Effectiveness of α-tocopherol and selenium supplements in preventing lupinosis-associated myopathy in sheep

Objective To compare the effectiveness of combined selenium and α-tocopherol acetate treatments in preventing lupinosis-associated myopathy in sheep.
Design Measurement of plasma muscle and liver enzymes, and histopathological examination of muscle and liver in the treatment groups.
Procedure The treatments were: subcutaneous injections of selenomethionine and vitamin E (sc(SeM+E)) , an intraruminal selenium pellet and oral doses of vitamin E and intramuscular injections of selenomethionine combined with either oral doses of vitamin E (imSeM+orE) or intramuscular injections of vitamin E in an oily carrier. Another group received no supplements, while a control group was given selenium pellets on day 0 and fortnightly oral doses of vitamin E from day 0 to 72. To produce lupinosis-associated myopathy, the sheep were fed a diet low in vitamin E and given repeated injections of a crude extract of Diaphorthe toxica. Groups sc(SeM+E) and imSeM+orE were stressed by dosing with protected polyunsaturated fatty acids from day 56 onwards.
Results Lupinosis-associated myopathy was induced in all unsupplemented sheep. In these sheep the storage of Se increased and that of vitamin E decreased. The subcutaneous treatment was highly effective in preventing lupinosis-associated myopathy and also produced the highest vitamin E concentrations in plasma and liver. Supplemental vitamin E was more efficacious than supplemental Se. Concentrations of vitamin E in the livers of sheep given intramuscular vitamin E were higher than expected based on plasma concentrations. Oral doses of vitamin E proved the least effective method of increasing concentrations in liver. Lupinosis did not affect Se concentrations in liver or muscle.
Conclusion The sc(SeM+E) treatment is highly effective in preventing lupinosis-associated myopathy but needs to be further assessed when selenium and vitamin E are both limiting in the diet.     

The serological responses of chickens to mass vaccination with a live V4 Newcastle disease virus vaccine in the field and in the laboratory 1. Meat chickens

Meat chickens on commercial broiler farms were vaccinated once at 1 to 15 days of age with a live V4 Newcastle disease virus (NDV) vaccine administered by drinking water, aerosol or coarse spray. Hatchmates were housed and similarly vaccinated in laboratory isolation pens. Samples of birds were bled at weekly to fortnightly intervals and the serums tested for haemagglutination inhibiting antibody to NDV. Log2 mean titres of up to 6.26, and assumed protection levels (based on the percentage of birds with log2 titres of 4 or greater) of up to 89%, were obtained in field trials within 4 weeks of vaccination. Differences were observed between the results obtained from parallel field and laboratory trials. The presence of maternal NDV antibody reduced the response to vaccination. The results show that this V4 vaccine can produce an adequate serological response following mass administration to Australian meat chickens housed under commercial conditions.     

The medium frequency (7.5 MHz) ultrasound image characteristics of cattle skin

SUMMARY The medium frequency (7.5 MHz) ultrasound images of cattle skin, as a model for other domestic animals, are described and compared with the published information for human skin. Although some difficulties are apparent in identifying the skin surface and therefore measuring tissue thicknesses, the papillary and reticular layers of cattle skin, about 2 and 4 mm thick, respectively, can be differentiated using a water standoff with a vegetable oil coupling medium. The difference in echo intensities and patterns between these dermal components supports the concept that ultrasound tissue characterisation using higher frequencies may prove to be a useful non-invasive procedure in livestock production and veterinary science. However, a detailed protocol is required. Care is needed in the choice of ultrasound coupling medium for good resolution of cattle skin. Higher frequency ultrasound equipment would be necessary for imaging the skin of small animals. Potential applications of this new technology are discussed.     

The influence of mineral supplementation on skeleton formation and growth in Lusitano foals

Diets traditionally used in the horse industry are very often imbalanced in mineral composition, mainly in what concerns Ca, P, Mg and Ca/P ratio. The main objective of this study was to evaluate the effect of calcium, phosphorus and magnesium supplementation of traditional diets, on bone formation and growth in Lusitano breed foals, from weaning to 1 year old. Two homogenous groups of eight colts each received for 140-day iso-energetic and iso-proteic diets, which differed only on Ca, P and Mg levels (respectively, 0.26%, 0.27% and 0.12% vs. 0.56%, 0.43% and 0.18%). Throughout the experiment, blood samples were periodically collected for evaluation of total calcium, inorganic phosphorus, magnesium, copper, zinc, intact parathyroid hormone, bone alkaline phosphatase and osteocalcin concentrations. Animals were weighed and measured (wither height, hip height, girth and cannon circumference) for body growth evaluation. No significant differences were observed between treatments, with respect to growth, plasmatic concentrations of analysed minerals or biochemical markers. The linearity of growth in both groups is in agreement with studies reported for other light breeds. The observed results could be explained by the fact that calcium, phosphorus and magnesium levels in the base diet were close to supply the animal needs for a moderate growth. Further studies concerning the relationship between bone biochemical markers and mineral nutrition, in the growing horse, should consider the evaluation of bone mineral density and content.     

Complex Optical Surfaces Formed by Replica Molding Against Elastomeric Masters

Complex, optically functional surfaces in organic polymers can be fabricated by replicating relief structures present on the surface of an elastomeric master with an ultraviolet or thermally curable organic polymer, while the master is deformed by compression, bending, or stretching. The versatility of this procedure for fabricating surfaces with complex, micrometer- and submicrometer-scale patterns was demonstrated by the production of (i) diffraction gratings with periods smaller than the original grating; (ii) chirped, blazed diffraction gratings (where the period of a chirped grating changes continuously with position) on planar and curved surfaces; (iii) patterned microfeatures on the surfaces of approximately hemispherical objects (for example, an optical surface similar to a fly's eye); and (iv) arrays of rhombic microlenses. These topologically complex, micropatterned surfaces are difficult to fabricate with other techniques.     

Hydrogen-Bond Breaking and Proton Exchange in Collisions of Gaseous Formic Acid with Liquid Sulfuric Acid

Gas-liquid scattering experiments provide direct observations of the fate of hydrogen-bonding molecules striking the surfaces of acidic liquids. Collisions of gaseous formic acid with concentrated sulfuric acid show that impinging monomers (HCOOH and DCOOD) scatter inelastically from the interface or become trapped by surface H2SO4. Most trapped DCOOD molecules undergo proton exchange before desorbing from the acid, indicating that gas-surface accommodation almost always leads to reaction with H2SO4 molecules. This proton transfer is not inhibited by dimerization of the formic acid: The dimers readily undergo intramolecular hydrogen bond cleavage and D-H exchange before desorbing from the acid.     

Nitric oxide stimulates progesterone and prostaglandin E2 secretion as well as angiogenic activity in the equine corpus luteum

Cytokines and nitric oxide (NO) are potential mediators of luteal development and maintenance, angiogenesis, and blood flow. The aim of this study was to evaluate (i) the localization and protein expression of endothelial and inducible nitric oxide synthases (eNOS and iNOS) in equine corpora lutea (CL) throughout the luteal phase and (ii) the effect of a nitric oxide donor (spermine NONOate, NONOate) on the production of progesterone (P4) and prostaglandin (PG) E(2) and factor(s) that stimulate endothelial cell proliferation using equine luteal explants. Luteal tissue was classified as corpora hemorrhagica (CH; n = 5), midluteal phase CL (mid-CL; n = 5) or late luteal phase CL (late CL; n = 5). Both eNOS and iNOS were localized in large luteal cells and endothelial cells throughout the luteal phase. The expression of eNOS was the lowest in mid-CL (P < 0.05) and the highest in late CL (P < 0.05). However, no change was found for iNOS expression. Luteal explants were cultured with no hormone added or with NONOate (10(-5) M), tumor necrosis factor-α (TNFα; 10 ng/mL; positive control), or equine LH (100 ng/mL; positive control). Conditioned media by luteal tissues were assayed for P4 and PGE(2) and for their ability to stimulate proliferation of bovine aortic endothelial cells (BAEC). All treatments stimulated release of P4 in CH, but not in mid-CL. TNFα and NONOate treatments also increased PGE(2) levels and BAEC proliferation in CH (P < 0.05). However, in mid-CL, no changes were observed, regardless of the treatments used. These data suggest that NO and TNFα stimulate equine CH secretory functions and the production of angiogenic factor(s). Furthermore, in mares, NO may play a role in CL growth during early luteal development, when vascular development is more intense.