Microscopic lesions associated with the isolation of Haemophilus somnus from pneumonic bovine lungs

Sixty-one of 68 sets of bovine lungs from which only Haemophilus somnus was isolated had microscopic lesions of purulent bronchiolitis and bronchopneumonia. In 37 of 61 lungs, the bronchiolar exudates were markedly necrotic with accompanying necrosis of the adjacent bronchiolar epithelium. Bronchiolitis obliterans was prominent in 23 of 28 lungs affected with chronic lesions with abscesses present in seven. Alveolar filling with inflammatory cells (neutrophils with fewer macrophages) was limited to peribronchiolar alveoli in 25 of 61 lungs and was multifocal to diffuse in the other 36. Lesions in the remaining lungs (7 of 68) were classified as fibrinous pneumonia with bronchiolitis (2), fibrinous pleuritis (2), suppurative interstitial pneumonia with vasculitis (2), and diffuse congestion (1).     

Plasma and synovial fluid pharmacokinetics of a single intravenous dose of meropenem in adult horses

The objective of this study was to determine the pharmacokinetics of meropenem in horses after intravenous (IV) administration. A single IV dose of meropenem was administered to six adult horses at 10 mg/kg. Plasma and synovial fluid samples were collected for 6 hr following administration. Meropenem concentrations were determined by bioassay. Plasma and synovial fluid data were analyzed by compartmental and noncompartmental pharmacokinetic methods. Mean ± SD values for elimination half‐life, volume of distribution at steady‐state, and clearance after IV administration for plasma samples were 0.78 ± 0.176 hr, 136.1 ± 19.69 ml/kg, and 165.2 ± 29.72 ml hr^‐1 kg^?1, respectively. Meropenem in synovial fluid had a slower elimination than plasma with a terminal half‐life of 2.4 ± 1.16 hr. Plasma protein binding was estimated at 11%. Based on a 3‐compartment open pharmacokinetic model of simultaneously fit plasma and synovial fluid, dosage simulations were performed. An intermittent dosage of meropenem at 5 mg/kg IV every 8 hr or a constant rate IV infusion at 0.5 mg/kg per hour should maintain adequate time above the MIC target of 1 μg/ml. Carbapenems are antibiotics of last resort in humans and should only be used in horses when no other antimicrobial would likely be effective.     

Effects of modified tall oil and creatine monohydrate on growth performance, carcass characteristics, and meat quality of growing-finishing pigs

The effects of feeding modified tall oil (MTO) and creatine monohydrate (CMH) on growing-finishing pig growth performance, carcass characteristics, and meat quality were determined. Eighty cross-bred barrows (initially 45.4 kg) were allotted randomly to one of four dietary treatments by weight and ancestry. The experiment was arranged as a 2 x 2 factorial with two levels of MTO (0 or 0.50%), which were fed throughout the growing-finishing period, and two levels of CMH (0 or 25 g/d), which were fed for the final 10 d before slaughter. The corn-soybean meal diets were fed in two phases (45.4 to 78.9 kg and 78.9 to 117.5 kg BW). When CMH was added to the diet in place of corn, average BW was 107.5 kg. Feeding MTO increased (P < 0.05) ADG and gain:feed ratio (G/F) during the 45.4- to 78.9-kg growth interval and tended to improve (P = 0.10) G/F during the 45.4- to 107.5-kg growth interval. Dietary treatment did not affect (P > 0.15) growth performance during the 78.9- to 107.5-kg growth interval. Modified tall oil increased (P = 0.02) G/F during the 10-d CMH supplementation period, and CMH numerically (P = 0.11) increased ADG and G/F. Supplementation of CMH did not affect (P > 0.20) any measured carcass characteristic or measures of meat quality at 24 h or 14 d postmortem. Feeding MTO reduced average back-fat (P = 0.05) and 10th rib backfat (P = 0.01) but did not affect (P > 0.10) other measured carcass characteristics or measures of meat quality at 24 h postmortem. Modified tall oil increased (P = 0.02) L* values (lightness) and tended to increase (P < 0.10) thawing and cooking losses of longissimus muscle chops at 14 d postmortem. These data demonstrate that MTO improves growth performance and reduces backfat in growing-finishing pigs, but supplementation of CMH, under the conditions of this experiment, was not beneficial for growing-finishing pigs.     

Localized dispersal and recruitment in great barrier reef corals: the helix experiment

To examine the problem of how far coral larvae disperse from their natal reef, coral recruitment densities were experimentally determined at distances up to 5 kilometers from a small, relatively isolated platform reef, Helix Reef, on the central Great Barrier Reef for 7 months. High concentrations of recruits, accounting for up to 40 percent of all recruitment, were found downstream of the reef in areas of high water residence time, suggesting that near-field(proximal) circulation has a profound influence on dispersal and recruitment of coral larvae. Coral recruitment declined logarithmically with distance from the reef, decreasing by an order of magnitude at radial distances of only 600 to 1200 meters. On an ecological time scale, advective dispersal of semipassive marine larvae with relatively short planktonic lives(minimally days) may be extensive, but success of recruitment is highly limited. Through evolutionary time, sufficient dispersal occurs to ensure gene flow to reef tracts hundreds or possibly thousands of kilometers apart. In the short term, however, coral reefs appear to be primarily self-seeded with respect to coral larvae.     

Oocyte holding in the Iberian red deer (Cervus elaphus hispanicus): Effect of initial oocyte quality and epidermal growth factor addition on in vitro maturation

Current in vitro embryo production protocols in the Iberian red deer (Cervus elaphus hispanicus) need to be optimized; oocyte harvesting in situ followed by overnight holding could reduce the human effort and shipping costs. In our work, post‐mortem ovaries were retrieved, and the oocytes were harvested and allocated to G1 group (good quality) or G2 + G3 group (low quality). The oocytes were separately subjected to immediate in vitro maturation (IVM) or held overnight in a holding medium composed of 40% of TCM 199 with Earle's salts, 40% TCM 199 with Hanks' salts and 20% fetal bovine serum (FBS), at room temperature (16 hr). In vitro maturation was carried out in a basal medium supplemented or not with 50 ng/ml of epidermal growth factor (EGF). Our data showed that addition of EGF to the maturation medium increases the percentage of G1 oocytes reaching metaphase II (3.9% vs. 50%, basal vs. EGF; p < .001) and decreased their degeneration rate (69.9% vs. 22.2%, basal vs. EGF; p < .01) when oocytes were immediately matured. Overnight holding increased the meiotic competence of G1 oocytes (37.5% matured in basal medium) and EGF increased prophase arrest in G2 + G3 oocytes (16.1% vs. 38.8% in germinal vesicle [GV] stage in basal medium vs. EGF added medium; p < .05). Our data demonstrate that oocyte holding can be used in Iberian red deer oocytes. Interestingly, EGF addition increases the oocytes' meiotic competence in immediately matured oocytes but not after oocyte holding depending upon initial oocyte quality.     

Immune response to Sarcocystis neurona infection in naturally infected horses with equine protozoal myeloencephalitis

Equine protozoal myeloencephalitis (EPM) is one of the most common neurologic diseases of horses in the United States. The primary etiologic agent is Sarcocystis neurona. Currently, there is limited knowledge regarding the protective or pathophysiologic immune response to S. neurona infection or the subsequent development of EPM. The objectives of this study were to determine whether S. neurona infected horses with clinical signs of EPM had altered or suppressed immune responses compared to neurologically normal horses and if blood sample storage would influence these findings. Twenty clinically normal horses and 22 horses with EPM, diagnosed by the presence of S. neurona specific antibodies in the serum and/or cerebrospinal (CSF) and clinical signs, were evaluated for differences in the immune cell subsets and function. Our results demonstrated that naturally infected horses had significantly (P<0.05) higher percentages of CD4 T-lymphocytes and neutrophils (PMN) in separated peripheral blood leukocytes than clinically normal horses. Leukocytes from naturally infected EPM horses had significantly lower proliferation responses, as measured by thymidine incorporation, to a non-antigen specific mitogen than did clinically normal horses (P<0.05). Currently, studies are in progress to determine the role of CD4 T cells in disease and protection against S. neurona in horses, as well as to determine the mechanism associated with suppressed in vitro proliferation responses. Finally, overnight storage of blood samples appears to alter T lymphocyte phenotypes and viability among leukocytes.     

Evaluation of a wireless ambulatory capsule (SmartPill®) to measure gastrointestinal tract pH, luminal pressure and temperature, and transit time in ponies

Reasons for performing study: This study investigated the use of a wireless ambulatory capsule (WAC; SmartPill^® pH.p GI Monitoring System) to determine WAC‐gastric emptying time (GET) in ponies. Objectives: To measure WAC‐GET and compare it to those findings with GET assessed by nuclear scintigraphy (S‐GET). Hypothesis: WAC‐GET will be slower than S‐GET, but will be significantly correlated. Methods: Seven healthy adult mixed‐breed pony mares were used in this study. Feed was withheld for 12 h prior to the WAC administration. After administration, a complete‐feed diet was fed to allow the WAC to pass into the stomach. Luminal pH, temperature and pressure were collected by a modified receiver secured to the pony. Once the pH reached a value of ≥8.0, it was determined that gastric emptying had occurred, and ponies were fed grass hay. After 5 days, data were downloaded and analysed using proprietary software. During the second period of the study, after at least 2 weeks, 4 of the ponies underwent a standard S‐GET test. Results: The WAC was successfully administered, and data were collected from all ponies. The mean percentage of data packets collected by the receiver was 84.9 ± 3.51% (range 66.8–95.1%). Mean WAC‐GET was 7.38 h (range 0.15–46.65 h). Mean gastric pH was 4.75 (range 2.07–6.99). Mean small intestinal transit time was 4.6 h. The mean pH for the small intestine was 8.0. The mean S‐GET time (in hours) when 10% of the radioactive feed is present in the stomach (T‐90%) was 2.3 h. The S‐GET did not correlate significantly with the WAC‐GET. Conclusions and potential relevance: The WAC was safely administered to ponies, and data were collected using a modified receiver. The WAC‐GET varied considerably between ponies, but was ≤3 h in 5 of the 6 ponies. The WAC used in this study provided a noninvasive technique that produced novel information about the pony gastrointestinal tract, but owing to the substantial variability in GET values and long transit time it may not be a reliable clinical tool at this time.