Administration of recombinant porcine somatotropin (rpST) changes hormone and metabolic status during early pregnancy

The objective of this study was to examine the effects of somatotropin (ST) on porcine reproductive and metabolic statuses during early pregnancy. Four pregnant crossbred gilts received 6 mg of recombinant porcine somatotropin (rpST) daily from days 10 to 27 after artificial insemination while six pregnant gilts served as controls. Blood samples were taken on days 8, 10, 12, 14, 18, 22, and 27 prior to rpST injections (8:00 h) and subsequently at 9:00, 10:00, 12:00, 14:00, 16:00, 18:00, and 20:00 h. On all remaining days of treatment, samples were taken once daily before injections (8:00 h). The samples were assayed for the metabolic hormones: ST, insulin-like growth factor I (IGF-I), insulin, thyroxine (T₄), triiodothyronine (T₃), and cortisol; for metabolites: free fatty acids (FFA) and glucose; and for the reproductive hormones: luteinizing hormone (LH), progesterone, estradiol-17β, estrone sulfate, and prostaglandin F₂. Delivery of rpST daily induced a 20- to 40-fold increase in plasma ST concentrations. Moreover, repeated administration of rpST resulted in a continuous increase in plasma IGF-I concentration (P<0.001), from 191.0±22.3–340.0±15.3 ng/mL 24 h after initial injection to 591.3±46.8 ng/mL after final injections. Mean serum insulin tended to be greater in rpST-treated gilts. Blood concentrations of T₄ were reduced (P<0.05) from day 14 of gestation in treated gilts while T₃ concentrations remained unchanged. Concentrations of both glucose and FFA were greater (P<0.01) and cortisol concentrations were unchanged in treated gilts. Changes in reproductive steroid hormones were minimally affected. Circulating progesterone (P=0.078), and estradiol-17β (P=0.087) concentrations tended to be lower in treated animals. These data show that treatment of pregnant gilts with rpST during early gestation mainly impacts metabolic rather than reproductive status.     

Drought sensitivity of Norway spruce is higher than that of silver fir along an altitudinal gradient in southwestern Germany

Context

For Central Europe, climate projections foresee an increase in temperature combined with decreasing summer precipitation, resulting in drier conditions during the growing season. This might negatively affect forest growth, especially at sites that are already water-limited, i.e., at low elevation. At higher altitudes trees might profit from increasing temperatures.

Aims

We analyzed variations in radial growth of silver fir (Abies alba Mill.) and Norway spruce (Picea abies (L.) Karst.) along an altitudinal gradient from 400 until 1,140 m a.s.l. in the Black Forest, to assess climate responses with increasing elevation.

Methods

Climate–growth relationships were analyzed retrospectively using tree-ring and climate data. In total, we sampled stem discs of 135 trees to build 27 species- and site-specific chronologies (n _fir?=?13, n _spruce?=?14).

Results

Our results indicate distinct differences in climate–growth relations between fir and spruce along the gradient. Growth of high-altitude fir was positively related to temperature from January till March. Growth of low-altitude fir and spruce at all elevations was positively related to precipitation and negatively to temperature during the growing season, particularly in July. A self-calibrating Palmer drought severity index underlined summer drought sensitivity of these trees.

Conclusion

Overall, we found that climatic control of tree growth changes over altitude for fir. For spruce, a remarkable synchrony in growth variation and climate response was shown, which indicates that this species is drought sensitive at all studied elevations. In a future warmer climate, the growth of low-altitude fir and spruce along the entire studied gradient may be negatively affected in the Black Forest, if an increased evaporative demand cannot be compensated by increased water supply.     

A computer program for monitoring and controlling ultrasonic anemometers for aerodynamic measurements in animal buildings

Ultrasonic anemometers (USAs) are widely implemented in animal housing to measure the air velocity in different measuring points throughout the whole barn, which ultimately leads to determine the velocity fields and the air flow patterns drawing a clear vision of aerodynamics inside animal buildings. The problem is the timely inconsistent data transmission from the different USAs leading to varied data recording, which makes the comparison between the recorded velocities in different points timely inappropriate. One key issue is to monitor and control the USAs, meanwhile, debug and record the data. Therefore, LabVIEW 8.5, which is a platform and development environment for a visual programming language, was used to configure a computer program to monitor and control the USAs. The principal functions of the system are represented in a main block diagram which consists of 39 sub-diagrams. Five versions of the program were consecutively developed, and then each version was validated and further developed to get the next enhanced version, and so on till Version 5.0. The evaluation and data recording are carried out simultaneously, where the data are transferred from the USAs to the program which detects accidental errors that may have been introduced during data transmission or storage using a checksum algorithm. The developed computer program has been implemented successfully for monitoring and controlling USAs used for carrying out air velocity measurements in livestock housing. Three measurements campaigns were performed to investigate the air profile inside a dairy barn under two conditions, which are “ceiling fans on” and “ceiling fans off”, where the average air velocities were 0.98 and 0.59 m s⁻¹, respectively.     

Short-term and long-term effects of human trampling on above-ground vegetation, soil density, soil organic matter and soil microbial processes in suburban beech forests

Understanding the effects of disturbance by human trampling on ecosystem processes is essential for the management of recreational areas. Discussions on recreational impacts are based either on data from trampling experiments or on field survey data from sites subjected to long-term recreational use, but rarely on a combination of both. We examined whether results from a short-term trampling experiment reflect the impact of long-term trampling around frequently used fire places. We compared short- and long-term effects of human trampling on above-ground forest vegetation and soil physical, chemical and microbial characteristics. We found both similarities and differences in short- and long-term trampling effects. Both short- and long-term trampling reduced plant cover, plant height and species density, though long-term effects were more pronounced than short-term effects. In both approaches, leaf litter biomass decreased, whereas soil density increased with trampling intensity. Other soil characteristics including soil moisture, total soil organic matter content and total organic nitrogen content were not or only marginally affected by short- and long-term trampling. Furthermore, soil microbial biomass and the activity of dehydrogenase did not change in both approaches. In contrast, the activity of β-glucosidase was only reduced by short-term trampling, whereas activity of phosphomonoesterase was reduced only by long-term trampling. Soil compaction was one factor reducing microbial activities at low and medium trampling intensities in our experiment and in the highly compacted area around the fire rings. We conclude that it could be problematic to use the results of short-term trampling experiments to predict general long-term trampling effects. Our results imply also that the restoration of degraded sites might be hampered by the low nutrient turnover resulting from the reduced litter layer and changes in enzyme activities, mitigating a successful re-establishment and growth of plants.     

Concentrations and uptake of macronutrients by oat and pea in intercrops in response to N fertilization and sowing ratio

Intercropping is of increasing interest in temperate-arable farming systems. The influence of nitrogen (N) fertilization and sowing ratio on concentrations and uptake of calcium (Ca), potassium (K), magnesium (Mg) and phosphorus (P) by oat and pea was assessed in three substitutive intercrops on a fertile soil in eastern Austria. N decreased Ca in oat grain and increased P in pea grain as well as Ca and Mg in oat residue and Mg and P in pea residue. Intercropping did not affect nutrient concentrations of oat grain, whereas a lower pea share in intercrops increased P in pea grain. In residue, Ca, K and Mg concentrations were higher in oat and Ca and K partly lower in pea with a lower share of each crop. The oat-dominated intercrops could partly achieve a slightly higher total grain nutrient yield than pure stands at no or low N; however, these benefits diminished with a higher pea share and N input. In comparison to pure stands, higher residue nutrient yields were obtained by intercropping in all sowing ratios and fertilization levels. Consequently, oat–pea intercropping can be a strategy for increasing the macronutrient yield of grain and especially of residue for ruminant feeding.     

Management of roadside populations of invasive Ambrosia artemisiifolia by mowing

Ambrosia artemisiifolia (common ragweed) is a highly allergenic alien weed in Europe, which spreads rapidly along roadsides. Road verges are subject to frequent mowing, which further increases the spreading of the plants' seeds. Ambrosia artemisiifolia reacts to cutting by producing new shoots, which are able to develop flowers and ultimately new seeds. An effective mowing regime that would decrease the production of seeds and their dispersal is desirable to control the spread of the plant, but an appropriate way of mowing has yet to be found. In this study, we explored how the reproductive traits of A. artemisiifolia plants in seven spontaneous roadside populations reacted to the application of different mowing regimes over 3 years. The mowing regimes that were applied differed in the timing and frequency of cuttings. We found that the cutting regime, if appropriately timed, can strongly influence the production of male inflorescences (i.e. allergenic pollen), of female flowers (i.e. seeds) and had an impact on the phenological development of the plant. Based on our findings, we suggest that the optimal management of the plant along roadsides must be adjusted to its phenological development. The most effective mowing method of control consists of a first cut shortly before male flowering, to limit the quantities of released pollen, followed by subsequent cuts before the onset of new flowers on the resprouting lateral shoots.     

An Evaluation of Error Variance Bias in Spatial Designs

Spatial design and analysis are widely used, particularly in field experimentation. However, it is often the case that spatial analysis does not significantly enhance more traditional approaches such as row–column analysis. It is then of interest to gauge the degree of error variance bias that accrues when a spatially designed experiment is analysed as a row–column design. This paper uses uniformity data to study error variance bias in \(7\times 12\) spatial designs for 21 treatments.     

Effect of NO3 and NH4 concentrations in nutrient solution on yield and nitrate concentration in seasonally grown leaf lettuce

The effect of suboptimal supply of nitrogen (N) and of replacing nitrate in the nutrient solution with ammonia on growth, yield, and nitrate concentration in green and red leaf lettuce was evaluated over two seasons (autumn and spring) using multiple regression analysis. The plants were grown in a greenhouse on a Nutrient Film Technique (NFT) system. Nitrogen concentrations in the nutrient solution were either 3?mM or 12?mM, and the form of N was varied as follows: 100% NO₃, 50% NO₃?+?50% NH₄, and 100% NH₄. In both seasons, the biomass (fresh weight) of lettuce heads increased with increasing NO₃ concentrations and in autumn, NO₃ even at 1.5?mM was sufficient for high yield. However, head dry weight was affected neither by the season nor by changes in the composition of the nutrient solution. The concentration of NO₃ had no effect on root dry weight, but it decreased at higher concentrations of NH₄. The number of leaves increased as the ratio of NO₃ to NH₄ in the nutrient solution increased and was higher in autumn because of the longer growth period. Increasing the concentration of NO₃ in nutrient solution increased both total N and nitrate concentration in lettuce heads (dry weight) but decreased the concentration of total C. Also, leaf nitrate concentration was lower in spring than in autumn and decreased with increasing NH₄ concentration. Nitrogen utilization efficiency was maximum when NH₄ levels in the nutrient solution were either 0% or 50% irrespective of the season. Our results thus show that suboptimal N supply in autumn will not affect lettuce yield, and that nitrate concentration in leaves is lower when NH₄ concentrations in nutrient solution are higher and also much lower in red lettuce than in green lettuce.