Considerations for Scottish soil monitoring in the European context

Two contrasting phases of work are described that help inform the development and requirements of a soil monitoring system: firstly, the development and application of a multi-criterion analysis of soil quality indicators grounded in the basic natural sciences; and secondly, scrutiny of the outcome of that process by a wide range of non-specialist but key stakeholders at a workshop. This process ensures that the final monitoring design meets both the scientific rigour expected from a monitoring system and as far as possible meets the aspirations of policy and regulatory stakeholders. Individual indicators of soil quality were evaluated in terms of their applicability against a number of important environmental and logistical parameters and therefore their overall fitness for purpose. These included relevance to different soil types, functions, habitats and threats to soil, the inherent variability of soil, and a range of technical aspects such as analytical complexity, precision and reproducibility of analytical results and whether a standard operating procedure (SOP) existed for the technique. A tiered approach to soil monitoring was supported by workshop delegates. This will require indicators that are suitable and effective at national, site-specific and process-level scales. In addition, the opportunities for synchronizing soil monitoring with air and water quality monitoring should be considered and the potential for integrating on-site measurements with remote methods should be researched further. It was considered by workshop attendees that soil monitoring should be rooted in pedological principles (i.e. recognizing defined soil horizons) to ensure that results can be extrapolated from individual sites and to retain flexibility.     

Characterisation of Pasteurella multocida isolated from fowl cholera outbreaks on turkey farms

SUMMARY: Biochemical profiles, restriction endonuclease analysis (REA) and ribotyping were used to investigate Pasteurella multocida isolates from outbreaks of fowl cholera on 7 turkey farms in New South Wales. While only a single isolate was available from 5 of the farms, multiple isolates, 4 and 12 respectively, were available from the other 2 farms. The available field evidence suggested that 8 outbreaks had occurred with one farm suffering 2 outbreaks. The isolates obtained were all confirmed as Pasteurella multocida . Biochemical profiles allocated the isolates to 4 groups, 3 being variants of P multocida subsp multocida and the fourth being P multocida subsp septica . REA performed with Hpall established 7 groups. Ribotyping using the Hpall digests probed with the 16S rRNA operon of Haemophilus paragallinarum recognised the same 7 groups as REA. Unlike the biochemical profiles, both REA and ribotyping provided a fine subdivision that identified outbreaks as either related or unrelated. The REA and ribotyping patterns as well as biochemical profiles were stable for all isolates from the outbreaks in which multiple isolates were obtained from either the same bird or from different birds. REA and ribotyping were found to be superior to biotyping methods for the investigation of fowl cholera outbreaks.     

Nitrogen metabolism and fertility in cattle: II. Development of oocytes recovered from heifers offered diets differing in their rate of nitrogen release in the rumen

In vitro blastocyst production was determined for oocytes recovered postmortem from 48 beef x dairy heifers offered low (Low NH3) or high (High NH3) plasma ammonia-generating diets during the period of late antral follicle development. Following the establishment of a reference estrus (d 0), the experimental diets were offered for an 18-d period starting on d 3 and during which a second estrus was induced (d 16) 4 d before the animals were slaughtered. Blood samples collected at varying intervals were analyzed for ammonia, urea, progesterone, and LH. Ovarian folliculogenesis was monitored daily by transrectal ultrasonography. Ovaries were collected at slaughter and cumulus-oocyte complexes were aspirated from small (1 to 4 mm) and medium-sized (> 4 to 8 mm) sized follicles. In vitro-matured and -fertilized putative d-1 zygotes were cultured for a further 7 d in vitro and embryo development and metabolism were assessed. Relative to the low-NH3-generating diet, the high-NH3-generating diet increased peak postprandial levels of plasma ammonia (326.1 +/- 43.3 vs 52.1 +/- 7.4 micromol/L; P < .001), mean levels of plasma urea (7.0 vs 5.7 mmol/L; SED = .2; P < .001), peak levels of plasma progesterone prior to induced luteolysis (8.9 +/- .4 vs 6.8 +/- .3 microg/L; P < .001), and follicular fluid levels of ammonia (267 +/- 18 vs 205 +/- 20 nmol/mL; P < .05) and progesterone (351 +/- 69 vs 199 +/- 26 ng/mL; P < .05). The timing and level of the preovulatory LH surge was not affected by dietary treatment. Of oocytes cultured, cleavage (47.4 vs 62.4%; P = .02) and blastocyst production (10.9 vs 20.6%; P = .06) rates were reduced when the oocytes were derived from heifers offered the high- rather than the low-NH3-generating diets. There were interactions between dietary treatment and follicle size class, which indicated that fewer blastocysts were produced from cleaved oocytes derived from medium-sized follicles of heifers offered the high-NH3 treatment but that de novo protein synthesis was increased in such embryos. In conclusion, exposure to high levels of ammonia and(or) urea in vivo can significantly compromise the subsequent capacity of oocytes to develop to blastocysts in vitro, and oocytes recovered from medium-sized follicles are particularly sensitive to this effect.     

Cold hardiness of interspecific hybrids between Pinus strobus and P. wallichiana measured by post-freezing needle electrolyte leakage

Interspecific hybrids between eastern white pine (Pinus strobus L.) and Himalayan blue pine (P. wallichiana A. B. Jacks.) were developed in Ontario, Canada, to introduce blister rust (Cronartium ribicola Fisch.) resistance genes to P. strobus. There is concern that introducing blister rust resistance has resulted in reduced cold hardiness of the progeny compared with non-hybridized eastern white pine. To test the efficacy of backcrossing with P. strobus to improve cold hardiness, 1-year-old seedlings from hybrid crosses differing in P. strobus genome composition were artificially freeze-tested. In Experiment 1, unhardened seedlings were allowed to acclimate to progressively lower temperatures in a growth room, whereas in Experiment 2, seedlings were hardened outdoors under natural weather conditions in Sault Ste Marie, Ontario. Needle cold injury was determined by calculating relative electrical conductivity based on post-freezing electrolyte leakage. Results indicated that needle fascicles from unhardened seedlings of all genotypes in the greenhouse tolerated -5 degrees C for 3 hours with little or no injury. Cold hardiness increased in parallel with declining growth room minimum temperature over the 7-week period of hardening. Cold hardiness was improved for hybrid crosses with increased Pinus strobus genome composition in Experiment 2, but the results were less conclusive in Experiment 1.