Predictors of outcome in dogs undergoing thoracic surgery (2002–2011)

ObjectiveTo evaluate mortality in a canine population undergoing thoracic surgery and identify factors which may be associated with outcome.Study designRetrospective cohort study.Animals286 dogs anaesthetized for thoracic surgery at the Royal Veterinary College between June 2002 – June 2011.MethodsVariables examined included: signalment; ASA status; nature of disease; presence of co-morbidities; pre-anaesthetic oxygen requirement; surgical approach; anaesthesia management [anaesthetic agents; requirement for thoracocentesis; central venous pressure measurement; duration of surgery and anaesthesia; use of colloids, blood products, inotropes or neuromuscular blocking agents (NMBA)]. Outcome was defined as either non-survival to 24 hours after surgery or (having survived to 24 hours) to discharge. Univariate and multivariable logistic regressions were performed to identify risk factors associated with non-survival.ResultsOverall non-survival (excluding those euthanased) to discharge was 5.9%. Non-survival was 2.2% at 24 hours and 3.6% at time of discharge. Non-survival to 24 hours was associated with pre-anaesthetic oxygen requirement (odds ratio (OR) 12.2 [95% CI 1.8–84.5]) and NMBA use (OR 9.6 [95% CI 1.6–57.9]). Non-survival to discharge was associated with surgical duration, with surgeries >180 minutes having OR 16.9 [95% CI 2.0–144.0] compared to surgeries ≤90 minutes and blood product use (OR 4.6 [95% CI 1.3–14.6]). No association was found between ASA category and non-survival at 24 hours (OR 1.4 [95% CI 0.2–11.7]) or discharge (OR 4.4 [95% CI 0.6–34.3]). Significant associations were found between NMBA use and ASA category (p = 0.046), surgical duration (p = 0.002), use of colloids (p = 0.011), blood products (p = 0.001) and inotropes and/or vasopressors (p < 0.001).Conclusions and clinical relevanceVariables significantly associated with non-survival from canine thoracic surgery at 24 hours include NMBA use and pre-anaesthetic oxygen requirement. Blood product use and increasing surgical duration were associated with non-survival to hospital discharge. The associations may relate to the need for such products in the most complicated cases.     

Leaf eating insect damage on different poplar clones and sites

As much for the geneticist as for the planter, information on sites, clones, and other factors would be decisive to reduce insect damage on poplars. In this perspective, a study was done in eight field trials in Belgium and in Luxembourg, considering two types of leaf damage on 24 clones from Italy, Belgium and the Netherlands. Damage varied considerably, depending on the clones, sites, species and parental individuals. Clone’s ranks concord on the different sites; site’s ranks are similar for the various clones. Clones with same parents have similar levels of resistance. The two types of damage are not correlated. Hybrids of P. deltoides × nigra show widespread variability; those with genetic material of P. trichocarpa are generally more resistant to caterpillar-like damage. The maximal differences are about 1 to 5 for the clones, and 1 to 10 for the sites. But the most vulnerable clone on the most favourable site was damaged almost 70 times more often than the opposite combination.     

Functional contribution of two perennial grasses to enhance pasture production and drought resistance under a leaf regrowth stage defoliation criterion

Lolium perenne L. (Lp) is the main pasture species in New Zealand, but climate change increases the likelihood of drought during summer and consequently lowers its growth rates. Bromus valdivianus Phil. (Bv) tolerates better the summer soil water restriction, but its competitiveness in a diverse pasture relates to the defoliation management and soil moisture levels. The performance of both species in terms of production, persistence and feed quality across seasons under different defoliation regimens was evaluated when the species were mixed and in monoculture. The treatments were applied in a randomised complete block design with three blocks. Bromus valdivianus and Lp monocultures and the 50/50 mixture (Mx) were grazed at low and high defoliation frequencies (i.e. based on Bv and Lp optimal leaf regrowth stage [LS], respectively). Herbage mass production was 15% higher in the Mx, mainly due to an increase in production in spring and summer. In spring, there was complementarity growth between the species, while during summer/early autumn, the Mx production relayed in the higher participation of Bv. Root biomass at depth (31–70 cm) was 38% greater for Bv monoculture and the Mx compared with Lp monoculture, which demonstrated the contribution of Bv to a better production of the mixture during and following the dry periods. In addition, the maintenance of the Bv tiller population and the higher growth rate during dry periods demonstrated its better fitness to low soil water availabilities than Lp. Although herbage mass was not modified by the defoliation frequency, forage quality of Bv showed values at low defoliation frequency that could compromise animal production during spring. However, there was an increase in root biomass under low defoliation frequencies, which suggested that a flexible grazing management across seasons would increase the niche utilisation between species in the mixture. The defoliation frequency of the mixture could be based on Lp LS during spring and winter, and slowed down, following Bv criteria, during summer and autumn.     

Conducting sustainability impact assessments of forestry-wood chains: examples of ToSIA applications

Within the EFORWOOD project, new methodological approaches to assess the sustainability impacts of forestry-wood chains (FWC) were developed by using indicators of environmental, social and economic relevance. This paper introduces and discusses the developed approach and the two main products developed in the EFORWOOD project: the Database Client and the Tool for Sustainability Impact Assessment (ToSIA), which hold, calculate and integrate the extensive information and data collected. Sustainability impact assessment (SIA) of FWCs is based on measuring and analysing environmental, economic and social indicators for all of the production processes along the value chain. The adoption of the method varies between applications and depends on the specification of the FWC in the assessment and what questions are studied. ToSIA is very flexible and can apply forest-, product-, industry- and consumer-defined perspectives. Each perspective influences the focus of the analysis and affects system boundaries. ToSIA can assess forest value chains in different geographical regions covering local, regional, national and up to the continental scale. Potential issues and scenarios can be analysed with the tool including, for example, the impacts of different forest policies on the sustainability of an FWC. This paper presents how ToSIA can be applied to solve such diverse problems and underlines this with examples from different case studies. Differences in chain set-up, system boundaries and data requirements are highlighted and experiences with the implementation of the sustainability impact assessment methods are discussed. The EFORWOOD case studies offer valuable reference data for future sustainability assessments.     

Priority for allocation of water-soluble carbohydrate reserves during regrowth of Lolium perenne

A glasshouse study was undertaken to determine the priority within the perennial ryegrass (Lolium perenne L.) plant for leaf and root growth and daughter tiller initiation after defoliation, in relation to various levels of water-soluble carbohydrate (WSC) reserves at defoliation. Individual plants were arranged in mini-swards, and underwent varying defoliation frequencies and ambient temperatures before defoliation, and harvest heights at defoliation, to obtain a gradient of WSC content at H₁, the date when all plants were defoliated. Defoliation interval consisted of defoliating either three times at the one new leaf tiller^–1 stage (1-leaf stage) of regrowth, or once only at the 3-leaf stage, up to H₁, while night temperature in the week prior to H₁ was altered from 15°C to either 8 or 20°C. At H₁, plants were defoliated to a stubble height of either 20 or 50 mm. Plants were subsequently destructively harvested at days 4, 6, 8, 12, 18 and 27. Leaf and root extension and tiller dynamics were also measured. On a regrowth timescale, tiller initiation was most sensitive, root regrowth moderately sensitive, and leaf regrowth relatively insensitive to a decrease in WSC. The time of daughter tiller initiation also coincided with replenishment of stubble WSC levels. In contrast to this sequence of regrowth events following defoliation, the quantitative effects on growth were different, with elongation and survival of roots most affected by reduced WSC levels. A 30-fold difference in stubble WSC at H₁ between high and low WSC plants (1·52 vs. 0·05 mg tiller^–1) produced only a 4-fold increase in leaf dry matter (DM) after 27 d (2·2 vs. 0·6 g plant^?1), while tiller number plant^?1 increased 6-fold (138 vs. 23% increase in tiller number from H₁). Root elongation rate was 59 times higher in the high than in the low WSC plants (1·18 vs. 0·02 mm d^?1). From a pasture management perspective, the study confirms that defoliation, coinciding with the 3-leaf stage of regrowth and around a stubble height of 50 mm, optimizes persistence and productivity of perennial ryegrass. By allowing more rapid replenishment of WSC reserves, this optimal defoliation strategy enables a greater proportion of WSC to be allocated to maintain a more active root system, and promotes tillering, compared with more frequent and close defoliation.