Cecotrophy behavior and use of urea as non-protein nitrogen (NPN) source for capybara (Hydrochoerus hydrochaeris)

Fifteen female adult capybaras, with initial average body weight (BW) of 32.7 (±?5.8) kg, were kept in individual pens to evaluate effect of supplementation of concentrate feed and its supply time on cecotrophy behavior frequency. The animals were allocated in a completely randomized design, with five animals per treatment, receiving three diets: grass only, grass and grain corn offered in a single meal, and grass and grain corn offered in two daily meals; all cecotrophy acts were recorded. Later, in a second experiment, five capybaras received five levels of urea in their diet: 0, 10, 20, 30, and 40 g urea/100 kg BW, replacing soybean meal as true protein source, in a 5?×?5 Latin square design. The animals were weighed and their blood was collected every 2 weeks. The frequency of cecotrophy (Ps?<?0.05) was higher when the capybaras were fed grass only (0.5?±?0.07 acts/h) than when they received grass and corn in a single meal (0.3?±?0.05 acts/h) and grass and corn supplied in separate meals (0.1?±?0.03 acts/h). With increased urea in their diet, the capybaras showed initial signs of chronic intoxication, together with increments in serum urea (r?=?0.87, P?<?0.05) and a decreasing trend in daily weight gain (r?=??0.38, P?=?0.06). Therefore, when including concentrate feeds in capybara diet, these must be mixed with roughage in a single meal to avoid high decrease in the frequency of cecotrophy behavior and increase in dry matter intake. The replacement of soybean meal with urea in capybara diet is not recommended.     

The effect of bovine viral diarrhea virus infections on health and performance of feedlot cattle

The aim of this study was to investigate the effect of bovine viral diarrhea virus (BVDV) infections (unapparent acute infections and persistent infections) on the overall health and performance of feedlot cattle. Calves from 25 pens (7132 calves) were enrolled in the study. Overall and infectious disease mortality rates were significantly higher (P < 0.05) in pens categorized at arrival as positive for type I BVDV and lower in pens that were positive for type II BVDV than in negative pens. Mortality attributed to BVDV infection or enteritis was significantly more common (P < 0.05) in the pens containing persistently infected (PI) calves than in pens not containing PI calves (non-PI pens). There were no statistically detectable (P > or = 0.05) differences in morbidity, overall mortality, average daily gain, or the dry matter intake to gain ratio between PI and non-PI pens. Although type-I BVDV infections in feedlots appear to contribute to higher mortality rates, the presence of PI calves alone does not appear to have a strong impact on pen-level animal health and feedlot performance.     

Comparison of three methods of surveillance with application to the detection of Johne's disease seropositivity in Texas cattle

Surveillance and monitoring are important for measuring the level of disease in a population, documenting changes in prevalence over time, determining high-risk areas for implementation of control measures, eradicating disease, and documenting freedom from disease. The documentation of freedom from disease has importance for international trade and the resumption of production after an outbreak. Johne's disease (JD) is an example of an endemic disease of cattle that has variable prevalence related to environmental and animal-level factors. Three methods of sample collection were used to describe the prevalence and distribution of JD seropositivity in Texas. Sampled cattle were: (1) extensively managed herds, (2) market cattle, and (3) clinically ill cattle examined by practicing veterinarians throughout Texas. Samples were evaluated for JD using a commercially available serum ELISA. Proportion of seropositive samples was compared and spatial distributions were evaluated for clustering. Difference of JD seropositivity was observed among the three sample populations suggesting that estimation of disease prevalence is dependant upon the source of samples.     

Evaluation of a core collection of Brassica oleracea accessions for resistance to Brevicoryne brassicae, the cabbage aphid

A rapid, simple and reliable technique was developed for evaluating Brassica accessions in the glasshouse for resistance to Brevicoryne brassicae, the cabbage aphid. Brassica accessions were grouped into crop types with similar habit and vigour for evaluation. 401 Brassica oleracea accessions, representing the genetic and geographic diversity of the species, were evaluated for resistance to a population of B. brassicae collected originally from HRI, Wellesbourne. Ninety eight accessions were identified as being moderately resistant (grade 3) or partially resistant (grade 4). Re-testing of accessions in the glasshouse identified 12 moderately resistant and 43 partially resistant accessions. The most promising gene pool was kale, where a higher than expected number of resistant accessions were found. Three of the kales were consistently rated as moderately resistant in all tests. In contrast the broccoli gene pool was a poor source of resistance with less (one out of 46) resistant accessions than expected. Eleven of the kales graded 3 were tested in the field in 1995 and resistance to B. brassicae was confirmed. Ten accessions were also tested for resistance to two additional populations of B. brassicae, one from Greece and the other from Portugal. The results provided no evidence of aphid biotype/host specific differences in the resistance of these B. oleracea accessions. This revised version was published online in August 2006 with corrections to the Cover Date.     

Major compositional units of the moon: lunar prospector thermal and fast neutrons

Global maps of thermal and fast neutron fluxes from the moon suggest three end-member compositional units. A high thermal and low fast neutron flux unit correlates with the lunar highlands and is consistent with feldspathic rocks. The South Pole-Aitken basin and a strip that surrounds the nearside maria have intermediate thermal and fast neutron flux levels, consistent with more mafic rocks. There appears to be a smooth transition between the most mafic and feldspathic compositions, which correspond to low and high surface altitudes, respectively. The maria show low thermal and high fast neutron fluxes, consistent with basaltic rocks.     

Lunar Fe and Ti abundances: comparison of lunar prospector and clementine data

The Lunar Prospector neutron spectrometer data correlate well with iron and titanium abundances obtained through analysis of Clementine spectral reflectance data. With the iron and titanium dependence removed, the neutron spectrometer data also reveal regions with enhanced amounts of gadolinium and samarium, incompatible rare earth elements that are enriched in the final phases of magma crystallization. These regions are found mainly around the ramparts of the Imbrium impact basin but not around the other basins, including the much larger and deeper South Pole-Aitken basin. This result confirms the compositional uniqueness of the surface and interior of the Imbrium region.     

Development of an ELISA to detect antibodies to a protective lipopolysaccharide fraction of Leptospira borgpetersenii serovar hardjo in cattle.

Monoclonal antibodies (Mabs) were produced against Leptospira borgpetersenii serovar hardjo-type Bovis antigens. A panel of 28 Mabs were characterised. Only the nine Mabs toward a lipopolysaccharide (LPS) fraction of 18, 24 kDa bands and a 26-28 kDa smear showed agglutinating, leptospiricidal and growth-inhibition activities, and passively protected hamsters against renal infection with hardjo. They also reacted strongly in the CH-ELISA, captured killed whole hardjo leptospires, gave good fluorescence in indirect FAT against smears of hardjo culture and exhibited no cross reactivity with strains in heterologous serogroups. On the basis of optimal activity in a range of tests, one IgG class Mab (designated 25) was selected for use in an antibody-capture ELISA system for the detection of bovine anti-hardjo antibodies. The system gave a wide separation of absorbance values between positive and negative sera at a 1:10 dilution. The antibodies detected by this assay are believed to be protective anti-LPS IgG.     

Peroxidase activity as a measure of neutrophil populations in inflammatory peritoneal exudates of rainbow trout, Oncorhynchus mykiss (Walbaum)

A quantitative peroxidase assay using tetramethylbenzidine was applied to exudates from peritoneal cavities of rainbow trout which had been inflamed by intraperitoneal injection of Yersinia ruckeri . Most of the peroxidase activity was cell-associated, with values for extracellular peroxidase below 5% of total peroxidase. No free peroxidase activity was detected in resting cavities. The kinetics of neutrophil numbers and peroxidase activity in peritoneal exudates during the 6 days of inflammation studied followed identical patterns, with a correlation coefficient of 0.996. This shows that the peroxidase assay can be used as an indirect, quantitative evaluation of neutrophil responses during peritoneal inflammation.