A comparison of two intramuscular doses of xylazine–ketamine combination and tolazoline reversal in llamas

The anesthetic and cardiorespiratory effects of a low dose (LD, 0.4 mg kg^?1 xylazine and 4 mg kg^?1 ketamine) and a high dose (HD, 0.8 mg kg^?1 xylazine and 8 mg kg^?1 ketamine) of IM xylazine–ketamine combination were compared in a randomized cross‐over study using six castrated male llamas. Three llamas in each dosage group (LDT, HDT) were assigned to receive IM tolazoline (2 mg kg^?1) after 30 minutes of recumbency. All IM injections were given in the semitendinosus or semimembranosus muscles. Pulse, respiratory rate, and indirect arterial blood pressure were recorded every 10 minutes, and hemoglobin oxygen saturation was recorded every 5 minutes during lateral recumbency. Samples for arterial blood gas analysis were collected 5 minutes following recumbency and every 30 minutes thereafter. Base‐to‐apex ECG was monitored continuously. Analgesia was evaluated every 5 minutes by both a 30 minutes skin pinch and a needle prick of the toe. Most llamas breathed room air throughout anesthesia. Two llamas that developed severe hypoxemia (SpO₂ < 75%) received 5 minutes of nasal oxygen insufflation, but were maintained on room air for the rest of the anesthetic period. anova for repeated measures and Tukey's test were used to analyze cardiorespiratory data. Fischer's exact test was used to compare the ability of each to provide >30 minutes of lateral recumbency and analgesia. A p‐value < 0.05 was considered significant. Both dosages provided reasonably rapid induction following injection (LD: 10.8 ± 6.3 minutes; HD: 5.0 ± 1.1 minutes; p = 0.07). Duration of lateral recumbency and analgesia were 34.7 ± 6.7 and 27.3 ± 4.6 minutes, respectively, in the LDT llamas. None of the three remaining LD llamas remained in lateral recumbency for longer than 12 minutes. Duration of lateral recumbency and analgesia were 87.3 ± 18.5 and 67.7 ± 16.0 minutes, respectively, for the HD llamas that did not receive tolazoline. The HDT llamas were recumbent for a significantly shorter time (43.3 ± 0.6 minutes; p = 0.05). The ability to provide >30 minutes of recumbency and analgesia was better in the HD group (6/6) than in the LD group (2/6) (p = 0.03). No differences between dosages were seen in pulse rate, respiratory rate, or arterial pressures. No ECG abnormalities were seen. Transient hypoxemia was seen in the first 10 minutes of lateral recumbency in the HD group by both hemoglobin oxygen saturation (84 ± 9.5%) and by blood gas PaO₂ (44.5 ± 5.8 mm Hg). It was concluded that the HD provided more consistent results than the LD, but induced transient hypoxemia. Tolazoline shortened the recovery time in llamas receiving the HD.     

Chromosome set manipulations in the black carp

The mollusc-eating black carp (Mylopharyngodon piceus) has economic and health-care potential for biological control of nuisance aquatic molluscs. The present study investigates the production of gynogenetic-monosex and triploid-sterile populations of black carp. The goal was to provide a method which would eliminate unwanted biological and environmental impacts of introducing this exotic species into areas with nuisance mollusc infestation. Meiotic gynogenesis was induced by inseminating black carp eggs with UV-irradiated (800 Jm⁻²) sperm of common carp (Cyprinus carpio) or Japanese ornamental (koi) carp. Diploidy was restored through retention of the second polar body (2PB), by shocking activated eggs at 1–8 min post-fertilization (embryological age of 0.07–0.57τ₀, a parameter defined by the cell cycle duration) at 1 min intervals, with heat-shocks (41.0±1.0 °C for 1 min) or pressure-shocks (7500–7600 psi for 1.5 min). Highest survival was found when embryos were heat-shocked 1.5–4.5 min post-fertilization (0.10–0.25τ₀). The highest survival of free-swimming larvae from pressure-shocked eggs, was achieved at 7500 psi at 1–2 min post-fertilization (0.08–0.16τ₀). Triploidy was induced by retention of 2PB following normal fertilization. Batches of 30 000 eggs were fertilized with intact sperm and pressure-shocked (6000–8500 psi for 1.5 min) 2 min post-fertilization (0.15–0.16τ₀). The highest survival of triploid swim-up larvae was 5.1% in eggs shocked with 7500 psi. In random samples of individual larvae taken from each treatment, triploidy was analysed by cytofluorometry of the cellular DNA content. In DNA analysis performed in fingerlings (N≥15), 50% of the fish were triploids.     

Performance of ‘Coscia’ pear (Pyrus communis) on seven rootstocks in a warm climate

Summary

The vegetative and reproductive performance of ‘Coscia’ pear (Pyrus communis L.) growing on seven rootstocks [OHF 69, OHF 97, OHF 513 and BP 1 (P. communis), clonal seedling (Davis AxB) of P. betulifolia, and quince BA 29 and EMA (Cydonia oblonga)] were compared over an 8-year period. The trial was conducted at the Experimental Orchard Farm Station in northern Israel, on a well-drained soil with pH 7.5. Trees were planted in December 1998 at a distance of 4.0 m 2.0 m, and trained with a central axis. The most vigorous trees were on P. betulifolia seedling, followed by BP 1 and the three OHF rootstocks (69, 97, 513). All the above rootstocks demonstrated greater vigour than quince BA 29 or EMA. The reason for this effect, at least in part, appeared to be the excellent water status (high midday stem water potential values) of trees on P. betulifolia in comparison with the other rootstocks. The highest cumulative yields per tree were harvested from trees on P. betulifolia and BP 1, followed by the three OHF rootstocks (69, 97, 513). However, the highest cumulative yield of large fruit (> 60 mm) was obtained from trees on P. betulifolia, followed by the OHF series and BP 1. The two quince rootstocks had the lowest cumulative yield, and the lowest yield of large fruit. A positive correlation was found between the vigour of the tree, as affected by the rootstock, and both total yield and fruit size. We conclude that, in a warm climate, yield efficiency is not the only parameter that should be taken into account, and building a strong tree for the weak scion cultivar is the first requirement for establishing an orchard. Fruit quality at harvest and during cold storage were examined for fruit from three rootstocks only. The highest soluble solids content values at harvest were obtained in fruit grown on quince EMA, compared to values for BP 1 and P. betulifolia fruit.     

Deposition of litter and nutrients in leaves and twigs in different plant communities of northeastern Mexico

Studies on litterfall and decomposition provide estimations of decomposition rates of different ecosystems.This is key information to understanding ecosystem dynamics and changes in a scenario of global warming.The objective of this research was to assess litterfall production,the potential deposition of macro and micronutrients through leaf and twig fall as well as macronutrient—use efficiency in three forest ecosystems at different altitudes: a pine forest mixed with deciduous species(S1); a Quercus spp.forest(S2); and,a Tamaulipan thornscrub forest(S3).Total annual litterfall deposition was 594,742 and 533 g m~(-2) for S1,S2 and S3.Leaf litter was higher (68%) than twigs(18%),reproductive structures(8%) or miscellaneous material(6%).Micronutrient leaf deposition was higher for Fe followed by Mn,Zn and Cu.Macronutrient leaf deposition was higher for Ca followed by K,Mg and P.Even though P deposition in leaves and twigs was lower than other macronutrients,its nutrient use efficiency was higher than Ca,Mg or K.Altitude and species composition determine litter and nutrient deposition,with higher values at mid-altitudes(550 m).Altitude is an important factor to consider when analyzing litter production as well as nutrient deposition as shown in this study.Litter production and nutrient deposition are expected to change in a scenario of global warming.     

Integrated pest management in western flower thrips: past,present and future

Western flower thrips (WFT) is one of the most economically important pest insects of many crops worldwide. Recent EU legislation has caused a dramatic shift in pest management strategies, pushing for tactics that are less reliable on chemicals. The development of alternative strategies is therefore an issue of increasing urgency. This paper reviews the main control tactics in integrated pest management (IPM) of WFT, with the focus on biological control and host plant resistance as areas of major progress. Knowledge gaps are identified and innovative approaches emphasised, highlighting the advances in ‘omics’ technologies. Successful programmes are most likely generated when preventive and therapeutic strategies with mutually beneficial, cost‐effective and environmentally sound foundations are incorporated. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Effects of land use change and seasonal variation in the hydrophysical properties in Vertisols in northeastern Mexico

The impact of the use of natural resources associated with anthropogenic activities has increased evidently, mainly through land use changes which have altered hydrophysical properties of soils. We hypothesized that, in the same soil type (Vertisol), four types of land use system (grassland, agricultural, Eucalyptus plantation and thornscrub) and seasonal variation can modify the soil hydrophysical properties. Results showed significant differences between land use systems and seasons for hydraulic conductivity (K), infiltration capacity (fp) and cumulative infiltration (fc). There were no seasonal differences in soil penetration resistance (SPR), bulk density (ρd) and total porosity (φP). Grassland presented higher values for ρd (1.2 g cm^?3) and SPR (5.3 kg cm^?2) and lower for K (0.8 × 10^?5 cm s^?1) and φP (53%), unlike thornscrub. Agriculture presented lower SPR (0.4 kg cm^?2), while plantation showed similar values when compared to the thornscrub. Kostiakov infiltration model was fitted to land use infiltration curves, showing differences between land use and season. The values for fp oscillated between 53.6 and 548.8 mm hr^?1 and fc ranged from 105.3 to 1,061 mm. The order of the infiltration values goes as follows: agriculture > plantation > thornscrub > grassland. Land use changes in Vertisols induced modification of soil physical properties affecting processes like permeability, soil compaction and water availability.