Late Spring Period Research Articles

Dynamics of automated body condition scores in grazing Holstein cows in a year-round calving system

This observational study aimed to characterize the seasonal dynamics of automated body condition scores (BCS) through the lactation of Holstein cows in a pasture-based system with year-round calvings. Examining the association between nadir BCS (nBCS; defined as the lowest daily BCS after calving) and peak milk yield within each calving period (calendar seasons equally divided in early and late) was a secondary objective of this research. Retrospective data included 2,164 lactations in 539 primiparous (PRI) and 1,625 multiparous (MLT) Holstein cows that calved from July 2021 to June 2023 in a commercial dairy farm located in Southern Chile. Individual BCS were generated in every milking by an automated BCS camera system. Body condition score at calving (BCSc), nBCS, and the change in BCS from calving to nadir (ΔBCS) were considered for the analysis. Peak milk yield (greatest daily milk yield) values were retrieved from on-farm software and lactations were categorized considering quartiles (Q1 = 25% lowest peak milk yield; Q4 = 25% greatest peak milk yield). Data were examined in PRI and MLT cows separately using multivariable linear models that considered calving period and peak milk yield as the main explanatory variables of interest, while BCSc and health status were included as covariables when appropriate. The differences in BCSc among calving periods were more evident in primiparous cows that had the lowest BCSc in early spring (3.13 ± 0.03) and the greatest BCSc in late fall (3.51 ± 0.03). In MLT cows, the lowest and greatest BCSc were recognized in late fall (3.07 ± 0.04) and early summer (3.23 ± 0.03), respectively. Only MLT cows had differences in nBCS and ΔBCS across calving periods: The lowest nBCS were identified in late spring (2.71 ± 0.02), early summer (2.71 ± 0.02), and in late summer (2.71 ± 0.02). The greatest losses in BCS also occurred in early summer (−0.41 ± 0.02) and in late spring (−0.41 ± 0.02). Time from calving to nBCS varied among calving periods and depended on parity category. Primiparous cows reached nBCS earlier in late summer (65 ± 8 DIM) and late spring (68 ± 7 DIM), while MLT had the shortest times to nBCS in late and early fall (67 ± 5 DIM; 68 ± 5 DIM). Greater values at milk peak were associated with lower nBCS only in multiparous cows during the late spring period. We concluded that the dynamics of BCS were associated with calving period in both parity groups. This data could help guide decisions on nutrition and breeding strategies in farms facing comparable conditions.

The influence of mowing frequency on the growth and development of Phragmites australis

The research focused on the evaluation of the growth and development of common reed Phragmites australis and its yield depending on the frequency and time of mowing, as well as hydrothermal conditions in particular years of the study. The foundation for the study was proper classification of the habitat, which is wet meadows. The research confirmed the hypothesis that after mowing, the Phragmites australis does not develop inflorescences in the same growing season, regardless of the time of mowing. Therefore, the presence of old common reed inflorescences in a wet meadow proves that it was not mown last year, assuming mowing after June 15. The height and density of reed shoots and biomass yield depended on hydrothermal conditions, especially on the amount and distribution of precipitation and the groundwater table. Frequent mowing (twice or thrice) stimulated the density of common reed shoots. Such treatments also reduced reed growth, while a single autumn mowing had the least impact on this feature. The development of reed inflorescences was observed to be eliminated by frequent mowing, as well as by mowing performed in the late spring period. On the other hand, throughout the growing season, inflorescences occur only in plots without any treatments and those mown in autumn. The obtained results will help field inspectors to properly assess the controlled wet meadows. For managers and farmers, it will support rational management of common reed cultivation.

Plant potential and ecological and economic suitability of reindeer pastures on the right bank of the Norilsk River

Purpose : identification of plant potential, ecological and economic suitability of deer pastures of the forest-tundra zone located in the zone of anthropogenic influence Material and methods . Ground geobotanical survey of the vegetation cover of deer pastures was carried out by route method in accordance with the method of geobotanical studies. The ecological and economic value of each type of pasture was determined based on the data of the ecological and economic classification of deer pastures in the north. Results . 25 species of reindeer pastures are described on the right bank of the Norilsk River in the northwestern part of the Putorana Plateau. On the basis of signs of uniformity in the structure of vegetation (proximity of species composition, similarity of vertical and horizontal structures), they are combined into 4 types: tundra, swamps, shrubs and light forests. Tundra (30.9%) and shrub (27.6%) types of pastures dominate. The most important feature is the active participation in the structure of phytocenoses of shrubs (Betula nana s. str, Salix glauca s. str, S. lanata s. str.) and shrubs (Ledum palustre. Vaccinium uliginosum s. str, V. vitis-idaea s. str.). Green fodder is most nutritious in the first half of summer. The nutritional value of fruticose lichens does not change during the year. Reindeer pastures with lichen cover and high (from 5 to 12 o-days/ha) reindeer capacity during the snowy period occupy insignificant (24.3%) areas. Basically, these are willow and dwarf dwarf shrub-lichen tundras and larch sparse forests of dwarf-shrub moss-lichen. The participation of lichens in the ground cover of plant communities does not exceed 25–35%. The following lichen species have been recorded: Cladonia arbuscula, C. stellaris, C. rangiferina, C. cornuta, C. deformis, C. mitis, Cetraria cucullata, and C. islandica. The most widespread species of the genus Cetraria: Cetraria islandica and C. cucullata, with a clear advantage of the latter. The main forage species of the genus Cladonia (Cladonia arbuscula, C. stellaris, C. rangiferina) are not widely distributed. Pastures with a high (from 9 o-days/ha to 14 o-days/ha) reindeer capacity in the summer, early autumn and late spring periods prevail in the study area. Basically, these are communities of shrub and marsh types. Shrubs (Salix glauca s. str, S. lanata s. str., S. hastata, Betula nana s. str.), shrubs (Salix reticulata, Vaccinium vitis-idaea s. str.) and forbs (species of the genera Petasites, Pedicularis, Astragalus, Hedysarum, Equisetum, Bistorta).

Semen qualitative parameters and spermatozoon ultrastructure of Phasianus colchicus mongolicus

In many European countries, the common pheasant is one of the most popular game bird species. Despite its popularity, little information has been published related to its sperm profile, including the common semen parameters used to characterise the quality of this material. Additionally, the spermatozoon’s ultrastructure has never been characterised, and very few data on reproductive performance in the male bird are available. The aim of the present study was to provide these data and fill these gaps in the literature. Semen was collected by the dorso-abdominal massage technique for pheasants and evaluated during the late spring period (May to mid-June). For the ultrastructure and morphometric descriptions, scanning electron and transmission electron images were obtained. The data show that pheasants produce ejaculates of a smaller volume (average volume = 131 µL) but with a higher sperm concentration compared with roosters. Semen pH values tended towards alkaline values (average pH = 8.3). The general shape of the pheasant spermatozoon resembles that of roosters and turkeys, although a bigger sub-acrosomal space was observed compared with these species. As a consequence, its perforatorium occupies two-thirds of the acrosome. A lower number of mitochondria (20–24) was also detected compared with roosters and turkeys. The pheasant spermatozoon’s dimensions are most similar to those observed in turkeys and guineafowl. The present study provides basic information useful for assisted reproductive techniques and conservation programmes. HIGHLIGHTS Basic information on the common pheasant semen is given. A morphometric description of the common pheasant sperm cell is reported. The characterisation of the sperm ultrastructure by scanning and transmission electron microscopy is shown.

ADAPTIVE POTENTIAL OF FENUGREEK SPECIES AT DIFFERENT SOWING TIMES

Among the unexplored technological elements of growing fenugreek in the conditions of Ukraine is the creation of conveyor cultivation of the culture. Therefore, the problem of the influence of sowing dates on the growth and development of plants, the parameters of the harvest and the qualitative composition of marketable products is acute. The purpose of this study was to substantiate the optimal sowing dates of fenugreek species to increase the yield of dried products in the conditions of Polissia on sod-podzolic soils. The leading methods employed to investigate this issue were the field method – to find the interaction of the object of research with biotic and abiotic factors, statistical method – to evaluate the research results to find the parameters of fenugreek’s adaptive capacity. During 2012-2014, for different sowing periods, the average yield of dry mass in blue fenugreek varied from 0.5 to 1.3 t/ha, and in hay fenugreek – from 0.6 to 1.5 t/ha. The early spring period and the late spring period of the 1st sowing period were characterized by the highest overall adaptive capacity. The highest value of the specific adaptive capacity was established during the late spring 2nd sowing period. The relative stability index ranged from 2.6 to 11.4. Blue fenugreek during the late spring 1st and 2nd sowing periods responds well to improved growing conditions (bi >1), and fenugreek hay during the late spring 2nd and summer sowing periods. Early spring and late spring 1st sowing period samples are characterized by high breeding value. An increase in the sum of effective temperatures by 1°C contributed to the fluctuation of green mass yield from 4.82 to 128 kg/ha, and dry mass yield from 0.401 to 6.63 kg/ha. At the same time, an increase in precipitation by 1 mm affected the fluctuation of the yield of green mass from 15.0 to 146 kg/ha, and of dry mass from 0.145 to 25.9 kg/ha. Commercial production of fenugreek species was formed within the range of the sum of air temperatures (>10°C) 383.9-487.1°C, the amount of precipitation 70.7-144.3 mm, and the growing season ranged from 35 to 55 days. The highest productivity of fenugreek species was found during sowing from the second decade of April to the first decade of May. The materials of this paper are of practical value for expanding the species diversity of vegetables and increasing the supply of the population with valuable food products and during the application of new and improved elements of technologies for growing valuable rare crops to achieve the maximum effect of fulfilling the genetic potential of plants

Herbage Yield, Lamb Growth and Foraging Behavior in Agrivoltaic Production System

Agrivoltaic systems are designed to mutually benefit solar energy and agricultural production in the same location for dual-use of land. This study was conducted to compare lamb growth and pasture production from solar pastures in agrivoltaic systems and traditional open pastures over 2 years in Oregon. Weaned Polypay lambs grew at 120 and 119 g head−1 d−1 in solar and open pastures, respectively in spring 2019 (P = 0.90). The liveweight production between solar (1.5 kg ha−1 d−1) and open pastures (1.3 kg ha−1 d−1) were comparable (P = 0.67). Similarly, lamb liveweight gains and liveweight productions were comparable in both solar (89 g head−1 d−1; 4.6 kg ha−1 d−1) and open (92 g head−1 d−1; 5.0 kg ha−1 d−1) pastures (all P > 0.05) in 2020. The daily water consumption of the lambs in spring 2019 were similar during early spring, but lambs in open pastures consumed 0.72 L head−1 d−1 more water than those grazed under solar panels in the late spring period (P < 0.01). No difference was observed in water intake of the lambs in spring 2020 (P = 0.42). Over the entire period, solar pastures produced 38% lower herbage than open pastures due to low pasture density in fully shaded areas under solar panels. The results from our grazing study indicated that lower herbage mass available in solar pastures was offset by higher forage quality, resulting in similar spring lamb production to open pastures. Our findings also suggest that the land productivity could be greatly increased through combining sheep grazing and solar energy production on the same land in agrivoltaics systems.

Assessing the laboratory mass rearing of Predator Beetle Rhizophagus grandis Gyll. (Coleoptera: Monotomidae)

The aim of this study was to determine the progeny production of predator beetle Rhizophagus grandis (Gyllenhal) (Coleoptera: Monotomidae) under laboratory conditions. Different numbers of male and female predators introduced into breeding logs and the numbers of new progenies and their sex ratios were determined in the early and late spring periods. A total of 8776, 13,402, 5742 and 7864 R. grandis individuals were reared in 60, 109, 128 and 56 breeding logs in four consecutive years, respectively. Of the prepupae that have dropped from breeding logs to enter the sand in experimental basins, 81.4 % of them have emerged as adults at the end of the experimental periods. The average number of R. grandis per log was 146.2, 123, 44.9 and 140.4 according to experimental years, and 181.7 and 93.2, 123, 62.4 and 32.9, 163.8 and 101.5 according to the early and late spring periods in the experimental years, respectively. In the second year of the experiments, only early spring rearings have been performed that have yielded 123 R. grandis per log on average. Progeny production of a female R. grandis was 18.3, 18.7, 5.8 and 17.6 on average, 2004, 2005, 2006 and 2007 respectively. Different numbers of predator females and males were used in early and late spring experiments in the study. Progeny production was higher in early spring when the experiments were performed with 6 females and 2 males. Of the 35,784 R. grandis individuals that were obtained from the experiment, 16.4 %, 28.3 % and 55.3 % were collected from the first, second and third part of the sand environment where the breeding logs kept during experiment.

Pasture production, persistence of legumes and lamb growth in summer‐dry hill pastures

AbstractPasture legumes that persist under challenging agroecological conditions are crucial to ensure high lamb growth rates in dryland pastures. Pasture and lamb production from binary and diverse mixtures (Mix) of tall fescue (TF) with white clover (Whc), balansa clover (Bc), subterranean clover (Sc) and birdsfoot trefoil (Bft) were compared in a summer‐dry hill site in Corvallis, Oregon over a two‐year period. In 2018, all pasture combinations provided similar lamb liveweight gains (LWG, mean 177 g/day) in the first half of spring. Lambs in TF‐Bc and TF‐Mix pastures grew 31 to 41 g/day faster than those grazing TF‐Sc, TF‐Whc and TF‐Bft in the second half of spring (p < .05). Overall, TF‐Bc and TF‐Mix had higher (p < .05) legume contents (32% and 37% respectively) compared to other pasture combinations. In spring 2019, lambs that grazed the TF‐Mix and TF‐Whc pastures had higher LWG than those on other pastures (p < .05). The superior lamb growth rates were associated with the higher legume content and pasture quality maintained into the late spring period. Overall, the legume content of all pastures decreased over the course of the two‐year trial, with the decline being substantial for balansa clover. The present study confirmed that a high legume content of pastures leads to greater lamb growth rates. Total annual yields of pastures that had greater legume contents were superior to others (p < .05). Thus, a combination of self‐regenerating annual clovers with perennial legumes in pasture mixtures may ensure a higher legume content and longer persistence in dryland hill pastures.

Properties of Nanosilica-Modified Concrete Cast and Cured under Cyclic Freezing/Low Temperatures

Abstract Cold weather concreting is one of the most challenging problems facing concrete placement in many regions. For example, in Canada, low temperatures limit the construction season to a few months, usually between May and September. The incorporation of nanosilica in concrete, which has vigorous reactivity because of its ultrafine surface area, may enhance the hydration process and properties of concrete cast at low temperatures; however, this has not been substantiated. Therefore, this study focused on developing nanomodified concrete mixtures that were mixed, placed, and cured at cyclic temperatures (−5°C and 5°C), targeting applications in early fall and late spring periods in North America. The study followed the design of experiments modeling approach to test 15 concrete mixtures based on the response surface method. Three parameters were considered in the model: incorporation of fly ash (up to 25 %) and nanosilica (up to 4 %) as well as a combination of two types of antifreeze admixtures (calcium nitrate and nitrite). The mixtures were assessed based on setting time (placement), 3- and 28-day compressive strengths (hardened properties) and absorption (infiltration of fluids). Moreover, mercury intrusion porosimetry, thermal analysis, and scanning electron microscopy were conducted to characterize the microstructural features. The results showed that nanosilica, even with the inclusion of fly ash, significantly enhanced the overall performance and development of the microstructure of concrete mixed, cast, and cured at cyclic freezing/low temperatures. Thus, nanomodified concrete has promising potential for extending the construction season during early fall and late spring periods in cold regions.

Metagenomic Analysis of Virioplankton from the Pelagic Zone of Lake Baikal.

This study describes two viral communities from the world’s oldest lake, Lake Baikal. For the analysis, we chose under-ice and late spring periods of the year as the most productive for Lake Baikal. These periods show the maximum seasonal biomass of phytoplankton and bacterioplankton, which are targets for viruses, including bacteriophages. At that time, the main group of viruses were tailed bacteriophages of the order Caudovirales that belong to the families Myoviridae, Siphoviridae and Podoviridae. Annotation of functional genes revealed that during the under-ice period, the “Phages, Prophages, Transposable Elements and Plasmids” (27.4%) category represented the bulk of the virome. In the late spring period, it comprised 9.6% of the virome. We assembled contigs by two methods: Separately assembled in each virome or cross-assembled. A comparative analysis of the Baikal viromes with other aquatic environments indicated a distribution pattern by soil, marine and freshwater groups. Viromes of lakes Baikal, Michigan, Erie and Ontario form the joint World’s Largest Lakes clade.

Эффективность возделывания озимой пшеницы по различным стерневым фонам в агроландшафте зоны Центрального Предкавказья

Abstract. The research results are devoted to assessing the effectiveness of cultivating winter wheat on various taxonomic elements (taxa) of the agrolandscape: the outskirts of the plakor (A1), the root slope of the SE exposure (A2), the lower part of the root slope (A4), the root slope of the SV exposure (A4) using the stubble system backgrounds, including three options: stubble (control); leaving stubble and plant residues; removal of stubble and plant residues in the zone of unstable moistening of the Central Ciscaucasia. Soils of taxa of light-loamy granulometric composition, range of agrochemical parameters: humus 2.65–3.85%; P2O5 15.7–21.1 mg/kg; K2O 127.5–189.8 mg/kg. The method of dimensions determined the possibility, according to the humidity and the presence of plant residues, to predict the relative biological activity of the soil, taking into account the adaptation coefficient C, obtained experimentally for a specific type of soil. Over the years of research, the amount of precipitation of the early spring period (March) averaged 58 mm, and of the late spring period (May) 126 mm. Statistical processing of experimental data on the biological activity of the soil, according to the degree of decomposition of flax linen at different levels of moisture, showed the greatest biological activity in the lower part of the root slope (A3) – 35 %. Established a significant increase in the yield of winter wheat on the facial elements A2, A3 and A4 in comparison with the poster (A1), amounting to 4.2; 14.3 and 5.5 c/ha, respectively, with the highest yield observed in the lower part of the root slope (A3) – 33.3 c/ha. Stubble backgrounds are not a significant factor in the formation of a crop of winter wheat, the yield on stubble backgrounds is 24.8–25.2 c/ha.

Benthic ctenophore (Order Platyctenida) reproduction, recruitment, and seasonality in south Florida

AbstractReproductive structures, modes, and seasonal patterns of size–class abundances are examined in two benthic platyctene (Family Coeloplanidae) ctenophore species present in dissimilar shallow marine environments in subtropical southeast Florida. Coeloplana waltoni, a minute (1–3 mm body length) epizoic associate of octocorals, occurs in exposed environments often under turbulent conditions, and Vallicula multiformis (2–10 mm) commonly occurs epiphytically on macroalgae in protected, calm‐water environments. Reproductive activity in C. waltoni is most active during the warm‐water summer season (June–October); gonadal development in V. multiformis occurs year‐round, and is most pronounced during sea‐warming periods in late spring (May) and late summer to early autumn (August–October), with release of cydippid larvae. Both species are hermaphroditic brooders, exhibiting paedogenesis (early gonadal development) at body lengths approximately one‐third (Coeloplana) to one‐sixth (Vallicula) of maximum adult size. Juvenile individuals (<0.6 mm) increased in abundance in C. waltoni during the summer reproductive period, and large (≥1 mm) pink‐colored individuals comprised 50% or more of samples from July through September. Seasonal abundance of gravid individuals and the timing of cydippid larval release in V. multiformis did not correspond closely with juvenile or adult population densities. Asexual fragmentation occurred in both ctenophore species, but was observed more frequently in individuals of V. multiformis. This asexual mode of reproduction probably accounted in part for the discordance between ctenophore abundances and larval recruitment events by sexual means. Morphological structures and behaviors associated with reproduction are described in this study. Uncommon images of reproductive products (gametes, embryos, larvae), spawning events, brooding, and asexual fragmentation are included, some for the first time in the published literature.

Stability of dissolved and soluble Fe(II) in shelf sediment pore waters and release to an oxic water column

Shelf sediments underlying temperate and oxic waters of the Celtic Sea (NW European Shelf) were found to have shallow oxygen penetrations depths from late spring to late summer (2.2–5.8 mm below seafloor) with the shallowest during/after the spring-bloom (mid-April to mid-May) when the organic carbon content was highest. Sediment porewater dissolved iron (dFe, <0.15 µm) mainly (>85%) consisted of Fe(II) and gradually increased from 0.4 to 15 μM at the sediment surface to ~100–170 µM at about 6 cm depth. During the late spring this Fe(II) was found to be mainly present as soluble Fe(II) (>85% sFe, <0.02 µm). Sub-surface dFe(II) maxima were enriched in light isotopes (δ56Fe −2.0 to −1.5‰), which is attributed to dissimilatory iron reduction (DIR) during the bacterial decomposition of organic matter. As porewater Fe(II) was oxidised to insoluble Fe(III) in the surface sediment layer, residual Fe(II) was further enriched in light isotopes (down to −3.0‰). Ferrozine-reactive Fe(II) was found in surface porewaters and in overlying core top waters, and was highest in the late spring period. Shipboard experiments showed that depletion of bottom water oxygen in late spring can lead to a substantial release of Fe(II). Reoxygenation of bottom water caused this Fe(II) to be rapidly lost from solution, but residual dFe(II) and dFe(III) remained (12 and 33 nM) after >7 h. Iron(II) oxidation experiments in core top and bottom waters also showed removal from solution but at rates up to 5-times slower than predicted from theoretical reaction kinetics. These data imply the presence of ligands capable of complexing Fe(II) and supressing oxidation. The lower oxidation rate allows more time for the diffusion of Fe(II) from the sediments into the overlying water column. Modelling indicates significant diffusive fluxes of Fe(II) (on the order of 23–31 µmol m−2 day−1) are possible during late spring when oxygen penetration depths are shallow, and pore water Fe(II) concentrations are highest. In the water column this stabilised Fe(II) will gradually be oxidised and become part of the dFe(III) pool. Thus oxic continental shelves can supply dFe to the water column, which is enhanced during a small period of the year after phytoplankton bloom events when organic matter is transferred to the seafloor. This input is based on conservative assumptions for solute exchange (diffusion-reaction), whereas (bio)physical advection and resuspension events are likely to accelerate these solute exchanges in shelf-seas.

Post-weaning performance of East Friesian cross ewe lambs grazing ryegrass or plantain-based pastures after rearing on two contrasting diets

Abstract Artificial rearing is used routinely on dairy sheep farms. Different strategies are used to optimise the growth and development of the young lamb with an economic ration of milk and other feed components. Early weaning, and early introduction to pasture can both reduce these costs, but may also reduce the liveweight gains of the growing lamb. Can differences in pre-weaning feeding strategies be mitigated using specialist pastures such as plantain/red/white clover? Lambs from an experiment investigating the impacts of rearing with and without meal access (n=30/group) and weaned at 12 weeks of age were grazed on either perennial ryegrass-based or plantain/red clover-based pastures in 3 replicates. Liveweight gain, animal health, feed supply and feed quality parameters were recorded over the following 5 weeks. Liveweights of the lambs reared on the different feeding regimens were similar at 12 weeks of age when the grazing study began (25.9 kg). Using plantain/red clover-based pastures provided no advantage to the liveweight gain of lambs reared under different milk and concentrate feeding regimens. Both feed types provided adequate nutrition to ensure growth rates of approximately 180 g/day over the 5 week measurement period in late spring. However, lambs reared under a high concentrate system has consistently lower liveweight gains (160 g/day) over the 5 weeks than those lambs reared with access to pasture (200 g/day; P

Preliminary Results of Sugar Maple Carbohydrate and Growth Response under Vacuum and Gravity Sap Extraction

Recent technological advancements have increased the amount of sugar-enriched sap that can be extracted from sugar maple (Acer saccharum). This pilot study quantified overall sugar removal and the impacts of vacuum (60 cm Hg) and gravity sap extraction on residual nonstructural carbohydrate (NSC) concentrations and on stem and twig growth. Vacuum sap extraction (VSE) resulted in significantly greater mean sugar removal (1.19 ± 0.46 kg [SE]) than gravity sap extraction (GSE) (0.48 ± 0.14 kg). Residual stem NSC displayed a pattern of increased concentration with increased extraction. Twig residual NSC concentrations were highly variable, perhaps because of the highly dynamic late spring period, and no clear patterns were observed. Mean radial stem growth in the year after sap extraction was greater in untapped trees (2.93 ± 0.58 mm) than with VSE (1.99 ± 0.44 mm) or GSE (1.67 ± 0.12 mm). The results raise the possibility that sap removal shifts sugar maple NSC source-sink relationships toward storage at the expense of growth.

Performance of indigenous and exotic×indigenous sheep breeds fed different diets in spring and the efficiency of feeding system in crop–livestock farming

SUMMARYGenetic variation in feed efficiency may have a significant impact on sheep production in integrated crop livestock farming systems in dry areas, where the shortage and poor quality of feed is widespread. Thus, the present study was carried out to investigate the effects of sheep genotype and feed source on liveweight gain, feed conversion efficiency and dry matter (DM) intake in feedlot lambs finished on diets based on low-cost forages or a high-cost concentrated feed as a means of assessing the efficiency of this feeding system. Early weaned lambs of the purebred fat-tailed Akkaraman breed were compared with synthetic Anatolian Merino (0·80 German Mutton Merino×0·20 Native Akkaraman) breed. The lambs were kept in individual pens for 8 weeks and fed four diets: daily harvested forages of triticale (T), Hungarian vetch (HV), a triticale-Hungarian vetch mixture (T+HV), and a concentrate-based feed (CF). Lamb liveweight gain (LWG) was monitored during the early (18 April–16 May) and late (17 May–13 June) spring periods. Diet×period and diet×breed interactions were detected in LWG of the lambs. Lambs from both genotypes on the concentrate-based diet had higher liveweight gains, DM intakes and better feed conversion ratios compared with lambs finished on the forage-based diets. The LWG of lambs offered triticale forage decreased from 177 g/head/day in the early spring to 95 g/head/day in the late spring period, as plant maturity increased. Liveweight gains did not change for the other forage rations during the same period. The LWG of Akkaraman lambs were similar for both the early (189 g/head/day) and the late (183 g/head/day) spring periods, whereas Anatolian Merino lambs gained 41 g/head/day less LW and had 3·8 higher feed conversion rate for the late spring period compared with the early spring period. The present study showed that fat-tailed Akkaraman lambs were better able to utilize forages with low nutritive value compared to Anatolian Merino lambs, and may be better suited to semi-arid areas, where crop and livestock are highly integrated in the farming system.

ECOBEE: a tool for long-term honey bee colony monitoring at the landscape scale in West European intensive agroecosystems

SummaryIn Central Western France, as in many other areas, traditional apiculture has been replaced by more intensive practices to compensate for colony losses and current decreasing honey yields. One neglected aspect concerns the choice by professional beekeepers of apiary sites in intensive agrosystems, with regard to landscape features, a choice which appears to be largely empirical. ECOBEE is a colony monitoring scheme specifically intended to provide beekeepers and researchers with basic ecological data on honeybees in intensive agrosystems, as well as colony population dynamics. ECOBEE was launched in 2008 as a long-term ecological project with three specific aims: 1. to monitor seasonal and inter-annual population dynamic parameters of honeybee colonies in a heterogeneous farming system; 2. to provide relevant and robust datasets to test specific hypotheses about bees such as the influence of landscape planning, agricultural inputs or human pressure; and 3. to offer opportunities for assessing the effectiveness of agro-environmental schemes or the effects of changes in agricultural policies on honey bee wellbeing. Here we present an overview of ECOBEE, the type of datasets collected over the first four years of monitoring, and their possible application and use. We found that colony dynamics were largely influenced by the phenology of the main mass-flowering crops foraged by bees, namely oilseed rape and sunflowers. Furthermore, we detected a sharp food shortage period in late spring between the flowering of oilseed rape and sunflowers, possibly temporarily constraining colony sustainability. We further discuss the research perspectives offered by ECOBEE, especially with regard to spatial ecotoxicology.

Effects of year-round stocking methods and stocking rates on seasonal forage response and cow-calf weight gain in the gulf coast region of the United States

<h2>ABSTRACT</h2> The present research is the second phase (2 yr) of a multiyear cow-calf study employing fixed stocking rates and examining the effect of stocking method, i.e., continuous and rotational, and stocking rate on beef cattle production. Two sets of 4 adjacent pastures, each containing a mixed warm-season, perennial grass sod [common bermudagrass, Cynodon dactylon (L.) Pers.; dallisgrass, Paspalum dilatatum Poir.], were overseeded to ‘Marshall' annual ryegrass (Lolium multiflorum) in the autumn of 2 consecutive years. Within each set of 4 pastures, one of the following grazing treatments was randomly assigned each pasture: rotationally stocked (8 paddocks) at a low, medium, or high stocking rate and continuously stocked at a moderate stocking rate. Low, medium, and high stocking rates were 1.25, 2, and 2.75 cows/ha. Brangus cows and their suckling calves were stocked on treatment pastures in March 2004. Stocking treatment affected prebreeding cow BW (P < 0.01) and tended to affect precalving (P = 0.13), postbreeding (P = 0.07), weaning (P = 0.11), and subsequent precalving cow BW (P = 0.08). Stocking-method treatments were similar in forage allowance in the early- and late-spring periods (P = 0.67 and P=0.65, respectively), but in the summer period, rotationally stocking at a medium stocking rate was greater (P < 0.01) than continuously stocking at a moderate stocking rate. There was a consistent trend across seasons for the percent CP in the simulated bite sample DM to be greater (P < 0.1) for the continuously stocking at a moderate stocking rate compared with the rotationally stocking at a medium stocking rate stocking methods. Based upon cow BW outcomes in this research, stocking rate is the most important consideration in design of a grazing program.

Underwater ambient noise on the Chukchi Sea continental slope from 2006–2009

From September 2006 to June 2009, an autonomous acoustic recorder measured ambient noise north of Barrow, Alaska on the continental slope at 235 m depth, between the Chukchi and Beaufort Seas. Mean monthly spectrum levels, selected to exclude impulsive events, show that months with open-water had the highest noise levels (80-83 dB re: 1 μPa(2)/Hz at 20-50 Hz), months with ice coverage had lower spectral levels (70 dB at 50 Hz), and months with both ice cover and low wind speeds had the lowest noise levels (65 dB at 50 Hz). During ice covered periods in winter-spring there was significant transient energy between 10 and 100 Hz from ice fracture events. During ice covered periods in late spring there were significantly fewer transient events. Ambient noise increased with wind speed by ~ 1 dB/m/s for relatively open-water (0%-25% ice cover) and by ~ 0.5 dB/m/s for nearly complete ice cover (> 75%). In September and early October for all years, mean noise levels were elevated by 2-8 dB due to the presence of seismic surveys in the Chukchi and Beaufort Seas.

Organosulfates and oxidation products from biogenic hydrocarbons in fine aerosols from a forest in North West Europe during spring

Abstract Organosulfates of monoterpenes and isoprene, as well as their oxidation products have been identified in biogenic secondary organic aerosols (BSOA) from both laboratory and field studies. Organosulfates provide an interesting coupling between air pollution and formation of low-volatility BSOA. HPLC quadrupole time-of-flight mass spectrometry was used to study polar acidic monoterpene and isoprene oxidation products including pinic acid, pinonic and terpenylic acid along with organosulfates and nitrooxy organosulfates in aerosols from ambient air. The method was first validated by analysis of spiked quartz filters, which showed acceptable recoveries >74% for pinic acid, pinonic acid, camphor sulphonic acid and adipic acid. Acetonitrile was identified as a better solvent than methanol for extraction and analysis of pinonic acid and adipic acid, due to improved analytical sensitivity and prevention of methyl ester formation during sample extraction. PM1 (i.e, aerosols with an aerodynamic diameter ≤1 μm) were collected during spring 2008 in a forest in Denmark with mixed deciduous and coniferous trees. Average concentrations of the most abundant compounds were: pinic acid: 1.5 ng m−3, pinonic acid: 3.0 ng m−3, terpenylic acid: 0.8 ng m−3 and 3-methyl-1,2,3-butanetricarboxylic acid: 3.0 ng m−3. Organosulfates and nitrooxy organosulfates were identified in a majority of the daily samples and the highest levels were observed during a warm period in late spring. As a first approach, due to the lack of authentic standards, organosulfates and nitrooxy organosulfates were tentatively quantified based on the analytical response of camphor sulphonic acid. Generally the concentrations of organosulfates and nitrooxy organosulfates were lower than first generation oxidation products. The maximum concentration of a total of 10 organosulfates and nitrooxy organosulfates were found to be about three times lower than pinonic acid with a maximum concentration of 8 ng m−3. A correlation between total organosulfates (including nitrooxy organosulfates) and organic acids was observed with R2 = 0.89, indicating that the presence of organosulfates is closely connected to photochemical oxidation and aging of volatile organic compounds.