Effect of different dietary ratios of sunflower and linseed oils on growth and carcass traits of rabbits

As part of an experiment aiming to modify the meat fatty acid profile, this work studied the growth and carcass traits as affected by various dietary ratios of sunflower oil and linseed oil. A diet without added oil served as a control (C). Four other diets were equally 4% oil-enriched but they differed in the incorporation ratios of sunflower oil (S) to linseed oil (L), i.e. 4% S to 0% L (diet 4%S), 3% S to 1% L (diet 3:1%SL), 2% S to 2% L (diet 2:2%SL) and 0% S to 4% L (diet 4%L). The oil-rich diets had slightly higher digestible energy contents (11.4 vs 10.6 MJ/kg) than the C feed. In each group 10 litters of 7 to 9 Pannon White kits per litter were studied in the pre-weaning period from 21 to 35 days old. Growth and slaughter traits were assessed with 50 and 30 rabbits per group, respectively. No significant effects of diets were found on litter and doe performances. The only significant differences in growth performance of the C, 4%S, 3:1%SL, 2:2%SL and 4%L rabbits were for the 35–49 day feed intake (88, 86, 84, 84 and 83 g per day, respectively, P = 0.046), the 35–84 day growth rate (36, 38, 37, 35 and 37 g/day, P = 0.034) and the 84-day body weight (2608, 2703, 2664, 2565 and 2628 g, respectively, P = 0.022). There were several significant differences in carcass traits including the weight of reference carcass (1357, 1391, 1388, 1380 and 1369 g, respectively, P = 0.004) and left longisimus dorsi meat (78, 79, 81, 81 and 76 g, respectively, P = 0.046) of rabbits. The diets had major effects on the L*, a* and b* colour values (lightness, redness and yellowness) of meat and fat. Carcass colour of the C and 4%S rabbits was closer and the 4%L rabbits was further from the European consumer's preference of light coloured, less red and slightly yellow rabbit meat. Our result reveals the importance of age and body weight at slaughter. Taking the growth and slaughter performances and, the recent belief of human health benefits from lower n− 6/n− 3 FAs dietary ratios into account, the 2:2%SL diet seems most appropriate if the interests of the raisers, meat processors and buyers are considered equally.     

Attraction of Chrysoperla carnea complex and Chrysopa spp. lacewings (Neuroptera: Chrysopidae) to aphid sex pheromone components and a synthetic blend of floral compounds in Hungary

BACKGROUND: The deployment of synthetic attractants for the manipulation of lacewing populations as aphid predators is currently used in integrated pest management. This study investigates a synthetic bait comprising floral compounds previously found to attract the Chrysoperla carnea complex, and, for the first time, the aphid sex pheromone components (1R,4aS,7S,7aR)‐nepetalactol and (4aS,7S,7aR)‐nepetalactone, in field experiments in Hungary, for their ability to manipulate lacewing populations. RESULTS: The synthetic floral bait attracted both sexes of the Chrysoperla carnea complex, and Chrysopa formosa Brauer showed minimal attraction. The aphid sex pheromone compounds alone attracted males of C. formosa and C. pallens (Rambur). When the two baits were combined, Chrysopa catches were similar to those with aphid sex pheromone baits alone, but carnea complex catches decreased significantly (by 85–88%). CONCLUSION: As the floral bait alone attracted both sexes of the carnea complex, it showed potential to manipulate the location of larval density via altering the site of oviposition. Aphid sex pheromone compounds alone attracted predatory males of Chrysopa spp. and can potentially be used to enhance biological control of aphids. For the carnea complex, however, a combination of both baits is not advantageous because of the decrease in adults attracted. Assumptions of intraguild avoidance underlying this phenomenon are discussed. Copyright © 2010 Society of Chemical Industry     

Report on the survey for Bursaphelenchus xylophilus and the occurrence of other Bursaphelenchus species in Hungarian coniferous forests

An ongoing official survey to detect the pine wood nematode Bursaphelenchus xylophilus, a quarantine pest, started in 2003 in coniferous forests in Hungary. Based on the results of the study from 2003–11, B. xylophilus has not yet been detected in Hungary. Two other Bursaphelenchus species (B. mucronatus and B. vallesianus) were identified in samples in 2009. Details of the survey and the measurements of B. mucronatus and B. vallesianus are provided.     

Bacterial pollution induced community tolerance (PICT) to Cu and interactions with pH in long-term polluted vineyard soils

Pollution induced community tolerance (PICT) has been suggested as an end-point measurement less affected by confounding environmental factors compared to standard methods of microbial growth, activity and community composition. We evaluated the use of PICT to determine Cu toxicity in vineyard soils polluted with Cu based fungicides (25-1120 mg Cu kg⁻¹). These soils also varied in pH (4.3-7.3), organic C (0.31-6.91%) and texture (14-56% silt). PICT was estimated as bacterial community tolerance to Cu measured by the [³H]leucine incorporation method. Bacterial tolerance to Cu increased 9 times in the most polluted compared to the unpolluted soils. Cu tolerance was also affected to a minor degree by pH, organic C and soil texture. Lower bacterial tolerance was found in soils with high pH and organic C, probably due to Cu becoming less bioavailable in soils with high pH and organic C content. The silt content appeared to increase bacterial tolerance, probably due to fine soil particles decreasing Cu bioavailability during the PICT detection phase. Despite the effects of other environmental factors, the main determinant of increased bacterial community tolerance to Cu was the pollution level. PICT measured with the leucine incorporation technique thus appears to be a sensitive and stable concept to evaluate toxic impacts, unless soils with very different pH, organic C or texture are studied.     

Biochemical properties and microbial community structure of five different soils after atrazine addition

Atrazine is one of the most used herbicides worldwide; however, consequences of its long-term agricultural use are still unknown. A laboratory study was performed to examine changes in microbial properties following ethylamino-¹⁵N-atrazine addition, at recommended agronomic dose, to five acidic soils from Galicia (NW Spain) showing different physico-chemical characteristics, as well as atrazine application history. Net N mineralization was observed in all soils, with nitrate being the predominant substance formed. The highest values were detected in soils with low atrazine application history. From 2% to 23% of the atrazine-¹⁵N was found in the soil inorganic-N pool, the highest values being detected after 9 weeks in soils with longer atrazine application history and lower indigenous soil N mineralization. The application of atrazine slightly reduced the amount of soil N mineralized and microbial biomass at short term. Soluble carbohydrates and β-glucosidase and urease activity decreased with incubation time, but were not significantly affected by the single application of atrazine. Microbial community structure changed as consequence of both soil type and incubation time, but no changes in the phospholipid fatty acid (PLFA) pattern were detected due to recent atrazine addition at normal doses. The saturated 17- to 20-carbon fatty acids had higher relative abundance in soils with a longer atrazine history and fungal biomass, as indicated by the PLFA 18:2ω6,9, decreased with the incubation time. The results suggested that the PLFA pattern and soil N dynamics can detect the long-term impact of repeated atrazine application to agricultural soils.     

Effect of mineral and organic fertilization on soil organic carbon content as well as on grain production of cereals in the IOSDV (ILTE) long-term field experiment,Keszthely, Hungary

The study was conducted in the international mineral and organic nitrogen fertilization trial (IOSDV) located in Keszthely in the western part of Hungary. The soil class of the study site was Ramann-type brown forest soil (Eutric Cambisol). The factors of the experiment are the increasing rate of mineral N fertilization and the complementary application of different forms of organic fertilizers in a three-course crop rotation (maize, winter wheat and winter barley) set up in 1983. The organic carbon content of the soil (C_org%) definitely increased after application of organic manure (OM), similarly to the average yield of the cultivated crops. After application of OM the increase in C_org content was 0.20%, and after straw + complementary N application it was 0.12%, compared with plots without organic manures. Mineral N fertilizer did not significantly influence the C_org content in soil over this period. Depending on the type of crop, the specific year and the N content of the soil, the combined application of mineral fertilizers and organic manures resulted in a 12–17% increase in crop yield, in general, whereas at maximum yields the increase accounted for 5–10%.     

Microbial dynamics after adding bovine manure effluent together with a nitrification inhibitor (3,4 DMPP) in a microcosm experiment

The application of animal manure effluents in agriculture in combination with nitrification inhibitors should be beneficial for nutrient recycling, soil quality, plant productivity, and greenhouse gas emission and offer economic advantages to make them an alternative to conventional fertilizers. The present study aims to estimate the effects of the addition of bovine manure effluent alone or together with a nitrification inhibitor (3,4-dymethylpyrazol-phosphate (3,4 DMPP)) on the microbial community dynamics in a Mediterranean soil in an incubation experiment over 28 days. The application of the bovine manure effluent increased respiration, microbial biomass carbon, fungal and bacterial growth, and enzyme activities and changed the microbial community structure evaluated by the phospholipid fatty acid pattern. Adding the bovine manure effluent together with the nitrification inhibitor, although partly negating the positive effect of the effluent on soil microbial activity, still resulted in higher or similar growth and activity as in the control. Our results indicate that the addition of the nitrification inhibitor 3,4 DMPP together with a bovine manure effluent could be a promising solution to control the animal manure effluent application effects on soil microbiological properties and microbial dynamics, as well as counteracting direct inhibiting effects of 3,4 DMPP on the soil heterotrophic community.     

小型超宽温度范围模拟温补晶振

本分析并改进了温补晶振的补偿网络，运用计算机技术等设计了在－５５℃至＋１０５℃内都能良好地工作，且频率稳定度优于±２．５×１０＾－６的小体积，低功耗模拟温补晶振，其主要指标已达到国外同类产品的水平，弥补了种类晶振温度适应范围太窄的缺陷。