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Simple Summary: The lack of welfare guidelines in the insect rearing sector is an aspect of growing concern. This study investigates the larval stage of the black soldier fly (L.) (Diptera: Stratiomyidae), examining how different feeding rates and densities during the rearing period impact their welfare, applying dietary regimes already validated in previous research. Feeding rates of 50, 100, and 200 mg feed/larva/day and densities of 5, 10, or 15 larvae/cm2 were studied. By using performance parameters as indirect indicators of welfare, guided by the Five Freedoms framework and applying performance optimization models, the results showed that in the Omnivorous diet, a medium feeding rate (90 mg/larva/day) and density of 5 larvae/cm2 led to optimal performances without providing excessive feed or causing overcrowding. This represents an innovative and relevant indication for the future improvement of insect rearing from a welfare perspective, especially at an industrial scale. The large-scale insect rearing sector is expected to grow significantly in the next few years, with Hermetia illucens L. (black soldier fly, BSF) playing a pivotal role. As with traditional livestock, it is essential to improve and ensure BSF welfare. A starting point can be an adaptation of the Five Freedoms framework. Feed availability must be optimized to meet larvae nutritional needs (freedom from hunger) while maximizing substrate conversion efficiency. Similarly, rearing density needs to be optimized to ensure well-being, particularly in large-scale operations. In this study, Control (commercial laying hen feed) and Omnivorous substrates (vegetable and meat) were used as dietary regimes. In the first trial, three feeding rates were tested: 50, 100, and 200 mg feed/larva/day; in the second trial, three rearing densities were evaluated: 5, 10, and 15 larvae/cm2. Performance parameters, including final larval weight, final frass biomass, growth rate, substrate reduction, feed conversion ratio, larval length, survival rate, larvae chemical composition, and process optimization, were studied. Our results show that a feeding rate of approximately 90 mg feed/larva/day in the Omnivorous diet and 175 mg feed/larva/day in the Control diet, along with a rearing density of 5 and 7.57 larvae/cm2, respectively, in the Omnivorous and Control diets, produced optimal growth performances ensuring larval well-being. This outcome offers valuable insights for implementing good welfare practices in the insect farming sector and optimizing rearing management and efficiency. [ABSTRACT FROM AUTHOR]

Parabens are recognized as emerging contaminants. Used in the pharmaceutical and cosmetic industries, they present significant ecological risks to aquatic ecosystems. This study evaluated the effects of two parabens—methyl 4-hydroxybenzoate (methylparaben) and propyl 4-hydroxybenzoate (propylparaben)—both individually and as a mixture on daphnids. Through a series of controlled exposure experiments, phenotypic endpoints, including mortality, feeding behaviour, and enzymatic activity, were measured. The results demonstrate that propyl paraben and the mixture of propyl and methyl paraben exhibit greater toxic potential compared to methyl paraben alone. We observed a dose-dependent impact on key enzymes, indicating significant metabolic disruption. These findings underscore the necessity of utilizing model systems to investigate the complex interactions and cumulative impacts of pollutant mixtures in aquatic environments. Furthermore, this study provides critical insights regarding the underlying toxicity mechanisms of parabens, highlighting the need for comprehensive water quality monitoring and risk assessment frameworks to address the challenges posed by emerging contaminants. [ABSTRACT FROM AUTHOR]

Simple Summary: Applications of nanoparticles as well as their use have increased over the past decades without sufficient research on their environmental impact. Focusing on Daphnia magna, a widely adopted aquatic organism employed to evaluate the adverse effects of pollutants, we investigated several aspects of the experimental design used in D. magna toxicity testing which could impact the observed effect of exposure to nanoparticles. Furthermore, we evaluated the feasibility of a miniaturized version of D. magna toxicity test as a potential candidate for nanoparticle toxicity assays. Results showed that the exposure vessel and its characteristics can affect the impact of nanoparticles and, therefore, skew the observed effects. Additionally, the miniaturized exposure showed that for physiology markers such as toxicity and feeding rate it can be a good alternative to the traditional setups, as it vastly reduces the amount of media and number of nanoparticles required as well as generated waste. The rapid progress of the modern world has resulted in new materials and products created at an accelerating pace. As such, nanoparticles have widespread applications and often find their way into the aquatic ecosystem. In the case of freshwater ecosystems, one of the commonly used bioindicators species used for pollution assessment is Daphnid magna. The Organization for Economic Co-operation and Development (OECD), and other organizations such as the European Chemicals Agency (ECHA) and Environmental Protection Agency (EPA), have set guidelines for acute toxicity testing in daphnids that are severely lacking in terms of information on the characteristics of the exposure vessel when studying the adverse effects of nanoparticles (NPs). Understanding the toxicity mechanisms of nanomaterials is imperative given the scarcity of information on their adverse effects. Furthermore, miniaturization of nanotoxicity assays can reduce the number of daphnids used, as well as the cost and nanomaterial waste, and provide results even at the individual animal level with enhanced reproducibility of testing. In this study, the impact of the exposure vessel on the observed physiological changes of daphnids was investigated for a silver nano ink. Exposures in eleven commercially available vessels; nine made of plastic and two made of glass were compared for 24 h. The effect of surface to volume ratio of the exposure vessel and the animal number or "crowding" during exposure was investigated in the context of miniaturizing biomarker assays as alternatives to traditional experimental setups in Daphnid magna. Toxicity curves showed differences depending on the vessel used, while a novel feeding rate assay and the activity of key enzymes were assessed as physiology endpoints. [ABSTRACT FROM AUTHOR]

Feeding rates serve as a vital indicator for adjusting the working parameters of the combine harvester. A non-invasive diagnostic approach to predicting the feed rates of combine harvesters by collecting vibration signals of the inclined conveyor was introduced in this study. To establish a feed rate prediction model, the correlation between feeding rates and vibration signal characteristics was investigated. Vibration signal characteristics in both the time domain and frequency domain were also analyzed in detail. The RMS (root mean square) value and the total RMS value of the one-third octave extracted from the vibration signal were utilized to establish a feed rate prediction model, and field tests were conducted to verify the model performance. The experimental results indicated that the relative errors of the established model range from 3.1% to 4.9% when harvesting rice. With the developed feed rate prediction system, the control system of the combine harvester can acquire feed rate information in real time, and the working parameters can be adjusted in advance, thereby, it can be expected to greatly enhance the working performance of the combine harvesters. [ABSTRACT FROM AUTHOR]

Simple Summary: Although our knowledge of the interactions between the underground and aboveground communities of organisms is growing, little is known about the impact of soil predatory mites on aboveground communities of plants, herbivores and their natural enemies. Blattisocius mali is a polyphagous predatory mite that disperses on the bodies of drosophilid fruit flies, on which it feeds; after disembarkment, it also preys on their eggs. This mite is mostly associated with soil or litter, but it has also been found in fruit and seed storage sites and on plants. In our tests, the starved predatory females readily fed on various stages of the common herbivores two-spotted spider mite and western flower thrips as well as the fruit fly Drosophila hydei. The predator came from cultures fed on acarid mites, and its identity was validated molecularly. Although B. mali shows the potential to prey upon herbivorous insects and mites, to determine whether it can also effectively reduce their population densities, further studies, including tests on the predator's survival, fecundity and prey preference, are required. Research in recent years has shown that some species of predatory mites, considered to be typically associated with soil and litter, can also be found on plants. Such species include Blattisocius mali, which is an effective predator of acarid mites, nematodes and the eggs of moths and which can disperse by means of drosophilid fruit flies. Apart from soil and litter or storage, it has also been recorded on the bark of apple trees and the leaves of strawberries, thus suggesting its possible predation of/feeding on herbivorous mites and insects. Our goal was to examine whether B. mali could consume different development stages of two polyphagous herbivores, the two-spotted spider mite, Tetranychus urticae, and the western flower thrips, Frankliniella occidentalis, as well as the drosophilid fruit fly Drosophila hydei. In 24 h cage tests, single, starved B. mali females consumed all types of prey offered, i.e., the eggs, males and females of spider mites; the first-instar larvae and prepupae of thrips; and the eggs and first-instar larvae of fruit flies. The potential for B. mali to prey upon these insects and mites was confirmed. However, to estimate whether it can also effectively reduce their population, additional tests on the predator's survival, fecundity and prey preference are needed. [ABSTRACT FROM AUTHOR]

The Organization for Economic Co-operation and Development (OECD) has set widely used guidelines that are used as a standardized approach for assessing toxicity in a number of species. Given that various studies use different experimental setups, it is difficult to compare findings across them as a result of the lack of a universally used setup in nano-ecotoxicology. For freshwater species, Daphnia magna, a commonly used filter feeding crustacean, can generate significant molecular information in response to pollutant exposure. One factor that has an effect in toxicity induced from nanomaterials in daphnids is the surface-to-volume ratio of the exposure vessels; however, there is limited information available about its impact on the observed effect of exposure. In this study, daphnids were exposed to silver nanoparticle ink in falcon tubes and Petri dishes for 24 h. Toxicity curves revealed differences in the observed mortality of daphnids, with animals exposed in Petri dishes displaying significantly higher mortality. Differences in the activities of a number of key enzymes involved in the catabolism of macromolecules and phosphate were also observed across the exposure setups, indicating possible differences in the toxicity mechanism of silver nano-ink. Understanding the impact of factors relevant to experimental setups in ecotoxicology can increase the reproducibility of testing, and also reduce experimental costs, time, generated waste, and daphnids used in research. [ABSTRACT FROM AUTHOR]

Corn is a crucial crop and has a vital application value in many aspects of our lives. Mechanical grain harvesting is the developing direction of corn harvesting technology, with corn threshing as its most imperative procedure. The quality of the threshing device of the corn harvester has a major influence on its damage rate, loss rate, and other parameters. Therefore, it is of great significance to effectively lower the damage rate in the process of corn threshing. This review presents the research progress and the application status of corn threshing technology and corn threshing machinery. The conclusions and suggestions on low-damage corn threshing technology and corn threshing machinery are summarized to provide a reference for the reduction in the damage rate of mechanical grain harvesting and promote the development of mechanical grain harvesting technology. [ABSTRACT FROM AUTHOR]

For existing problems, such as the complex interactions between a crop and a machine, the measuring difficulty and the limited measurement precision of the feeding quantity within the corn silage harvester, a method of feeding rate measurement based on key conditions data, working data cleaning, and multiple variate regression is proposed. Non-destructive rotation speed, rotation torque, and power consumption sensors are designed for the key mechanical components. The data conditions, such as rotating speed, rotating torque, power consumption, hydraulic pressure, and hydraulic flow for the key operation of parts including cutting, feeding, shredding, and throwing are monitored and collected in real-time during field harvesting. The working data are screened and preprocessed, and the Mann-Kendall boundary extraction algorithm is applied, as is multiple component time lag correction analysis, and the Grubbs exception detection method. Based on a Pearson correlation analysis results, one-factor and multiple-factor regression models are respectively developed to achieve an accurate measurement of the corn feeding rate. The field validation tests show that the working data boundary extraction results among the load-stabilizing components such as shredding roller and throwing blower are highly reliable, with a correct rate of 100%. The power monitoring data of the shredding roller and throwing blowers are significantly correlated with the crop feeding rate, with a max correlation coefficient of 0.97. The determination coefficient of the single-factor feeding rate model based on the shredding roller reaches 0.94, and the maximum absolute error of the multi-factor feeding rate model is 0.58 kg/s. The maximum relative error is ±5.84%, providing technical and data support for the automatic measuring and intelligent tuning of the feeding quantity in a silage harvester. [ABSTRACT FROM AUTHOR]

Simple Summary: Sustainability in livestock production includes the use of strategies to reduce natural resource requirements. In this study, we investigated the relationship among feed efficiency, water efficiency, ingestive behavior, performance, and carcass traits in beef cattle. The results revealed interesting aspects of both feed efficiency and water efficiency on ingestive behavior and growth traits. The combined use of residual water intake and residual feed intake is an important option available for improving the environmental sustainability of beef cattle production that could be used in animal breeding programs. Feed and water efficiency are important traits to improve beef cattle production's economic and environmental sustainability. This study evaluated residual feed intake (RFI) and residual water intake (RWI) and their relationship with performance, ingestive behavior, and carcass traits in Caracu beef cattle. The data were analyzed using a generalized linear model with least squares means. The ingestive behavior, performance, and carcass traits were influenced by sex (p < 0.05). Males showed higher dry matter intake (DMI), average daily gain (ADG), mid-test metabolic weight (BW0.75), rib eye area, and rump fat thickness than females, besides spending more time drinking and eating. Low RFI animals exhibited higher DMI than high RFI animals. Low RWI animals ingested 3.89 L/d of water further than high RWI animals. The interaction between sex and RWI influenced the DMI, BW0.75, and backfat thickness. The ingestive behavior of low and high RFI animals was similar, although high RWI animals visited a smaller number of drinkers than low RWI animals. Water intake positively affects productive efficiency, and the combined use of RWI and RFI may help improve the selection of more efficient animals contributing to reducing the costs of beef cattle production and improving environmental sustainability. [ABSTRACT FROM AUTHOR]

This study aimed to determine the optimal live feed regime (i.e., initial feeding moment, density, and frequency) for maximum growth and survival of pangasius catfish (Pangasianodon hypophthalmus) early life history stages. The first experiment assessed the optimal initial feeding moment (30, 36, 42, and 48 h post hatching, hph). The second experiment assessed feeding density (3, 5, 8 and 11 individuals per mL, ind/mL) at the optimal initial feeding moment (30 hph) which was the best result from the first experiment. The third experiment assessed optimal feeding frequency (1, 2, 4, and 6 times per day) at the optimal initial feeding moment (30 hph) and density (8 ind/mL) which was drawn upon from the second experiment. All experiments were conducted in 20 L containers containing 20 hph P. hypophthalmus larvae at a density of 10 ind/L and fed rotifers (Brachionus angularis) for 3 days and then water fleas (Moina macrocopa) for 7 days. The first experiment demonstrated that larvae initially fed at 30 hph exhibited a significantly higher survival rate (24%) than larvae initially fed at 36, 42, and 48 hph (19%, 16%, and 16%), respectively. The second experiment demonstrated that larvae fed at 8 and 11 ind/mL densities exhibited significantly higher survival rates (32% and 32%) than larvae fed at 3 and 5 ind/mL densities (13% and 23%), respectively. The third experiment demonstrated that the highest survival rate (66%) was obtained when larvae were fed 6 times per day. These results provide valuable insights regarding the optimal live feed regime for better growth and survival of P. hypophthalmus larvae, which are commercially important and numerously cultured throughout the Mekong Delta region. [ABSTRACT FROM AUTHOR]

Laboratory-made particleboards were tested for their resistance to subterranean termite, Coptotermes curvignathus Holmgren (Order Isoptera, Family Termitidae) by Indonesian standard SNI 01.7207-2006, during four weeks and at the end of the test their mass loss percentage and feeding rate were determined. Particleboards consisted of: jabon (Anthocephalus cadamba, Family Rubiacea) with a density of 0.41 g/cm³; sungkai (Peronema canescens, Family Verbenaceae) with a density of 0.46 g/cm³; mangium (Acacia mangium, Family Rhamnaceae) with a density of 0.60 g/cm³ separately and the three species mixture at a rate of 1:1:1. Densities of the boards were targetted at 0.60 g/cm³ and 0.80 g/cm³ by using 12% urea formaldehyde as binder with 2% paraffin as additive based on oven dry wood particle weight. The hand-formed mats and hot-pressing at 130 °C and 2.45 MPa for 10 min were applied. The results showed that particleboards density did not affect mass loss and feeding rate, but the particleboards made from higher density wood resulted in higher resistance to subterranean termite attack. The most resistant particleboards were made of magium, followed by sungkai, mixed species, and jabon. [ABSTRACT FROM AUTHOR]

Bentho-pelagic life cycles are the dominant reproductive strategy in marine invertebrates, providing great dispersal ability, access to different resources, and the opportunity to settle in suitable habitats upon the trigger of environmental cues at key developmental moments. However, free-dispersing larvae can be highly sensitive to environmental changes. Among these, the magnitude and the occurrence of elevated carbon dioxide (CO2) concentrations in oceanic habitats is predicted to exacerbate over the next decades, particularly in coastal areas, reaching levels beyond those historically experienced by most marine organisms. Here, we aimed to determine the sensitivity to elevated pCO2 of successive life stages of a marine invertebrate species with a bentho-pelagic life cycle, exposed continuously during its early ontogeny, whilst providing in-depth insights on their metabolic responses. We selected, as an ideal study species, the American lobster Homarus americanus, and investigated life history traits, whole-organism physiology, and metabolomic fingerprints from larval stage I to juvenile stage V exposed to different pCO2 levels. Current and future ocean acidification scenarios were tested, as well as extreme high pCO2/low pH conditions that are predicted to occur in coastal benthic habitats and with leakages from underwater carbon capture storage (CCS) sites. Larvae demonstrated greater tolerance to elevated pCO2, showing no significant changes in survival, developmental time, morphology, and mineralisation, although they underwent intense metabolomic reprogramming. Conversely, juveniles showed the inverse pattern, with a reduction in survival and an increase in development time at the highest pCO2 levels tested, with no indication of metabolomic reprogramming. Metabolomic sensitivity to elevated pCO2 increased until metamorphosis (between larval and juvenile stages) and decreased afterward, suggesting this transition as a metabolic keystone for marine invertebrates with complex life cycles. [ABSTRACT FROM AUTHOR]

The effects of feeding rate (0.5%, 1.0%, 1.5%, 2.0%, 2.5%, and 3.0% body weight [BW] per day [BW day−1]) on the growth, body composition, and blood properties of juvenile mandarin fish, Siniperca scherzeri, (initial BW 18.4 ± 0.2 g) were investigated in a water recirculating aquaculture system. Triplicate groups of fish were fed an experimental diet (55.4% protein, 14.1% lipid) for 10 weeks. Weight gain and specific growth rate increased with increasing feeding rates of up to 2.5% BW day−1, after which no significant increase in growth was observed. Feed efficiency, protein efficiency ratio, and protein retention were not significantly different among the fish fed 1–2.5% BW day−1 but decreased significantly in those fed 3.0% BW day−1. The lipid content of fish fed 2.5% BW day−1 was significantly higher than that at 0.5–1.5% BW day−1. The total plasma cholesterol content was significantly lower in fish fed 0.5 BW day−1 than fish provided with other feeding rates. Based on the growth, feed efficiency, body composition, and blood content analyses, including regression analysis, the optimal feeding rate for juvenile S. scherzeri weighing between 18 g and 54 g was estimated at 1.88–2.80% BW day−1 depending on weight gain, specific growth rate, and feed efficiency under 26.9 °C conditions. [ABSTRACT FROM AUTHOR]

Pomacea canaliculata (known as invasive apple snail) is a freshwater snail native to South America that was introduced into many countries (including Asia and North America) as a food source or for organic farming systems. However, it has invaded freshwater ecosystems and become a serious agricultural pest in paddy fields. Water temperature is an important factor determining behavior and successful establishment in new areas. We examined the behavioral responses of P. canaliculata with water temperature changes from 25 °C to 30 °C, 20 °C, and 15 °C by quantifying changes in nine behaviors. At the acclimated temperature (25 °C), the mobility of P. canaliculata was low during the day, but high at night. Clinging behavior increased as the water temperature decreased from 25 °C to 20 °C or 15 °C. Conversely, ventilation and food consumption increased when the water temperature increased from 25 °C to 30 °C. A self-organizing map (an unsupervised artificial neural network) was used to classify the behavioral patterns into seven clusters at different water temperatures. These results suggest that the activity levels or certain behaviors of P. canaliculata vary with the water temperature conditions. Understanding the thermal biology of P. canaliculata may be crucial for managing this invasive snail. [ABSTRACT FROM AUTHOR]

The present study aims to use behavioral responses of the freshwater planarian Girardia tigrina to assess the impact of anthropogenic activities on the aquatic ecosystem of the watershed Araguaia-Tocantins (Tocantins, Brazil). Behavioral responses are integrative and cumulative tools that reflect changes in energy allocation in organisms. Thus, feeding rate and locomotion velocity (pLMV) were determined to assess the effects induced by the laboratory exposure of adult planarians to water samples collected in the region of Tocantins-Araguaia, identifying the sampling points affected by contaminants. Furthermore, physicochemical and microbiological parameters, as well as the presence of inorganic compounds (dissolved aluminum, total barium, total chloride, dissolved iron, total fluoride, total manganese, nitrates, nitric nitrogen, total sulfate, total zinc) and surfactants, were determined on each specific sampling point. The behavioral biomarkers (feeding rate and pLMV) of the freshwater planarians were significantly decreased when organisms were exposed to water samples from four municipalities (Formoso do Araguaia, Lagoa da Confusão, Gurupi and Porto Nacional), sites of the Tocantins-Araguaia hydrographic region—TAHR. Both behavioral biomarkers decreased up to ~37–39% compared to organisms in ASTM medium only. Our results showed that these behavioral biomarkers can be used for fast screening monitoring of environmental samples of freshwater ecosystems, since a decrease in feeding rate and locomotor activity was observed in sites impacted by anthropogenic activities. However, the absence of effects observed in some sampling points does not represent the absence of contamination, since several other classes of contaminants were not determined. In these negative results, the absence of deleterious effects on behavioral biomarkers might only be indicative that the potential presence of contaminants on such sites does not significantly affect the performance of planarians. This fast screening approach seems to be useful to determine contaminated sites in freshwater ecosystems for biomonitoring purposes. This knowledge will help to develop biomonitoring programs and to decide appropriate sampling sites and analysis. [ABSTRACT FROM AUTHOR]

Simple Summary: Changes in environmental conditions cause animals to adjust their behavioral strategies to survive. We investigated foraging behavior in different habitats of wintering Bewick's swans. We found that the observed feeding rate was not affected by food density but showed a negative relationship with flock size and disturbance time. Handling time had a negative relationship with food density and flock size, but a positive relationship with disturbance. Searching rate was negatively correlated with food density, flock size, and disturbance time. This provides insight into how wintering waterbirds adapt their foraging behavior in complex environments. Perceiving how animals adjust their feeding rate under a variety of environmental conditions and understanding the tradeoffs in their foraging strategies are necessary for conservation. The Holling functional response, which describes the relationship of feeding rate and food density to searching rate and handling time, has been applied to a range of waterbirds, especially with regard to Type II functional responses that describe an increasing feeding rate with food density but at a decelerating rate as the curve approaches the asymptote. However, feeding behavior components (feeding rate, searching rate, and handling time) are influenced by factors besides prey density, such as vigilance and flock size. In this study, we aim to elucidate how Bewick's swans (Cygnus columbianus bewickii) adopt flexible foraging strategies and vary their feeding behavior components in response to disturbance, flock size, and food density. We collected focal sampling data on the foraging behavior of swans that foraged rice grains, foxnut seeds, and tubers in paddy field, foxnut pond, and lake habitats, respectively, in Shengjin and Huangpi lakes during winter from 2016 to 2018. The observed feeding rate was not correlated with food density and displayed a positive relationship with searching rate but negative relationships with handling time, flock size, overall vigilance time, and disturbance time. Handling time was negatively correlated with food density and flock size, yet it increased with disturbance, overall vigilance time, and normal vigilance time. Searching rate was negatively correlated with food density, flock size, and disturbance time. Feeding rate was affected by the combined effects of handling time and searching rate, as well as food density and searching rate. The shape of the observed functional response could not be fitted to Holling's disc equation. However, the disc equation of the predicted feeding rate of wintering swans was found to be driven by food density. This provides insight into how wintering waterbirds adopt appropriate foraging strategies in response to complicated environmental factors, which has implications for wildlife conservation and habitat management. [ABSTRACT FROM AUTHOR]