Feeding Intensity Research Articles

Application of high-throughput sequencing to analyze the diet of black croaker (Atrobucca nibe) in southern coastal waters of Zhejiang

This study investigated the feeding habits of black croaker (Atrobucca nibe) to fully understand its role in the food web in southern coastal waters of Zhejiang, China. In total, 225 black croakers were collected in a bottom trawl survey, of which 195 were used for the stomach contents analysis and 30 for high-throughput sequencing (HTS). Both approaches showed that the main prey was shrimp, with Alpheus japonicus being the most predominant. In addition, black croaker also fed on other benthic species, suggesting that it was a demersal predator. Feeding intensity also varied with black croaker body length, as did prey preference, from small-sized species to larger species with increases in fish size; in addition, prey species were more diverse in the large-bodied prey group. Canonical correspondence analysis indicated that the feeding habit of black croaker was most significantly correlated with temperature and dissolved oxygen. HTS was shown to be a feasible high precision semi-quantitative analytical approach, although it must be combined with morphological methods to obtain more complete feeding data; thus, it could provide an effective scientific basis for feeding ecology studies of marine organisms.

Influence of gender status and feeding intensity on the growth curves of body weight, dry matter intake and feed efficiency in crossbred beef cattle

Influence of gender status and feeding intensity on the growth curves of body weight, dry matter intake and feed efficiency in crossbred beef cattle

Production of organic beef from dairy bull calves in Denmark - Effect of different production strategies on productivity, carbon footprint and biodiversity estimated by modelling

In Denmark, organic male calves from the dairy system are typically raised as steers leading to a high carbon footprint per kg meat produced, compared to other types of rearing. Therefore, there is a need to find mitigation options and develop future production systems with a lower climate impact. The aim of this study was to develop strategies for the rearing of organic bull calves considering the following factors: season of birth, feeding strategy, age at slaughter, and breed-type, where all strategies focus on achieving the lowest possible carbon footprint per kg carcass. A total of 10 strategies were compared for each of three breed types: Holstein, Charolais x Holstein, and Angus x Holstein. The carbon footprint was estimated using Life Cycle Assessment including all emissions until the animals leave the farm for slaughter and expressed per kg carcass taking into account different dressing percentages due to breed and age at slaughter.The carbon footprint per kg carcass including contribution from soil carbon changes was 18–32% lower for raising organic young bulls compared with that of organic steers. The strategy with a high feeding intensity and a slaughter age of 13 months had the lowest carbon footprint per kg carcass due to the lowest feed consumption per kg live weight gain (4.9 kg DM compared to 7.4 kg DM for the steer) and use of a high proportion of concentrated feed in the ration. In the strategy with slaughter age of 17 months, but the same high feeding intensity, carbon footprint per kg carcass increased around 6%. This was due to an increase in feed consumption and reduction in feed conversion due to the increasing age at slaughter. The strategy with a low feeding intensity and a high slaughter age (17 months) gave the highest carbon footprint per kg carcass amongst the rearing strategies compared for organically produced bulls, as a greater proportion of roughage in the ration increases enteric methane production from the digestion of the feed. The crossbred bulls compared to purebred dairy bulls had a lower carbon footprint (4–7%) due to higher dressing percentage, higher carcass weight (both types of crosses), and higher growth rates (Charolais crosses).

Stimulating effects of whooper swans’ behaviors on nutrient releasing from the sediments caused by different human feeding intensities in the swan Lake, China

In many shallow water lakes of China, as the numbers of tourists observing waterflow increases, the amount of supplemental food provided to waterflow also increases. However, little attention has been paid to the role of waterfowl’s behavior perturbation in N and P nutrients releasing from the sediment. In this study, five feeding experiments were undertaken in the Swan Lake (Shandong Province, northern China) during the wintering season and a noticeable release of nutrients in all experiments was found by the disturbance of the swan behaviors. The release of TN and TP was through three stages including the non-release stage, the rapid release stage, and the stable release stage. Moreover, supplemental food also influenced the swan behavior changes and triggered the frequency of the swans’ grazing and aggression. The aggressive behaviors among the swans stirred nutrient (N & P) releasing from sediments and altered TN and TP concentrations in the water columns, indicating that the aggressive behaviors may be a significant factor in affecting the TN and TP releasing from the sediment. Human feeding intensity (HFI) suggested > 850 g of supplemental corn can be an optimal way to aid in avoiding foraging competition among the swans to control nutrient release by three levels of human feeding intensity assessment. Our findings demonstrate that under the swans’ optimal foraging need in natural versus artificial feeding scenarios, the swans acted as biological pumps to increase nutrient release. There is a need for a systematic and evidence-based feeding strategy for swans, with greater restrictions on the provision of small food items scattered by visitors. Our study provided novel insights into the release mechanism of N and P from bioturbation and could help to inform a whooper swan conservation strategy in coastal wetlands and nature reserves.

Trophic ecology and diet of the deep-sea penaeid shrimp Metapenaeopsis andamanensis (Wood-Mason in Wood-Mason and Alcock, 1891) by fatty acid signatures and stomach content analysis.

Metapenaeopsis andamanensis, a deep-water penaeid shrimp, plays a significant ecological role in the deep-sea food web. However, studies on its feeding ecology and trophic relationships in the tropical region remain limited. This study aimed to investigate the diet composition of M. andamanensis from the southwest coast of India, focusing on intrinsic factors (size, sex, maturity) and extrinsic factors (seasons), as well as the fatty acid profile. Our findings revealed that M. andamanensis is an active feeder, with females exhibiting higher feeding intensity than males, while immature individuals of both sexes showed minimal feeding activity. Additionally, females displayed a more pronounced carnivorous feeding behavior compared to males. Gut somatic index ranged between 1.1 and 1.42. Feeding conditions varied significantly with seasons, maturity stages, and ontogenetic classes. The primary diet components comprised detritus, foraminifera, and crustaceans, followed by gastropods and fish. Statistical analysis using PERMANOVA indicated significant differences in diet components between sexes and seasons (p < 0.05), sexes and size (p < 0.1), and sexes and maturity stages (p < 0.05). Notably, the percentage composition of diet components exhibited substantial variation with seasons, sex, ontogenetic classes, and maturity stages. Fatty acid analysis revealed an omnivorous-carnivorous feeding strategy of M. andamanensis, characterized by high proportions of essential fatty acids such as 20:5n-3, 22:6n-3, and 18:1n-9, indicating bentho-pelagic feeding activity. The shrimp exhibited notable levels of palmitic acid, oleic acid, EPA, and DHA, which are nutritionally valuable. Seasonal variations in fatty acid profiles were associated with the availability of different food sources. Principal component analysis (PCA) performed on the fatty acid profiles explained 72.4% of the total cumulative variance using the first two dimensions, highlighting the distinct dietary patterns of M. andamanensis based on its stomach contents.

Feeding Biology of Barilius bendelisis (Hamilton 1807) from the Hill Streams of Manas River, Assam, India

The present paper is concerned with the study of food and feeding habits including feeding intensity, the nature of food consumed, and the index of preponderance of food items. The gut contents of 158 specimens of Barilius bendelisis caught from the hill streams of Manas River, Assam, India revealed that the main food consists of insect larvae (48.78%) occupying the first rank in grading among all the other food items, followed by phytoplankton (22.55%), sand and mud (14.49%), others (10.45%) and debris (1.42%). The mean value of relative length of the gut (RLG) was calculated 1.271 indicates the omnivorous nature of Barilius bendelisis. Average seasonal Gastro-somatic index (GSI) ranged from 5.089 ± 1.94 to 9.344 ± 2.48 for males and that of female from 5.095 ±1.98 to 11.166 ±2.89. Moreover, instances of poor feeding and empty stomachs were rarely observed in all the four seasons. These findings suggest that the feeding intensity of Barilius bendelisis is high and it is an active feeder.

The Low Ontogenetic Diet Diversity and Flexibility of the Pike-Perch, Sander lucioperca (Linnaeus, 1758) (Osteichthyes, Percidae): A Case Study

This study reveals the diet of pike-perch from two habitats within the Tersko-Caspian region. The feeding habits of pike-perch in the Sulak and Terek rivers and Tersko-Caspian region were investigated based on 354 specimens sampled monthly from a commercial catch in 2019. Their diet consisted of different prey, with fish representing the most important prey group (up to 90%). Rutilus caspicus dominated with a frequency of occurrence of 20.5, and Aspius aspius, Perca fluviatilis, and Chondrostoma oxyrhynchum, had 13, 9.5, and 8.3%. In the earlier ages 1+ and 2+, zooplankton dominated, followed by mysids and chironomids, which continues into the older ages but at decreasing rates. Analysis of monthly variations in stomach fullness indicated that feeding intensity fluctuated in time, with the highest values in March–April, and lowest in September and November. It was found that the diet of pike-perch in the western Caspian changed considerably from season to season. They begin to actively feed after wintering and before, or even during, spawning period. The spectrum of the diet of Sander lucioperca includes more than 20 elements, mainly juveniles of commercially valuable fish. This fish is characterized by a relatively low ontogenetic diet diversity and flexibility, which makes it sensitive to environmental changes, including anthropogenically induced ones. This fish partially compensates for this disadvantage with its lifestyle, namely, its active foraging movements and migrations from fresh water to salt water and back, following its prey species.

Recommendations for growing young Australian red-clawed crayfish (Cherax quadricarinatus) in industrial conditions

The Australian thermophilic red-clawed crayfish (Cherax quadricarinatus) is characterized by a number of qualities that ensure its effective cultivation in commercial aquaculture. At the same time, the year-round cultivation of this species in natural reservoirs of Russia is limited by the seasonal course of temperatures. In this regard, the cultivation of tropical crayfish in certain periods of life in regulated conditions is a necessary stage of full-cycle technology. In particular, the successful maintenance of ARCC juveniles until they are transferred to natural conditions (after reaching a mass of 5 g) in installations with a controlled temperature regime is due to a number of factors. First of all, this is the planting density, which naturally depends on the area and capacity of installations with a closed water supply cycle, the size, mass and age characteristics of the object. The physiological and biological state of crayfish, the intensity and quality of feeding, and the duration of cultivation play an important role. The purpose of this work is to determine the main technological indicators of growing juveniles Australian red-clawed crayfish in industrial conditions up to 5 g. Data on the results of growing juveniles Australian red-clawed crayfish under controlled temperature conditions showed the main differences in mass indicators and survival of groups of juveniles Australian crayfish depending on the initial average weight, planting density, order of offspring. The terms of growing juveniles up to 5 g have been established, the feed costs for this period have been calculated, the chemical composition of the body of juvenile crayfish has been determined.

A BlendMask-VoVNetV2 method for quantifying fish school feeding behavior in industrial aquaculture

Quantification of fish feeding behavior from an image is crucial for achieving smart feeding in industrial aquaculture. Because fish images provide a wealth of spatial information about their behavior, which can be used to determine the fish feeding intensity. However, most studies only use a single spatial feature to quantify fish feeding behavior. For the extraction of multiple spatial feature indicators, a computational approach is lacking due to image challenges caused by occlusion, overlapping, and clustering during the feeding stage. In this paper, a novel emerging BlendMask-VoNetV2 method is developed to segment two-class fish and distinguish different instance individuals for extracting multiple spatial features. Serial indicators are proposed for analyzing spatial feature variations from the time-series-based videos, such as the number of fish, the number of pixels, and the distance between individual fish. Additionally, we present the first fish dataset with fish occlusion and aggregation for feeding image segmentation in industrial aquaculture. It contains 1038 images consisting of 67,519 instance individuals with pixel annotations for two semantic categories: fish1 (non-occlusion and non-aggregation), and fish2 (occlusion or aggregation). Extensive experiments demonstrate that BlendMask-VoVNetV2 achieves competitive segmentation performance with an accuracy of 83.7% on the feeding dataset, outperforming other instance segmentation algorithms such as SOLOV2, SOTR, ConInst, Mask RCNN.et.al. A distinctive advantage of our idea proposed is beneficial to deal with the problem of inaccurate segmentation caused by severe occlusion and overlapping fish. Finally, the BlendMask-VoVNetV2 method is verified on four videos with non-feeding, strong feeding, medium feeding, and weak feeding. The results show that the method we proposed is effective, which can accurately and objectively depict each moment of the entire feeding process using multiple spatial feature indicators.

Microplastic ingestion and plastic additive detection in pelagic squid and fish: Implications for bioindicators and plastic tracers in open oceanic food webs

The ubiquitous presence of microplastics (MPs) in the ocean represents a potential threat to marine organisms, with poorly understood long-term adverse effects, including exposure to plastic additives. The present study investigated the ingestion of MPs in two epipelagic fish species (Trachurus picturatus and Scomber colias) and three pelagic squid species (Loligo vulgaris, Ommastrephes caroli and Sthenoteuthis pteropus) from an open oceanic region of the Northeast Atlantic. Seven phthalate esters (PAEs) were also analysed in the organisms' tissue, and the potential correlation between PAEs concentrations and ingested MPs was investigated. Seventy-two fish and 20 squid specimens were collected and analysed. MPs were found in the digestive tract of all species and in the squid species' gills and ink sacs. The highest occurrence of MPs was in the stomach of S. colias (85 %) and the lowest in the stomach and ink sac of O. caroli and L. vulgaris (12 %). Most of the particles identified (>90 %) were fibres. Among all the ecological and biological factors considered (dietary preferences, season, body size, total weight, liver weight, hepatosomatic index and gastrosomatic index), only gastrosomatic index (GSI) and season were significant predictors of MPs ingestion in fish species, with a greater likelihood of ingestion in the cold season and in specimens with higher GSI values (i.e. higher feeding intensity). Four PAEs (DEP, DIBP, BBP, DEHP) were detected in all the species analysed, with average ∑PAEs concentrations ranging between 10.31 and 30.86 ng/g (wet weight). DIBP was positively correlated with ingested MPs, suggesting this compound might represent a “plastic tracer”. This study looks into the problem of MPs ingestion for pelagic species in an open oceanic region, highlighting the most suitable bioindicators and providing essential insights into the factors that may influence ingestion rates. Additionally, the detection of PAEs in all species indicates the need for further research on the contamination sources, the effects of these chemicals on marine organisms, and the potential risks to human health through seafood consumption.

Feeding intensity assessment of aquaculture fish using Mel Spectrogram and deep learning algorithms

Accurately and objectively analyzing fish feeding intensity is essential to guiding feeding and production techniques. Fish feeding intensity in recirculating aquaculture systems (RAS) can be used to indicate a fish's appetite. However, the low efficiency and lack of objectivity of manual observation are problems with current fish feeding intensity assessment processes. Applying acoustic techniques to aquaculture issues is an insufficiently explored area that requires new investigations, particularly into methods that explore temporal information in acoustic spectrograms. With Oplegnathus punctatus as the experimental species, we proposed a fish feeding intensity detection method based on the Mel Spectrogram and MobileNetV3-SBSC lightweight networks. First, the Oplegnathus punctatus feeding sound dataset, which has a total of 3 types—"strong," "medium," and "none," was built. Next, Mel Spectrogram feature maps were extracted using steps including preprocessing, Fast Fourier Transform (FFT), Mel filter bank (MFB), etc. Finally, the MobileNetV3-SBSC lightweight network was used to detect and recognize the obtained feature maps. Experimental results indicated that the proposed MobileNetV3-SBSC model, as compared to the MobileNetV3-S model, improved test accuracy by 4.6% and decreased test loss by 67.4% with only a 0.84% increase in the number of parameters and a 3.08% increase in the model size. Additionally, we have verified that the accuracy of the test set was 59.6%, 53.3%, 83.3%, 85.3%, and 85.9% for groups of 5, 15, 40, 70, and 100 fish, respectively. This study demonstrated that the proposed method is not applicable to a small number of fish, which means that when the numbers of fish are small, changes in the feeding of individual fish would have a significant effect on the whole feeding feature map, leading to negligible changes in feeding features. However, in view of the commonly high aquaculture density, the proposed method can be used to automatically and objectively examine fish feeding, which could provide a theoretical basis and methodological support for further feeding decisions.

Contact and Gastric Effect of Peppermint Oil on Selected Pests and Aphid Predator Harmonia axyridis Pallas.

Peppermint essential oil (EO) has been extensively tested to date in reducing stored-product insects and insects of public health concern with very promising results, while only a few studies target important crop pests. There is also very little information on the effects of peppermint EO on non-target organisms, especially concerning contact and gastric effects at the same time. The goal of the investigation was the determination of the effect of peppermint EO on the mortality of Aphis fabae Scop.; the feeding intensity and weight gain of Leptinotarsa decemlineata Say. larvae; and the mortality and voracity of non-target organism Harmonia axyridis Pallas larvae. Our research indicates promising use for the M. piperita EO against aphids and young larvae (second instars) of the Colorado potato beetle. M. piperita EO showed good insecticidal efficacy against A. fabae with LC50 = 0.5442% for nymphs and 0.3768% for wingless females after 6 h. Over time, the LC50 value decreased. For the second instar larvae of L. decemlineata, the LC50 values were 0.6278%, 0.3449%, and 0.2020% after 1, 2, and 3 days of the experiment, respectively. On the other hand, older larvae (fourth instar) were characterized by significant resistance to the tested oil concentrations with LC50 value = 0.7289% after 96 h. M. piperita oil (contact and gastric effects) at a concentration of 0.5% was found to be toxic to young larvae (2 and 5 days old) of H. axyridis, while EO at a concentration of 1% was toxic to 8-day-old larvae. Thus, for the sake of ladybug safety, it would be advisable to use EO from M. piperita against aphids at concentrations lower than 0.5%.

Predicting infant feeding intention and intensity in Oman using a path analysis approach.

Low breastfeeding rates are a global concern, and few studies have examined breastfeeding in Oman. We examined the associations of mothers' sociodemographic characteristics, breastfeeding knowledge, attitudes, subjective norms, perceived control, previous breastfeeding experience, and early breastfeeding support with infant feeding intention at birth and breastfeeding intensity at 8 weeks postpartum. We used a descriptive, prospective cohort design. Data collection was in 2016. We administered a structured questionnaire to mothers at postpartum discharge from 2 hospitals in Oman and followed up once via a 24-hour dietary recall at 8 weeks. We used a path analysis model (n = 427) using SPSS, version 24.0, and Amos, version 22. During the postpartum hospitalization, 33.3% of mothers reported that their babies received formula milk. At the 8-week follow-up, 27.3% of mothers were exclusively breastfeeding. Subjective norms (measured by social and professional support) were the strongest predictors. Infant feeding intention significantly predicted breastfeeding intensity. Returning to work/school was the only sociodemographic variable to significantly correlate with breastfeeding intensity (r = -0.17; P < 0.001); mothers who planned to return to work/school had significantly lower intensity. Knowledge significantly predicted positive and negative attitudes, subjective norms and perceived control. Early breastfeeding support negatively correlated with breastfeeding intensity (r= -0.15; P < 0.001). Infant feeding intention positively predicted breastfeeding intensity with subjective norms or social and professional support and had the strongest correlation with mothers' intentions.

Tree species richness increases spatial variation but not overall wood decomposition

Empirical evidence for the positive relationship between tree species richness and wood decomposition is weak, despite the greater numbers of decomposers in diverse stands. Tree species identity affects decomposition rates strongly by altering soil communities and micro-environments. It is therefore likely that tree species richness influences spatial variation rather than the mean rate of decomposition. We used a neighbourhood approach to test this hypothesis by quantifying decomposition rates and decomposer activities within deadwood, whilst measuring the surrounding micro-environments.Using the BEF-China experimental platform, we placed three fine branches from seven tree species across richness gradients for one and two years. As expected, plot species richness increased the spatial variation of wood decomposition of three species but decreased the mean rate of wood decomposition of two species. Neighbourhood trees altered wood decomposition in two ways. First, increasing amounts of leaf tannins reduced termite activities and the number of fungal fruitbodies. Second, higher species richness increased tree volumes and thus cooled the understory, which reduced the occurrence and feeding intensity of ectothermic termites. Neighbourhood species richness showed positive effects on decomposer activities (i.e. termite occurrence, fruitbody number and mycelium cover) after two years, probably by weakening resource limitation of deadwood biomass and increasing the stages of decay. Neighbourhood metrics had comparable (after 1 year) and even stronger effects (after 2 years) on decomposer activities than wood traits. Our study reveals that tree species richness promotes spatial variation in wood decomposition rates by enhancing environmental heterogeneity. Our results explain how young regenerating species-rich forests, where termites are the dominant decomposers, can maintain deadwood stocks and decomposer activities over relatively longer time spans.

An FSFS-Net Method for Occluded and Aggregated Fish Segmentation from Fish School Feeding Images

Smart feeding is essential for maximizing resource utilization, enhancing fish growth and welfare, and reducing environmental impact in intensive aquaculture. The image segmentation technique facilitates fish feeding behavior analysis to achieve quantitative decision making in smart feeding. Existing studies have largely focused on single-category object segmentation, ignoring issues like occlusion, overlap, and aggregation amongst individual fish in the fish feeding process. To address the above challenges, this paper presents research on fish school feeding behavior quantification and analysis using a semantic segmentation algorithm. We propose the use of the fish school feeding segmentation method (FSFS-Net), together with the shuffle polarized self-attention (SPSA) and lightweight multi-scale module (LMSM), to achieve two-class pixel-wise classification in fish feeding images. Specifically, the SPSA method proposed is designed to extract long-range dependencies between features in an image. Moreover, the use of LMSM techniques is proposed in order to learn contextual semantic information by expanding the receptive field to extract multi-scale features. The extensive experimental results demonstrate that the proposed method outperforms several state-of-the-art semantic segmentation methods such as U-Net, SegNet, FCN, DeepLab v3 plus, GCN, HRNet-w48, DDRNet, LinkNet, BiSeNet v2, DANet, and CCNet, achieving competitive performance and computational efficiency without data augmentation. It has a 79.62% mIoU score on annotated fish feeding datasets. Finally, a feeding video with 3 min clip is tested, and two index parameters are extracted to analyze the feeding intensity of the fish. Therefore, our proposed method and dataset provide promising opportunities for the urther analysis of fish school feeding behavior.

Gastrointestinal morphology and feeding intensity of Periophthalmus gracilis caught from some coastal provinces in the Mekong Delta, Vietnam

This study provided data on gastrointestinal morphology and feeding intensity of slender mudskipper Periophthalmus gracilis distributed in some coastal provinces in the Mekong Delta, Vietnam (VMD). Fish specimens were sampled monthly by hand-catching, from 01/2022 to 12/2022, in four provinces in the VMD: Tra Vinh, Soc Trang, Bac Lieu, and Ca Mau. After sexing, the fish total length and weight, gut length, and gastrointestinal morphology were measured and described. The study showed that Periophthalmus gracilis had a protruding upper jaw with a longer upper jaw bone length. The teeth are large and sharp, with pointed molars and unevenly distributed in a row on the upper jaw. The tongue was short and had a round tip. The gastrointestinal had an elastic tube-shaped esophagus, a short sac-shaped stomach, and long, straight, curving tube intestines. The feeding intensity of the mudskipper varied by season and month, with differences between males and females. These findings provided new information on the mudskipper’s gastrointestinal morphology and feeding habit.

Feeding Ecology of Red Seabream, Pagrus major (Sparidae) in the Korea Strait

The feeding ecology of red seabream, Pagrus major was studied using 1046 specimens collected by danish seine and bottom trawl from January to December 2018 in the Korea Strait. The size of the individuals ranged from 18.4 to 70.4 cm in fork length. Red seabream was a carnivore that consumed mainly anthozoans, brachyurans, and cephalopods. Its diets included also small quantities of amphipods, anomurans, ophiurids, gastropods, polychaetas, etc. We calculated the trophic level as 3.57 for red seabream. As red seabream grows, the proportion of relatively small prey items such as anomurans and ophiuroids decreases, while that of large prey items such as anthozoans, brachyurans, and cephalopods increases. In the largest size class (≥45 cm FL), cephalopods and pisces are its main prey. Alsoe, the body size of red seabream increased the mean weight of prey per stomach tended to increase significantly (One-way ANOVA: p 0.05). The diet composition of red seabream showed seasonal changes. The cephalopods were the dominant prey items for all seasons. The weight proportion of brachyurans was higher in summer and autumn, whereas anthozoans feeding rate was the highest in winter. PERMANOVA analysis showed significant variations among size classes and seasons. The feeding intensity by size class and season observed no significant difference (One-way ANOVA: p 0.05). As a result of the feeding strategy analysis, red seabream was a generalized feeder, with a wide niche width.

Effect of varied daily feeding intensities on growth performance and feed utilisation of South African dusky kob (Argyrosomus japonicus) juveniles reared in a recirculating aquaculture system

Several aquaculture studies have concluded that feed constitutes the heaviest cost in aquaculture enterprises. Consequently, researchers continue to investigate strategies that can lower feed costs such as the use of protein rich plant sources and insect meals to partially or completely substitute the expensive fishmeal in aquafeeds. However, this approach has often faced numerous challenges such as anti-nutrients in plant protein sources that limit their use and suboptimal polyunsaturated fatty acids profile in terrestrial protein sources such as insect meal. Precision feeding is a strategy that could also reduce aquafeed feed costs and enhance the economic sustainability of aquaculture. There is discordance regarding the feeding intensity that should be used for fish such as dusky kob. The current study was designed to compare the effect of three feeding intensities (2.8 %, 3.5 % and 4 % of body weight (BW)) on growth performance and feed utilisation of juvenile dusky kob (Argryrosomus japonicus). Dusky kob juveniles were randomly and evenly allocated to 18 tanks with a volume of 465 L. Each feeding intensity was randomly allocated to six tanks carrying 66 fish each. The average temperature and dissolved oxygen were 25°C and 5.5-6.0 mg/l, respectively. Commercial dusky kob diet was offered twice daily at the rate of 2.8%, 3.5% and 4% of body weight (BW). A feeding intensity × fish age (weeks) interaction effect was noted on fish feed intake (P&lt;0.05) but not on weight gain, feed conversion ratio (FCR), and specific growth rate (SGR). The overall weight gain after six weeks of feeding was similar across the three feeding intensities (P&gt;0.05). The 2.8% BW feeding rate promoted 1.06%/day SGR as compared to 1.21%/day and 1.48%/day for 3.5% and 4.0% BW feeding rates, respectively. Similar weight gains and FCR recorded across the three feeding intensities may suggest that the lowest feeding intensity (2.8% BW) should be used for dusky kob feeding to reduce feeding costs. Key words: Aquaculture, Feed, Dusky kob, Rations, Growth performance, FCR, RAS, SGR

Effects of rumen cannulation combined with different pre-weaning feeding intensities on the intestinal, splenic and thymic immune system in heifer calves several month after surgery.

Fistulation is a helpful procedure in animal nutritional research and also common practise in human medicine. However, there are indications that alterations in the upper gastrointestinal tract contribute to intestinal immune modulations. The present study aimed to investigate effects of a rumen cannulation in week 3 of life on the intestinal and tissue specific immune system of 34-week old heifers. Nutrition influences the development of the neonatal intestinal immune system to a high extent. Therefore, rumen cannulation was investigated in combination with different pre-weaning milk feeding intensities (20% (20MR) vs. 10% milk replacer feeding (10MR). Heifers of 20MR without rumen cannula (NRC) showed higher cluster of differentiation (CD)8+ T cell subsets in mesenteric lymph nodes (MSL) compared to heifers with rumen cannula (RC) and 10MRNRC heifers. CD4+ T cell subsets in jejunal intraepithelial lymphocytes (IELs) were higher in 10MRNRC heifers compared to 10MRRC heifers. CD4+ T cell subsets in ileal IELs were lower and CD21+ B cell subsets were higher in NRC heifers compared to RC heifers. CD8+ T cell subsets in spleen tended to be lower in 20MRNRC heifers compared to all other groups. Splenic CD21+ B cell subsets were higher in 20MRNRC heifers compared to RC heifers. Splenic toll like receptor (TLR) 6 expression was increased and IL4 expression tended to be increased in RC heifers than NRC heifers. Splenic TLR2, 3 and 10 gene expression was higher in 20MR compared to 10MR heifers. Jejunal prostaglandin endoperoxide synthase 2 expression was higher in RC heifers than NRC heifers, and MUC2 expression tended to increase in 20MR heifers compared to 10MR heifers. In conclusion, rumen cannulation modulated T and B cell subsets in the down streaming gastrointestinal tract and spleen. Pre-weaning feeding intensity seemed to affect intestinal mucin secretion and T and B cell subsets in MSL, spleen and thymus until several month later. Interestingly, in MSL, spleen and thymus the 10MR feeding regime evoked similar modulations of T and B cell subsets like rumen cannulation.

First spectroscopic study of odd-odd Cu78

Nuclei in the vicinity of Ni78 are important benchmarks for nuclear structure, which can reveal changes in the shell structure far from stability. Spectroscopy of the odd-odd isotope Cu78 was performed for the first time in an experiment with the EURICA setup at the Radioactive Isotope Beam Factory at RIKEN Nishina Center. Excited states in the neutron-rich isotope were populated following the β decay of Ni78 produced by in-flight fission and separated by the BigRIPS separator. A level scheme based on the analysis of γ−γ coincidences is presented. Tentative spin and parity assignments were made when possible based on the β-decay feeding intensities and γ-decay properties of the excited states. Time correlations between β and γ decay show clear indications of an isomeric state with a half-life of 3.8(4) ms. Large-scale Monte Carlo shell-model calculations were performed using the A3DA-m interaction and a valence space comprising the full fp shell and the 1g9/2 and 2d5/2 orbitals for both protons and neutrons. The comparison of the experimental results with the shell-model calculations allows interpreting the excited states in terms of spin multiplets arising from the proton-neutron interaction. The results provide further insight into the evolution of the proton single-particle orbitals as a function of neutron number, and quantitative information about the proton-neutron interaction outside the doubly magic Ni78 core.Received 6 October 2022Revised 3 January 2023Accepted 9 January 2023DOI:https://doi.org/10.1103/PhysRevC.107.044301©2023 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBeta decayEnergy levels & level densitiesIsomer decaysNuclear spin & parityNuclear structure & decaysNucleon-nucleon interactionsShell modelProperties59 ≤ A ≤ 89Nuclear Physics