Levels of some reproductive diseases in the dairy cattle of Colombia

Of 4,144 serum samples collected from cows on 113 farms from eight areas of Colombia 3.3% had positive and 8.8% inconclusive titres to Brucella abortus, 21.7, 6.3, 1.6, 0.6 and 0.7% of cows had positive titres to Leptospira serovars hardjo, pomona, canicola, icterohaemorrhagiae and grippotyphosa respectively. Questionnaires completed on 110 farms revealed that 6, 2.5 and 4.6% of cows had had metritis, aborted or retained their placentas respectively in the previous 12 months. Trichomonas foetus and Campylobacter fetus were isolated from 13.7% and 15% of the bulls sampled on 103 farms. Six and two bulls had inconclusive and positive titres to Brucella abortus. Eight and 23 bulls had positive titres to pomona and hardjo. The results were discussed and remedies for control suggested.     

Exogenous leptin advances puberty in domestic hen

The present study was undertaken to examine the effect of recombinant chicken leptin administered to fed ad libitum and feed-restricted immature chickens of a layer strain on ovarian development and the timing of sexual maturity. In the first experiment 11-week-old pullets (77 days of age) fed ad libitum were injected daily with leptin at four dose levels (4, 16, 64 and 256 microg/kg body weight) until sexual maturity (lay of the first egg). Leptin treatment at the highest dose significantly (P<0.05) advanced the onset of puberty (day 116.3+/-1.0) in comparison to controls (day 121.3+/-1.2). The rises of luteinizing hormone, estradiol and progesterone in blood plasma were also advanced by leptin treatment. In the second experiment, both full-fed and feed-restricted pullets (79 days of age) were injected daily with leptin (256 microg/kg body weight). In birds fed ad libitum, exogenous leptin again significantly (P<0.05) advanced first ovipostion (day 118.4+/-1.4 versus day 124.4+/-1.7), while abolishing the significant (P<0.05) delay caused by feed restriction (day 131.5+/-1.6) and restoring the normal onset of sexual maturity (day 125.7+/-1.6). Analysis of the ovaries in 106-day-old pullets revealed that leptin injections advanced follicular development, particularly in birds fed ad libitum, and significantly (P<0.01) reduced follicular apoptosis both in full-fed and feed-restricted birds. In conclusion, we have shown that in female chickens exogenous leptin advances the onset of puberty by attenuation of ovarian apoptosis and enhancement of folliculogenesis.     

Virucidal efficacy of four new disinfectants

Virucidal efficacy was evaluated for four recently available disinfectants: chlorine dioxide, potassium peroxymonosulfate, a quaternary ammonium compound, and citricidal (grapefruit extract). Sodium hypochlorite (3%) and tap water were used as positive and negative controls respectively. Feline herpesvirus, feline calicivirus, and feline parvovirus were exposed to the manufacturers' recommended dilutions of the evaluated disinfectants. Both chlorine dioxide and potassium peroxymonosulfate completely inactivated the three viruses used in this study. These disinfectants can aid in controlling nosocomial transmission of viruses with less of the deleterious effects of sodium hypochlorite. The quaternary ammonium compound evaluated in this study and citricidal were not effective against feline calicivirus and feline parvovirus.     

增施氮肥和地面管理对酸樱桃园土壤营养状况的影响

在一个连续进行了 ８年Ｎ肥定位试验的酸樱桃园,调查了每年施用 Ｎ６０ ｋｇ· ｈｍ~(－２)和行间生草制对土壤营养状况的影响。结果表明：在肥沃土壤里ＮＨ_４~＋是速效Ｎ的主要存在形式,而ＮＯ_３~－的含量很低。生草地土壤中含有较多的 ＮＨ_４~－,而清耕带土壤中含有较多的 ＮＯ_３~－。施肥增加土壤速效 Ｎ的含量。土壤 ＮＯ_３~－的季节性变化表明 ５至 ６月份土壤中 ＮＯ_３~－的含量高,而花前和 ７月份土壤中 ＮＯ_３~－含量低。 Ｐ、Ｋ在清耕带 １０ ｃｍ以下土壤的含量低于生草地土壤,但在 ０～ １０ｃｍ土层中Ｋ的含量高于生草地。Ｐ的含量不受影响。施Ｎ减少了土壤Ｐ、Ｋ的含量。土壤中Ｍｇ的含量分布均匀,不受施Ｎ和地面管理制度的影响。     

An antisense coat protein gene confers immunity to potato leafroll virus in a genetically engineered potato

The Bzura commercial potato cultivar was transformed by sense or antisense constructs which included the coat protein gene of potato leafroll virus RNA. In the sense construct, the coat protein gene was preceded by a leader sequence shorter than that in the subgenomic RNA formed in infected cells. The antisense construct consisted of a sequence complementary to the first 2020 nucleotides of the subgenomic RNA. Selected transformants expressing viral RNA were resistant to virus challenge by viruliferous aphids. In one line, expression of the antisense RNA prevented virus infection even after grafting with scions from infected plants and therefore this transformant might be regarded as virus immune.     

Forest recovery in set-aside windthrow is facilitated by fast growth of advance regeneration

Key message

The disturbance of a research plot by a windstorm allowed us to study the role of the seedling bank in the regeneration processes. The released advance regeneration dominated among the saplings; taller individuals retained their position until the end of the study. Pioneer species occurred sporadically. Seven years after the disturbance, the windthrow was covered by a dense thicket of young trees.

Context

The dominant role played by advance regeneration in natural regeneration processes after intense wind disturbances is still a matter of dispute.

Aims

We took advantage of a windstorm in one of our research plots to study the role of the seedling bank released by the disturbance in the regeneration processes.

Methods

We collected data in 70 plots, recording the survivorship of seedlings, annual height growth, and signs of browsing. The height ranking was analyzed with Kendall’s concordance coefficient, and the height growth rates were compared using Dunn’s test.

Results

The density of seedlings increased from 6.7/m² in 2008 to 8.1/m² in 2010 and then decreased to 1.2/m² in 2015. The density of saplings increased continuously from 0.14 to 1.9/m². The highest size differentiation occurred in sycamore maple; the individuals which were taller before the windstorm retained their position until the year 2015. The only species that was recruited mainly from germinants was European hornbeam.

Conclusion

The advance regeneration released by the windstorm played a major role in the regeneration process, while pioneer species occurred only sporadically. Seven years after the disturbance, the windthrow was already covered by a dense thicket of young trees.

     

Functional response of <Emphasis Type="Italic">Quercus robur</Emphasis> L. to taproot pruning: a 5-year case study

Key message

Quercus robur seedling mass was affected more by planting density than by taproot pruning. Root pruning enhanced stem biomass at the expense of roots in later growth stages. Alteration of biomass allocation due to nursery practices may result in greater susceptibility to injury and death of the seedlings under unfavorable environmental conditions.

Context

Plants adjust their growth and modulate the resource allocation in response to applied treatments and environmental conditions.

Aims

The aim was to examine how taproot pruning in seedlings grown at different densities affected long-term growth of Quercus robur.

Methods

Seedlings, sown as acorns at two planting densities, with or without pruned roots were harvested in the second, fourth, and fifth years of growth. The effect of root pruning on biomass allocation was determined by measuring leaf, stem, and root mass fractions; carbohydrate concentrations in the roots; and C/N ratios. Specific leaf area and root length were also determined to assess morphological adaptations to growth conditions.

Results

Total seedling mass was affected more by planting density than by taproot pruning. After 4 years of growth, root mass fractions were lower and stem mass fractions were greater in seedlings planted at a higher density. Five-year old root-pruned seedlings also had a lower root mass fraction and higher stem mass fractions than unpruned seedlings. Specific root length was not affected by root pruning or planting density.

Conclusion

Decrease of relative root biomass with simultaneous increase of stem biomass may be a long-term consequence of taproot pruning of Q. robur, and the effects may manifest years after the seedling stage.

     

Urban soil resources of medium-sized cities in Poland: a comparative case study of Toruń and Zielona Góra

Purpose

Despite the many studies of urban soils, a comparative analysis for cities of a similar size has not yet been conducted. Thus, the aim of this review paper was to compare the soil distribution patterns in the area of two medium-sized Polish cities (Toruń and Zielona Góra). The authors attempted to answer the question of how natural and technogenic factors contributed to the transformation of urban soils and what the similarities and differences are between these two studied cities.

Materials and methods

First, both the natural and the human-related (including historical) factors influencing the soil formation in the studied cities were analysed. Then, a comparison of the degree of transformation of the urban soil environment was presented. The data obtained by the authors during nearly two decades of research (over 200 soil profiles) were used.

Results and discussion

Intensive development of the built-up areas in Toruń brought heavy and long-term transformations of soils, which demonstrate the typical properties of Urbic Technosols, Ekranic Technosols and other technogenic soils. Zielona Góra showed a similar state of soil transformation over a considerably smaller area. Currently, the differences in the soil properties in many built up areas have been blurred, despite the habitat and historical base. The similarities of the soil properties concerned, in particular, a high content of skeletal remains (from a few to over 30%), elevated pH (in KCl) values (even above 8.0) and the artificial soil horizons formation. Both cities struggle with similar problems regarding the changes in the land use within the areas covered by these soils.

Conclusions

It was found that, despite the significant habitat and historical differences between the two studied cities, most of the urban soils, especially Urbic Technosols, Ekranic Technosols and Regosols (Relocatic and Technic), are characterised by similar morphology and properties. The most important differences are the time and scale of the area transformation, which influence the extent of Technosols and Anthrosols within the city borders. The most distinct differences concern the natural and slightly transformed soils, which are the results of various soil-forming factors.

     

Effects of genotype and environment on seed quality traits variability in interspecific cross-derived <Emphasis Type="Italic">Brassica</Emphasis> lines

Genotype (G), environment [i.e. year (Y) and location (L)] and their interaction (GYL) play an important role in the final expression of quality attributes. A multi-environment trial in selected interspecific cross-derived Brassica lines was conducted to evaluate the magnitude of G, Y, L and GYL effects on seed quality traits of Brassica genotypes under three locations in Poland, during the 2011–2013 cropping season. The oil, protein, fiber (Acid Detergent Fiber and Neutral Detergent Fiber) as well as glucosinolate contents was determined by near-infrared reflectance spectroscopy (NIRS) and significant differences were observed between tested Brassica genotypes and across harvesting years and growing locations. Generally, all tested hybrid lines displayed wider genetic variability for studied quality traits than control genotypes. Analysis of variance indicated that the main effects of genotypes, years and locations as well as all interactions were significant for all traits of study (except year?×?location interaction for glucosinolates). However, location had the most significant effect on oil, protein and fiber content while genotype had significant impact on glucosinolates content in Brassica seeds. Moreover, the individual lines having combination of desirable traits were also identified from F₅ to F₇ generations of tested hybrids.