Dispersal of vascular plants by game in northern Germany. Part I: Roe deer (<Emphasis Type="Italic">Capreolus capreolus</Emphasis>) and wild boar (<Emphasis Type="Italic">Sus scrofa</Emphasis>)

The endozoochorous and epizoochorous dispersal of vascular plant species by roe deer (Capreolus capreolus) and wild boar (Sus scrofa) was investigated in forest areas of Schleswig-Holstein and Lower Saxony, Germany. The primary aim of this study was to learn about which plant species and in what numbers diaspores are dispersed by the two wild ungulate species. In particular, the significance of zoochory for species composition and biodiversity of forests was evaluated. Fresh faecal pellets were collected from April–November 2001 in the forests of the two study areas. In addition, the coats and hooves of shot roe deer and wild boar were brushed out. The number of viable seeds was determined by greenhouse germination (seedling emergence method). The samples were spread in trays over sterilized soil from the study forests and were kept under controlled conditions in the greenhouse for 12 months. A total of 2,473 individuals from 77 vascular plant species were recorded. While roe deer exceeded wild boar concerning seed contents in the faeces, the significance of roe deer for epizoochorous dispersal was relatively low compared with wild boar. An analysis of the habitat preference of the vascular plant species dispersed by the two ungulate species revealed a high proportion of species growing in forests as well as in the open landscape, and also of non-forest species, while woody plants and herbaceous species closely tied to forest habitats were severely underrepresented. We also discuss consequences for forest ecology and nature conservation.     

A multiscale soil–landform relationship in the glacial‐drift area based on digital terrain analysis and soil attributes

Understanding the linkages between structure and processes in soil landscapes involves analyses across several spatial and temporal scales. The transfer of information between scales requires the (1) identification of respective scale levels and (2) procedures for regionalization. Here, we present a multiparameter delineation of landform units and their attribution with typical Reference Soil Groups (RSG) of a landscape of NE Germany which is representative of young moraine regions. Data sources are a digital elevation model (DEM, 5 m × 5 m), a reference data set from sections of an intensively augered landscape, and expert knowledge. A conceptual digital soil map was constructed in the scale 1:5000 based on the Topographic Position Index (TPI). The methodology is applicable for multiscale analyses. Results are (1) the landform unit classified by digital terrain analysis of a DEM, (2) the attribution of RSG, and (3) the evaluation of the classification. Accuracy of the method was 57% overall, with 70% accuracy on typical erosional sites. The developed method allows identification of terrain‐related soil pattern with high spatial resolution in glacial‐drift areas. The high resolution of soil information can be used for delineation of management zones in precision farming, or as input for process studies and models requiring a translation of typological soil information into relevant soil properties (e.g., by pedotransfer functions).     

Chicken anemia virus in broilers: dynamics of the infection in two commercial broiler flocks

Chicken anemia virus (CAV) can cause a disease syndrome characterized by severe anemia, bone marrow atrophy, and severe immunosuppression in young chicks. Maternal antibodies prevent these clinical signs but do not prevent infection, transmission of the virus, or immunosuppression. The clinical disease is rare today because of the widespread practice of vaccinating breeders, but the subclinical form of the disease is ubiquitous. The dynamics of CAV infection, CAV antibody responses, relative lymphoid organ weights, and associated lesions were studied in two broiler flocks from a commercial producer. Both groups had detectable CAV antibodies at hatch, which waned over the first 3 wk of life. Both groups had detectable CAV DNA in both thymi and bursae over the same period. At 35 days of age, virus was detectable by polymerase chain reaction in 16 of 20 chickens, and 7 of 20 had detectable antibodies. By 42 days of age, virus was detectable in 18 of 20 chickens, and 18 of 20 had antibodies to CAV. We observed a decrease in relative thymic weights beginning at 35 days of age, coincidental withthe detection of CAV in the thymus. Bursal sizes began to decrease at 28 days of age, coincidental with a rise in antibody titers to infectious bursal disease virus. In this study, we demonstrated that under typical field conditions CAV infections in broilers have unique dynamics unlike those reported in egg laying strains of chickens managed under specific-pathogen-free conditions.     

In vitro Development of Buffalo Oocytes in Media-containing Fluids from Different Size Class Follicles

Studies were conducted to investigate the effect of supplementation of fluid from different sized class [small (SFF, < 3 mm), medium (MFF, 3-8 mm) and large (LFF, > 8 mm)] of normal and cystic (CFF) ovarian follicles in oocyte culture media on oocyte maturation rate and embryo development in vitro and to test the efficacy of follicular fluid (FF) from different size classes as a whole oocyte maturation medium. Results suggested that FF were capable of developing buffalo oocytes to embryonic stage in vitro although its efficacy was lower than that of serum. Regardless of high maturation rates after in vitro maturation (IVM) in media containing FF or IVM in whole FF, low blastocyst rates were obtained after in vitro fertilization (IVF) and culture of embryos. Follicular fluid from small follicles had significantly (p < 0.05) higher potential of developing buffalo oocytes to embryonic stage in vitro than that from medium and large follicles. Cystic FF was not capable of supporting development of buffalo oocytes in vitro.     

Modeling irrigated cotton with shallow groundwater in the Aral Sea Basin of Uzbekistan: I. Water dynamics

In Khorezm, a region located in the Aral Sea basin of Uzbekistan, water use for irrigation of predominantly cotton is high whereas water use efficiency is low. To quantify the seasonal water and salt balance, water application, crop growth, soil water, and groundwater dynamics were studied on a sandy, sandy loam and loamy cotton field in the years 2003 and 2005. To simulate and quantify improved management strategies and update irrigation standards, the soil water model Hydrus-1D was applied. Results showed that shallow groundwater contributed a substantial share (up to 399 mm) to actual evapotranspiration of cotton (estimated at 488–727 mm), which alleviated water stress in response to suboptimal quantities of water applied for irrigation, but enhanced concurrently secondary soil salinization. Thus, pre-season salt leaching becomes a necessity. Nevertheless, as long as farmers face high uncertainty in irrigation water supply, maintaining shallow groundwater tables can be considered as a safety-net against unreliable water delivery. Simulations showed that in 2003 around 200 mm would have been sufficient during pre-season leaching, whereas up to 300 mm of water was applied in reality amounting to an overuse of almost 33%. Using some of this water during the irrigation season would have alleviated season crop-water stress such as in June 2003. Management strategy analyses revealed that crop water uptake would only marginally benefit from a permanent crop residue layer, often recommended as part of conservation agriculture. Such a mulch layer, however, would substantially reduce soil evaporation, capillary rise of groundwater, and consequently secondary soil salinization. The simulations furthermore demonstrated that not relying on the contribution of shallow groundwater to satisfy crop water demand is possible by implementing timely and soil-specific irrigation scheduling. Water use would then not be higher than the current Uzbek irrigation standards. It is argued that if furrow irrigation is to be continued, pure sandy soils, which constitute <5% of the agricultural soils in Khorezm, are best to be taken out of annual cotton production.     

The hormonal response in bulls to the administration of zeranol and rumensin

The objective of the study was to investigate the influence of the growth stimulators Ralgro zeranol and Rumensin on changes in concentrations of certain hormones in the blood of beef bulls. In the first experiment 21 bulls were investigated which were divided into three groups. The first group was control, the second was administered the Ralgro stimulator (3X) and the third the Ralgro and Rumensin stimulators. In the second experiment there were 12 bulls. The animals in the test group were implanted Ralgro five times during the fattening period. Alternate changes, mostly insignificant, were recorded between the groups in the concentration of triiodothyronine and cyclic adenosine phosphate. Thyroxine concentrations were reduced during all investigations of the first and second experiments in the animals stimulated by the Ralgro preparation. A significant increase was recorded in the bulls at the age of 14.3 months in the second experiment (62.8 nmol.l-1, in comparison with 56.9 nmol.l-1). In both experiments an identical trend of insulin content was observed--in seven out of the total number of eight observations the animals treated with the Ralgro preparation had statistically insignificantly higher values. The largest differences were recorded at the age of 11.1 and 14.3 months in the second experiment (3.9 microIU.ml-1 and 3.6 microIU.ml-1). Significant differences were observed in testosterone concentrations in the second bulls of the test group were lower by 1.9+ nmol.l-1 and 3.4++ nmol.l-1, respectively.     

In vitro Growth and Maturation of Caprine Oocytes

This study was conducted to culture in vitro caprine pre-antral follicles for determining the competence of growth and maturation of oocytes and establishing a suitable culture system for oocyte maturation from pre-antral follicles. Two different culture methods (microdrop and agar gel clot) were employed to culture caprine pre-antral follicles. The pre-antral follicles were isolated from prepubertal goat ovaries by treatment with collagenase and DNase. The isolated pre-antral follicles were cultured in basic culture medium for 9 days (for growth). And oocytes were cultured in maturation culture medium for another 2 days for maturation. The result demonstrated that the growth rate of oocytes cultured in microdrops was significantly (p < 0.05) higher than that in agar gel clots, whereas the viability of oocytes in microdrops was considerably (p < 0.05) lower than that in agar gel clots. The oocytes grew over 150 microm in diameter, and two of 151 oocytes cultured in microdrops yielded morphologically abnormal first polar bodies. However, the size of oocytes cultured in agar gel approached to 120 microm in diameter and no polar body was produced.