IMPACT OF LOW RATES OF NITROGEN APPLIED AT PLANTING ON SOYBEAN NITROGEN FIXATION

Environmental conditions in the northern Great Plains can delay emergence, nitrogen (N) fixation and growth of soybean due to cool and wet soil conditions at planting. The objective was to evaluate the impact of low rates of N applied at planting on soybean N fixation and crop growth. A field experiment was established within corn soybean rotation using a split-plot design with four replications. Whole plots were no-tillage and conventional tillage and split plots were starter fertilizer. Nitrogen sources were ammonium nitrate or urea applied at four rates. The amount of plant N fixation increased with growth stage reaching a maximum fixation at the R5 growth stages. Plant ureide content decrease with increase N applied for all growth stages except R7. The increase in plant biomass contributed to an overall increase in yield indicating that in unfavorable environments application of N at planting can have a positive impact on soybean growth.     

Field studies on equine influenza vaccination regimes in thoroughbred foals and yearlings

SUMMARY: The purpose of these studies was to examine the response of Thoroughbred foals and yearlings to different influenza vaccines and vaccination regimes. The horses' antibody levels against haemagglutinin, an established correlate of protection were measured by haemagglutination inhibition. The first study investigated the extent to which maternal antibodies interfered with the humoral response to a subunit vaccine. The findings suggest that repeat vaccination in the face of maternal antibodies may induce tolerance as defined by serological testing. The second study compared the immune response elicited by a subunit immune stimulating complex (ISCOM) vaccine, an inactivated whole virus vaccine and the same product containing equine herpesviruses and equine reoviruses in addition to equine influenza virus. The monovalent vaccine induced a significantly better response than the ISCOM or the multivalent vaccine. The final study demonstrated that the inclusion of an additional booster vaccination, between the second and third vaccination recommended by the vaccine manufacturers and required under the rules of racing in certain countries, is of benefit to young horses. Since these studies were performed, several of the vaccines have been updated with more recent virus strains in line with WHO/OIE recommendations. However, the general principles investigated in the studies remain relevant to these vaccines.     

WHOLE‐BODY BIODISTRIBUTION OF 3′‐DEOXY‐3′‐[18F]FLUOROTHYMIDINE (18FLT) IN HEALTHY ADULT CATS

Positron emission tomography/computed tomography (PET/CT) utilizing 3′‐deoxy‐3′‐[¹⁸F]fluorothymidine (¹⁸FLT), a proliferation tracer, has been found to be a useful tool for characterizing neoplastic diseases and bone marrow function in humans. As PET and PET/CT imaging become increasingly available in veterinary medicine, knowledge of radiopharmaceutical biodistribution in veterinary species is needed for lesion interpretation in the clinical setting. The purpose of this study was to describe the normal biodistribution of ¹⁸FLT in adult domestic cats. Imaging of six healthy young adult castrated male cats was performed using a commercially available PET/CT scanner consisting of a 64‐slice helical CT scanner with an integrated whole‐body, high‐resolution lutetium oxy‐orthosilicate (LSO) PET scanner. Cats were sedated and injected intravenously with 108.60 ± 2.09 (mean ± SD) MBq of ¹⁸FLT (greater than 99% radiochemical purity by high‐performance liquid chromatography). Imaging was performed in sternal recumbency under general anesthesia. Static images utilizing multiple bed positions were acquired 80.83 ± 7.52 (mean ± SD) minutes post‐injection. Regions of interest were manually drawn over major parenchymal organs and selected areas of bone marrow and increased tracer uptake. Standardized uptake values were calculated. Notable areas of uptake included hematopoietic bone marrow, intestinal tract, and the urinary and hepatobiliary systems. No appreciable uptake was observed within brain, lung, myocardium, spleen, or skeletal muscle. Findings from this study can be used as baseline data for future studies of diseases in cats.     

Studies on Plant Growth-Regulating Substances: III. The Production of Parthenocarpic Pomaceous Fruits by Chemical Treatment

Yields of plot-edge trees of an inferior variety planted alongside vigorous varieties declined over the years, relative to those of guarded trees. At interfaces between two varieties, initially of similar vigour, yields of the heavier bearer declined while those of the poorer yielder, which continued vigorous growth at the expense of cropping, tended to rise, relative in each case to guarded trees of the variety.     

Calcium oxalate crystalluria in a goat.

As part of a routine health evaluation of an 8-month-old female Nubian goat, serum biochemical analyses and urinalysis were performed. Most serum biochemical values including concentrations of blood calcium and indicators of urinary system dysfunction, such as blood urea nitrogen, creatinine, and phosphorous concentrations, were within reference ranges. An aliquot of voided urine was hypersthenuric and acidic and contained numerous typical cuboidal-bipyramidal calcium oxalate dihydrate crystals and unique rectangular parallelepiped crystals that were confirmed by energy dispersive X-ray microanalysis as being of calcium oxalate dihydrate composition. We hypothesize that the calcium oxalate crystals resulted from a diet containing calcium and oxalic acid. Treatment was not administered, and the goat remained healthy during the ensuing year.