Physiological consequences of captive conditions in water voles (Arvicola terrestris)

Re-introductions of captive-bred animals are increasingly common in wildlife conservation and it is important that they fulfil their potential. To foster this goal we examined variations in stress levels in a captive-bred population of water voles Arvicola terrestris in response to housing conditions and radio-collaring, using weight loss and leukocyte coping capacity (LCC) as measures of relative stress, to investigate the impacts of housing conditions, handling and radio-collaring on this species. Thirty-eight water voles (22 males and 16 females) were used in the investigation, 25 housed in outdoor enclosures and 13 in laboratory cages. During the 6-week study, LCC, body weight and urine refractive index (URI, an indicator of hydration levels) were recorded once a week for each individual in weeks 1, 2, 4 and 6. After the first sample, radio-collars were attached to 20 individuals (10 males and 10 females) taken from both housing types. Throughout the experiment laboratory-cage housed voles weighed less, had lower LCC scores – indicating a reduced ability to combat infection – and had higher URIs than outdoor-enclosure voles. This suggests that the laboratory-cage voles were more stressed and dehydrated than the outdoor-enclosure voles. Weights and LCC scores of both housing groups decreased as the study progressed, suggesting that elements of the study, such as repeated handling, may have caused stress to both groups. Evidence suggested a short-term effect of radio-collaring on immuno-competence. We conclude that captive housing conditions, repeated manipulation and radio-collaring had demonstrable physiological effects on the water voles studied. We recommend that the effects of husbandry and tagging practices upon captive-bred mammals be closely studied as part of the quest to improve the success of the re-introductions to which they contribute.     

Balanced dispersal or source–sink–do both models describe wood mice in farmed landscapes?

Plant responses to browsing can affect root and shoot morphology, which is important to subsequent herbivory, nutrient acquisition and competition. This paper examines the above- and below-ground responses of three browse species, with different growth strategies, to simulated browsing damage at different times of year. Saplings were grown in pots in sand culture to enable whole sapling analysis. At winter dormancy or budburst, 50% of previous year's shoots (and associated leaves/buds) were clipped. Subsequent sapling growth and morphology was compared with that of unclipped control saplings. Treatment differences in growth parameters of each species were observed, including changes in branching patterns, shoot lengths, diameters and ratios, leaf sizes and end-of-season bud numbers. Some responses were damage-induced per se; others differed according to timing of damage. Compensatory growth by the two deciduous species ( Betula pendula , Sorbus aucuparia ) resulted in few biomass differences by the end of the year of damage as compared to controls, but both above- and below-ground growth of clipped Pinus sylvestris was poor, particularly those damaged at budburst, giving strong differences between control, dormant, and budburst clipped saplings.     

Individual differences in den maintenance effort in a communally dwelling mammal: the Eurasian badger

Group living has potential costs in terms of relative fitness for individuals that invest effort in activities providing general benefit, if other competing individuals exploit those activities and accrue similar benefits at no cost. We examined the roles of individual badgers, Meles meles, in the den maintenance activities of digging and bedding collection at their communal setts. Twenty per cent of adults and yearlings were responsible for 60-90% of the observed digging and bedding collection effort. Overall males tended to dig more than females, while durations of bedding collection were similar. Among adult and yearling males and females, individuals with a high percentage of days observed at the sett (high site fidelity) performed more digging and collected more bedding than transients and badgers of low site fidelity. Males of high status (large, mature, frequently copulating individuals) were more likely to dig than males of low status. Principal component analysis indicated negligibly low correlation between status and site fidelity for males. We hypothesize that while highly resident adult females benefit from extending the sett to avoid direct reproductive competition, males of high status and site fidelity might extend the sett to encourage receptive breeding females in their home group to stay and/or to improve survivorship of sired litters. Other categories of individual depend on the sett for shelter but, perhaps having less to gain from extending it, adopt a less active role in sett maintenance. Copyright 1999 The Association for the Study of Animal Behaviour.     

Association of immune parameters with clinical outcome in stage III colon cancer: results of Southwest Oncology Group Protocol 9009

Levamisole (LMS), utilized in the adjuvant treatment of patients with stage III colon cancer, is immunomodulatory. To determine whether alterations in immune parameters before, during and after 12 months of 5FU/LMS therapy correlate with disease-free survival, 38 patients enrolled on Southwest Oncology Group (SWOG) protocol 8899 received extensive lymphocyte phenotypic analysis prior to therapy and 3, 6, 12 and 15 months after treatment initiation. The median follow-up of patients is 41 months. Significant increases in the proportion and total number of CD56⁺ natural killer cells were seen, starting at 3 months and continuing until 15 months (P < 0.001). Increases in the total numbers of cells expressing CD25 (interleukin-2 receptor), VLA4 and the combinations of CD4: CD45RA and CD4:CDw29 were not evident during therapy but were seen at 15 months (P < 0.05: CD25, CD4:CDw29, CD4:CD45RA; P < 0.001: VLA4). Low levels of CD8⁺ cells prior to treatment initiation and after 3 months of therapy correlated with early relapse within the first year of 5FU/LMS treatment. Patients who have remained disease-free (n = 22, median follow-up 45 months) demonstrated increases in the total numbers of CD8⁺, CD25⁺, CD56⁺, VLA4⁺, CD4: CDw29 and CD4:CD45RA cells, primarily at 15 months. In contrast, patients who relapsed had decreased numbers of CD8⁺, CD4:CDw29, CD4: CD45RA and VLA4⁺ cells and minimal increases in CD56⁺ and CD25⁺ cells. Statistically significant differences between the late-relapse group and the group remaining disease-free were seen for CD25⁺, CD4: CD45RA and CD4:CDw29 cells at the 15-month assay time (P = 0.0276, P = 0.0349, P = 0.0178 respectively). In conclusion, multiple alterations in lymphocyte phenotype, with increases in the proportion and total number of cells involved in cell-mediated immune responses, were seen during and especially following completion of therapy with 5FU/LMS. Many of these changes are significantly associated with clinical outcome and may be useful for risk stratification of stage III colon cancer patients following completion of adjuvant therapy. Received: 9 July 1999 / Accepted: 11 August 1999     

Fusarium mycotoxins: a review of global implications for animal health, welfare and productivity

Trichothecenes, zearalenone (ZEN) and fumonisins are the major Fusarium mycotoxins occurring on a worldwide basis in cereal grains, animal feeds and forages. Other important Fusarium mycotoxins include moniliformin and fusaric acid. Spontaneous outbreaks of Fusarium mycotoxicoses have been recorded in Europe, Asia, New Zealand and South America and, in addition, chronic exposure occurs on a regular and more widespread scale. The metabolism and adverse effects of the Fusarium mycotoxins are considered in this review with particular reference to recent data on specific and proposed syndromes and to interactions among co-occurring mycotoxins. Within the trichothecene group, deoxynivalenol (DON) is associated with emesis, feed refusal and depressed feed intake in pigs, while T-2 toxin and diacetoxyscirpenol (DAS) are now clearly linked with oral lesions in poultry. The gut microflora of farm livestock are able to transform DON to a de-epoxy derivative. In contrast, the ovine metabolism of ZEN results in the production of five metabolites and relatively high levels of these forms may be excreted in the urine as glucuronides. There is now undisputed evidence that ZEN and its metabolites possess estrogenic activity in pigs, cattle and sheep, but T-2 toxin has also been implicated in reproductive disorders in farm livestock. Fumonisins are positively linked with pulmonary edema in pigs, leukoencephalomalacia in equines and with deranged sphingolipid metabolism in these animals. Fusarium mycotoxins have also been provisionally implicated in ovine ill-thrift, acute mortality of poultry and in duodenitis/proximal jejunitis of horses. Several Fusarium mycotoxins may co-occur in a particular feed ingredient or in compound feedingstuffs. In general, combinations of Fusarium mycotoxins result in additive effects, but synergistic and/or potentiating interactions have been observed and are of greater concern in livestock health and productivity. Synergistic effects have been reported between DON and fusaric acid; DON and fumonisin B₁ (FB₁); and DAS and the Aspergillus-derived aflatoxins. Limited evidence of potentiation between FB₁ and DON or T-2 toxin has also emerged recently. Additive and synergistic effects between known and unidentified mycotoxins may account for enhanced adverse effects observed on feeding Fusarium-contaminated diets. The potential for transmission of DON into eggs and of ZEN into porcine kidney and liver has been demonstrated. However, lactational carry-over of FB₁ appears not to occur, at least in cows and sows. It is concluded that livestock health, welfare and productivity may be severely compromised by consumption of DON, T-2 toxin, DAS, ZEN and fumonisins and by interactions among these mycotoxins. Safety of some animal products may also be at risk. Furthermore, in view of the limited options available for remediation, it is concluded that exploitation of crops resistant to Fusarium infection offers the most viable strategy for reducing mycotoxin contamination of grain and animal feed.     

Cardiorespiratory responses to underwater treadmill walking in healthy females

This study compared the cardiorespiratory responses of eight healthy women (mean age 30.25 years) to submaximal exercise on land (LTm) and water treadmills (WTm) in chest-deep water (Aquaciser). In addition, the effects of two different water temperatures were examined (28 and 36°C). Each exercise test consisted of three consecutive 5-min bouts at 3.5, 4.5 and 5.5 km · h⁻¹. Oxygen consumption (V˙O₂) and heart rate (HR), measured using open-circuit spirometry and telemetry, respectively, increased linearly with increasing speed both in water and on land. At 3.5 km · h⁻¹ V˙O₂ was similar across procedures [χ = 0.6 (0.05) l · min⁻¹]. At 4.5 and 5.5 km · h⁻¹ V˙O₂ was significantly higher in water than on land, but there was no temperature effect (WTm: 0.9 and 1.4, respectively; LTm: 0.8 and 0.9 l · min⁻¹, respectively). HR was significantly higher in WTm at 36°C compared to WTm at 28°C at all speeds, and compared to LTm at 4.5 and 5.5 km · h⁻¹ (P ≤ 0.003). The HR-V˙O₂ relationship showed that at a V˙O₂ of 0.9 l · min⁻¹, HR was higher in water at 36°C (115 beats · min⁻¹) than either on land (100 beats · min⁻¹) or in water at 28°C (99 beats · min⁻¹). The Borg scale of perceived exertion showed that walking in water at 4.5 and 5.5 km · h⁻¹ was significantly harder than on land (WTm: 11.4 and 14, respectively; LTm: 9.9 and 11, respectively; P ≤ 0.001). These cardiorespiratory changes occurred despite a slower cadence in water (the mean difference at all speeds was 27 steps/min). Thus, walking in chest-deep water yields higher energy costs than walking at similar speeds on land. This data has implications for therapists working in hydrotherapy pools. Accepted: 3 September 1997     

The effects of arable field margin management on the abundance and species richness of Araneae (spiders)

The effects of ten different management regimes on the abundance and species richness of Araneae on pre-existing and newly expanded zones of field margins surrounding arable fields are compared in a large-scale experiment conducted between 1987 and 1991. Most of the management regimes involved varying the Liming and frequency with which the field margins were cut. There was no evidence of consistent temporal trends in the abundance and species richness of Araneae on either the existing or expanded zones of the field margins during the first four years of the experiment. However, lowest numbers were recorded before expansion of the margins in 1987, and highest numbers in the final sample, in 1991. Araneae remained less abundant, and less species rich, on the newly expanded than on the existing zones of the field margins four years after they were set-aside'. Culling reduced both abundance and species richness. Regimes which included culling in mid-summer had a greater impact which persisted for longer than did those involving cutting in spring and autumn. Removal of cut material was associated with lower species richness than leaving it in situ. Sowing the margins with a wild flower seed mixture was associated with increased abundance and species richness of Araneae. Annual spraying with a broad-spectrum, non-persistent herbicide reduced the abundance of Araneae but the effect was not detectable until several months after the application of the spray. Both the species richness and abundance of Araneae were positively correlated with a measure of vegetation height made on the field margins in September, on both the pre-existing and newly expanded zones of the margins. The extent to which management practices which benefit Araneae are compatible with both the management requirements for various other taxa. and the overriding constraint of effective pernicious weed control on field margins, is discussed.