in both GV and MII porcine oocytes. PLIN2 protein expression was higher in GV oocytes than that in MII oocytes (p < 0.05), although PLIN2 mRNA expression was similar in both groups. These findings suggested that PLIN2 was a major lipid droplet‐associated protein in porcine oocytes.     

Conserved sequence and structural elements in the HIV-1 principal neutralizing determinant

The principal neutralizing determinant (PND) of human immunodeficiency virus HIV-1 is part of a disulfide bridged loop in the third variable region of the external envelope protein, gp120. Analysis of the amino acid sequences of this domain from 245 different HIV-1 isolates revealed that the PND is less variable than thought originally. Conservation to better than 80 percent of the amino acids in 9 out of 14 positions in the central portion of the PND and the occurrence of particular oligopeptide sequences in a majority of the isolates suggest that there are constraints on PND variability. One constraining influence may be the structural motif (beta strand--type II beta turn--beta strand--alpha helix) predicted for the consensus PND sequence by a neural network approach. Isolates with a PND similar to the commonly investigated human T cell lymphoma virus IIIB (HTLV-IIIB) and LAV-1 (BRU) strains were rare, and only 14 percent of sera from 86 randomly selected HIV-1 seropositive donors contained antibodies that recognized the PND of these virus isolates. In contrast, over 65 percent of these sera reacted with peptides containing more common PND sequences. These results suggest that HIV vaccine immunogens chosen because of their similarity to the consensus PND sequence and structure are likely to induce antibodies that neutralize a majority of HIV-1 isolates.     

Industrial innovation policy: lessons from american history

The historical interrelations of government support of R & D and technical change in seven major American industries point to three types of policy that have been successful in the past: (i) government R & D support for technologies in which the government has a strong and direct procurement interest; (ii) decentralized systems of government-supported research in the "generic" area between the basic and the applied; and (iii) a decentralized system of clientele-oriented support for applied R & D. A fourth type of policy, under which the government attempts to "pick winners" in commercial applied R & D, has been a clear-cut failure.