High-sensitivity radioimmunoassay screening method for fentanyl

A radioiodinated analog of fentanyl was synthesized for use with a commercially available radioimmunoassay for fentanyl. The sensitivity of the modified assay was at least 100 times greater than that of the original assay. Using this modified assay, concentrations of fentanyl as low as 1 pg/ml of fentanyl or fentanyl equivalents in equine urine were detected. Doses of fentanyl 100 times smaller than the minimum dose for a pharmacologic effect were detectable and a pharmacologically effective dose of fentanyl was detectable for up to 96 hours or more. The high sensitivity of the assay indicated that large numbers of urine samples (ie, 10 to 20) probably could be pooled and screened simultaneously, which would result in an economical analysis for fentanyl in the urine of horses after a race. Sufentanil and its metabolites also were detectable, using this assay, but at only about 1% of the efficiency at which fentanyl was detectable.     

Surgical management of an abdominal abscess in a Malayan tapir

A captive Malayan tapir was observed to have inappetence, weight loss, signs of depression, mild dehydration and diar rhoea. Haematological and serum biochemical tests showed anaemia, hypoproteinaemia, hyperfibrinogenaemia and neu-trophilia with a left shift. Ultrasonic examination of the abdomen under anaesthesia revealed a well-encapsulated abscess. The abscess was marsupialised to the ventral body wall. Culture of the pus produced a mixed bacterial growth. Antimicrobial therapy was based on bacterial sensitivity results. Follow-up ultrasonic examinations showed resolution of the abscess. Ninety-one days after surgery the tapir began regurgitating food and water. An abscess originating from the stomach and occluding the lumen of the duodenum was identified at surgery. The abscess ruptured during surgical manipulations and the tapir was euthanased.     

Dietary phosphorus for beef cows

Hereford heifers (48 initially) were individually fed variable amounts of dietary phosphorus (P) from weaning through their 8th gestation. During phase I, 2 groups (24 cows each) were given 20.6 to 38.1 g of P/day and 6.0 to 12.1 g of P/day (increasing as animals grew). During phase II (the 4th gestation), half of the animals from each group were maintained with the same respective diets, and the other half were given 5.1 to 6.6 g of P/day. Within 6 months, animals given 5.1 to 6.6 g of P/day gradually developed signs of P deficiency. Clinical signs of deficiency and lesions included general unthriftiness, body weight loss, reduced feed consumption, reluctance to move, abnormal stance, spontaneous bone fractures, and finally, impaired reproductive performance. Cows given 7.8 to 8.9 g of P/day in diet 2 during phase II did not develop discernible clinical signs of P deficiency. Cows that were given 5.1 to 6.6 g of P/day apparently regained their health and reproductive capability when fed 11.7 to 12.6 or 17.1 to 20.5 g of P/day. The data indicate that bones serve as an effective storage source of P and support and buffer body needs until there is serious depletion of skeletal P. These results indicate that common recommendations for dietary P, such as those outlined by the National Research Council (17.5 g of P/day over the entire year for cows weighing 450 kg), exceed the basic requirements for beef cattle; 12 g of P/day is adequate for 450-kg beef cows.     

Occurrence of barley yellow dwarf virus in autumn-sown cereal crops in the United Kingdom in relation to field characteristics

The incidence of barley yellow dwarf virus and of its aphid vectors was surveyed in untreated parts of autumn-sown cereal crops, mainly wheat and barley, in the United Kingdom in 1995-8. The incidence of virus in the spring was related to the incidence of aphids in the preceding autumn. Both virus and aphid incidences could also be related to a range of crop and field characteristics, in particular sowing date, regions as defined by their geographical position, topography and climate, the proximity of the field to the sea, the extent of arable land in the vicinity of the field, and the aspect and size of the field. Proximity of cropped fields to setaside areas had no significant effect on either aphid or virus incidence.     

Growth and carbohydrate status of coppice shoots of hybrid poplar following shoot pruning

Fifteen, 1-year-old Populus maximowiczii Henry x P. nigra L. 'MN9' trees were decapitated and allowed to sprout. After 8 weeks, all had 6 to 10 coppice shoots. All shoots, except the tallest (dominant) shoot, were removed from five of the trees (pruned treatment), and shoot growth, gas exchange and carbohydrate status were compared in the pruned and unpruned trees. Although photosynthetic rate of recently mature leaves of pruned trees was approximately 50% greater than that of leaves on the dominant shoot of unpruned trees, and the dry weight of leaves of pruned trees was 37% greater than that of the leaves on the dominant shoot of unpruned trees, the shoot dry matter relative growth rate did not differ between treatments. Concentrations of water-soluble carbohydrates and starch in the uppper stem and leaves of the dominant shoot were similar in pruned and unpruned trees. However, relative to that of the dominant shoot in unpruned trees, the lower stem in pruned trees was depleted in both soluble carbohydrates and starch. Starch deposition, assessed as the quantity of (14)C-starch in tissues 24 h after a fully expanded source leaf was labeled with (14)CO(2), was 3.9 times greater in roots of pruned trees than in roots of unpruned trees. We conclude that early removal of all but the dominant shoot reduces the carbohydrate status of the roots and the lower portion of the stem by eliminating the excised shoots as a source of photosynthate.     

Potential infection-control benefit for Ireland from pre-movement testing of cattle for tuberculosis

Pre-movement testing for bovine tuberculosis (BTB) was compulsory in Ireland until 1996. We determined the proportion of herd restrictions (losing BTB-free status) attributable to the recent introduction of an infected bovid; described events between restoration of BTB-free status (de-restriction) and the next herd-level test for BTB; estimated the proportion of undetected infected cattle present at de-restriction; identified high-risk movements between herds (movements most likely to involve infected cattle); and determined the potential yield of infected cattle discovered (or herds that would not lose their BTB-free status) by pre-movement testing, relative to the numbers of cattle and herds tested. We used national data for all 6252 herds with a new BTB restriction in the 12 months from 1 April 2003 and 3947 herds declared BTB-free in the 12 months from 1 October 2001. We identified higher-risk animals from our logistic generalized estimating-equation models. We attributed 6-7% of current herd restrictions to the recent introduction of an infected animal. There were considerable changes to herd structure between de-restriction and the next full-herd test, and infection was detected in 10% of herds at the first assessment (full-herd test or abattoir surveillance) following de-restriction. Following movement from a de-restricted herd, the odds of an animal being positive at the next test increased with increasing time in the source herd prior to movement, increasing time between de-restriction and the next full-herd test and increasing severity of the source herd restriction. The odds decreased with increasing size of the source herd. We estimated that 15.9 destination-herd restrictions per year could be prevented for every 10,000 cattle tested pre-movement and that 3.3 destination-herd restrictions per year could be prevented for every 100 source herds tested pre-movement. The yield per pre-movement test can be increased by focusing on high-risk movements; however, this would result in a substantial decrease in the total number of potential restrictions identified.     

Demographic and Density Response of Northern Bobwhites to Pyric Herbivory of Non-Native Grasslands

Usable space for northern bobwhites (Colinus virginianus) has declined significantly over the past 3 decades in Texas because non-native grasses have replaced native vegetation. We hypothesized that burning patches in pastures dominated by buffelgrass (Pennisetum ciliare) and Old World bluestems (Bothriochloa spp. and Dichanthium spp.) followed by livestock grazing would increase limiting habitat attributes, thereby increasing usable space and bobwhite demographic parameters and population densities. Our study was conducted during 2009–2011 in LaSalle County, Texas on a ranch dominated by non-native grasses. Our experimental design was composed of 2 blocks with two 240-ha pastures, one control (graze only), and one treatment (patch-burn and graze) in each. We estimated grass standing crop in grazing exclosures (June–September) and habitat attributes along transects (October) 2009–2011. Bobwhites were captured and monitored via radiotelemetry 2–3 times/wk during March–November. Means of vegetation metrics important to bobwhites such as bare ground, traversibility, and forb and subshrub cover were similar between control and treatment units in post-treatment years. However, grass standing crop tended to be lower in treatment (June and August 2010 and September 2011—110.5 ± 26.2 g/m²) compared with control units (June and August 2010 and September 2011—145.5 ± 58.6 g/m²). Plant species richness was also greater (21%) in treatment (4.6 ± 0.4/0.1 m²) compared with control units (3.8 ± 0.4/0.1 m²) during the last year of the study (P ≥ 0.057). Patch heterogeneity was increased in treatment units. There was an increase in bobwhite densities in treatment units, although demographic metrics remained similar between treatment and controls. Patch burning and grazing is a viable tool for managing monotypic non-native grasslands for bobwhites in semiarid environments.