Scrotal circumference,bodyweight and semen characteristics in growing dairy-breed natural-service bulls in Tasmania,Australia

Aims: To provide herd managers with a set of decision rules allowing them to predict the likelihood that a juvenile bull is ready for Bull Breeding Soundness Evaluation (BBSE), or breeding, if bodyweight and scrotal circumference are known.

Methods: This was a longitudinal study following two groups of young pasture-fed Holstein and Jersey bulls from northwest Tasmania, Australia. Individual scrotal circumference, bodyweight and semen characteristics were recorded at 6–8 weekly intervals, from 6–18 months of age. Classification and regression tree analyses were used to predict the probability that a bull had ≥70% normal sperm morphology based on scrotal circumference and bodyweight measurements.

Results: Overall 1,661 scrotal circumference and bodyweight measurements were obtained, and 518 semen samples from 356 bulls were assessed for sperm morphology, from 16 examination sessions that took place between 29 May 2015 and 17 August 2016. Classification and regression tree analyses generated a decision tree for Holstein bulls with four node endpoints, and for Jersey bulls with three node endpoints. Diagnostic test performance showed that for Holstein bulls, using the node endpoints of scrotal circumference ≥27?cm and bodyweight ≥349?kg, 98% had ≥70% normal sperm (positive likelihood ratio 10.4; 95% CI?=?2.7–41), and using the node endpoints of scrotal circumference ≥27?cm and bodyweight between 282–349?kg, 89% had ≥70% normal sperm (positive likelihood ratio 1.6; 95% CI?=?0.9–2.6). For Jersey bulls, using the node endpoints of bodyweight ≥259?kg and scrotal circumference ≥29?cm, 88% had ≥70% normal sperm (positive likelihood ratio 3.4; 95% CI?=?1.6–7.0).

Conclusions: This study provides a set of relatively simple decision rules based on bodyweight and scrotal circumference measurements that allows herd managers to assess the likelihood that juvenile bulls are ready for BBSE or breeding.

Abbreviations: BBSE: Bull breeding soundness evaluation; BRT: Boosted regression tree     

Regional differences in the in vitro penetration of methylsalicylate through equine skin

Commercial formulations of non-steroidal anti-inflammatory drugs (NSAIDs) are developed for human use but the extent to which they will pass through equine skin is unknown. Skin was harvested from five Thoroughbred geldings from the thorax, groin and leg (dorsal metacarpal) regions and frozen (-20 degrees C) until required. Two grams of methylsalicylate (MeSa) gel was applied to defrosted full-thickness samples in diffusion cells and the penetration of MeSa and its active metabolite, salicylate (Sa), through skin samples were measured over 24 h. Significantly higher (P < or = 0.02) total salicylate (AUC; MeSa + Sa) penetrated through skin from the leg region (5491.3 h mg/L), compared to thorax (3710.7 h mg/L) and groin (3571.5 h mg/L). In addition, there was a significantly higher (P0.01) rate of penetration of total Sa through leg skin in the first 6h after application. It was concluded that the commercial formulation of MeSa would achieve therapeutic levels of total salicylate beneath sites of topical application, with a faster and more pronounced response through the leg region, compared to the upper body.     

Coherent optical control of the quantum state of a single quantum Dot

Picosecond optical excitation was used to coherently control the excitation in a single quantum dot on a time scale that is short compared with the time scale for loss of quantum coherence. The excitonic wave function was manipulated by controlling the optical phase of the two-pulse sequence through timing and polarization. Wave function engineering techniques, developed in atomic and molecular systems, were used to monitor and control a nonstationary quantum mechanical state composed of a superposition of eigenstates. The results extend the concept of coherent control in semiconductors to the limit of a single quantum system in a zero-dimensional quantum dot.     

Accumulation of 60Co and 134Cs in Lake Whitefish in a Canadian Shield Lake

Radionuclides were added to the anaerobic hypolimnion of a Canadian Shield lake during the summer of 1989 to simulate nuclear fuel waste leakage into the bottom waters of a lake with deep groundwater flow. Lake whitefish (Coregonus clupeaformis) were sampled in mid-October each year from 1989 to 1994, except for 1992, to determine the concentration of ⁶⁰and ¹³⁴Cs in their tissues. The radionuclides remained in the hypolimnion until lake mixing in the autumn. Subsequently, there was more loss of ⁶⁰than¹³⁴Cs from the water. After one year, 4% of the⁶⁰Co and 15% of the ¹³⁴Cs remained in the water. This decreased to about 0.4% of the ⁶⁰and 0.6% of the ¹³⁴Cs in the water after five years. Little ⁶⁰and ¹³⁴Cs were present in lake whitefish the first autumn following the radionuclide addition. In fish, the highest concentrations were recorded in October, 1990, after which concentrations gradually decreased. Cobalt-60 concentrations were lower than ¹³⁴Cs concentrations, probably because ⁶⁰has a high affinity for organic particles and was not available for uptake. The relatively high ¹³⁴Cs concentrations in fish reflects its tendency to remain in the water and its continued availability to biota. Both ⁶⁰and ¹³⁴Cs concentrations were high in the soft tissues. Co-60 was mainly distributed in the flesh, gut, gill, kidney, and liver, whereas¹³⁴Cs was mainly distributed in the flesh. The occurrence of relatively high ¹³⁴Cs concentrations in lake whitefish five years after their addition to the lake, long after ¹³⁴Cs concentrations are no longer detectable in lake water, attests to the continued persistence of this contaminant in aquatic biota.     

Ecoviability for ecosystem‐based fisheries management

Reconciling food security, economic development and biodiversity conservation is a key challenge, especially in the face of the demographic transition characterizing many countries in the world. Fisheries and marine ecosystems constitute a difficult application of this bio‐economic challenge. Many experts and scientists advocate an ecosystem approach to manage marine socio‐ecosystems for their sustainability and resilience. However, the ways by which to operationalize ecosystem‐based fisheries management (EBFM) remain poorly specified. We propose a specific methodological framework—viability modelling—to do so. We show how viability modelling can be applied using four contrasted case‐studies: two small‐scale fisheries in South America and Pacific and two larger‐scale fisheries in Europe and Australia. The four fisheries are analysed using the same modelling framework, structured around a set of common methods, indicators and scenarios. The calibrated models are dynamic, multispecies and multifleet and account for various sources of uncertainty. A multicriteria evaluation is used to assess the scenarios’ outcomes over a long time horizon with different constraints based on ecological, social and economic reference points. Results show to what extent the bio‐economic and ecosystem risks associated with the adoption of status quo strategies are relatively high and challenge the implementation of EBFM. In contrast, strategies called ecoviability or co‐viability strategies, that aim at satisfying the viability constraints, reduce significantly these ecological and economic risks and promote EBFM. The gains associated with those ecoviability strategies, however, decrease with the intensity of regulations imposed on these fisheries.     

Real-time RT-qPCR assay to detect sequences in the Piscine orthoreovirus-1 genome segment S1 associated with heart and skeletal muscle inflammation in Atlantic salmon

During the last decade, Piscine orthoreovirus was identified as the main causative agent of heart and skeletal muscle inflammation (HSMI) in Atlantic Salmon, Norway. A recent study showed that PRV-1 sequences from salmonid collected in North Atlantic Pacific Coast (NAPC) grouped separately from the Norwegian sequences found in Atlantic Salmon diagnosed with HSMI. Currently, the routine assay used to screen for PRV-1 in NAPC water and worldwide cannot differentiate between the two groups of PRV-1. Therefore, this study aimed at developing a real-time polymerase chain reaction (RT-qPCR) assay to target the PRV-1 genome segments specific for variants associated with HSMI. The assay was optimized and tested against 71 tissue samples collected from different regions including Norway, Chile and both coast of Canada and different hosts farmed Atlantic Salmon, wild Coho Salmon and escaped Atlantic Salmon collected in British Columbia, West Coast of Canada. This assay has the potential to be used for screening salmonids and non-salmonids that may carry PRV-1 potentially causing HSMI.     

Differential antibody responses to Corynebacterium pseudotuberculosis in sheep with naturally acquired caseous lymphadenitis

Enzyme-linked immunosorbent assays (ELISA) with Corynebacterium pseudotuberculosis cell wall and bacteria-free supernatant with exotoxin preparations as antigens, and hemolysis inhibition tests were used to detect antibodies in the sera of adult range sheep with naturally acquired caseous lymphadenitis (CL). The extent and severity of lesions were quantitated on the basis of a lesion score, derived from an examination of the carcass (peripheral lymphoid tissue) and viscera (including internal lymphoid tissue) at the time of slaughter. The overall prevalence of C pseudotuberculosis-positive CL lesions in 104 sheep was 31.7%. The cell wall ELISA detected antibodies in 96.9% (32/33) of sheep with C pseudotuberculosis-positive CL lesions. The exotoxin ELISA detected antibodies in 84.8% (28/33) of positive sheep in the same group. Both ELISA resulted in a high number of apparent false-positives, with 64.7% and 49.2%, respectively, positive optical density (OD) values in sheep with no gross CL lesions and no apparent C pseudotuberculosis infection. There was no significant relationship between the extent of lesion development (lesion score) and OD values in both cell wall (r = 0.472) and exotoxin (r = 0.464) ELISA. Similarly, there was no significant relationship between the titer of antitoxin antibodies, as measured by the hemolysis inhibition test, and the extent of disease. These investigations indicate that those ELISA that use crude C pseudotuberculosis antigens are of questionable utility in the field, where C pseudotuberculosis infection is endemic in many sheep populations. Furthermore, these studies suggest that antibodies that are reactive with components of C pseudotuberculosis and that develop in response to infection may have little impact on the recovery of the host.     

Exploring for senescence signals in native scots pine (Pinus sylvestris L.) in the Scottish Highlands

The main aim of this project was to explore whether the pine trees in Glen Affric (GAF), one of the more extensive pine woodlands in the northern Scottish Highlands, are, on average, reaching a senescent stage which could ultimately be detrimental to the sustainability of the pine woodland in this region under present management conditions. This aim was realized by (1) comparing the mean stand age of the GAF trees to other pine woodlands around Scotland, (2) exploring whether there was a significant pre-death trend in ring-width series from naturally dead trees and (3) assessing whether a notable change in response of tree growth to climate was noted as a function of age which could indicate that trees were entering a state of senescence.     

‘MaxClover’ grazing experiment: I. Annual yields,botanical composition and growth rates of six dryland pastures over nine years

Six dryland pastures were established at Lincoln University, Canterbury, New Zealand, in February 2002. Production and persistence of cocksfoot pastures established with subterranean, balansa, white or Caucasian clovers, and a perennial ryegrass‐white clover control and a lucerne monoculture were monitored for nine years. Total annual dry‐matter (10.0–18·5 t DM ha^?1) and sown legume yields from the lucerne monoculture exceeded those from the grass‐based pastures in all but one year. The lowest lucerne yield (10 t ha^?1 yr^?1) occurred in Year 4, when spring snow caused ungrazed lucerne to lodge and senesce. Cocksfoot with subterranean clover was the most productive grass‐based pasture. Yields were 8·7–13·0 t DM ha^?1 annually. Subterranean clover yields were 2·4–3·7 t ha^?1 in six of the nine years which represented 26–32% of total annual production. In all cocksfoot‐based pastures, the contribution of sown pasture components decreased at a rate equivalent to 3·3 ± 0·05% per year (R² = 0·83) and sown components accounted for 65% of total yield in Year 9. In contrast, sown components represented only 13% of total yield in the ryegrass‐white clover pastures in Year 9, and their contribution declined at 10·1 ± 0·9% per year (R² = 0·94). By Year 9, 79% of the 6.6 t ha^?1 produced from the ryegrass‐white clover pasture was from unsown species and 7% was dead material. For maximum production and persistence, dryland farmers on 450–780 mm yr^?1 rainfall should grow lucerne or cocksfoot‐subterranean clover pastures in preference to ryegrass and white clover. Inclusion of white clover as a secondary legume component to sub clover would offer opportunities to respond to unpredictable summer rainfall after sub clover has set seed.