Plant and soil intake by organic broilers reared in tree- or grass-covered plots as determined by means of n-alkanes and of acid-insoluble ash

Free-range birds such as organic broilers may ingest soil and plants during exploration. The estimation of such intakes is of great interest to quantify possible nutritional supplies and also to evaluate the risk of exposure to parasites or to environmental contaminants. Marker-based techniques are now available and would allow to quantify plant and, especially, soil intake in free-range birds, and this quantification was the aim of this study. Methodologically, the proportion of plants in diet intake was determined first using a method based on n-alkanes. Subsequently, the fraction of soil in the total intake was estimated with a second marker, acid-insoluble ash. This approach was carried out to estimate ingested amounts of plants and soil for five successive flocks of organic broilers, exploring grass-covered yards or those under trees, at two time points for each yard: 51 and 64 days of age. Each factor combination (yard type×period=flock number×age) was repeated on two different yards of 750 broilers each.The birds’ plant intake varied widely, especially on grass-covered yards. The proportion of plant intake was significantly higher on grass-covered plots than under trees and was also affected, but to a lesser extent, by age or flock number. The ingestion of plants would generally not exceed 11 g of DM daily, except two extreme outliers of nearly 30 g. The daily plant intake under trees tended to be lower and never exceeded 7 g of DM. The amount of ingested plants increased significantly for spring flocks. It increased slightly but significantly with age. The proportion of ingested soil was significantly higher under trees than on grass-covered yards. Dry soil intake was generally low with not more than 3 g per day. Only in adverse conditions – that is, older birds exploring yards under trees in winter – soil intake reached the extreme value of nearly 5 g. Broilers on yards under trees ingested significantly more soil than on grass-covered yards with least square means of, respectively, 2.1 and 1.1 g dry soil per day. These quantifications would allow us to evaluate the impact of plant and soil intake in the management of free-range broilers, especially for the management in organic farming systems. Nevertheless, under the two rearing conditions tested in the current study, the quite low proportions of soil intakes would represent a low risk for the safety of the produced food, unless the birds explore yards on heavily contaminated soil.     

Comparative morphometric and chemical analyses of phenotypes of two invasive ambrosia beetles (Euwallacea spp.) in the United States

The polyphagous shot hole borer (PSHB), Euwallacea sp., was first detected in 2003 in Los Angeles County, California, USA. Recently, this invasive species has become a major pest of many hardwood trees in urban and wildland forests throughout southern California. PSHB is nearly identical in morphology and life history to the tea shot hole borer (TSHB), Euwallacea fornicatus, an invasive pest of hardwoods in Florida, USA and many other parts of the world. However, molecular studies have suggested that the taxa are different species. We conducted morphometric and chemical analyses of the phenotypes of Euwallacea sp. collected in southern California (Los Angeles County) and E. fornicatus collected in Florida (Miami‐Dade County). Our analyses indicated that PSHB has 3 larval instars. The third larval instar was separated from the first 2 instars by head capsule width with 0 probability of misclassification. The body length, head width, and pronotal width of PSHB adult males were significantly less than those of females. Head width and pronotal width of female PSHB were significantly less than those of female TSHB. In contrast, body length, and ratio of body length to pronotal width of female PSHB were significantly greater than those of female TSHB. However, females of these 2 species could not be separated completely by these 4 measurements because of the overlapping ranges. Cuticular hydrocarbons detected in both species were exclusively alkanes (i.e., n‐alkanes, monomethylalkanes, dimethylalkanes, and trimethylalkanes). Cuticular hydrocarbon profiles of PSHB males and females were similar, but they both differed from that of TSHB females. Cuticular hydrocarbons of PSHB were predominantly internally branched dimethylalkanes with backbones of 31 and 33 carbons, whereas cuticular hydrocarbons of TSHB females were dominated by internally branched monomethylalkanes and dimethylalkanes with backbones of 28 and 29 carbons. Multiple compounds within these classes appear to be diagnostic for PSHB and TSHB, respectively.     

黄土高原子午岭大披针苔草能量与养分特征

对黄土高原子午岭林区不同植被群落的优势伴生种--大披针苔草的能量和养分特征进行了研究.结果表明:随着演替的进展,处于不同演替阶段群落的大披针苔草地上部分和地下部分去灰分热值呈下降趋势.狼牙刺群落的大披针苔草地上部分去灰分热值最高,沙棘群落的最低; 狼牙刺群落的大披针苔草地下部分去灰分热值最高, 辽东栎群落的最低.不同群落大披针苔草地上部分热值均明显高于地下部分, 且不同群落大披针苔草地下部分干质量热值和去灰分热值均呈极显著差异.处于演替早期的各群落(狼牙刺、沙棘、山杨和白桦群落)内的大披针苔草热值差异较大,而演替后期的油松和辽东栎群落的大披针苔草热值差异较小.大披针苔草地下部分干质量热值与C/N呈显著正相关关系.     

Microbial control of Agrilus planipennis (Coleoptera: Buprestidae) with Beauveria bassiana strain GHA: field applications

The effects of Beauveria bassiana strain GHA, applied as BotaniGard ES, on newly colonised and well-established populations of emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae) were evaluated in the field using foliar and trunk sprays in Michigan in 2004–2005. Results from field trials at a newly colonised white ash site showed a 41% reduction in A. planipennis population in fungal-treated trees compared with that of untreated controls. In addition, fungal infection was also found in 20% of the larval population within 14 days of incubation under laboratory conditions. At a site with a well-established Agrilus planipennis population in green ash trees, larval density was reduced by 47% for trees treated with the fungus compared with that of the controls; 21% of larvae from the current generation were found infected after 14 days of laboratory incubation. Fungal-treated green ash trees also produced fewer adults emerging in the next generation, with a 63% reduction in adult density observed in treated trees compared to that of controls. As a result, fungal-treated trees sustained 42% less crown dieback than did controls. A. planipennis larval density was negatively correlated with trunk height above the ground, and positively correlated with log diameter. Results of laboratory leaf bioassays on A. planipennis adults showed that fungal conidia persisted well under field conditions, with mortality of 78–100% at 7 – days post – exposure for leaves collected between 2 and 264 h after application. Potential strategies for using B. bassiana strain GHA for managing A. planipennis are discussed.     

Physiological age-grading and ovarian physiology of Prostephanus truncatus

Abstract. The reproductive tracts of male and female Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) were described for beetles between emergence and 30 days old in order to determine age-grading criteria. Seminal vesicles were bigger among non-mated males than among mated males due to accumulation of sperm; no age-specific differences were found for male P. truncatus. Ovaries (germarium size, number of follicles and follicle size) were similarly developed for females between 5 and 30 days old and did not differ between mated and non-mated females. Starved females were found to resorb follicles. Yellow body formation was strongly dependent on age, and was used as an age-grading criterion for female P. truncatus. Females flying off maize cobs and caught with pheromone traps were of varying physiological age and mated, and their ovarian development was suspended. All migrating females were mated, indicating that lone females may act as colonizers, independently of males. The applicability of migration theories to P. truncatus and adaptive inter-reproductive dispersal as part of its life history strategy are discussed.     

Histone H3.3 K27M and K36M mutations de-repress transposable elements through perturbation of antagonistic chromatin marks

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Influence of micronization (fine grinding) of soya bean meal and fullfat soya bean on productive performance and digestive traits in young pigs

Two trials were conducted to test the effect of micronization (very fine grinding) of soya bean meal (SBM) and fullfat soya bean (FFSB) on productive performance and digestive traits of piglets. The experimental design was completely randomized with four treatments arranged factorially (SBM and FFSB, micronized and ground). The mean particle size (MPS) was 47 and 881 μm for the SBM and 41 and 778 μm for the FFSB, micronized and ground, respectively. In trial 1 growth traits from 23 to 45 days of age and the coefficient of total tract apparent digestibility (CTTAD) of dietary components at 33 and 45 days of age were assessed. In trial 2 the coefficient of ileal apparent digestibility (CIAD) of dietary components, the pH of the gastro intestinal tract (GIT) and the weight of digestive organs and spleen were measured at 45 days of age. From 23 to 33 days of age pigs fed SBM grew faster (253 g/d versus 213 g/day; P<0.05) and were more efficient (0.87 g/g versus 0.98 g/g; P<0.01) than pigs fed FFSB. For the entire experiment (23–45 days of age) pigs fed SBM tended to grow more (360 g/day versus 324 g/day) and to eat more feed (414 g/day versus 380 g/day) than pigs fed FFSB (P<0.10). The CTTAD of crude protein (0.798 g/kg versus 0.778 g/kg), organic matter (0.864 g/kg versus 0.839 g/kg) and gross energy (0.849 g/kg versus 0.830 g/kg) were higher for pigs fed SBM than for pigs fed FFSB (P<0.001). In addition, CIAD of organic matter (0.765 g/kg versus 0.705 g/kg) and gross energy (0.761 g/kg versus 0.711 g/kg) were higher for SBM than for FFSB diets (P<0.001). The pH of the different segments of the GIT was not affected by the protein source (P>0.10). Particle size did not affect any trait studied (P>0.10). The poor performance and digestibility of pigs fed FFSB as compared to pigs fed SBM might be related to the conditions applied during processing. It is concluded that pigs fed soya bean meal perform better than pigs fed FFSB and that micronization of the soya protein sources does not affect any trait studied.     

金华市郊10种杂草的热值和灰分含量及其适应意义

在金华市郊,选择了婆婆纳(Veronica didyma)、水蓼(Polygonum hydropiper)、车前(Plantago asiatica)、北美车前(Plantago virginica)、毛茛(Ranunculus japonicus)、商陆(Phytolacca acinosa)、鹅观草(Roegneriakamoji)、早熟禾(Poa annua)、北美独行菜(Lepidium virginicum)、窃衣(Torilis japonica)等10种常见杂草,测定了生殖生长时期这些杂草不同器官的热值和灰分含量.研究结果表明,10种杂草花穗、叶、茎和根的干重热值的平均值分别为15.942、14.293、13.344和13.463 kJ/g,去灰分热值平均为16.983、16.219、14.480和15.233 kJ/g,整体上表现出花穗>叶>根>茎的趋势;10种杂苹的花穗、叶、茎和根中的平均灰分含量为6.127%、11.899%、8.071%、11.383%,叶片和根中的灰分含量较高,花穗与茎中的较低.对于北美车前来讲,随着生长时间的推移,北美车前的营养器官热值下降,随着种群密度的上升,北美车前的繁殖器官干重热值上升.采取低热值策略可能是杂草适应严酷环境的选择方式,具有进化上的积极意义.     

Pollen germination and pollen tube growth in Fraxinus pennsylvanica

With regard to adaptation of green ash (Fraxinus pennsylvanica Marshall) to ecological conditions in Croatia, pollen germination and pollen tube length after 2, 4 and 6 hours were examined in vitro at 10, 15, 20 and 25°C during two years 2001 and 2002. Narrow leaved ash (F. angustifolia Vahl) pollen served as a control in 2002. The year, time and temperature, and the interaction between time and temperature were significant for both germination percentage and pollen tube length. Interactions year × temperature and year × time were significant for pollen tube length only. The highest germination percentage (17.86% in 2001 and 19.40% in 2002) of green ash pollen was at 15°C after 6 hours. The pollen tube length was greatest at 20°C (393.46 μm) in 2001 and 25°C (899.50 μm) in 2002 after 6 hours. Narrow leaved ash pollen had the highest germination percentage (19.22%) at 20°C after 6 hours and was significantly reduced at 25°C. The pollen tube length was greatest at 25°C (518.90 μm) after 6 hours. It can be concluded that green ash pollen has satisfactory germination in ecological conditions in Croatia and that the optimum temperature for pollen germination is higher than 20°C.