Transverse and dorso-ventral changes in thoracic dimension during equine locomotion

Changes in shape of the equine thorax during locomotion are not well defined, although it has been shown recently that the transverse hemi-diameter changes its dimension by up to 80 mm on the side of the trailing forelimb during gallop, despite minimal change in thoracic circumference. The aim of this project was to analyse transverse and dorso-ventral changes in shape of the thorax simultaneously, and to determine if leading limb, treadmill slope and speed have an effect on these shape changes. Reflective markers were placed on the horse’s hemi-thorax and movement of the markers was recorded using a motion capture system while the horse trotted and cantered on a treadmill. Treadmill speed and slope, and the lead the horse cantered on were varied to determine the effects these had on transverse hemi-diameter and dorso-ventral diameter.There was a negative correlation between transverse and dorso-ventral changes in thoracic dimension, the strength of which increased with speed on the trailing limb side. On the leading side, the relationship was either weakly negative or positive. The changes in dimension of the hemi-thorax were significantly greater on the trailing side compared to the leading side. Speed had small effects on thoracic shape changes, but inclined exercise caused an increase in transverse hemi-diameter on the trailing side of the thorax. The changes in thoracic shape are unlikely to contribute substantially to ventilation and rib motion is likely to be due to protraction and retraction of the forelimbs. However, it may reflect asynchronous ventilation of lung lobes and partially explain the prevalence of exercise-induced pulmonary haemorrhage.     

A recombinant-based ELISA evaluating the efficacy of netobimin and albendazole in ruminants with naturally acquired fascioliasis

The therapeutic efficacy of albendazole and netobimin in ruminants with naturally occurring fascioliasis was investigated using a recombinant-based ELISA. The variation in the IgG response against a 2.9-kDa recombinant protein (FhrAPS), termed efficacy index (EI) 1, and the egg-output changes, termed EI 2, were used to evaluate drug efficacy.The values of EI 1 ranged between 0% and 50% in sheep, and between 0% and 30% in cattle after treatment with albendazole and netobimin. Similar EI 2 values were observed in sheep receiving albendazole or netobimin, but the highest values were found in cattle treated with netobimin. The significant reduction in the IgG response to FhrAPS found in this study shows promise in terms of developing alternative methods for evaluating the efficacy of chemotherapy against Fasciola hepatica in grazing ruminants.     

Growth, slaughter performance and feeding behaviour of young bulls belonging to three native cattle breeds raised in the Alps

Most studies on lactation curves only consider milk yield and describe a standard lactation curve of dairy cows, showing a peak or maximum daily yield occurring between 4 and 8 weeks after calving, followed by a daily decrease in milk yield until the cow is dried off. Wood's model is a widely used lactation curve function. Wood's model was fitted to test-day records of 95,405 lactations of parities lower than 5. Milk traits were milk yield (MY), fat percentage (F%), protein percentage (P%), fat yield (FY) and protein yield (PY), and the lactation curve was individually considered as a cluster of five linked curves. Milk trait and parity influence the goodness of fit of Wood's model. In 19.3% of the lactations, the shape of the MY, FY and PY curves follows the standard lactation curve while F% and P% have the reversed standard shape. The initial phase of lactation with the FY and PY curves contributes to the high variability of shapes.     

Use of clinical information to predict the characteristics of bacteria isolated from clinical cases of bovine mastitis

Farmers recorded the clinical signs of cows with clinical mastitis and submitted milk samples for bacteriological examination, so that the clinical signs could be correlated with the bacteriological findings. Odds ratios for the demeanour of the cow, the appearance of the milk, milk yield, udder texture, and the administration of parenteral antibiotics were calculated for mastitis cases classified in terms of their microbiology as either enterobacteriaceae, major Gram-positive pathogens, minor pathogens, 'no growths' or 'all other pathogens'. Animals infected with enterobacteriaceae had the highest odds of being reported as having a reduced milk yield, swollen or hard udders, watery milk and/or being systemically sick. A logistic regression model was used to predict the Gram-staining characteristics of the bacteria causing clinical mastitis. The clinical findings found to be significant predictors in the model were the demeanour of the cow and its milk yield. The regression model was used as a basis for a predictive test. Using a test data set, the sensitivity of the test was 28 per cent, its specificity was 96 per cent, the positive predictive value was 74 per cent and the negative predictive value was 80 per cent. The overall accuracy of these predictions was 79 per cent.     

A RETROSPECTIVE ANALYSIS OF 140 DOGS WITH ORAL MELANOMA TREATED WITH EXTERNAL BEAM RADIATION

Despite the early notion that canine oral malignant melanoma is radioresistant, recent data suggest that external beam radiotherapy is effective in local tumor control. However, optimal fractionation schedules have not been established. The high rate of regional and distant metastasis is another problem that has hindered long-term control. The role of chemotherapy in the management of canine oral melanoma has also not been determined. In this study, data from 140 dogs irradiated at North Carolina State University were evaluated with the following objectives: (1) to compare the efficacy of three radiation therapy protocols (36 Gy, 9 Gy x 4 fractions; 30 Gy, 10 Gy x 3 fractions; or >45 Gy, 2-4 Gy x 12-19 fractions) for the treatment of dogs with oral malignant melanoma, (2) to identify any host or tumor factors influencing prognosis, and (3) to determine the impact of systemic chemotherapy on treatment outcome. Information regarding response to therapy, disease progression, and survival were determined from the medical records or from information obtained by telephone or mail survey. Relationships between host, tumor, and treatment variables and outcome measures (response, time to first event, and survival) were evaluated using Fisher's exact test (response) and the Cox regression model (time to first event and survival). The median time to first event for the 140 dogs was 5.0 months (95% C.I., 4-6 months) and the median survival was 7.0 months (95% C.I., 6-9 months). In the univariate analysis, the following variables were associated with increased time to first event and survival: (1) rostral tumor sublocation; (2) lack of bone lysis observed on skull imaging, and (3) microscopic tumor burden. In a multivariate analysis of 111 dogs with complete data for these variables, tumor sublocation, bone lysis, and tumor volume were identified as joint predictors of time to first event (p < .001, p < .001, and p = .04, respectively) and survival (p < .001, p < .001, and p = .05, respectively). There were no differences in response, time to first event and survival between the three radiation therapy protocols used. Systemic chemotherapy had no impact on the development of metastatic disease, time to first event, or survival, although the dosages used in this study were suboptimal. External beam radiation therapy is effective in local disease control of canine oral malignant melanoma; however, the optimal fractionation scheme has yet to be determined. The high metastatic rate observed with this disease and the inefficacy of systemic chemotherapy indicate that further investigation into novel therapies is warranted.     

A dynamic model of metabolizable energy utilization in growing and mature cattle. I. Metabolizable energy utilization for maintenance and support metabolism

Models to predict heat production attributable to maintenance and support metabolism in growing and mature cattle were developed on the basis of three concepts. The first concept is that animals fed fixed amounts of the same diet achieve weight equilibrium over an extended feeding period, and that the ME consumed at weight equilibrium is the maintenance requirement. The second concept is that a part of the heat production resulting from ME consumed above the maintenance requirement is associated with an elevation of vital functions (support metabolism), and this heat production can be modeled as a function of the level of feeding. The third concept is that previous levels of nutrition affect current estimates of heat production, and that this impact can be modeled as a delayed response in heat production associated with support metabolism. Experimental data on feed consumption showed that maintenance requirements varied in simple proportion to BW, not only for different breeds of mature cattle at BW equilibrium, but also for calves and growing steers held at BW stasis. Experimental data in which different breeds of cattle achieved weight equilibrium when fed fixed amounts of a specific diet were used to estimate breed parameters associated with maintenance for 21 breeds of cattle and 15 biological types of crossbred cattle. Level of feeding was estimated as a multiple of the maintenance intake and used to model heat production associated with support metabolism. Other experimental data on growing cattle were used to estimate breed parameters for predicting heat production associated with support metabolism for 21 breeds of cattle and 15 biological types of crossbred cattle. A distributed lag function was used to model the delayed response in heat production associated with support metabolism with changes in plane of nutrition. The models were tested by simulating experimental data for three breeds of weaned steers finished on high-energy diets. Results for the total heat production associated with maintenance and support metabolism expressed on a unit BW basis showed a similar response with stage of maturity when compared with other experimental data.     

Osteomyelitis secondary to trauma involving the proximal end of the radius in horses: five cases (1987-2001)

OBJECTIVE: To determine clinical, radiographic, and scintigraphic abnormalities in and treatment and outcome of horses with trauma-induced osteomyelitis of the proximal aspect of the radius. DESIGN: Retrospective study. ANIMALS: 5 horses. PROCEDURE: Data collected from the medical records included signalment; history; horse use; degree of lameness; radiographic, ultrasonographic, and scintigraphic findings; treatment; and outcome. RESULTS: Duration of lameness prior to referral ranged from 14 to 60 days. Mean severity of lameness was grade 3 of 5, and all horses had a single limb affected. All horses had signs of pain during elbow joint manipulation and digital palpation over the lateral aspect of the proximal end of the radius. Radiographic lesions consisted of periosteal proliferation, osteolysis, and subchondral bone lysis. Scintigraphy in 3 horses revealed intense pharmaceutical uptake diffusely involving the proximal end of the radius. Two horses had sepsis of the elbow joint. All horses were treated with antimicrobials long-term; 1 horse was also treated by local perfusion of the radial medullary cavity through an indwelling cannulated screw. At follow-up, all horses had returned to their previous function. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that osteomyelitis of the proximal end of the radius can result from a traumatic injury to the antebrachium. Because lesions may be an extension of septic arthritis, a thorough examination of the wound area and elbow joint is recommended. Prolonged systemic antimicrobial treatment can result in a successful outcome.     

Plant Species Composition and Forage Production 14 Yr After Biosolids Application and Grazing Exclusion

This paper examines the effects of a single surface application of biosolids (at 20 dry Mg ha^{? 1}) on plant species composition, forage quality and quantity, and C stocks after 14 yr of rest in rangelands of the Central Interior of British Columbia. More than two times the aboveground biomass of grasses and the percent cover of plant litter were found in the biosolids treatment relative to the control, along with reductions in bare soil and microbiotic crust cover. Significantly greater plant uptake of all macronutrients (C, N, P, K, S, Ca, and Mg); most micronutrients (B, Cu, Mn, Mo, and Zn); and Al occurred in the biosolids treatment. P and Cu were the only two nutrients to be more concentrated in the biosolids-treated forage relative to the control forage, while N, Mg, and protein were more concentrated in the control forage. No significant difference in forage digestibility was found between biosolids and control treatments. Bluebunch wheatgrass, the late-seral native grass species, had significantly increased cover and aboveground biomass in the biosolids treatment relative to the control; however, between 2006 and 2016, non-native Kentucky bluegrass had reached > 25% cover in the biosolids plots, perhaps restricting the full recovery of bluebunch wheatgrass. Our findings indicate that biosolids application to ungrazed rangeland can increase long-term forage production and reduce bare soil. However, at our study site biosolids application also led to a long-term shift in the plant community composition away from the late-seral (i.e., bluebunch wheatgrass) trajectory, and the effects of this shift on rangeland health and productivity require further investigation.     

Pharmacokinetics and bioequivalence of parenterally administered doramectin in cattle

Plasma concentrations of doramectin in 40 cattle dosed by subcutaneous (sc) or intramuscular (i.m.) injection (200 μg/kg) were compared to assess the bioequivalence of the two routes of administration. Peak concentration ( C _max), and areas under the concentration curve ( AUC_0– ) were determined from plasma concentrations. Animals treated by the sc route showed a mean AUC_0– of 457 ± 66 ng±day/mL (± SD) and a mean C _max of 27.8 ± 7.9 ng/mL. Results from the i.m. treatment group showed a mean AUC _0– of 475 ± 82 ng-day/mL and a mean C _max of 33.1 ± 9.0 ng/mL Absorption constants ( k _a) determined by modelling were 0.542 ± 0.336 day^-1after sc administration and 0.710 ± 0.357 day^-1after i.m. administration. The 90% confidence limits on the difference between mean AUC _0– values for the sc and i.m. groups fell within 20% of the mean value for the subcutaneous group. C _max was somewhat greater for the i.m. route. The 90% confidence limits on the difference in mean In ( T _max+1) also fell within 20% of the mean sc value. Based on this analysis, bioequivalence of the sc and i.m. formulation has been established.