Risk factors for musculoskeletal injuries in 2-year-old Thoroughbred racehorses

Musculoskeletal injuries (MSI) in racehorses have been identified as the most common cause of lost training days and weeks spent resting at pasture. Several training-, track- and horse-related risk factors have been identified. However, there is no clear understanding of the inter-relationship between these factors. The aim of this longitudinal cohort study was to investigate risk factors for MSI in 2-year-old Thoroughbred racehorses. Australian Thoroughbred trainers were convenience sampled and enrolled in a 27-month longitudinal cohort study. The study population consisted of all 2-year-old Thoroughbred racehorses trained by a participating trainer. Horses were followed from the time of enrollment until the completion of the study or until they were lost to follow-up. Trainers were visited at approximately 14-day intervals to collect training and injury data. Training days were categorised as fast days if the maximum speed during training exceeded 800 m/min. For each horse, the first training period that included one or more fast days was analysed. A multiple logistic regression model was used to determine those horse- and training-related variables that were associated with MSI. Data from 274 horses trained by 14 trainers at five racetracks were analysed. Forty percent of the horses sustained a MSI during their first fast preparation. The average distance trained at speeds >or=800 m/min and the percentages of fast days from the first fast day until the end of the preparation were the only variables associated with MSI. After accounting for these variables there were still significant differences between trainers. This suggests that there are other training-related variables such as the rate of increase in distance trained at speeds >or=800 m/min that may be risk factors for MSI. In addition, other factors such as the level of veterinary involvement and the training centre/racetrack may be risk factors for MSI. More analysis using multi-level modelling is required to determine the relationship between trainer- and track-related risk factors.     

Otolith chemistry of triplefin Forsterygion nigripenne indicates estuarine residency

Fisheries Science - Understanding the role different habitats play in the life histories of fishes is important for the development of holistic aquatic ecosystem management plans. We used otolith...     

Should spring wheat breeding for organically managed systems be conducted on organically managed land?

Organic spring wheat (Triticum aestivum L.) producers in the northern Great Plains use cultivars which have been bred for conventional management systems or heritage cultivars released before the widespread use of synthetic fertilizers and pesticides. To investigate the feasibility of organic wheat breeding and to determine common genetic parameters for each system, we used a random population of 79 F₆-derived recombinant inbred sister lines from a cross between the Canadian hard red spring wheat cultivar AC Barrie and the CIMMYT derived cultivar Attila. The population, including the parents, was grown on conventionally and organically managed land for 3 years. Heritability estimates differed between systems for 6 of the 14 traits measured, including spikes m⁻², plant height, test weight, 1,000 kernel weight, grain protein, and days to anthesis. Direct selection in each management system (10% selection intensity) resulted in 50% or fewer lines selected in common for nine traits, including grain yield, grain protein, spikes m⁻², and grain fill duration. The results of this study suggest that indirect selection (in conventionally managed trials) of spring wheat destined for organically managed production would not result in the advance of the best possible lines in a breeding program. This implies that breeding spring wheat specific to organic agriculture should be conducted on organically managed land.     

Building resilience to climate change in rain-fed agricultural enterprises: An integrated property planning tool

In response to a drying climate, an integrated property planning tool was developed over three years to help landowners make better use of available rainfall. A sequence was identified which indicated how parts of each property are affected by soil moisture limitations. The sequence was combined with soil properties to indicate targeted strategies for each location aimed to improve soil moisture availability, biomass utilisation, and long-term viability of the farm or ranching enterprise. As a result of training of land owners and operators in use of this tool, 97% of participants indicated that they have begun or intend to make changes in land management; 78% are intending to make three or more substantial changes; and 91% felt better prepared for the impacts of climate change. The key to the success of this technique is that it identifies critical sustainable production drivers in a simple plan format and offers tailored management options which can address more variable climate conditions. The integrated planning tool has application as a driver of climate change adaptation in agricultural regions where farm units contain substantial landscape variation and seasonal rainfall is frequently limiting to production.     

Trauma‐associated acute mesenteric ischemia in a dog

Objective – To describe the successful management of acute mesenteric ischemia (AMI) in a dog. Case Summary – An 11‐year‐old, 21.4 kg, male castrated Rough‐Coated Collie was referred for evaluation of an acute abdomen following sustaining injuries in a vehicular accident. On presentation to the hospital, clinicopathologic assessments were within normal limits and distended intestinal loops were evident on abdominal palpation. Plain and contrast radiography demonstrated diffusely distended gas‐filled intestinal loops with a delayed barium transit time. Emergency surgical exploration was performed. The cecum and the proximal two‐thirds of the colon were dark purple to black in color and there were no palpable pulses in the mesenteric arteries associated with the cecum and colon. The cecum and proximal two‐thirds of the colon were resected and an ileocolic anastomosis was performed. The dog recovered well from surgery and was discharged 2 days later. Histopathologic examination was consistent with AMI. New or Unique Information Provided – AMI is uncommonly reported in human medicine and is a rare complication from even minor blunt abdominal trauma. This is the first reported case of trauma‐associated AMI in a dog.     

In vitro erythrocytic membrane effects of dibenzyl trisulfide, a secondary metabolite of Petiveria alliacea

We investigated the in vitro effect of dibenzyl trisulfide (DTS), a secondary metabolite of Petiveria alliacea, on erythrocyte elasticity, relaxation time and membrane morphology. Blood samples from 8 volunteers with hemoglobin AA were exposed to 100, 200, 400, 800 and 1000 ng/ml of DTS respectively and the elasticity and relaxation time measured. There were statistically significant, dose-dependent increases in elasticity and relaxation times. The changes in membrane morphology observed also increased with increased concentration of DTS. This suggests that DTS interaction with membrane protein resulted in increased elasticity, relaxation time and deformation of the erythrocyte membrane.     

Temperature,ethylene and the postharvest performance of cut snapdragons (Antirrhinum majus)

The effects of temperature and ethylene on the quality of snapdragon flowers (Antirrhinum majus L. cvs. ‘Potomac Pink’ and ‘Rocket’) after harvest were investigated. The flowers were stored dry or wet at 6 temperatures ranging from 0 to 12.5 °C for 5 days. Vase life and gravitropic bending were measured at 20 °C after storage. Respiration rates of flowers at 8 different temperatures (0, 2.5, 5, 7.5, 10, 12.5, 15 and 20 °C) were measured continually using a computerized system. The respiration of cut snapdragon flowers increased exponentially as the temperature increased from 0 to 20 °C, with a mean Q₁₀ of 2.6. The vase life of flowers of the ‘Potomac Pink’ cultivar stored dry at 0 °C was 10.8 days, similar to that of freshly harvested controls (10.6 days), and 4.4 days longer than that of flowers stored at 7.5 °C. When spikes were placed horizontally at 20 °C, growth became negatively gravitropic within 20 min. Bending was significantly higher than controls (stored vertically) in all flowers stored horizontally at temperatures above 5 °C. Vase life of flowers stored for 5 days at a range of temperatures then placed in an interior environment was directly correlated with respiration rate at the storage temperature. Wet storage of cut snapdragon flowers reduced the loss of quality at storage temperatures above 5 °C but the vase life of flowers stored in water at 12.5 °C was less than half that of flowers stored dry at 0 °C. Ethylene treatment caused 100% floret abscission which was prevented by pre-treatment either with 1-methycyclopropene (1-MCP) or with silver thiosulfate (STS), but neither of these inhibitors prevented gravitropic bending.