The spread of ringspot virus X by cutting knife

American Journal of Potato Research -     

Injection of the insertion of the deep digital flexor tendon in horses using radiographic guidance

Insertional tendinopathies of the DDFT have been reported both as the sole lesion and as part of a multifocal lesion (Dyson et al. 2003). Computed tomography (CT) and magnetic resonance imaging allow specific diagnosis of deep digital flexor tendon lesions within the hoof capsule; however, direct intralesional treatment of such lesions is difficult because of the hoof's rigid structure. A technique designed to mimic intralesional injection of insertional tendinopathies of the DDFT in the standing horse using radiographic guidance was assessed. Radiographic and contrast CT imaging and sectioning of the limbs confirmed accurate injection in all cases although inadvertant administration of injectate into adjacent structures was also evident.     

Clinical Sarcocystis neurona encephalomyelitis in a domestic cat following routine surgery

Sarcocystis neurona is an important cause of equine protozoal myeloencephalitis (EPM) in horses in the Americas. An EPM-like neurological disease also has been reported from other mammals but it is difficult to induce this disease in the laboratory. A 4-month-old male domestic cat developed neurological signs 3 days following castration. The cat was euthanized 12 days later because of paralysis. Encephalomyelitis was the only lesion and was associated with numerous Sarcocystis schizonts and merozoites in the brain and spinal cord. The protozoa reacted positively with S. neurona-specific polyclonal rabbit antibody. Two unidentified sarcocysts were present in the cerebellum. It may be possible that stress of surgery triggered relapse of S. neurona infection in this cat.     

Heifer development: reproduction and nutrition.

The nutritional development of heifers from birth to the time they become pregnant with their second calf is a critical component of cowherd management. Veterinarians can use targeted body weights and condition scores to monitor progress and gauge future reproductive success throughout heifer development. Meeting Nutrient Requirements of Beef Cattle recommendations for net energy and metabolizable protein is the single most successful strategy for maximizing reproductive performance from birth through the second pregnancy. Supplementation with fat, minerals, and additional undegraded intake protein has not been consistently reported to enhance the reproductive function of heifers.     

MALDI‐MS Lipid Profiles of Oocytes Recovered by Ovum Pickup from Bos indicus and 1/2 indicus × taurus with High vs Low Oocyte Yields

The aim of the present study was to compare the lipid profile in oocytes of indicus and 1/2 indicus × taurus cows with high and low antral follicle count (AFC)/oocyte yields. After an OPU procedure (D0), antral follicles ≥3 mm were counted by ultrasonography (D4, 19, 34, 49, 64), and cows were assigned to groups with either high AFC (≥30 follicles; indicus, NH group; 1/2 indicus × taurus, AH group) or low AFC (≤15 antral follicles; indicus, NL group; 1/2 indicus × taurus, AL group). The lipid profiles of the oocytes were determined by MALDI‐MS. For GI, GII and GIII oocytes, the indicus samples tend to cluster separately from the 1/2 indicus × taurus samples. The lipid species [PC (P‐38:5) + H]⁺ and/or [PC (P‐36:2) + Na]⁺, [PC (38:2) + H]⁺, [PC (38:5) + Na]⁺ and [TAG (60:8) + NH⁴]⁺ were more abundant in indicus (NH and NL groups) than 1/2 indicus × taurus. The higher lipid content in the indicus oocytes likely reflects differences in the rate of lipid metabolism and may contribute to oocyte competence and embryo development.     

Advances in modeling machine-soil-plant interactions

Modern agriculture involves mechanized operations which affect crop growth and yields through changes in the soil environment. Field research to study the phenomena involved in the soil-machine-crop system is usually site-specific with respect to edaphic, climatic and management factors. Field experiments are often expensive to conduct, and generalization to other sites or practices is usually tenuous at best. Computer-based techniques to simulate machine-soil-plant (or crop) systems can test many combinations of site characteristics and management practices, and screen the most promising combinations. Once these promising combinations are validated, the simulation techniques, together with stochastically-supported data bases can be used to predict tillage management systems suitable for specific sites and crops.Current efforts to model plant response to soil conditions created by tillage and machines have serious shortcomings, because the link between tool action, subsequent soil structure, and the parameters that describe fluxes of water, heat and gas need further development for deterministic modeling. Machine-soil models focus on efficiency of the tillage operation, while soil-plant models focus on soil structure and related parameters influencing plant growth. While current models for simulating the machine-soil-crop system have limitations, an approach to bridge between the two model applications offers great promise and should be a high research priority. When used with improved measurements of tool action and of soil structural properties before and after tillage and traffic, including position or placement of the crop residues, current models can be doubly effective for improving tillage management.