Susceptibility to and transmission of H5N1 and H7N1 highly pathogenic avian influenza viruses in bank voles (Myodes glareolus)

The study of influenza type A (IA) infections in wild mammals populations is a critical gap in our knowledge of how IA viruses evolve in novel hosts that could be in close contact with avian reservoir species and other wild animals. The aim of this study was to evaluate the susceptibility to infection, the nasal shedding and the transmissibility of the H7N1 and H5N1 highly pathogenic avian influenza (HPAI) viruses in the bank vole (Myodes glareolus), a wild rodent common throughout Europe and Asia. Two out of 24 H5N1-infected voles displayed evident respiratory distress, while H7N1-infected voles remained asymptomatic. Viable virus was isolated from nasal washes collected from animals infected with both HPAI viruses, and extra-pulmonary infection was confirmed in both experimental groups. Histopathological lesions were evident in the respiratory tract of infected animals, although immunohistochemistry positivity was only detected in lungs and trachea of two H7N1-infected voles. Both HPAI viruses were transmitted by direct contact, and seroconversion was confirmed in 50% and 12.5% of the asymptomatic sentinels in the H7N1 and H5N1 groups, respectively. Interestingly, viable virus was isolated from lungs and nasal washes collected from contact sentinels of both groups. The present study demonstrated that two non-rodent adapted HPAI viruses caused asymptomatic infection in bank voles, which shed high amounts of the viruses and were able to infect contact voles. Further investigations are needed to determine whether bank voles could be involved as silent hosts in the transmission of HPAI viruses to other mammals and domestic poultry.     

Is the Production of Embryos in Small‐Scale Farming an Economically Feasible Enterprise?

The present assay attempts to evaluate the feasibility of using embryo transfer in small community farmers by in vivo study and by modelling the results obtained. From the total of 59 donor cows, 62.7% responded to treatment, with a significant difference (p = 0.002) in the percentage of the response between breeds, being 90.5% (19/21) in Holstein and 47.4% (18/38) in Brahman. A total of 283 embryos were graded as transferable, while 141 as non‐transferable, without difference in the percentage of transferable embryo by breed (p = 0.18). The mean of transferable embryos graded as class I and II was not different between Holstein and Brahman (p = 0.96 and p = 0.92, respectively); besides, no differences were observed in the other grades (non‐transferable). The highest difference in costs, regardless of its quality by breed, was seen in the lower levels of probable fertility of the embryo transferred, even reaching several hundred dollars. When modelling the expected costs for embryo produced and transferred, values can reach nearly $2000.00 when the probable fertility is only 10%. However, when the probable fertility was 60%, embryo cost was close to $300.00. This technology seems to be viable on average or high‐scale systems, having a superovulatory response between 60 and 80% with 4–6 transferrable embryos. Yet, in small‐scale farming, due to the reduced number of donors and/or recipients, the costs surpass the economical feasibility of the technique.     

Influence of high dose of phytase and an emulsifier on performance,apparent metabolisable energy and nitrogen retention in broilers fed on diets containing soy oil or tallow

1. The effects of high dose of microbial phytase and an emulsifier on the performance, apparent metabolisable energy (AME) and nitrogen (N) retention in broilers fed on diets containing different fat sources were examined in a 5-week trial. Two fat sources (soy oil and tallow), two inclusion levels of E. coli phytase (500 or 1000 phytase units (FTU)/kg diet) and two inclusion levels of lysolecithin emulsifier (0 or 3.5 g/kg of diet) were evaluated in a 2 × 2 × 2 factorial arrangement of treatments.

2. Throughout the 5-week trial, soy oil supplementation improved weight gain and feed per gain compared with tallow, but had no effect on feed intake.

3. The high dose of phytase increased the weight gain and feed intake and lowered the feed per gain during d 1–21, but had no effect on performance parameters over the whole trial period.

4. An effect of emulsifier was observed for feed intake during d 1–21 and over the whole trial period. Addition of emulsifier increased feed intake compared with diets without emulsifier.

5. During weeks 1, 2, 3 and 5, birds fed on soy oil–based diets had higher nitrogen-corrected AME (AME_N) compared with those fed on tallow-based diets. During weeks 2, 3 and 5, the effect of phytase was significant for AME_N, with the high dose increasing the AME_N. During week 2, AME_N was increased with emulsifier addition.

6. During weeks 1, 2, 3 and 5, birds fed on soy oil–based diets had higher fat retention compared with those fed on tallow-based diets. The high dose of phytase improved the retention of fat during week 5 and the addition of emulsifier resulted in higher fat retention during week 1.

7. During weeks 2, 3 and 5, an interaction between fat source × phytase × emulsifier was observed for N retention. In soy oil–based diets, emulsifier plus 1000 FTU/kg phytase increased N retention compared with other groups, while in tallow-based diets, emulsifier addition increased N retention in diets with 500 FTU/kg, but not in 1000 FTU/kg diet.

8. Overall, the present data suggest that the dietary fat source influenced performance, AME_N and fat retention in broiler chickens. There is opportunity to improve bird performance during d 1–21, AME_N and fat retention with higher doses of microbial phytase. Addition of the emulsifier increased the AME_N during week 2 and tract retention of fat during week 1, but this effect was not translated into improvements in performance.

     

Impact of Land Use and Land Cover Changes on Organic Carbon Stocks in Mediterranean Soils (1956–2007)

During the last few decades, land use changes have largely affected the global warming process through emissions of CO₂. However, C sequestration in terrestrial ecosystems could contribute to the decrease of atmospheric CO₂ rates. Although Mediterranean areas show a high potential for C sequestration, only a few studies have been carried out in these systems. In this study, we propose a methodology to assess the impact of land use and land cover change dynamics on soil organic C stocks at different depths. Soil C sequestration rates are provided for different land cover changes and soil types in Andalusia (southern Spain). Our research is based on the analysis of detailed soil databases containing data from 1357 soil profiles, the Soil Map of Andalusia and the Land Use and Land Cover Map of Andalusia. Land use and land cover changes between 1956 and 2007 implied soil organic C losses in all soil groups, resulting in a total loss of 16·8 Tg (approximately 0·33 Tg y⁻¹). Afforestation increased soil organic C mostly in the topsoil, and forest contributed to sequestration of 8·62 Mg ha⁻¹ of soil organic C (25·4 per cent). Deforestation processes implied important C losses, particularly in Cambisols, Luvisols and Vertisols. The information generated in this study will be a useful basis for designing management strategies for stabilizing the increasing atmospheric CO₂ concentrations by preservation of C stocks and C sequestration. Copyright © 2012 John Wiley & Sons, Ltd.     

Performance of peach and plum based rootstocks of different vigour on a late peach cultivar in replant and calcareous conditions

The field performance of fifteen peach and plum based rootstocks of different vigour (Adesoto, Evrica, Garnem, GF 677, HM-2, Krymsk^® 1, PAC 9801-02, PAC 960, PAC 9907-02, PAC 9917-26, PAC-MUT, PADAC 9907-23, ROOTPAC^® 40, ROOTPAC^® 70 and Tetra) grafted with ‘Calrico’ cultivar was compared after 7 years of establishment on an Armillaria infested replant site. ‘Calrico’ is a selected clone of “Calanda” late peach cultivar. Differences in parameters such as tree survival, leaf chlorophyll content, vigour, yield, cumulative yield, yield efficiency and fruit size were analyzed among rootstocks. All PAC 9801-02 and Tetra trees survived and the mortality rate was low in Evrica, PADAC 9907-23 and ROOTPAC^® 40. The rest of genotypes showed higher mortality rates. Leaf chlorophyll concentration was higher when grafted on Adesoto and Evrica and lower when grafted on PAC 9907-02 and PAC 9917-26. Garnem and PADAC 9907-23 were the most vigorous rootstocks. The highest yield efficiency was induced by Krymsk^® 1 and PAC 9801-02 due to their lower vigour. The highest fruit weight was also induced by Krymsk^® 1 but its cumulative yield was low. Other rootstocks that showed high fruit weight and cumulative yields were ROOTPAC^® 70 and Tetra. Overall, Evrica, PAC 9801-02, ROOTPAC^® 40 and Tetra were among the best adapted to soil sickness and calcareous soil showing a good agronomic performance. The first three rootstocks (Evrica, PAC 9801-02, ROOTPAC^® 40) also exhibited a high capacity to control tree vigour associated with high yield efficiency.     

Is partial root-zone drying an effective irrigation technique to improve water use efficiency and fruit quality in field-grown wine grapes under semiarid conditions?

We investigated the effects of partial root-zone drying (PRD) applied at different periods on leaf water relations, vegetative development, fruit yield, must and wine quality in wine grapes (Vitis vinifera L. cv. Monastrell) during a 3-year field experiment in order to determine the importance of the timing of PRD application on physiological and agronomical vine response under semiarid conditions. Two irrigation treatments were applied: conventional drip irrigation (CI) and PRD. Both treatments received the same annual water quantity. Each year the PRD treatment was applied at different periods of the growth cycle. In 1999 PRD was applied from veraison to harvest (end July–early September); in 2000 from fruit set to harvest (mid June–early September); and in 2001 PRD from budburst to harvest (mid April–early September). Leaf water relations and gas exchange during the experimental period were not significantly affected by PRD treatment. In 1999 and 2000 there was no significant treatment effect on vegetative development, yield or fruit quality. However, in 2001 (when PRD was applied from budburst to harvest), reproductive and vegetative development was clearly altered in PRD vines. Fruit set percentage and vegetative development (shoot length, pruning weight and primary and lateral leaf area) were significantly increased in PRD vines compared to CI. This resulted in both higher yield (kg per vine) (43%) and water use efficiency (40%) compared to CI vines. Berry number per cluster and cluster weight were also significantly increased in PRD vines. Notwithstanding higher yield in PRD vines and a similar berry size, the must and wine quality was not significantly altered, indicating a higher synthesis and accumulation of photoassimilates and metabolites in the berries of PRD vines. We conclude that there was an positive effect on vegetative and reproductive growth when long-term PRD was applied from the beginning of growing season (budburst), suggesting that early onset of PRD is desirable to intensify PRD response under these semiarid conditions. Nevertheless from these results we need to further investigate the long- and short-term effects of PRD, with moderate water amounts, on vegetative and reproductive development such as flowering and fruit set processes in wine grapes.     

Are landscapes over-irrigated in Southwest Florida? A spatial�Ctemporal analysis of observed data

Monthly water billing records for eleven cities in Hillsborough County Florida were available from 2001 through 2007. Irrigation was estimated from total water use based on two different methods to estimate basic indoor water use and assumed impervious areas. Estimated irrigation use was compared with a calculated irrigation requirement by a water balance to test if homeowners were over-irrigating. Results showed that on average, the mean estimated irrigation was lower than the calculated irrigation requirements in most of the cities and years given the uncertainties in this analysis. The calculated irrigation ranged from 612 to 744 mm year⁻¹, whereas the average estimated irrigation ranged from 264 to 684 mm year⁻¹. However, there were some homeowners that greatly exceeded the calculated irrigation requirement. The estimated irrigation increased temporarily in areas under urban development, which was evidenced by built landscape expansion. Good correlation was found between the annual estimated irrigation and the annual calculated irrigation requirements, when the per capita method was used, but not between the annual estimated irrigation and the annual rainfall. Future conservation programs can use this methodology to identify users where substantial opportunity for water savings exists.     

Coffee agroecosystem performance under full sun, shade, conventional and organic management regimes in Central America

Changes in coffee economics are leading producers to reduce agrochemical use and increase the use of shade. Research is needed on how to balance the competition from shade trees with the provision of ecological services to the coffee. In 2000, long-term coffee experiments were established in Costa Rica and Nicaragua to compare coffee agroecosystem performance under full sun, legume and non-legume shade types, and intensive and moderate conventional and organic inputs. Coffee yield from intensive organic production was not significantly different from intensive conventional in Nicaragua, but in Costa Rica it was lower during three of the six harvests. Full sun coffee production over 6 years was greater than shaded coffee in Costa Rica (61.8 vs. 44.7 t ha^?1, P = 0.0002). In Nicaragua, full sun coffee production over 5 years (32.1 t ha^?1) was equal to coffee with shade that included Tabebuia rosea (Bertol.) DC., (27?C30 t ha^?1) and both were more productive (P = 0.03) than coffee shaded with Inga laurina (Sw.) Willd. (21.6 t ha^?1). Moderate input organic production was significantly lower than other managements under all shade types, except in the presence of Erythrina poepiggina (Walp.) O.F. Cook. Inga and Erythrina had greater basal area and nutrient recycling from prunings than other shade species. Intensive organic production increased soil pH and P, and had higher K compared to moderate conventional. Although legume shade trees potentially provide ecological services to associated coffee, this depends on management of the competition from those same trees.     

Changes in the phenolic composition of virgin olive oil from young trees (Olea europaea L. cv. Arbequina) grown under linear irrigation strategies.

This study reports the HPLC profiles of phenolic compounds of virgin olive oils obtained from young olive trees (Olea europaea L. cv. Arbequina) and how the application of a linear irrigation strategy affected these. Hydroxytyrosol, tyrosol, vanillic acid, vanillin, 4-(acetoxyethyl)-1,2-dihydroxybenzene, p-coumaric acid, the dialdehydic form of elenolic acid linked to hydroxytyrosol and to tyrosol, lignans, and the oleuropein aglycon were found in all the oils. Hydroxytyrosol, tyrosol, vanillic acid, and p-coumaric acid contents in the oils were unaffected by linear irrigation. The concentration of lignans was lower in the oils from the least irrigated treatment and the concentration of vanillin increased as the amount of irrigation water applied to olive trees increased. However, 4-(acetoxyethyl)-1,2-dihydroxybenzene, the dialdehydic form of elenolic acid linked to hydroxytyrosol and to tyrosol, and the oleuropein aglycon, all of them hydroxyphenyl derivatives, decreased as the level of irrigation water increased. The latter three compounds represented the most considerable part of the phenolic fraction of the oils and they were shown to be correlated to the oxidative stability, the bitter index (K(225)), and the bitter, pungent, and sweet sensory attributes. Linear irrigation strategy changed the profile of the oil phenolic compounds and, therefore, changed both the organoleptic properties and the antioxidant capacity of the product.