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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]

The study aimed to investigate the effects of different feeding rates on the growth, muscle composition, intestinal digestive enzyme activities, and intestinal microbiota composition of juvenile crayfish (Procambarus clarkii). A total of 240 crayfish with an initial body weight of 8.33±0.50 g were randomly distributed into five groups, and each group had three replicates. The five groups corresponded to five different feeding rates of 2%, 4%, 6%, 8%, and 10% body weight per day (BW/day). The feeding trial lasted for six weeks. The results showed that the final body weight (FBW), weight gain rate (WGR), and specific growth rate (SGR) first increased when the feed rate increased from 2% to 6 % (P<0.05) and then showed a decreased trend with the further increase of the feeding rate, but no significant differences were observed. The feed conversion ratio (FCR) increased with a rise in feeding rate, which reached a peak at the feeding rate of 10% (P<0.05). The survival rate (SR), hepatosomatic index (HSI), and condition factor (CF) were unaffected by the feeding rates (P>0.05). The moisture, crude protein, crude fat, and ash contents of crayfish muscle remained unchanged among all feeding rate groups. Intestinal activities of lipase and amylase increase with the feeding rate (up to 6%) increasing (P<0.05). The ACE and Chao indices in the groups fed at 2% of feeding rate were significantly lower than those at a feeding rate of 10% (P<0.05). The relative abundance of Firmicutes in the groups fed at feeding rates of 4%, 6%, and 8% was higher than that in other groups (P<0.05), Citrobacter in the group fed at feeding rate of 6% was lower than that in different groups (P<0.05). The intestinal microbiota primarily functions in connection to amino acid, carbohydrate, and vitamin metabolism. Therefore, the optimum feeding rate could be 6.0% of the feeding rate of juvenile P. clarkii. [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]

Feeding rates (intake of both dry matter and fresh matter) by 79 species of mammals, 95 species of birds and 55 species of reptiles were estimated from doubly labeled water-based measurements of field metabolic rate on each species (Table 1). Allometric (scaling) regression analyses of log10-transformed feeding rates vs. body mass yielded statistically significant relationships for 90 different taxonomic, dietary and habitat groupings of species. The resulting exponential equations can be used to predict the daily food requirements needed to maintain energy balance for free-living mammals (Table 2), birds (Table 3), and reptiles (Table 4) with an average error of about 5% to 60%, depending on the group. The ability to predict feeding rates of terrestrial vertebrates should be useful to zoo keepers, animal nutritionists, veterinarians, pet hobbyists, wildlife zoologists, game managers, range biologists, preserve directors and planners, conservationists, paleontologists and ecosystem modelers. These equations should underestimate somewhat the feeding rates of free-living animals that are growing, reproducing or storing up fat. The equations probably overestimate the feeding rates of captive wild animals (e.g. in zoos) and of free-ranging animals during some phases of their lives when they either do not or cannot feed normally.

In many animal species, including most birds, parental care is performed by both parents, which has important implications for mate choice (good parent hypothesis) and parental investment strategies. Partitioning the variance in measures of parental care into heritable and nonheritable components is important to understand the evolvability of parental investment and its potential role in mate choice. We employed an automated system to monitor provisioning behavior at 817 blue tit nests over 10 years (totaling ~3 million visits). Daily provisioning rates of males and females were moderately repeatable between years (Radj = 0.16 and 0.15, respectively), which was almost entirely explained by additive genetic effects. While this degree of heritability is sufficient for parental investment to respond to selection, we argue that the modest level of repeatability provides limited potential for a "provisioning phenotype" to be used as a criterion in mate choice. Daily visit rates were positively correlated between pair members, but after accounting for shared environmental factors, this relationship became clearly negative, thereby providing support for models of partial compensation. Visit rates also differed substantially between years, and between days within a year. Thus, it is important to account for these variables when comparing the parental investment between individuals. Our results highlight the interplay between genetic, social, and environmental influences on provisioning behavior. [ABSTRACT FROM AUTHOR]

Traditional approaches for monitoring aquatic pollution primarily rely on chemical analysis and the detection of pollutants in the aqueous environments. However, these methods lack realism and mechanistic insight and, thus, are increasingly supported by effect‐based methods, which offer sensitive endpoints. In this context, daphnids, a freshwater species used extensively in molecular ecotoxicology, offer fast and noninvasive approaches to assess the impact of pollutants. Among the phenotypic endpoints used, feeding rate is a highly sensitive approach because it provides evidence of physiological alterations even in sublethal concentrations. However, there has been no standardized method for measuring feeding rate in daphnids, and several approaches follow different protocols. There is a diversity among tests employing large volumes, extensive incubation times, and high animal densities, which in turn utilize measurements of algae via fluorescence, radiolabeling, or counting ingested cells. These tests are challenging and laborious and sometimes require cumbersome instrumentation. In the present study, we optimized the conditions of a miniaturized fast, sensitive, and high‐throughput assay to assess the feeding rate based on the ingestion of fluorescent microparticles. The protocol was optimized in neonates in relation to the concentration of microplastic and the number of animals to increase reproducibility. Daphnids, following exposures to nonlethal concentrations, were incubated with microplastics; and, as filter feeders, they ingest microparticles. The new approach revealed differences in the physiology of daphnids in concentrations below the toxicity limits for a range of pollutants of different modes of action, thus proving feeding to be a more sensitive and noninvasive endpoint in pollution assessment. Environ Toxicol Chem 2024;43:2211–2221. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

The razor clam (Sinonovacula constricta, Class Bivalvia) is a kind of burial filter-feeding shellfish. Salinity fluctuation is an important source of pressure for water habitats. High salinity in some coastal areas of Shandong and Jiangsu impact the survival and germplasm conservation of razor clam. To study the ecological behavior response of S. constricta to high salt culture environment, two populations of razor clams were used, including "Shenzhe No.1" population (SZSC) and a natural population (ZRSC). The semi-lethal salinity level of each population was determined. The effects of control group (20) and high salinity (24, 28, 32) on burrowing and feeding behavior of razor clams were studied. The differences in burrowing indices and feeding physiology between the two populations were compared. In the burrowing behavior experiment, two groups were set; razor clams from the temporary pond were put into each salinity group to start the experiment, while the other group of razor clams were stressed under each salinity condition for 24 h and then put into each salinity group to start the experiment. The results showed that the 120 h LC50 of SZSC was 34.04, while the 120 h LC50 of ZRSC was 32.04. The burrowing behavior of razor clams could be divided into four periods: The preparation period of shell closure, the period of axe foot movement, mud digging period, and the end period of mud diving. In the non-stressed group, the burrowing time of 50% (BT50) of SZSC was significantly higher than that of ZRSC (P0.05). The BT50 of SZSC was closer to that of the control group at 24 and 28 salinity, and the vitality of SZSC was significantly better than that of ZRSC after 24 h of salinity stress. Under high salinity, the distribution of SZSC in mud was more concentrated than that in ZRSC, and the burrowing depth was shallower. In terms of feeding physiology, the feeding rate of SZSC was significantly higher than that of ZRSC under high salinity (P

Feeding rate is an important factor influencing the carbon and nitrogen input and greenhouse gas emission from aquaculture systems. However, the quantitative relationship between feeding rates and GHG emissions is still poorly understood. In this study, we conducted a laboratory-scale experiment to examine the impact of feeding rate (0%, 2%, 4%, 6%, and 8%) on the CH4 and N2O emissions from a pond rice-fish co-culture system. The results showed that the total amount of CH4 emission did not significantly differ when the feeding rate was no more than 6%, but increased more than four times when the feeding rate reach to 8%. The amount of N2O emission showed a linearly increasing trend with the feeding rate. The emission factors of CH4 and N2O was significantly higher for 8% feeding rate than other feeding rates. The variation of CH4 emission was primarily attributed to the ratio of mcrA/pmoA in the sediment and the contents of biological oxygen demand (COD) and dissolved oxygen (DO) in the water; and the variation of N2O was primarily affected by the available nitrogen in the water and sediment and the content of DO in the water. The overall emission of CH4 and N2O showed an exponential relationship with feeding rate. The total yields of fish and rice did not continuously increase when the feeding rate exceeded 4%. The lowest emission intensity per unit yield was reached at the feeding rate of 2.99%. These results can provide a reference for the determination of low-carbon feeding strategy for pond rice-fish co-culture system. [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]

A 10-week feeding trial was conducted to evaluate the effects of different feeding rates on growth performance, nutrient deposition, plasma metabolite, and immunity of juvenile starry flounder. Fish (initial mean body weight, 183.6 ± 2.3 g) were subjected to eight feeding rates (0.4, 0.8, 1.2, 1.6, 2.0, 2.4, 2.8, and 3.2% body weight/day [BW/d]) with a commercial diet containing 53.5% crude protein and 10.2% crude lipid. After the feeding trial, fish growth increased significantly (p < 0.05) from 0.4% to 2.0% BW/d, with no significant differences being observed beyond 2.0% BW/d. Protein and lipid gains in the whole body and liver of the fish fed 2.0–3.2% BW/d were significantly (p < 0.05) higher than those of the fish fed 0.4% and 0.8% BW/d. Conversely, protein retention in the whole body and the liver decreased with an increased feeding rate. Lysozyme activity was significantly (p < 0.05) higher in the fish fed 1.6–2.8% BW/d than in those fed 0.4–1.2% BW/d. The best-fit model analyses for optimum feeding rate (OFR) revealed that the estimate for each parameter varied between 0.7% (feed conversion ratio) and 3.1% (lipid gain in carcass) BW/d. The OFR for productivity (weight gain) and enhanced innate immunity (lysozyme) were estimated at 2.4% and 1.7% BW/d, respectively.

Rapana venosa is primarily distributed in the Yellow Sea and Bohai Sea of China, Japan, Korea, and Russia. In the natural sea area, the adult R. Venosa mostly inhabits the sand-mud bottom or the rocky bottom of the low intertidal zone up to 20 meters deep, and the young R. Venosa mostly inhabits the rocks near the coastal line. Its habitats are generally occupied by many other bivalves, such as Crassostrea gigas, Mactra chinensis, and Ruditapes philippinarum. The R. venosa is a large carnivorous Mollusca that mainly feeds on bivalves and other animal carcasses. R. venosa is often classified as an enemy of bivalve farming, but they can also be used to control fouling organisms, and it has potential for application in aquaculture and ocean engineering.In recent years, there have been some reports on the feeding selectivity of R. venosa, the effects of feed, temperature, and individual specifications on feeding, the effects of feed types, specifications, feeding amount, and breeding density on the survival and growth, the feeding preferences to different bivalves and the feeding cycle before and after reproduction. These studies mainly explored the effects of temperature, density, feed types, and specifications on its growth and development. The main purpose of these studies was to select suitable feed types and specifications for the temporary culture and breeding of R. venosa, to improve its growth and development speed, and increase economic benefits under artificial breeding conditions. However, the feeding selection and behavior process of R. venosa under natural conditions are not clear, and the feeding selection of R. venosa to C. gigas, Mytilus edulis and other fouling organisms was not clear under the environmental conditions of multiple bait bivalve habitats. Therefore, in this study, four kinds of bivalves (fixed type, attached type and buried type) were used as bait bivalves to understand the feeding selection. C. gigas and M. edulis are common fouling organisms in the habitat of R. venosa, while M. veneriformis and R. philippinarum are widely distributed in the habitat of R. venosa. The study attempts to simulate the habitat of R. venosa and different types of bait bivalves in the natural environment, to study its preference for bait bivalves species and feeding specifications, to compare and analyze the differences in feeding rates of different specifications of R. venosa, and further study its feeding rhythm and feeding process and to provide data reference for the feasibility of using R. venosa to control C. gigas, M. edulis and other bivalves fouling organisms, and improve the feeding habits of R. venosa.To achieve these objectives, three specifications of M. veneriformis, R. philippinarum, C. gigas, and M. edulis live baits were placed in the aquarium by simulating the natural environment. The feeding number, feeding weight, feeding specifications, feeding time, and feeding behavior process of three specifications of R. venosa to different baits were recorded. The experimental results showed that R. venosa fed on all four bivalves. The number and weight of R. venosa that fed on M. veneriformis with different specifications were significantly higher than those that fed on other bivalves (P < 0.05), and the feeding index was more than 50%, indicating its appetite. R. venosa fed normally on C. gigas and R. philippinarum, and only a small population of R. venosa fed on M. edulis with large specifications. In terms of the selection of feeding specifications, three specifications of R. venosa preferred large M. veneriformis and small C. gigas (P < 0.05). The feeding rate of the large specification R. venosa was 7.15%, which was significantly lower than that of the other two specifications (small specification, 10.98%; medium specification, 9.64%). Under the experimental conditions, the feeding cycle of R. venosa was apparent, feeding activities were carried out every three days, and the feeding time was 20:00–24:00 at night. The feeding process can be divided into four stages: Unfed stage, search stage, feeding stage, and feeding end. During the feeding process, the R. venosa actively searched for bivalves, removed them from the sand and wrapped them with their proleg, secreted mucus, and smacked them from the shell gap. After sucking the mollusks decomposed by digestive juice, the R. venosa dived into the sand or attached to the aquarium wall. The results showed that under the experimental conditions, R. venosa had a feeding preference for the species and specifications of bait bivalves. R. venosa preferred to eat M. veneriformis and rarely consumed M. edulis. Moreover, its feeding behavior was nocturnal and exhibited periodicity, feeding activity happened every three days in the first half of the night.

The flood disaster in the coastal area of Pekalongan City resulted in stagnant water, thus impacting the community's livelihoods previously. The adaptation that has been made to deal with these conditions is by cultivating saline tilapia. Feed is the most important factor in supporting the growth of saline tilapia production. However, research on feed quality and frequency that has been carried out for tilapia production has not been optimal in obtaining the results obtained. This study aims to determine the effect of different feeding rates on growth performance, feed utilization, and survival rate of tilapia reared in stagnant brackish water. The study consisted of feeding rates of 3%, 5%, 7%, and 9% with three replications, and parameters were observed every seven days. Based on the research results it is known that the optimal feeding rate in saline tilapia culture ranges from 6.67% - 7% based on growth parameters. Although the other parameters do not show the same feeding rate as the growth parameter, these parameters are still in a good range for saline tilapia culture. [ABSTRACT FROM AUTHOR]

• Larval density, substrate depth and feed dose affect bioconversion performance. • High depth can lead to lower survival but can be compensated by feed dose. • Bioconversion efficiency can be improved by balancing these factors. Inadequate organic waste management have detrimental impact on the environment and on public health. Black soldier fly (BSF) larvae composting is a biological treatment for biodegradable waste that align with circular economy principles. The bioconversion efficiency of bio-waste into larval biomass is influenced by various factors, such as substrate type and the process parameters employed in the larval rearing process. In this study, the influence of these parameters on survival, material reduction (Mat.Red), waste-to-biomass conversion efficiency (BCE) and larval yield per rearing unit was investigated through two sets of experiments. In Experiment 1, the impact of larval density in five distinct rearing substrates was evaluated, while the effect of larval feed dose and substrate depth was assessed in Experiment 2, using a model substrate (dog food). In Experiment 1 it was found that higher larval density lead to an increase in BCE and larval yield, up to a threshold (around 6.25 larvae cm−2). Surpassing this threshold led to the production of smaller larvae, while the yield remained relatively consistent. In Experiment 2 it was found that supplying the substrate in a shallow layer (1–1.5 cm depth) and providing a low feed dose (0.1 g volatile solids (VS) larva–1) led to higher BCE and Mat.Red, albeit with a reduced overall yield per unit. Increasing feed load and substrate depth reduced the conversion efficiency, Mat.Red and larval survival. This study enhances the understanding of the effect of various process parameters used in the BSF larvae treatment, and how they interrelate. [ABSTRACT FROM AUTHOR]

Feeding rates (intake of both dry matter and fresh matter) by 79 species of mammals, 95 species of birds and 55 species of reptiles were estimated from doubly labeled water-based measurements of field metabolic rate on each species (Table 1). Allometric (scaling) regression analyses of log10-transformed feeding rates vs. body mass yielded statistically significant relationships for 90 different taxonomic, dietary and habitat groupings of species. The resulting exponential equations can be used to predict the daily food requirements needed to maintain energy balance for free-living mammals (Table 2), birds (Table 3), and reptiles (Table 4) with an average error of about 5% to 60%, depending on the group. The ability to predict feeding rates of terrestrial vertebrates should be useful to zoo keepers, animal nutritionists, veterinarians, pet hobbyists, wildlife zoologists, game managers, range biologists, preserve directors and planners, conservationists, paleontologists and ecosystem modelers. These equations should underestimate somewhat the feeding rates of free-living animals that are growing, reproducing or storing up fat. The equations probably overestimate the feeding rates of captive wild animals (e.g. in zoos) and of free-ranging animals during some phases of their lives when they either do not or cannot feed normally.

Aim of study: To investigate the influence of environmental conditions and feed forms on productivity and feeding behavior of growing-finishing pigs. Area of study: Farm located in the North-East of Spain (42°03'11.0"N 2°06'59.5"E). Material and methods: Two trials were conducted (n = 72 pigs each). In the Hot-Temperate/Pelleted trial (HT-P), pigs were half the time under hot conditions (average temperature Ta=28.1℃) and half the time under thermoneutral conditions (Ta=25.5℃) and were fed in pellet. In the Temperate-Hot/Mash trial (TH-M), pigs were half the time under thermoneutral conditions (Ta=23.5℃) and half the time under hot conditions (Ta=27.3℃) and were fed in mash. Productivity and feeding behavior were registered. Main results: Hot conditions during the finishing period in TH-M trial reduced by 118 g/d growth rate and increased feed conversion ratio (2.28 vs. 2.07 kg/kg) compared to HT-P trial (p < 0.001) due to feed intake reduction. Growing pigs under hot conditions and fed in pellet increased total feeder visits (12.8 vs. 7.9 visits/d) and reduced visit size (147 vs. 230 g/visit, p < 0.001); whereas finishing pigs under hot conditions and fed in mash only tended to reduce visit size (308 vs. 332 g/visit, p = 0.08). Pigs fed with mash ate slower (22.8 vs. 34.8 g/min) than pelleted-fed pigs (p < 0.001), independently of environmental conditions. Research highlights: Feed form and environmental conditions affect both feeding behavior and performance of growing-finishing pigs. Unfortunately, due to a design weakness, it was not possible to obtain the sharp effect of both factors.

Ionic liquids have been described as green solvents, however, their presence in the aquatic environment may indicate a threat for key species. Focusing on the freshwater ecosystem, five ionic liquids containing the 1‑butyl‑3-methylimidazolium (BMIM) cation were compared for their acute toxicity and chronic responses on daphnids. Biochemical markers of physiology including the activity of phosphatases, β-galactosidase, peptidase, lipase and glutathione-S-transferase were used to assess changes in physiology of daphnids. Feeding and reproduction were investigated as surrogate phenotypic measures. Feeding rate was decreased in all exposures, and severely impacted in BMIM hexafluorophosphate, chloride, and tetrafluoroborate, while reproduction was unaffected by all ionic liquids. A diverse set of responses were triggered from each BMIM ionic liquid in reference to enzyme activities providing insight for the toxicity impact of these emerging contaminants. Phosphatase activities were significantly decreased in all exposure scenarios to ionic liquids, but different patterns of biochemical responses were documented among acute and chronic exposures and different ionic liquids, indicating distinct mechanistic patterns. The aforementioned results highlight the toxic potential of ionic liquids which are characterised so far as green solvents.

The current experiment was conducted in earthen ponds at the Agricultural Research Station belonging to the Aquaculture Unit- Agriculture College at Basrah University, Al-Hartha District about 16 km northern-east of Basrah Governorate (30o39`20.264"N, 47o 44`51.533"E) from 25th July to 23rd October 2021. The feeding experiment begin after ten days of fish acclimation. Six small earthen ponds (600 m2) were used for the current experiment to investigate the differences in growth criteria for 200 individuals of common carp fed (2 T1, 3 T2 and 4 T3) % of total fish weight. Fishes were fed daily on commercial pellets manufactured by Agricultural Consultant Office belonging to Agriculture College. The total length and weight of fish were measured at the beginning and the end of the experiment, while subsamples of fish were weighed periodically and daily food changed after each weighing. Initial fish weights were 530.0± 132.7, 513.4±118.3 and 477.3±122.5 for T1, T2 and T3 respectively. Daily feed was divided into three meals, the first given early in the morning, the second at mid-day and the third given in the afternoon. Results of current experiments showed a high growth rate (FW= 1341.4 g, WI= 873.0 g, DGR=9.59 g/day and SGR=1.16 %/day) for fish fed on 4% feeding ratio compared with the two feeding ratios. Feed conversion rates were 2.46, 4.01 and 3.28 for T1, T2 and T3 respectively. Statistical analysis showed that there were no significant differences (P>0.05) between values of b with value 3 (Isometric pattern of growth) of common carp before and after the experiment. Statistical analysis of three models for condition factor proved that there were significant differences (P≤0.05) between the values before the experiment with values after the experiment, while there were no significant differences (P>0.05) after the experiment between different condition factors for common carp reared on different feeding ratio.

To improve the declining performance of a full-feed peanut picking device or solve the mechanical failures that occur due to fluctuations in the feeding rate during operation, the 4HLJI-3000 peanut intelligent picking combine harvester, which is a picking device with a self-adaptive adjustment of the working clearance, was developed as the research object in this study. Moreover, the key components, such as the picking roller, concave plate sieve and clearance adjustment mechanism of the concave plate sieve, were designed and analysed. Through the force analysis of the concave plate sieve of the picking device, the mathematical model of the concave plate sieve displacement of the picking device and feeding rate was obtained. The software system for monitoring, storing and analysing the concave plate sieve displacement of the picking device based on EasyBuilder Pro was designed, and the road monitoring test of displacement variation of concave plate sieve of the picking device and feeding rate was carried out. The linear function, power function, exponential function, quadratic function, compound function, logarithmic function and cubic function fitting were used to perform regression analysis of the test results by using IBM SPSS software. The results showed that the cubic function model had a higher fitting precision, and its determination coefficient was 0.992. Model verification experiments were proposed, and the results showed that the established cubic function model had a good accuracy. The absolute deviation rate ranged from 0 to 4.83%, and the average deviation rate was 2.22%. The deviation rate increased with an increasing feeding rate. The field experiments also proved that there was a cubic function relationship between the feeding rate and concave plate sieve displacement, the measured concave plate sieve displacement deviation rate ranged from 0 to 6.19%, and the average deviation rate was 2.73% compared with the calculated results. This study can provide a reference for the optimization design of the structure of full-feeding picking devices for peanuts and other crops and the intelligent measurement and control of the feeding rates. [ABSTRACT FROM AUTHOR]

When evaluating avian reproduction, life history theory examines the trade‐offs between parental effort, the number and size of offspring, and the rate of nestling development. The growth rates and body sizes of developing birds vary geographically and can diverge with both latitude and migratory strategy. In terms of offspring size, growth rate can deviate in nestlings of the same or similar species due to the correlated influences of weather events, predation pressure, food availability, number of nestmates and parental provisioning. Furthermore, a longer photoperiod for species nesting at higher latitudes increases the duration over which a nestling can be fed each day, and increased nestling provisioning has been positively correlated with growth rate. Whether the amount of time a bird is fed during development drives this variation in growth rate and morphology is unknown. By removing supplemental environmental stressors (e.g. weather, predation) and standardizing feeding rate and environment, we explored the influence of daily duration of nestling provisioning on dark‐eyed junco Junco hyemalis nestlings. We hand‐reared 65 chicks of a sedentary junco subspecies J. h. carolinensis under both their natural photoperiod and the longer photoperiod of a closely related migratory subspecies J. h. hyemalis and compared growth rate, mass, morphology and the amount of food consumed. Average growth rate, fasted mass, wing length and total daily food consumption were all greater in birds hand‐reared under the longer, more northern photoperiod treatment. These findings suggest that increased daily photoperiod at higher latitudes may allow for greater total food provisioning and thus may play a role in the ability of parents in compressed breeding seasons to produce high quality offspring. This points to a trade‐off between provisioning effort and nestling growth rate in lower latitude (shorter photoperiod) populations and points to an important role of developmental plasticity on growth rate and morphology. [ABSTRACT FROM AUTHOR]

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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]

Parasites are known to mediate trophic interactions and can, for example, modify how consumers acquire resources. These modifications of host feeding behaviour can be imposed through three interconnected mechanisms affecting: 1) host food acquisition, 2) host food digestion or 3) host energy budgets. As a result, infected hosts may consume more, less or the same amount of food compared to their uninfected conspecifics. It is commonly assumed that infected hosts have lower consumption rates than uninfected hosts, but a comprehensive quantitative synthesis investigating the effects of parasites on host consumption rate has been lacking thus far. To fill this knowledge gap, we systematically searched for experimental studies that evaluated changes in consumption rate of infected vs uninfected hosts. In total, we extracted 158 effect sizes from 68 studies. We then performed meta‐analyses of mean differences in host consumption rates and their variation. The analyses were carried out for all taxonomic groups as well as separately for vertebrate and invertebrate hosts. The main‐effects meta‐analyses confirmed a generally negative effect of parasites on host consumption rates; infected hosts consumed on average 25% less food than their uninfected conspecifics. In addition, there was a significant increase in the variability in host consumption rate, on average by 25%, indicating that parasites can have variable effects on the foraging behaviour of their hosts. The meta‐regression models revealed that several moderator variables related to host and parasite characteristics influence host consumption rate. Experimental infection had a stronger influence on variance effects than natural infection. Parasitic infections reduced consumption rate of vertebrate hosts by 28% and thus more strongly than those of invertebrates, which were reduced by 22%. We conclude with recommendations to facilitate future ecological research syntheses on host–parasite interactions and beyond. [ABSTRACT FROM AUTHOR]

The current experiment was conducted in earthen ponds at the Agricultural Research Station belonging to the Aquaculture Unit- Agriculture College at Basrah University, Al-Hartha District about 16 km northern-east of Basrah Governorate (30°39`20.264"N, 47° 44`51.533"E) from 25th July to 23rd October 2021. The feeding experiment begin after ten days of fish acclimation. Six small earthen ponds (600 m²) were used for the current experiment to investigate the differences in growth criteria for 200 individuals of common carp fed (2 T1, 3 T2 and 4 T3) % of total fish weight. Fishes were fed daily on commercial pellets manufactured by Agricultural Consultant Office belonging to Agriculture College. The total length and weight of fish were measured at the beginning and the end of the experiment, while subsamples of fish were weighed periodically and daily food changed after each weighing. Initial fish weights were 530.0± 132.7, 513.4±118.3 and 477.3±122.5 for T1, T2 and T3 respectively. Daily feed was divided into three meals, the first given early in the morning, the second at mid-day and the third given in the afternoon. Results of current experiments showed a high growth rate (FW= 1341.4 g, WI= 873.0 g, DGR=9.59 g/day and SGR=1.16 %/day) for fish fed on 4% feeding ratio compared with the two feeding ratios. Feed conversion rates were 2.46, 4.01 and 3.28 for T1, T2 and T3 respectively. Statistical analysis showed that there were no significant differences (P>0.05) between values of b with value 3 (Isometric pattern of growth) of common carp before and after the experiment. Statistical analysis of three models for condition factor proved that there were significant differences (P≤0.05) between the values before the experiment with values after the experiment, while there were no significant differences (P>0.05) after the experiment between different condition factors for common carp reared on different feeding ratio. [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]

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: Residual feed intake (RFI) is commonly used to measure feed efficiency but individual intake recording systems are needed. Feeding behavior may be used as an indicator trait for feed efficiency using less expensive precision livestock farming technologies. Our goal was to estimate genetic parameters for feeding behavior and the genetic correlations with feed efficiency in Holstein cows. Data consisted of 75,877 daily feeding behavior records of 1,328 mid-lactation Holstein cows in 31 experiments conducted from 2009 to 2020 with an automated intake recording system. Feeding behavior traits included number of feeder visits per day, number of meals per day, duration of each feeder visit, duration of each meal, total duration of feeder visits, intake per visit, intake per meal [kg of dry matter (DM)], feeding rate per visit, and feeding rate per meal (kg of DM per min). The meal criterion was estimated as 26.4 min, which means that any pair of feeder visits separated by less than 26.4 min were considered part of the same meal. The statistical model included lactation and days in milk as fixed effects, and experiment-treatment, animal, and permanent environment as random effects. Genetic parameters for feeding behavior traits were estimated using daily records and weekly averages. Estimates of heritability for daily feeding behavior traits ranged from 0.09 ± 0.02 (number of meals; mean ± standard error) to 0.23 ± 0.03 (feeding rate per meal), with repeatability estimates ranging from 0.23 ± 0.01 (number of meals) to 0.52 ± 0.02 (number of feeder visits). Estimates of heritability for weekly averages of feeding behavior traits ranged from 0.19 ± 0.04 (number of meals) to 0.32 ± 0.04 (feeding rate per visit), with repeatability estimates ranging from 0.46 ± 0.02 (duration of each meal) to 0.62 ± 0.02 (feeding rate per visit and per meal). Most of the feeding behavior measures were strongly genetically correlated, showing that with more visits or meals per day, cows spend less time in each feeder visit or meal with lower intake per visit or meal. Weekly averages for feeding behavior traits were analyzed jointly with RFI and its components. Number of meals was genetically correlated with milk energy (0.48), metabolic body weight (−0.27), and RFI (0.19). Duration of each feeder visit and meal were genetically correlated with milk energy (0.43 and 0.44, respectively). Total duration of feeder visits per day was genetically correlated with DM intake (0.29), milk energy (0.62), metabolic body weight (−0.37), and RFI (0.20). Intake per visit and meal were genetically correlated with DM intake (0.63 and 0.87), milk energy (0.47 and 0.69), metabolic body weight (0.47 and 0.68), and RFI (0.31 and 0.65). Feeding rate was genetically correlated with DM intake (0.69), metabolic body weight (0.67), RFI (0.47), and milk energy (0.21). We conclude that measures of feeding behavior could be useful indicators of dairy cow feed efficiency, and individual cows that eat at a slower rate may be more feed efficient.

The effect of a machine feeding rate (FR; 1, 1.5 and 2 Mg/h) and/or three levels of selected fineness degree (FD; 3, 5 and 7 mm) on machine performance, pellet physical parameters, required energy and production cost of three main types of broilers diets were examined in this experiment. The examined broiler diets were formulated to meet the Ross 308 strain requirements. A complete factorial design (3x3x3) was used to identify the effects of studied factors on the pellet mill machine and pellet production. The obtained results indicated that the pellet mill productivity significantly (p<0.001) improved through increased pellet mill feeding rate level. In addition, the machine pelleting efficiency was found to be significantly affected by all studied variables and their interactions. While the total power consumption of the machine showed no variations under the impact of the tested factors or with any of their combinations. Regarding the pellet physical quality indices, all broiler diets with all selected FD and lower FR had the maximum durability and bulk density levels. Furthermore, lower feeding rates were associated with higher hardness degrees. The lowest production costs were substantially correlated with high FR and intermediate FD (5 mm). Furthermore, production costs were determined to be reduced in finisher broiler diets under different feeding rates. Moreover, manufacturing costs of finisher broiler meals were observed to decrease in several feeding rates. Overall, these findings indicate the capabilities of producing high-quality pellets and reducing the needed production costs by optimizing feeding rates to 2 Mg/h and 2 mm fineness in broiler diets. [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]

Three experimental groups with different feeding frequencies, different feeding rates and compensatory feeding were set up to study their effects on the growth of Micropterus salmoides. The results showed that different feeding rates of 2%, 3% and 4% had no significant effects on the growth of M. salmoides. Therefore, before the individual weight of 50 g, the fish could be fed with a feeding rate of 4%, which could be gradually decreased to 2% in the later period. Under the condition of relatively fixed feeding rate, different feeding frequencies had an impact on the growth of M. salmoides. Under the conditions of suitable water temperature, it is reasonable to feed twice daily. The experimental fish fed for 5 d and then deprived of feed for 1 d showed fully compensatory growth, and there were no significant differences in weight gain rate, daily weight gain and specific growth rate compared with the continuous feeding group (P >0.05). Therefore, according to the feeding conditions of fish in the breeding process, stopping feeding for 1 d every 5 d could save feed and labor and improve breeding efficiency. [ABSTRACT FROM AUTHOR]

Females are predicted to adjust their reproductive investment to optimize the trade-off between current and future reproduction. In many cooperatively breeding birds, females have been shown to reduce their investment both pre- and posthatching in response to the presence of food-provisioning helpers. However, in species where not all group members help during the posthatching stage, it is currently unclear to which social cues (i.e. group size versus number of helpers) females should tune their investment. Here, we used the cooperatively breeding placid greenbul, Phyllastrephus placidus , as a model species to examine whether and how group size and number of helpers affect female investment in eggs and food provisioning. We found that females used a contrasting strategy pre- and posthatching in response to different social cues: they laid larger eggs in larger groups while reducing their feeding rate when assisted by more helpers. We also found that fledging success increased with group size and that nestlings raised in groups with helpers fledged with longer wings but found no relation between condition of the young and number of helpers. Since the perceived contrasting investment strategies may have several underlying causes, we conclude that predicting the influence of social conditions on maternal investment may be more challenging than previously believed. • Maternal pre- and posthatching investment is associated with different social cues. • Maternal egg investment (egg size) increased with group size. • Maternal feeding rates decreased with number of helpers. • Fledging success increased with group size. • Wing length, but not condition, of fledglings increased with number of helpers. [ABSTRACT FROM AUTHOR]

Abstract Background During the mushroom production process, about one-fifth of the mushroom gets lost. The mushroom residues (MR) are rich in nutrients and can be utilized in diverse applications. Therefore, the goal of this research was to modify a local hammermill to improve the performance of chopping mushroom residues to be efficient used as a by-product. Results The experiments were conducted on a hammermill without and with six screen diameters, three drum rotational speeds, three feed rates, two average moisture content and two hammer rotation tracks (long–short). Then, chopper experiments were carried out with a focus on a specified size, power consumption and energy required. The findings of using any size screen offered little productivity since after a short time, the chopping MR was built blocks around the drum and blades. But using no screen gives these phenomena disappear. The chopping MR performed well in long track conditions, with a feeding rate of 700 kg/h, a drum speed of 300 rpm and moisture content of 43% . Conclusions The chopping operation had the best at feed rate of 700 kg/h, drum speed of 3000 rpm and 43% moisture content of which gave the appropriate MWD of 5.54 and 5.32 mm, consumed power of 1114.35 and 1189.125 W and required specific energy of 1.59 and 1.7 kW h/Mg for short and long tracks, respectively, and also largest mean weight diameter under such conditions due to a decrease in the amount of mushroom residues and an increase in their dryness, which increases the fragmentation impact of hammers on mushroom remnants.

Overfeeding intermittently induces metabolic liver diseases in aquaculture practice. Currently, less information regarding the impact of feeding rates on hepatic lipid metabolism was reported. Therefore, this study investigated the effects of feeding rates (2 %, 3 %, 4 %, and 5 % of body weight per day) on growth performance, hepatic lipid metabolism, immunity, inflammation, and apoptosis in juvenile largemouth bronze gudgeon (Coreius guichenoti) over 8 weeks. The results demonstrated that increasing feeding rates significantly enhanced weight gain rate and specific growth rate. Furthermore, the lipid content of the whole body increased progressively, with the highest levels observed in the 5 % group. High feeding rates also resulted in significant increases in hepatic TG, TC, and NEFA levels. This was accompanied by upregulated mRNA levels and enzyme activities of lipid synthesis-related genes (ACC1α and FASN). However, no significant differences were observed in mRNA levels and enzyme activities of lipolysis-related genes (HSL and CPT1). Histological observations identified two distinct hepatic phenotypes: no obvious abnormality liver and fatty liver. Overall, the proportion of fatty liver phenotype increased with the increasing feeding rate. Additionally, feeding rates significantly increased IgG, IgM, and lysozyme levels, and upregulated mRNA levels of inflammatory cytokines (TNFα and IL1β), apoptosis-related genes (CASP3 , CASP8 , and CASP9), and hepatic repair factors (YAP1 , FGF10 , FGF13 , FGF18 , FGF19 , and PCNA). Nevertheless, hepatic function indices, including ALT, AST, and AKP levels, remained unchanged. In conclusion, these findings indicated that a feeding rate exceeding 3 % led to hepatic lipid metabolism disorders, characterized by the accumulation of TG and TC, thus promoting the development of fatty liver, inflammation response, and cellular apoptosis in largemouth bronze gudgeon. Moreover, the largemouth bronze gudgeon may exhibit self-repair capability to mitigate liver damage induced by lipid metabolism disorders. Consequently, we infer that largemouth bronze gudgeon possesses a robust capability for lipid accumulation and utilization. • A feeding rate over 3 % may induce lipid metabolism disorders and fatty liver symptom • C. guichienoti responds positively to liver damage by enhancing self-repair ability • C. guichienoti possesses a strong capability to accumulate and utilize lipids [ABSTRACT FROM AUTHOR]

This study explores the food plant spectrum of the sugar beet weevil (Asproparthenis punctiventris Germar; Coleoptera: Curculionidae), one of the most important pests of sugar beet (Beta vulgaris subsp. vulgaris Altissima group). It examines the potential of various weeds and other plants to maintain populations of A. punctiventris adults and larvae outside sugar beet fields. To this end, leaf consumption of females and males on twelve Amaranthaceae and six Polygonaceae species was compared over a 24-h period in a laboratory environment. Both sexes consumed the greatest amount of leaf mass from Beta spp. and on average about a third less from Atriplex spp., indicating that these plants have the highest nutritional value for A. punctiventris. Weevils consumed between 30 and 60% of the amount of A. retroflexus and Chenopodium spp. than they fed on sugar beet leaves. Like Spinacia oleracea (Amaranthaceae), plant species of the Polygonaceae family were hardly or not at all fed on. Mated females generally consumed more leaf mass than unmated, especially from Chenopodium spp. and A. retroflexus, i.e. plants with low feeding value. Experiments with potted plants revealed that the most and heaviest 4th instar larvae developed on sugar beet, while fewer individuals with lesser weight were found on B. vulgaris subsp. maritima and A. hortensis. Very few larvae were able to develop on C. album, and none on A. retroflexus. To prevent promotion of pest population, special attention should be paid to the control of weeds from the Amaranthaceae family in sugar beet growing areas. [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]

A lack of knowledge about the long-term cultivation requirements of groundwater fauna is hampering the establishment of biological criteria to identify chemical threats to groundwater. As a contribution to solving this problem, we have carried out comprehensive laboratory studies on the diet and survival rates of the groundwater amphipod Niphargus aquilex. Preference tests indicated higher consumption of common ash (Fraxinus excelsior) than black alder (Alnus glutinosa) foliage. Compared to detritus from the sampling site, however, survival rates of N. aquilex significantly increased when living oligochaetes were added to ash foliage as an additional food source. Our results indicate that N. aquilex has evolved an omnivorous feeding strategy as an adaptation to the limited availability of nutrient-rich food sources in aquifers. The high acceptance of animal food sources and the predatory behaviour of N. aquilex underline the importance of and requirement for protein in its diet and suggest a high trophic position in groundwater food webs. Based on our results, we provide an optimized culturing protocol that opens up new perspectives for using N. aquilex as an organism for testing the biological quality of groundwater. [ABSTRACT FROM AUTHOR]

In cooperatively breeding species, helpers take higher risks of getting lower return of investment than breeders due to the incongruity between helping and breeding. Helpers can deal with the risk by curtailing their investment or, if possible, claiming immediate rewards in the cooperation. Given breeders may rely largely on the aid of helpers to raise their offspring, it can be hypothesized that helpers are more likely to make adaptive responses to the incongruity-associated risk in adverse habitats than in good ones. This hypothesis was tested in the giant babax (Babax waddelli) by comparing helpers’ provisioning behaviors between two breeding populations in adverse high-altitude and good low-altitude environments. These two populations differed significantly in their egg size and nestlings’ growth patterns. Helpers in both populations made great contributions to the raising of offspring. During provisioning, helpers in the high-altitude population exhibited significantly higher feeding rates but delivered fewer insects per feeding bout than their counterparts in the low-altitude population. Helpers in both populations displayed a cheating strategy of “non-feeding” to reduce investment in provisioning. They pursued immediate excess rewards via kleptoparasitism of nestling fecal sacs in the high-altitude population but not in the low-altitude one. Accordingly, breeders made different antagonistic actions toward the cheating helpers between populations. Our findings confirm that helpers are prone to deceiving cooperation under poor breeding conditions, and that breeders’ tolerance of the cheating behavior of helpers is determined by their dependence on the helpers’ aid. Significance statement: Giant babax is an obligated cooperatively breeding bird that breeds on the Tibetan Plateau. We found that helpers displayed cheating behaviors while they provisioned the brood. Although helpers in both high- and low-altitude populations adopt “non-feeding” strategy to reduce investment in the provisioning, they were more likely to perform contested kleptoparasitism to access the fecal sacs of nestling in the high-altitude population than in the low-altitude one. Our findings suggest that helpers in adverse high-altitude habitats are probable to claim immediate excess reward via cheating strategies. [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 article assesses strategies for managing the economic returns to an aquaponics production system with joint products of lettuce and tilapia. Experimental data from Brazil that varied fish stocking density and the fish feeding rate are analyzed using nonparametric efficiency testing methods to identify potentially profitable technologies and their sensitivities to prices of inputs and outputs. Plants and fish production are symbiotic in an aquaponics system, with fish waste providing nutrients for plant growth and plants helping maintain water quality for the fish via filtration. The optimal input/output mix among alternatives is identified, and sensitivity analysis is used to assess the price ranges around recent market conditions (0.18 R$/tilapia fingerling, 2.8 R$/kg for fish feed, 20 R$/kg for juvenile fish, and 1.57 R$/kg for lettuce) over which that technology choice remains optimal. The configuration of production controls is robust to price changes. Results show that at low fish stocking densities (100 fish/m3), the effluent in the water provides insufficient nutrients to plants. In addition, early lettuce harvests (before 26 days) are generally less efficient than treatments that allow more time for plant growth. Sensitivity analysis indicates that the optimality of the identified configuration of production controls is robust with respect to input and output prices. [ABSTRACT FROM AUTHOR]