Three-Dimensional X-ray Microtomography

The new technique of x-ray microtomography nondestructively generates three-dimensional maps of the x-ray attenuation coefficient inside small samples with approximately 1 percent accuracy and with resolution approaching 1 micrometer. Spatially resolved elemental maps can be produced with synchrotron x-ray sources by scanning samples at energies just above and below characteristic atomic absorption edges. The system consists of a high-resolution imaging x-ray detector and high-speed algorithms for tomographic image reconstruction. The design and operation of the microtomography device are described, and tomographic images that illustrate its performance with both synchrotron and laboratory x-ray sources are presented.     

Evaluation of a regimen using a progesterone releasing intravaginal device (CIDR) and PMSG as a treatment for post partum anoestrus in dairy cattle

Anoestrous dairy cows in seasonally calving herds in the Macalister Irrigation District of Gippsland, Victoria were treated at the start of the mating period with a progesterone releasing intravaginal device (CIDR). The CIDR was inserted for 7 days and 400 IU of PMSG was injected intramuscularly at removal. There was no clinically useful difference among cows receiving the CIDR, a placebo and untreated cows in the interval from treatment to either first oestrus or conception, the conception rate to first service or percent pregnant by the end of mating. Analyses of data from 2-year-old cows, older cattle, cows calved at least 45 days or cows calved at least 55 days and cows treated 3 weeks after the start of mating did not show improved reproductive performance following treatment with the CIDR.     

Beacon Chipper: A round white chip-processing potato variety

‘Beacon Chipper’ is a high-yielding, round white potato for the chip-processing market. This variety has an attractive round appearance with shallow eyes and high percentage of oversize tubers. Specific gravity in Michigan ranges from 1.077 to 1.083. Beacon Chipper may fit a window in raw product requirements between out-of-the-field ‘Atlantic’ crop and a late storage crop. This variety has some tolerance to common scab (Steptomyces scabies Thaxter) in comparison to Atlantic and ‘Snowden’. Beacon Chipper also has good chip-processing storage characteristics (light color and low amount of defects) and better tolerance to pressure bruise than Snowden. Based upon nitrogen and spacing management studies, we recommend that Beacon Chipper be planted at 20-cm within-row spacing with 180 lbs N/acre to maximize U.S. No. 1 yield and quality. The origin and pedigree of Beacon Chipper is currently unknown, despite extensive fingerprint analyses. The name Beacon Chipper was chosen to reflect the common nautical theme of Michigan and Maine.     

Survival and fertility after uterine prolapse in dairy cows

Sixty-eight cases of uterine prolapase in pastured dairy cows were treated in 2 consecutive spring calving seasons in East Gippsland, Victoria. Fifty cows survived (73.5%). Of 43 cows available for followup, 36 (84%) conceived in the mating period following the prolapse, taking 10 d longer to conceive than herd mates that calved on the same day. Three of the 36 cows (8%) that conceived, aborted, this occurring in the middle trimester of pregnancy. No prolapses occurred at the following calving but one case had suffered uterine prolapse 2 years previously. The conclusions drawn from these observations are that cows with uterine prolapse have a good chance of surviving if treated, that treatment is cost-effective, that uterine prolapse is unlikely to reoccur and treated cows have a good chance of conceiving. The veterinarians involved in this investigation were reasonably accurate in their ability to predict long term survival but not as good in predicting ability to conceive again.     

Black soil blindness: A new mycotoxicosis of cattle grazing Corallocytostroma-infected Mitchell grass (Astrebla spp)

A new, fatal mycotoxicosis of cattle has been recognised in north-western Australia. A feeding trial confirmed the toxicity of a previously unknown species of Corallocytostroma that grows on Mitchell grass (Astrebla spp). The disease has been colloquially named ‘black soil blindness’ because its most prominent features are its confinement to pastures on black soil, and blindness and death of affected animals. Over 500 cattle have died and considerable subclinical disease is present. Above average wet season rainfall and extended growing seasons may explain the emergence of the fungus. The disease is important because cattle production in large areas of Australia utilise Mitchell grass pastures.