Search

The Mexican pike silverside (Chirostoma estor) is a zooplanktivorous, agastric short-intestined species, and it has been found that increased-frequency feeding (twelve feedings a day) improved feed efficiency and promoted growth by 70%. This work determined the effect of different juvenile feeding frequencies upon the C. estor liver transcriptome. The level of the expression of appetite-regulating peptides was analyzed in silico to understand the mechanisms involved in appetite control in this species. Differential expression analysis showed that up-regulated genes between treatments were related to metabolism, digestive processes, immune system response, apoptosis, growth, and oxidative stress. This information explains the better performance of pike silverside fed 12 times daily. Appetite regulatory peptides were identified for the first time in the liver of C. estor in response to high feeding frequencies, contributing to the general knowledge of the roles of each family of neuropeptides in this agastric, short-intestined fish. The information presented here emphasizes the need to explore further the complex physiological processes involved in appetite regulation in C. estor. Additionally, it will serve as a basis for more specific targeted studies of appetite control to elucidate the mechanisms behind this process. [ABSTRACT FROM AUTHOR]

The study was to explore the effects of daily feeding frequency on the growth performance, feed utilization, digestive enzyme activity, and gut microbiota of large-mouth bass fry after domestication and feeding with a combination feed. The experiment selected 4 500 large-mouth bass with an initial weight of (0.65±0.01)g, randomly divided into five feeding frequency groups (1 to 5 meals/day), named F1 group, F2 group, F3 group, F4 group, and F5 group, with three replicates per group and 300 fish per replicate. The trial period was 30 days. The results showed that the final weight, specific growth rate, daily feeding rate, and condition factor of the fish in F1 group were significantly lower than those in the other groups (P<0.05), while the survival rates in F3 group and F4 group were significantly increased (P<0.05). The moisture content in the fish bodies of F1 group was increased (P<0.05), and the crude fat content was lower than that in the other groups (P<0.05). The intestinal protease activity in F1 group was significantly higher than in the other groups (P<0.05). The relative abundance of Aeromonas and Acinetobacter in the intestine of F1 group was significantly increased (P<0.05), while the relative abundance of Cetobacterium was significantly lower than in the other groups (P<0.05). The study indicates that based on growth performance and survival rate, the appropriate daily feeding frequency for large-mouth bass fry fed with compound feed is 3~4 meals per day. [ABSTRACT FROM AUTHOR]

The parent–offspring conflict in avian species encompasses resource allocation and a balance necessary for survival for both parties. Parental investment is modulated according to various factors, among which begging is important. Endogenous hormones, particularly corticosterone (CORT), play a role in modulating begging behavior. However, most studies on hormonal regulation of begging behavior induced elevated hormone levels in the offspring through feeding or injections, thus, limiting our knowledge of the evolution of the parent–offspring conflict under natural conditions. In this study, we aimed to identify the key signals that parents respond to during interactions with their nestlings in the wild, considering factors such as endogenous hormone CORT, nestling age, and brood size, which may affect nestling begging behavior. Begging performance was evaluated by measuring the begging frequency and score of the red‐whiskered bulbul (Pycnonotus jocosus), along with assessing CORT levels in feathers. CORT levels were significantly correlated with both the begging frequency and score of nestlings, while variables such as body mass and tarsus length did not influence parental feeding frequency. Additionally, factors such as the number of nestlings (brood size), age, and begging frequency were predictors of parental feeding frequency. Our findings indicate that begging frequency, nestling age, and brood size are signals that help navigate the intricacies of the parent–offspring conflict and that parents may rely on these key signals from the range of begging cues exhibited by nestlings to adjust their feeding strategies. [ABSTRACT FROM AUTHOR]

Pig slurry (PS) management is a challenge that needs appropriate strategies. Anaerobic digestion (AD) has proved to be an interesting option to follow when it comes to livestock effluent management. Although this technology is well established, it is crucial to investigate different scenarios that demonstrate its suitability to motivate farmers to adopt new strategies for PS management. Previous research, based on a daily feeding regime and a 2-day starvation-induced period, investigated the impact of feast/ famine cycles on the AD process. There was evidence of a positive link between AD performance and the starvation regime. From this assumption, new scenarios were designed combining different feeding frequencies: a) one daily feeding (F1) and six feedings per day (F6), b) two days of starvation with one feeding (S1) and with six feedings (S6). The operational parameters were settled in advance: organic loading rate (1.5±0.2 g VS/Lreactor. d), hydraulic retention time (15 days), and mesophilic conditions (37±1 °C). The results obtained in this work indicate a significant improvement (P < 0.05) of 92% in specific methane production when comparing the trial F1 with F6. VS reduction remained constant in F1 and F6, but the starvation period (S1) led to an increase in VS reduction compared to both F1 (27%) and F6 (33%). The results obtained are in agreement with the previous work conducted by the authors. This study highlights how feeding frequency and starvation affect biogas production, assessing their effectiveness on biogas yield. This tool will give farmers a key decision factor to make an evidence-based decision and can work as a contingency planning strategy, aligning their PS management needs with AD versatility. [ABSTRACT FROM AUTHOR]

Pig slurry (PS) management is a challenge that needs appropriate strategies. Anaerobic digestion (AD) has proved to be an interesting option to follow when it comes to livestock effluent management. Although this technology is well established, it is crucial to investigate different scenarios that demonstrate its suitability to motivate farmers to adopt new strategies for PS management. Previous research, based on a daily feeding regime and a 2-day starvation-induced period, investigated the impact of feast/famine cycles on the AD process. There was evidence of a positive link between AD performance and the starvation regime. From this assumption, new scenarios were designed combining different feeding frequencies: a) one daily feeding (F1) and six feedings per day (F6), b) two days of starvation with one feeding (S1) and with six feedings (S6). The operational parameters were settled in advance: organic loading rate (1.5 ± 0.2 g VS/Lreactor.d), hydraulic retention time (15 days), and mesophilic conditions (37 ± 1 ºC). The results obtained in this work indicate a significant improvement (P < 0.05) of 92% in specific methane production when comparing the trial F1 with F6. VS reduction remained constant in F1 and F6, but the starvation period (S1) led to an increase in VS reduction compared to both F1 (27%) and F6 (33%). The results obtained are in agreement with the previous work conducted by the authors. This study highlights how feeding frequency and starvation affect biogas production, assessing their effectiveness on biogas yield. This tool will give farmers a key decision factor to make an evidence-based decision and can work as a contingency planning strategy, aligning their PS management needs with AD versatility.

In order to evaluate the effects of the interaction between different proteins and feeding frequency on largemouth bass (Micropterus salmoides) and to provide scientific guidance for the application of novel proteins and the corresponding optimal feeding strategy, a two-factorial design (5 × 3) with five protein feeds (fishmeal (FM), Clostridium autoethanogenum protein (CAP), Tenebrio molitor (TM), Chlorella meal (ChM), cottonseed protein concentrate (CPC)), and three feeding frequency (1, 2, and 3 times/d; FF1, FF2, FF3) was designed in culturing largemouth bass (initial weight, 2.98 ± 0.22 g/fish) for 8 weeks. Z-score combined with cluster analysis was used to analyze and compare the effects of different treatments on different indicators, such as growth performance, feed utilization, antioxidant capacity, and immune response to draw a general picture of the relationship among all these massive biomarkers. The results showed that different protein sources and feeding frequencies had significant interactive effects on growth performance, feed utilization efficiency, body lipid, and health status of largemouth bass. Fish fed with ChM feed showed similar performance to that in FM group, implying its potential for complete replacement of fishmeal in largemouth bass. Fish fed with CAP, TM, and CPC feeds showed worse performance compared to FM and ChM groups, characterized by poor growth and feed utilization, enhanced stress, chronic inflammation, and varying symptoms of histological changes in the liver and intestine, which demonstrated the adverse effects of the complete replacement of fishmeal by these three proteins. In terms of feeding frequency, fish fed with FM feed in FF3 group led to liver hypertrophy, fat accumulation, and the risk of fatty liver, while inducing liver inflammation. In addition, the TM and CAP group had the higher expression levels of inflammatory factors at FF3 group, which displayed that the interactions between FM, CAP, TM feeds and feeding frequency at FF3 might aggravate the occurrence of liver inflammation and oxidative damage of hepatocytes. Overall, FF2 had higher feed efficiency, protein efficiency, antioxidant enzyme and lysozyme activities, lower MDA content, and lower gene expression of inflammatory cytokines and could be considered as the optimum feeding frequency for largemouth bass fed with different protein feeds. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. In commercial dairy production systems, feeding calves once daily could be an alternative to reduce labor expenses. Several studies comparing once-a-day (OAD) versus twice-a-day (TAD) milk feeding systems have not evidenced differences in calf growth, rumen development, blood parameters or health scores, but effect on ruminal microbiota remains to be investigated. The objective of this study was to determine the effects of OAD or TAD on the establishment of the ruminal microbiota and its metabolic activity. Sixteen male calves (45.9 ± 5.7 kg at birth) were involved in the trial from birth to weaning (63 d). After the colostrum phase, 2 feeding programs based on a milk replacer were tested and calves were allocated to these programs on d 5. To study the establishment of the bacterial community, ruminal fluid was obtained from each calf 1 h after the morning meal at 7, 35, and 63 d of age. The ruminal metabolome was evaluated at a 7-d interval from d 1 to d 63. Ruminal microbiota and metabolite profiles were characterized by 16 S rRNA gene sequencing- and by 1H nuclear magnetic resonance spectroscopy, respectively. Our results showed that feeding milk replacer once or TAD did not change the ruminal microbiota and metabolites of dairy calves from birth to weaning. Microbial data showed that diversity and richness increased with age, suggesting a shift from a heterogeneous and less diverse community after birth (d 7) to a more diverse but homogeneous community at 35 and 63 d. These findings suggest that feeding milk OAD can be successfully applied to a calf feeding system without compromising microbial establishment and functions. [ABSTRACT FROM AUTHOR]

The use of probiotics in shrimp farms has expanded as an alternative to antibiotics, improving shrimp health, growth, disease control and water quality. However, the efficacy of probiotics in intensive systems using biofloc remains uncertain. This study investigated bioremediation and biocontrol of commercial probiotics using biofloc, analysing water quality and bacterial groups influencing shrimp performance. Thirteen microbial colonies were observed in the biofloc samples, and their evolutionary history was inferred using the neighbour-joining method. Analysis using MEGA6 software revealed 99.6% similarity between colony 1P1 and Virgibacillus sp. and 99.8% similarity between colony 2P2 and Bacillus kochii. The study analysed the biochemical and amino acid content of shrimp cultured using biofloc technology for 85 days. The study found that biofloc-cultured L. Vannamei flesh had higher levels of moisture (31%), ash (15.2%), protein (34%) and lipid (12.6%). No seasonal variations were observed between biofloc samples in winter and summer seasons. Protein levels were found to be appropriate for shrimp growth in both ex situ and in situ biofloc systems. The average growth rate (kg/m2) of biofloc-cultured shrimp was significantly greater than in normal pond shrimp in both samples. The feed conversion ratio in the biofloc tank was lower than in the usual pond-cultured shrimp, possibly due to lower growth rate, lower feeding frequency (2 times per day) and higher density. The growth of L. vannamei shrimp is influenced by stocking density, with higher stocking density affecting the average weight. The study also examined the growth biochemical and amino acid content of shrimp cultured using biofloc technology. [ABSTRACT FROM AUTHOR]

Correlations between brood sex ratios (BSRs) and parental or environmental quality have been found in many species. This phenomenon is called sex ratio adjustment, and is expected to evolve if certain factors affect the fitness return from the offspring in a sex-dependent way. However, it is seldom studied whether biased sex ratios are indeed adaptive. We manipulated BSRs in a cross-fostering experiment, and investigated parental costs in terms of feeding rate and survival in the collared flycatcher (Ficedula albicollis). In our population, male nestlings can grow faster under good conditions, but are more sensitive to adverse conditions. Assuming that the sensitivity of the males results from their larger energy requirement, we predicted increased costs in broods with male-biased experimental BSR. Assuming that BSR adjustment is adaptive and related to parental care giving capacity, we expected higher feeding and survival rate by parents that originally had more sons, and predicted that low quality parents are less able to adjust their feeding rates to the needs of their foster broods or pay higher survival cost. However, we found that the manipulated BSR and its interaction with original BSR affected neither the feeding rate nor the survival of the parents. Only male feeding rate was correlated with original BSR, however, contrary to our prediction: males with female-biased original BSR fed their foster chicks more frequently. Our results, with those of a previous report about the effects of the experiment on nestlings, do not support that the observed BSRs are adaptive in our population. Significance statement: Many hypotheses propose that higher vertebrates adaptively adjust the primary sex ratio of their offspring to individual or environmental quality. While the potential adaptive value of the observed patterns is regularly discussed, studies that specifically test the adaptivity of sex ratio adjustment are very scarce and correlative. Using a special cross-fostering experiment, we investigated whether original brood sex ratios are related to the rearing capacity of the parents, and experimental sex ratios are related to the rearing costs in terms of feeding effort or survival. We found no effect of experimentally altered brood sex ratios on either parental feeding effort or survival. Furthermore, contrary to the adaptive scenario, males that had female-biased broods originally had higher feeding rates. So far, we have found no evidence that the sex ratio adjustment is adaptive in the collared flycatcher. [ABSTRACT FROM AUTHOR]

Anaerobic treatment of oily substrate, known as grease trap waste (GTW), was investigated for its practicability via continuous stirred tank reactor (CSTR) at different operating conditions and selected recovery strategies of feeding frequency efficacy. This study determine the performance of feeding frequency efficacy, namely feeding every 24 hours (R24H) and feeding every 12 hours (R12H). Under organic loading rate (OLR) of 2.2 gCOD/L.day, R12H exhibited methane composition of 57%, methane production rate of 0.27 LCH4/L.day, and methane yield of 0.14 LCH4/gCODremoved. At the same OLR, R24H recorded methane composition of 60%, methane production rate of 0.29 LCH4/L.day and similar methane yield as R12H. Findings indicated that R24H showed performance comparable to that of R12H. Given minor variation observed in performance, it is recommended that plant operators may consider scheduling two feedings per day for low loading conditions and switch to one feeding per day for higher loading conditions. This strategy is designed to balance the system and prevent shock loads, which could lead to plant shutdowns. This mechanism will induce their conversion to volatile fatty acids (VFAs); thus, reducing the risk of acid accumulation and pH drops, which could inhibit methanogens to produce methane, especially for oily substrate. HIGHLIGHTS Strategy for lipid inhibition recovery.; Enhanced methane yield.; Mono-digestion efficiency strategy.; Long-chain fatty acids individual profile inhibition.; Start-up strategy to enhance lipid degradation.;

The whitespotted conger (Conger myriaster) is an important fish species with high economic value in China and Japan owing to its high nutritional content. It occupies an important position in marine-eel export in China. C. myriaster has the potential to be artificially cultured and has promising economic prospects. Thus, there is growing international interest in C. myriaster research. Indeed, to meet the demands of domestic and foreign markets, artificial culturing of C. myriaster is urgently required. However, at present, there is no report on the research of C. myriaster reared in industrial recirculating aquaculture systems. Feeding frequency has been reported to affect feed intake and growth performance in a number of fish species. Feed management in terms of optimization of feeding frequency has emerged as one of the crucial areas of research in the field of aquaculture. Overfeeding and leftover food disrupts the water quality, while inadequate food supply has direct impact on production cost. Traditional flow through systems uses large volumes of water, and intensified aquaculture has drawbacks, such as large amount of discharged waste from effluent water. Among the excreted nutrients, nitrogen and phosphorus constitute the largest proportion. Sustainability with low environmental impacts is one of the concerns when developing aquaculture systems. Based on the concepts of reduced water consumption and efficient water management, recirculating aquaculture systems offer the possibility of creating a sustainable future for fish production. Thus, a 70-day experiment was conducted to investigate the effects of different feeding frequencies and water quality on the growth performance and physiological and biochemical indices of C. myriaster [body weight: (150.64±5.43) g] reared in industrial recirculating aquaculture systems; physiological and ecological methods were used in this study. The experiment comprised two feeding frequency groups, feeding once (group T1) and twice (group T2) per day, and each treatment group had three replicates. The average body weight of the fish in each culture pond and the water quality indices of the culture system were measured and analyzed every 14 d. At the end of the experiment, the blood, liver, and intestine samples of C. myriaster were collected to determine and analyze growth and physiological indices. The results indicated that (1) the growth performance of group T2 was better than that of group T1. The final body weight, final body length, weight gain, and specific growth rate of group T2 was significantly higher than those of group T1 (P < 0.05). The feed coefficient of group T1 was significantly higher than that of group T2 (P < 0.05). However, no significant differences were found in the final body height, liver body ratio, visceral body ratio, condition factor, or survival rate at different feeding frequencies (P > 0.05). (2) The serum malondialdehyde of group T1 was significantly higher than that of group T2 (P < 0.05). The hepatic alanine aminotransferase and hepatic aspartate transaminase of group T1 was significantly higher than those of group T2 (P < 0.05). The intestinal trypsin of group T2 was significantly higher than that of group T1 (P < 0.05). There were no significant differences in the levels of serum superoxide dismutase, serum catalase, intestinal amylase, or intestinal lipase between groups T1 and T2 (P > 0.05). (3) In the 24 h changes of ammonia nitrogen (NH4+-N) and nitrite nitrogen (NO2–-N), the change patterns of the two indices in outlet of the T1 group were similar to those of the outlet of the bio-filter; the two indices of the outlet water in T1 and T2 groups were one (24:00) and two peaks (20:00 and 08:00) respectively; the difference in NH4+-N in the outlet water of the two test groups within 24 h was significant (P < 0.05); at 04:00 and 08:00, the NO2–-N content of the outlet water of the biofilter was significantly lower than that of the other two test groups (P < 0.05); the 24 h changes range of NH4+-N and NO2–-N in T2 group were smaller than those in T1 group. (4) During the whole test period, each water quality index was maintained within the safe breeding range, and no significant differences were found in NH4+-N, NO2–-N, chemical oxygen demand, and active phosphate concentration between T1 and T2 groups (P > 0.05); at the end of the test, the total nitrogen and total phosphorus of T2 group were significantly higher than those of T1 group (P < 0.05); the biofilter has different treatment effects on various water quality indices, among which the treatment effect on NH4+-N is the most efficient, up to 54.23%. Based on the above results, the feeding frequency of twice per day was better than that of once per day in the industrial recirculating aquaculture mode for C. myriaster (body weight: 150~250 g). Without affecting the survival rate and condition factor, the twice per day group can save costs and improve economic benefits. However, due to the limitations of the test conditions, we did not explore more times of feeding, and further tests are needed in the future. The predominance, which was the high efficiency of water qualities treatment and optimal effect of culture, was demonstrated obviously in closed recirculating aquaculture systems. This study aims to provide a theoretical reference for the appropriate feeding strategy in the industrial recirculating aquaculture model of C. myriaster.

ABSTRACT: This study examined the influence of feeding frequency on the morphology of the reproductive tract in broiler breeder hens, with a focus on the liver, ovary, and oviduct. A total of 364 hens and 52 roosters, starting at 31 wk of age and continuing until the end of their 38th week, were divided into 13 groups with varying feeding frequencies (1, 2, or 3 times daily). Significant changes in reproductive and metabolic parameters were observed, where feeding hens twice or thrice daily resulted in significantly reduced ovary weight and follicle counts (P < 0.001), while liver weight increased (P < 0.05). These findings suggesting complex interactions between feeding practices and reproductive efficiency.

Parents confront multiple aspects of offspring demands and need to coordinate different parental care tasks. Biparental care is considered to evolve under circumstances where one parent is not competent for all tasks and cannot efficiently raise offspring. However, this hypothesis is difficult to test, as uniparental and biparental care rarely coexist. Chinese penduline tits (Remiz consobrinus) provide such a system where both parental care types occur. Here, we experimentally investigated whether parents in biparental nests are less capable of caring than parents in uniparental nests. We monitored parenting efforts at (1) naturally uniparental and biparental nests and (2) biparental nests before and during the temporary removal of a parent. Given the relatively small sample sizes, we have employed various statistical analyses confirming the robustness of our results. We found that total feeding frequency and brooding duration were similar for natural uniparental and biparental nests. Feeding frequency, but not brooding duration, contributed significantly to nestling mass. In line with this, a temporary parental removal revealed that the remaining parents at biparental nests fully compensated for the partner's feeding absence but not for brooding duration. This reflects that the manipulated parents are confronted with a trade‐off between feeding and brooding and were selected to invest in the more influential one. However, such a trade‐off may not occur in parents of natural uniparental care nests. The different capabilities of a parent independently coordinating feeding and brooding tasks suggest that parents from biparental and uniparental nests were exposed to different resource conditions, thereby foraging efficiency may differ between care types. [ABSTRACT FROM AUTHOR]

ABSTRACT: The objective of this study was to investigate the effect of feeding behavior on feed intake and body weight in growing layers and the underlying mechanisms, thereby providing a scientific foundation for optimal feeding practices in growing layers' management. A total of 144 Hy-line brown growing layers of 10 wk old and similar body weight, were divided into 3 treatment groups with different feeding frequency and equal cumulative daily feeding amount: the once-a-day feeding group (F1) was fed at 9:00 am every day, with feeding amount of 150 g/layer; the twice-a-day feeding group (F2) were fed at 9:00 am and 13:00 pm every day, with each feeding amount of 75 g/layer; the 4 times-a-day feeding group (F4) were fed at 9:00 am, 11:00 am, 13:00 pm, and 15:00 pm every day, with each feeding amount of 37.5 g/layer. Pre-experiment lasted for 1 wk and formal experiment lasted for 8 wk. The results indicated that the daily feed intake and body weight were decreased (P < 0.05) while feed conversion ratio was not affected (P > 0.05) as daily feeding times increased. The glandular stomach proportion was significantly increased in twice-a-day feeding group, while liver proportion and ileum length were significantly increased in 4 times-feeding group (P < 0.05). Additionally, 4 times-feeding daily resulted in a significant elevation of blood glucose levels, which may have suppressed feed intake (P < 0.05). In 4 times-feeding group, the plasma triglyceride levels increased as feeding times, accompanied by a notable up-regulation in the mRNA level of appetite-suppressing gene, hypothalamic pro-opiomelanocortin (POMC) and glandular stomach ghrelin. This modulation effectively suppressed the subsequent feed intake and body weight. Therefore, 4 times feeding daily is recommended in growing layers’ management, because it reduced the feed cost without affecting the feed conversion efficiency.

The rare and endemic largemouth bronze gudgeon (Coreius guichenoti) inhabits the middle and upper reaches of the Yangtze River. It is a typical migratory river fish found in the vicinity of rapids. Over the years, the construction of water conservancy facilities and overfishing by humans have harmed the ecological habitat of this species, resulting in a considerable population decline. Thus, the largemouth bronze gudgeon has emerged as an important conservation objective and artificial stocking target for protecting and restoring the ecological environment in the Yangtze River Basin. Artificial stocking is one of the most effective methods for restoring the population of rare and endangered fish, and it is widely used domestically and abroad. Culturing a healthy and sufficient number of fry is critical to stocking success. In the production of largemouth bronze gudgeon, the formulation of an effective feeding strategy plays an important role. A scientific and reasonable feeding rate and frequency serve as guidelines for improving the production and quality of cultured fry, which directly impact the survival rate, growth performance, and feed consumption of fish. In order to determine the appropriate feeding strategy for improving fry breeding efficiency, an 8-week feeding trial in a 5 × 2 two-factorial design was conducted to investigate the effects of feeding levels (1%, 2%, 3%, 4%, and 5%) and feeding frequency (2 and 3 times/d) on growth, whole-body composition, digestive enzyme activity, and liver structure of juvenile largemouth bronze gudgeons with an initial weight of (4.91±0.11) g. The results were as follows: After 8 weeks of culture, the survival status of largemouth bronze gudgeon in each treatment group was good. Only two fish mortalities were observed, one in each of the two feeding frequency groups at the 5% feeding level. There was no mortality in the other groups. Feeding level, feeding frequency, and the interaction of the two items had significant effects on the weight gain rate (WGR), specific growth rate (SGR), and feed efficiency (FE) of individuals, whereas only the feeding frequency had significant effects on the condition factor (CF) and viscerosomatic index (VSI). WGR and SGR significantly increased with the feeding level. Meanwhile, the FE increased with increasing feeding levels and then stabilized at the 3% feeding level. Fish fed 3 times/d had higher WGR, SGR, and FE than fish fed 2 times/d when feeding levels did not exceed 3%. As feeding frequency increased, the CF and VSI of individuals tended to decrease. Both whole-body moisture content and crude fat content were significantly affected by the feeding level. The increase in feeding level decreased the whole-body moisture content while increasing the whole-body crude fat content. Digestive enzymes in the foregut of individuals were not significantly affected by feeding level, feeding frequency, or their interactions; however, the feeding level had significant effects on hepatic trypsin (TPS) and lipase (LPS) activities. Increasing feeding levels considerably reduced the TPS activity when the feeding levels were higher than 3%, whereas the LPS activity initially increased and then decreased with increasing feeding levels at a feeding frequency of 3 times/d. Hepatic HE staining revealed that the hepatocytes of fish fed 2 times/d continued to increase in size and progressively swelled and vacuolated, exhibiting indications of a fatty liver when the feeding level reached 3% and increased further. Hepatocytes of fish fed 3 times/d were surrounded by a large number of round and ovoid lipid droplets at the 3% and 4% feeding levels, but there were no discernible changes in the structure of the cells. When the feeding level reached 5%, hepatocytes began to enlarge and swell in groups at a feeding frequency of 3 times/d, but to a lesser extent than the groups fed 2 times/d. In conclusion, under the conditions of this experiment, a comprehensive assessment of growth performance, feed utilization efficiency, and hepatic health revealed that feeding juvenile largemouth bronze gudgeons three times daily at a level of 3% body weight was the optimal feeding strategy. The objective of this study was to determine the optimal feeding strategy for the fry culturing process. The findings provide theoretical guidelines for the artificial reproduction of largemouth bronze gudgeon and contribute to the recovery of its native population. Additionally, as a species that inhabits torrential habitats, the largemouth bronze gudgeon possesses distinct digestive and physiological properties. This study lays the foundation and groundwork for future research on the nutritional requirements, feed production, and artificial breeding of these species.

The objective of this study was to investigate the influence of feeding frequency on a sow’s reproductive performance and stress response during gestation. A total of twenty multiparous sows (Yorkshire × Landrace) were used in a completely randomized design based on their parity, body weight (BW), and backfat thickness (BFT), and the sows were allotted to two different feeding systems: 1) once daily feeding (OF) and 2) twice daily feeding (TF) in corn-soybean meal based diets. The gestation diet was formulated to contain 3,265 kcal of metabolizable energy (ME) / kg, 12.90% of crude protein (CP), and 0.75 % of total lysine. The lactation diet was formulated to contain 3,265 kcal of ME / kg, 16.80% of CP, and 1.08% of total lysine and provided ad libitum during lactation. In gestation, sow BFT and BF changes were not affected by feeding frequency, but higher BW and BW gain from day 35 to 90 and day 35 to 110 were observed in OF sow (p < 0.10). In lactation, feeding frequency did not influence on BW, BW gain, BFT, BF changes, average daily feed intake, and wean-to-estrus interval. Also, there were no differences in litter size, litter weight and piglet weight in lactating sows. OF sows had higher (p < 0.05; p < 0.10) protein, solid-not-fat, and total solid concentrations in colostrum compared to TF sows, while OF sows had a lower (p < 0.05) lactose concentration in colostrum compared to TF sows. Sows in OF showed significantly lower average daily water consumption (ADWC) from day 35 to 110 of gestation (p < 0.05). While there were no significant differences in stereotypic behaviors and salivary cortisol levels during gestation between treatments, the OF sows showed less time spending on the activity at day 105 (p < 0.05). In conclusion, reduced feeding frequency increased BW gain during gestation, decreased activation time, and changed the colostrum composition. This information may contribute to the understanding of the physiological and behavioral change of gestating sows by manipulating feeding frequency.

The Mexican pike silverside (Chirostoma estor) is a zooplanktivorous, agastric short-intestined species, and it has been found that increased-frequency feeding (twelve feedings a day) improved feed efficiency and promoted growth by 70%. This work determined the effect of different juvenile feeding frequencies upon the C. estor liver transcriptome. The level of the expression of appetite-regulating peptides was analyzed in silico to understand the mechanisms involved in appetite control in this species. Differential expression analysis showed that up-regulated genes between treatments were related to metabolism, digestive processes, immune system response, apoptosis, growth, and oxidative stress. This information explains the better performance of pike silverside fed 12 times daily. Appetite regulatory peptides were identified for the first time in the liver of C. estor in response to high feeding frequencies, contributing to the general knowledge of the roles of each family of neuropeptides in this agastric, short-intestined fish. The information presented here emphasizes the need to explore further the complex physiological processes involved in appetite regulation in C. estor. Additionally, it will serve as a basis for more specific targeted studies of appetite control to elucidate the mechanisms behind this process.

Feeding strategies have a significant impact on growth and water quality in shrimp farming. Feed management also affects shrimp health, survival, and yields. All these factors contribute to production cost-effectiveness and the commercial shrimp industry sustainability. The effect of feeding frequency and two aquafeed cooking processes (extrusion and pelleting) on shrimp performance and water quality parameters was studied under controlled conditions in a 60-day trial with juvenile Litopenaeus vannamei fed once (10:00 h); twice (10:00 h, 12:00 h); four (10:00 h, 12:00 h, 15:00 h, 18:00 h) and six (10:00 h, 12:00 h, 15:00 h, 18:00 h, 21:00 h, 24:00 h) times/day frequencies. No statistical differences (p > 0.05) in growth rate, survival or feed efficiency were observed within pelleted feed treatments at any of the frequencies tested. Growth rate was significantly higher (p < 0.05) with extruded feed when administered once or twice in daylight (10:00–12:00 h). However, at such frequencies, growth was achieved at the cost of water quality and feed conversion ratio. At higher frequencies (six times a day) with extruded diets, the results in water quality suggest a reduction in total ammonia nitrogen and nitrite-nitrogen levels as frequency increased. The outcomes suggest that extruded feed with daylight feeding has the potential to improve growth rate, and an increased frequency could represent a suitable strategy to preserve water quality. The present research is the first to show that the extrusion process improves water quality; thus, extruded feeds could reduce effluent pollution impact and improve shrimp farming sustainability. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Larval cod require live prey as food, and prey concentration (PC) and feeding frequency (FF) often affect their growth and survival. Apart from this, water exchange rates/water flow (WER/WF) and water current (WC) also affect the prey resident time in the tank and larval/early juvenile behaviour, respectively. High water current is also known to induce stress in finfish larvae, and this stress response is believed to be dependent on larval developmental stage. Thus, we conducted a study to evaluate three larval rearing protocols varying in prey concentration, feeding frequency, and water current/exchange rate. Three protocols were used: low prey concentration (PC), low feeding frequency (FF), and low water flow (protocol 1); medium PC, medium FF, and medium WF (protocol 2); and high PC, high FF, and high WF (protocol 3) (see Table 1). Larvae were sampled periodically for growth and cortisol measurements. Cortisol extraction and radioimmunoassay (RIA) were conducted using methods previously validated for cod larvae. Larvae reared using protocols 2 and 3 were significantly bigger and heavier than larvae reared using protocol 1. Rearing protocol had a significant effect on the cortisol level in larval cod. Larvae showed a developmental stage-dependent stress response. Protocol 2 had significantly higher survival than protocols 1 and 3. Our results indicate that an intermediate PC, FF, and WF (protocol 2) is suitable during cod larval rearing. [ABSTRACT FROM AUTHOR]

Eating patterns, i.e. meal frequency and circadian timing of meals, are often modified in weight loss and metabolic healing strategies. However, in-depth research into the effects on the gut microbiome remains scarce, particularly across various colon regions and niches. We identified eating patterns to contribute in shaping the in vitro gut biomass production, metabolism, and microbial community compositions by subjecting four faecal microbiomes to a pattern that is standardized for a dynamic gut model (feeding at 09, 17, and 01 h), a typical Western (breakfast, lunch, and dinner at 09, 13, and 19 h, respectively), and a time-restricted pattern (single meal at 09 h). While eating patterns moderately affected the microbiome (2.4% and 1.8% significant variation in proportional and quantitative microbial compositions, respectively), significant changes were noted in the time-restricted pattern, including increased Bacteroides, Butyricicoccus, Dialister , and Faecalibacterium abundances. Sampling every 4 h revealed no significant circadian fluctuations in biomass production, microbial community compositions, or functionality. Longer fasting times favoured the growth of slower-growing species, such as Akkermansia, Dialister , and Parasutterella over faster-growers, such as Pseudomonas and Stenotrophomonas. Our findings illustrate the importance of recording and considering eating patterns as a gut microbiome determinant in in vivo and in vitro dietary intervention studies. [ABSTRACT FROM AUTHOR]

Introduction: The lack of animal feed resources and the increase in animal feed costs relative to the total production costs have created challenges in supplying society with animal protein. Therefore, correctly estimating the nutritional value of feed, especially protein sources, can be an important step in meeting the needs of livestock and reducing production costs. Protein is the most important and expensive nutrient used in ruminant diets. Using non-protein nitrogen (NPN) sources such as urea or its products can be considered a cheap alternative source in animal feeding. Iran is one of the most important urea-producing countries in the world; therefore, using urea or its slow-release products as a feed additive in animal nutrition can be beneficial. In the past years, various sources of slow-release urea have been produced and used in animal feeding. Biuret (heated urea) is one of the slowrelease urea compounds, and its production cost is lower than other slow-release urea sources. Compared to urea, it has less solubility in water and is converted to ammonia in the rumen at a much slower rate. It is also less toxic than urea and has a lower negative effect on feed palatability, so it can be used to a greater extent than urea in the diet of ruminants. Biuret is very safe and it can be included in the diet of animals in an amount of 20 times higher than the toxic dose of urea. Biuret usually contains 248.5% crude protein (39.8% nitrogen content), which is a little less than urea. On the other hand, increasing the daily feeding frequency is one of the management methods that may improve the productive performance of livestock, as well as the quantity and quality of the carcass. Increasing the feed frequency may improve nitrogen retention and reduce body fat. It is believed that increasing the frequency of daily feeding will keep the feed fresh, reduce the amount of feed waste, and improve livestock performance. Therefore, this study aimed to investigate the effect of NPN source, in high-protein diets, and feeding frequency on growth performance, rumen parameters, and the activity of rumen microbial enzymes of fattening lambs. Materials and methods: Twenty-eight male Lori-Bakhtiari fattening lambs (age: four to five months; live weight: 36.1±3 kg) were assessed for 60 days using a 2×2 factorial experiment in a completely randomized design with four treatments and seven replications. The experimental high-protein diets (16% of DM) contained urea or biuret, which were given to the lambs in the form of a total mixed ration two or three times a day. The lambs were kept in 1×1.5 m2 individual stalls. Nutrient intake, growth performance, and ruminal parameters [on day 45 of the experiment at fasting (before morning feeding), three, and six h after feeding] including pH, ammonia and volatile fatty acid concentrations, and microbial enzyme activity were measured. [ABSTRACT FROM AUTHOR]

Abstract Parents confront multiple aspects of offspring demands and need to coordinate different parental care tasks. Biparental care is considered to evolve under circumstances where one parent is not competent for all tasks and cannot efficiently raise offspring. However, this hypothesis is difficult to test, as uniparental and biparental care rarely coexist. Chinese penduline tits (Remiz consobrinus) provide such a system where both parental care types occur. Here, we experimentally investigated whether parents in biparental nests are less capable of caring than parents in uniparental nests. We monitored parenting efforts at (1) naturally uniparental and biparental nests and (2) biparental nests before and during the temporary removal of a parent. Given the relatively small sample sizes, we have employed various statistical analyses confirming the robustness of our results. We found that total feeding frequency and brooding duration were similar for natural uniparental and biparental nests. Feeding frequency, but not brooding duration, contributed significantly to nestling mass. In line with this, a temporary parental removal revealed that the remaining parents at biparental nests fully compensated for the partner's feeding absence but not for brooding duration. This reflects that the manipulated parents are confronted with a trade‐off between feeding and brooding and were selected to invest in the more influential one. However, such a trade‐off may not occur in parents of natural uniparental care nests. The different capabilities of a parent independently coordinating feeding and brooding tasks suggest that parents from biparental and uniparental nests were exposed to different resource conditions, thereby foraging efficiency may differ between care types.

In artificial breeding, feeding frequency is crucial for maintaining the liver health status in largemouth bronze gudgeon (Coreius guichenoti). Nevertheless, the underlying mechanism governing this relationship remains unclear. The present study aimed to elucidate the effects of feeding frequencies (2 T/D, 2 times day-1; 3 T/D, 3 times day-1) on the liver health of Coreius guichenoti. Groups of juveniles (60 fish group-1) with an initial body weight of 4.91 ± 0.11 g were randomly assigned to 6 tanks. Fish were fed with 2 T/D and 3 T/D for 8 weeks at a feeding rate of 3%. The results showed that the SGR and FER of the 3 T/D were higher than those of the 2 T/D (P

ABSTRACT: The aim of this systematic review was to summarize the literature assessing the effects of milk feeding practices on behavior, health, and performance on dairy calves. Peer-reviewed, published articles, written in English, directly comparing the effects of milk allowance, milk feeding methods, or milk feeding frequency on dairy calves were eligible for inclusion. Outcome measures could include sucking behavior, sucking on a teat (nutritive sucking, non-nutritive sucking on a teat), abnormal sucking behavior (non-nutritive sucking on pen fixtures, other oral behaviors, or cross-sucking), signs of hunger (vocalizations or unrewarded visits at the milk feeder), activity (lying time or locomotor play), feeding behavior (milk intake, starter intake, milk meal duration, or starter meal duration), growth (body weight or average daily gain), and health (occurrence of diarrhea, respiratory disease, or mortality). We conducted 2 targeted searches using Web of Science and PubMed to identify key literature. The resulting articles underwent a 2-step screening process. This process resulted in a final sample of 94 studies. The majority of studies investigated milk allowance (n = 69). Feeding higher milk allowances had a positive or desirable effect on growth, reduced signs of hunger, and increased locomotor play behavior during the preweaning period, whereas starter intake was reduced. Studies addressing health pointed to no effect of milk allowance, with no consistent evidence indicating that higher milk allowances result in diarrhea. Studies addressing milk feeding methods (n = 14) found that feeding milk by teat reduced cross-sucking and other abnormal oral behaviors. However, results on the effect of access to a dry teat were few and mixed. Milk feeding frequency (n = 14 studies) appeared to have little effect on feed intakes and growth; however, there is some evidence that calves with lower feeding frequency experience hunger. Overall, findings strongly suggest feeding higher volumes of milk using a teat; however, further work is needed to determine the optimal feeding frequency for dairy calves.

A 42 day factorial trial (3x2) was designed to evaluate the effect of short-term starvation with different feeding frequencies on performance, feed utilization, physiological status and appetite responses of red hybrid tilapia fingerlings. Eighteen plastic tanks with a capacity of (55 L) were used to accomplish this work. Fingerlings with an average initial weight of 23 g ± 0.2 (SE) were randomly stocked at a rate of 8 fingerlings/aquarium. Six groups were designated as the following: II/ED: fish was fed twice every day; IV/ED: fish fed four times every day; II/EOD: fish fed twice every other day (alternate-day feeding or one day of feeding followed by another of fasting); IV/EOD: was fed four times every other day; II/EO3D: fish fed twice every other three days (three day of feeding followed by another of fasting) and IV/EO3D: fish fed four times every other three days. Fish were fed on commercial diets 30 % protein (4 % of biomass). Results showed insignificant differences between fish fed every other day and those fed every day in some growth indicators. In the same trend, the interaction between feed deprivation and feeding frequency cleared that fingerlings of IV/EOD did not significantly differ with those fed every day in growth indices. Moreover this treatment was the best in feed conversion efficiency and several physiological indicators.

Body size shifts in ectotherms are mostly attributed to the Temperature Size Rule (TSR) stating that warming speeds up initial growth rate but leads to smaller size when food does not limit growth. Investigating the links between temperature, growth, and life history traits is key to understand the adaptive value of TSR, which might be context dependent. In particular, global warming can affect food quantity or quality which is another major driver of growth, fecundity, and survival. However, we have limited information on how temperature and food jointly influence life history traits in vertebrate predators and how changes in different life history traits combine to influence fitness and population demography. We investigate (1) whether TSR is maintained under different food conditions, (2) if food exacerbates or dampens the effects of temperature on growth and life history traits and (3) if food influences the adaptive value of TSR. We combine experiments on the medaka with Integral Projection Models to scale from life history traits to fitness consequences. Our results confirm that warming triggers a higher initial growth rate and a lower adult size, reduces generation time and increases mean fitness. A lower level of food exacerbates the effects of warming on growth trajectories. Although lower feeding frequency increased survival and decreased fecundity, it did not influence the effects of warming on fish development rates, fecundity, and survival. In contrast, feeding frequency influenced the adaptive value of TSR, as, under intermittent feeding, generation time decreased faster with warming and the increase in growth rate with warming was weaker compared to continuously fed fish. These results are of importance in the context of global warming as resources are expected to change with increasing temperatures but, surprisingly, our results suggest that feeding frequency have a lower impact on fitness at high temperature. [ABSTRACT FROM AUTHOR]

In order to explore the effects of feeding frequency on the growth and digestibility of Microp⁃ terus salmoides with fixed feeding rate that under satiation, five feeding frequencies (2 times/d, 3 times/d, 4 times/d, 5 times/d, 6 times/d) were evaluated in triplicate recirculating aquaculture systems for 56 days. The results show that: the specific growth rate of 3、4 and 5 times/d groups were significantly higher than that of 6 times/d group (P<0.05); the weight gain rate of 3 and 5 times/d groups were significantly higher than that of 6 times/d group (P<0.05); the feeding rate of the 5 times/d group was the highest; the protein efficiency of 2 and 3 times/d groups were significantly higher than that of 4 and 6 times/d groups (P< 0.05); the fatness of the 6 times/d group was significantly higher than that of the 3 times/d group (P< 0.05); the ratio of viscera to body in the 2 times/d group was significantly higher than that in the 3, 4 and 6 times/d groups (P<0.05). In stomach, the activity of AMS and LPS appeared in the 2 times/d group and 5 times/d group respectively (P<0.05). In py‐ loric caecum, the values of AMS activity and LPS activity appeared in the 6 times/d group and 5 times/d group respectively (P<0.05). In midgut, the activity of AMS and LPS appeared in the 5 times/d group and 3 times/d group respectively (P<0.05). In hepatopancreas, the activity of AMS and LPS appeared in the 4 times/d group and 2 times/d group respectively (P<0.05). The villus height of the foregut in the 3 times/d group was the largest (P<0.05), the villus width was significantly higher than that in the 4, 5 and 6 times/d groups (P<0.05), and the muscular layer thickness was significantly higher than that in the 2, 4 and 5 times/d groups (P<0.05); in midgut, the villus height and muscular layer thick‐ ness of the 2 times/d group were the largest (P<0.05), and the villus width of the 4 times/d group was sig‐ nificantly higher than that of the 3, 5 and 6 times/d groups (P<0.05); the maximum values of villus height, villus width and muscular thickness of the hindgut appeared in the 2 times/d group, 3 times/d and 6 times/d groups respectively (P<0.05). In the tissue sections of hepatopancreas, the cell contour and nuclear clarity of the 2 and 3 times/d groups were better than those of the high-frequency feeding groups. From the perspective of growth performance, digestion ability and tissue health of Micropterus salmoides, the appropriate feeding frequency for young Micropterus salmoides is 3 times/d in the circulat‐ ing water system. [ABSTRACT FROM AUTHOR]

The aim of this systematic review was to summarize the literature assessing the effects of milk feeding practices on behavior, health, and performance on dairy calves. Peer-reviewed, published articles, written in English, directly comparing the effects of milk allowance, milk feeding methods, or milk feeding frequency on dairy calves were eligible for inclusion. Outcome measures could include sucking behavior, sucking on a teat (nutritive sucking, non-nutritive sucking on a teat), abnormal sucking behavior (non-nutritive sucking on pen fixtures, other oral behaviors, or cross-sucking), signs of hunger (vocalizations or unrewarded visits at the milk feeder), activity (lying time or locomotor play), feeding behavior (milk intake, starter intake, milk meal duration, or starter meal duration), growth (body weight or average daily gain), and health (occurrence of diarrhea, respiratory disease, or mortality). We conducted 2 targeted searches using Web of Science and PubMed to identify key literature. The resulting articles underwent a 2-step screening process. This process resulted in a final sample of 94 studies. The majority of studies investigated milk allowance (n = 69). Feeding higher milk allowances had a positive or desirable effect on growth, reduced signs of hunger, and increased locomotor play behavior during the preweaning period, whereas starter intake was reduced. Studies addressing health pointed to no effect of milk allowance, with no consistent evidence indicating that higher milk allowances result in diarrhea. Studies addressing milk feeding methods (n = 14) found that feeding milk by teat reduced cross-sucking and other abnormal oral behaviors. However, results on the effect of access to a dry teat were few and mixed. Milk feeding frequency (n = 14 studies) appeared to have little effect on feed intakes and growth; however, there is some evidence that calves with lower feeding frequency experience hunger. Overall, findings strongly suggest feeding higher volumes of milk using a teat; however, further work is needed to determine the optimal feeding frequency for dairy calves. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural, Environmental & Veterinary Sciences is the property of Arab Journal of Sciences & Research Publishing (AJSRP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The polychaete Hediste diversicolor is a suitable species for industrial aquaculture; however, cost-effective culture techniques need to be developed for its intensive production. The aim of this study is to evaluate the effects of worm density and substrate height and their interaction, as well as feeding frequency, on the rearing performance of H. diversicolor. Two trials were conducted. In trial 1, the effects of two substrate heights—6 and 12 cm—and two rearing densities—1000 and 4000 individuals m−2—were assessed in terms of worm growth and biomass production. Worm initial wet weight was 48 mg, and specimens were fed with commercial fish feed during a 70-day assay. The results show no interaction between rearing density and substrate height, and confirm density as a key factor in growth; however, a density of 4000 individuals m−2 results in a significant increase in production (final biomass three times higher for the highest rearing density) without affecting survival. In trial 2, the effect of three levels of feeding frequency—seven days a week; three times a week; and once a week—on growth in individuals of three weight classes—small (25–50 mg); medium (100–150 mg); large (250–350 mg)—was evaluated in a 15-day growing assay. Feeding frequency showed a major influence on the smallest size class, with the best growth indicators obtained at the highest feeding frequency. This study shows that Hediste diversicolor can be reared at a high stocking density to obtain a higher biomass production, and that feeding frequency must be considered as an important factor and adapted to the culture phase.

Abstract Body size shifts in ectotherms are mostly attributed to the Temperature Size Rule (TSR) stating that warming speeds up initial growth rate but leads to smaller size when food does not limit growth. Investigating the links between temperature, growth, and life history traits is key to understand the adaptive value of TSR, which might be context dependent. In particular, global warming can affect food quantity or quality which is another major driver of growth, fecundity, and survival. However, we have limited information on how temperature and food jointly influence life history traits in vertebrate predators and how changes in different life history traits combine to influence fitness and population demography. We investigate (1) whether TSR is maintained under different food conditions, (2) if food exacerbates or dampens the effects of temperature on growth and life history traits and (3) if food influences the adaptive value of TSR. We combine experiments on the medaka with Integral Projection Models to scale from life history traits to fitness consequences. Our results confirm that warming triggers a higher initial growth rate and a lower adult size, reduces generation time and increases mean fitness. A lower level of food exacerbates the effects of warming on growth trajectories. Although lower feeding frequency increased survival and decreased fecundity, it did not influence the effects of warming on fish development rates, fecundity, and survival. In contrast, feeding frequency influenced the adaptive value of TSR, as, under intermittent feeding, generation time decreased faster with warming and the increase in growth rate with warming was weaker compared to continuously fed fish. These results are of importance in the context of global warming as resources are expected to change with increasing temperatures but, surprisingly, our results suggest that feeding frequency have a lower impact on fitness at high temperature.

Copyright of Journal of Dalian Ocean University is the property of Journal of Dalian Ocean University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was carried out to investigate the growth data, egg production and changes in the biochemical structure of meat of Abant trout depending on feeding frequency (once a day, twice a day, three times a day, four times a day) in order to contribute to the economy through the private sector. All fish in the groups were planned to be of similar weight at the beginning of the study. Individual fish weights were measured at the beginning of the study, and the average was found to be 224.87 ± 0.69 g. At the end of the study, the weights of the fish groups that were fed differently were 536.77 ± 37.46 g, 693.52 ± 67.53 g, 770.47 ± 37.29 g, and 810.63 ± 42.09 g, respectively. The absolute numbers of eggs taken per brood from the once meal group to the four-time meal group were found as 707 ± 38, 999 ± 77, 1036 ± 110, and 1053 ± 60 eggs/broodstock, respectively. In terms of fatty acids, which are an important contributor to meat quality, the second, third, and fourth meal groups were found to be advantageous compared to the first meal group. According to the data obtained at the end of this study, which lasted 392 days, it was seen that the groups which received meals twice, three times, and four times could be cultured by the private sector because of the good results. Especially the three-time meal group yielded the best results in terms of growth, egg production, biochemical data, and meat quality. It has been concluded that breeding and species-specific feed production studies will contribute to the cultivation studies. [ABSTRACT FROM AUTHOR]

The polychaete Hediste diversicolor is a suitable species for industrial aquaculture; however, cost-effective culture techniques need to be developed for its intensive production. The aim of this study is to evaluate the effects of worm density and substrate height and their interaction, as well as feeding frequency, on the rearing performance of H. diversicolor. Two trials were conducted. In trial 1, the effects of two substrate heights—6 and 12 cm—and two rearing densities—1000 and 4000 individuals m−2—were assessed in terms of worm growth and biomass production. Worm initial wet weight was 48 mg, and specimens were fed with commercial fish feed during a 70-day assay. The results show no interaction between rearing density and substrate height, and confirm density as a key factor in growth; however, a density of 4000 individuals m−2 results in a significant increase in production (final biomass three times higher for the highest rearing density) without affecting survival. In trial 2, the effect of three levels of feeding frequency—seven days a week; three times a week; and once a week—on growth in individuals of three weight classes—small (25–50 mg); medium (100–150 mg); large (250–350 mg)—was evaluated in a 15-day growing assay. Feeding frequency showed a major influence on the smallest size class, with the best growth indicators obtained at the highest feeding frequency. This study shows that Hediste diversicolor can be reared at a high stocking density to obtain a higher biomass production, and that feeding frequency must be considered as an important factor and adapted to the culture phase. [ABSTRACT FROM AUTHOR]

This study aimed to compare the growth performance and economic profitability of rearing Oreochromis niloticus in floating cages using three feeding strategies (5 days a week, 6 days a week, and 7 days a week) coupled with three stocking densities (20, 40, and 60 fish·m−3). Male monosex fish measuring 6.44 ± 0.18 cm and weighing 3.42 ± 0.7 g were used. The controls were weighed every 15 days from the 35th day of rearing until 185 days to assess zootechnical parameters. BioMar feed (Efico Cromis 832F) was used during the study, and the feed ration was adjusted for each treatment every 2 weeks. At the end of the study, the average weights varied from 293.09 g to 468.41 g for the conditions of 40 fish·m−3 with a 5/7-day diet and 20 fish·m−3 with a 7/7-day diet, respectively. The yield per m2 values were between 7.11 kg and 23.17 kg, respectively. On the other hand, the economic profitability was better with the condition of 40 fish.m−3 with daily feeding. These results suggest that in the Toho-Todougba lagoon complex, a stocking density between 40 and 60 fish·m−3 coupled with daily feeding (three times a day) promotes the optimization of fish production and profitability of fish farming. [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]

【Objective】This experiment was conducted to research the effects of feeding frequency, water temperature and breeding density on growth performance, intestinal structure and hepatic GH and IGF-1 gene expression levels of largemouth bass in an indoor recirculating aquaculture system so as to determine the appropriate feeding frequency, water temperature and breeding density of largemouth bass.【Method】The experiment consisted of 8 treatments (Ⅰ - Ⅷ). After 8 weeks of breeding, the growth performance indicators such as specific growth rate (SGR), feeding rate (FR), feed coefficient (FCR) and survival rate, the intestinal villus height, villus width and muscle thickness, and the expression of hepatic growth factor GH and IGF-1 genes of largemouth bass were evaluated.【Result】Only the main effects of breeding density on FR and feeding frequency on condition factor (CF) were significant, while the interaction effects had a significant effect on CF. The one-way ANOVA results showed that, the growth performance of treatment Ⅴ was significantly better than that of other treatments, and the SGR was significantly higher than that of treatments Ⅱ, Ⅳ, Ⅵ and Ⅷ, increasing by 10.16%, 10.61%, 9.27% and 8.4%, respectively; the FR was significantly higher than that of treatments Ⅰ, Ⅱ, Ⅳ and Ⅵ, increased by 10.94%, 27.02%, 26.45% and 17.38%, respectively; the FCR was significantly lower than that of treatments Ⅳ, Ⅷ and Ⅷ, decreasing by 7.87%, 8.89% and 8.89%, respectively. Compared with the treatmentⅤ, the FR of treatment I was significantly lower than that of treatmentⅤ, but there were no significant differences in SGR and FCR. The main effect and the interaction effect on intestinal villus height, villus width, muscle thickness and hepatic GH and IGF-1 gene expression levels were not significant. The intestinal villus height of treatment Ⅴ was significantly higher than that of treatments Ⅳ, Ⅵ and Ⅶ, villus width of treatments Ⅰ and Ⅴ was significantly higher than that of treatments Ⅲ, the intestinal muscle thickness of treatments Ⅰ and Ⅲ was thicker than that of treatment Ⅷ, and there was no significant difference in other treatments. The hepatic GH and IGF-1 gene expression levels of treatments Ⅰ and Ⅴ were significantly higher than those of other treatments.【Conclusion】The optimal feeding frequency for largemouth bass was 2-3 times/d, the water temperature was 25 ℃, and the breeding density was 25 fish per tank (150 L).

We aimed to investigate the eating frequency (EF) in children over age, and examined the influence of country, sex, feeding mode and weight status on EF. We used the dietary data of the Childhood Obesity Project, which comprised European children from five countries. Dietary data of 3-days weighed and estimated records were available monthly from 1 to 9 and at 12-, 24-, 36-, 48-, 60-, 72- and 96-months old. Generalized additive mixed effects models were used to estimate EF trajectories with EF as outcome and applying age splines. Additionally, the models were further adjusted for country, feeding mode, sex or weight status. Data from 1244 children were analysed. EF was highest at 1 month with on average 7.3 ± 1.9 feeds per day, and fell to 5.1 ± 1.1 eating occasions at the age 96 months. Night feeding was similarly often than day feeding at 1 month but declined thereafter. Significant differences in EF were observed between countries (p < 0.05), with the highest EF in Poland, and between infant feeding modes, with a higher EF in breastfed than non-breastfed infants (p < 0.05). Sex and body weight were not associated with EF. Despite the importance of EF towards total energy intake, no association with weight status was found. [ABSTRACT FROM AUTHOR]

Simple Summary: Diversification of cultured fish species is one key measure to promote the sustainable development of marine aquaculture. Mullets (Mugilidae) present great potential due to their eurythermal, euryhaline, and low-trophic nature. However, there are many similar mullet species, and their physiological differences and optimal culture conditions are quite unknown, mainly when reared under intensive systems. In this sense, increasing the knowledge about changes in their digestive biochemistry related to feeding strategies is essential for a sustainable and cost-effective culture of these species. For these reasons, the present study aimed to characterize the digestive biochemistry of two mullet species (Chelon labrosus and Liza aurata) and to evaluate how it is affected when fish are fed using two different feeding frequencies: one or three times per day. In addition, changes in the potential bioavailability of nutrients determined by the two feeding patterns were assessed using digestive simulations performed in vitro. The results demonstrated the convenience of a feeding pattern of three meals per day instead of one. Moreover, the results evidenced that although Chelon labrosus and Liza aurata are species placed in a similar trophic level, their digestive response to feeding patterns, as well as body composition, present differences when fish are reared under the same conditions. This suggests that such interspecific variation must be considered when fish are reared under intensive conditions. Mullets (Mugilidae) present significant potential for sustainable aquaculture diversification due to their eurythermal, euryhaline, and low-trophic nature. However, the physiological differences and optimal cultured conditions among the diverse mullet species are quite unknown. For these reasons, the present study aimed to address two main objectives: (1) to characterize the differences in digestive biochemistry, somatic indexes, and body composition between two mullet species (Liza aurata and Chelon labrosus); and (2) to evaluate the interactions of two different feeding frequencies (one against three meals per day) on the above-mentioned parameters, and also on the potential bioavailability of nutrients determined using in vitro assays. The results evidenced higher protease and amylase activities for Chelon labrosus than for Liza aurata, while the latter species presented a higher percentage of eviscerated weight and muscle lipids. Furthermore, the results from in vitro assays supported the higher enzyme activity of Chelon labrosus by an observed increase in the release of amino acids and reducing sugars measured for this species. Regarding feeding patterns, the results of the in vitro assays simulating enzyme: substrate (E:S) ratios corresponding to one or three meals per day point to a clear increase of nutrient bioavailability when the daily ration is split into several meals. The present results improve the physiological knowledge of mullet species and define criteria to develop better management protocols by producers. [ABSTRACT FROM AUTHOR]

Sika deer populations must be reduced to control their distribution expansion and decrease damage to agricultural crops and ecosystems. However, due to aging hunters, wildlife managers need to capture deer efficiently. Considering these aspects, capture by feeding has been proposed, but there is no information on the attractiveness of mineral salts to male or female deer. Therefore, we conducted feeding experiments from May to September 2019 to evaluate the attractiveness of mineral salt based on sex. Our results showed that the feeding frequency of mineral salts was higher than that of the other three baits, and the feeding frequency in female deer was higher than that in males. By contrast, we found no differences in the staying time of mineral salts between male and female deer, and the feeding frequency of mineral salts for males increased with time from the start of the attraction. Therefore, mineral salts may sufficiently attract male and female deer, especially during the initial phase of attraction, and may selectively attract females later. To efficiently attract females using mineral salts, it is necessary to know the herd composition in the target area and verify their attractiveness of mineral salts. [ABSTRACT FROM AUTHOR]

Dabry's sturgeon (Acipenser dabryanus) is critically endangered in China. However, the lack of research on the feeding strategy of this species is detrimental to its conservation management. The present study evaluated the effects of feeding frequency (1, 2, 3, 4 and 5 times per day) on the growth performance, feed transit and digestive enzyme activity of juvenile Dabry's sturgeons (initial weight 0.42 ± 0.09 g) in a continuous flow culture system at a water temperature of 18.2–18.5°C. Single‐meal and normal‐feeding (1, 2, 3, 4 and 5 times per day) experimental methods were adopted to assess the effect of different feeding frequencies on feed transit. The fish in each treatment of the normal‐feeding experiment were fed normally according to the original feeding frequency (1, 2, 3, 4 and 5 times per day). The optimum feeding frequency for juvenile Dabry's sturgeons was determined to be 4 times per day based on the growth performance, feed conversion rate and digestive enzyme activity. The results of the single‐meal experiment demonstrated that changes in daily feeding frequency modified residence time in the stomach (S1–S5: 27.2–10.4 h) and intestine (S2–S5: range from 14 to 29.85 h). However, the obtained gastric emptying time varied significantly depending on the experimental approach. The single‐meal experiment approach resulted in a longer gastric emptying time of fish fed 1 and 2 times per day (S1: >35 h; S2: 35 h) than those in the normal‐feeding experiment (N1: 16 h; N2: 24 h), demonstrating that the single‐meal method might change the gastrointestinal emptying strategy of fish. Furthermore, the digestive enzyme activity had daily rhythmic changes and the average digestive enzyme activity was affected by feeding frequency. The average digestive enzyme activity of the fish in N3 or N4 was higher than those of fish in other groups (p < 0.05). In summary, this study provides much useful information for the healthy farming of juvenile Dabry's sturgeons and towards the understanding of digestive physiology, which is of great significance for the protection of Dabry's sturgeon. [ABSTRACT FROM AUTHOR]

Urbanization brings new selection pressures to wildlife living in cities, and changes in the life-history traits of urban species can reflect their responses to such pressures. To date, most of the studies investigating the impacts of urbanization on avian life-history traits are conducted in Europe and North America, while such studies are often lacking in quickly developing countries in Asia (e.g., China). In this study, we examined the variations in reproductive life-history traits of Chinese Bulbuls (Pycnonotus sinensis) along the urbanization gradient in Hangzhou, China. We detected 234 natural nests of Chinese Bulbuls and continuously monitored them in two continuous breeding seasons from 2012 to 2013. We collected data on seven life-history traits (laying date, incubation period, nestling period, clutch size, egg volume, hatching success rate, and fledging success rate). We used infrared cameras to record the number of feedings per hour as the measure of food resources for the nestlings. We measured nest predation pressure by monitoring 148 natural breeding nests during breeding seasons and 54 artificial nests immediately after breeding seasons. We then calculated the urbanization synthetic index (USI) as a measure of the level of urbanization and examined its relationship with the seven life-history traits. We found that Chinese Bulbuls laid eggs significantly earlier with increasing USI. However, the other six life-history traits did not vary significantly with the USI. Moreover, the feeding frequency of chicks increased significantly with the USI, but the nest predation pressure of Chinese Bulbuls decreased significantly with the USI. Increased food resources and reduced nest predation pressure in cities may lead to earlier laying date of Chinese Bulbuls. Further study should test whether the earlier laying date of Chinese Bulbuls is the result of phenotypic plasticity or genetic change.

This study examined the effects of different feeding strategies (diluted diets and feeding frequency) on the behavior and performance of broiler breeder pullets. A total of 3,200 1-day-old female pullets (Ross 308) were randomly distributed over 16 floor pens in 4 rooms and allocated to 1 of 4 treatments: (1) control diet once a day (CON), (2) 20% diluted diet once a day (20-ON), (3) 20% diluted diet twice a day (20-TW), and (4) 30% diluted diet twice a day (30-TW). All the pullets of the different treatments were fed to the same body weight (BW) profile. The 30-TW pullets had the highest and the CON pullets the lowest feed intake, with the 20-ON and 20-TW pullets showing intermediate values. Total water intake was the highest for the 30-TW pullets, followed by the 20-TW and 20-ON pullets, and was the lowest for the CON pullets (P < 0.001). The pullets fed twice a day had the highest total water-to-feed ratio, and the pullets fed once a day had the lowest ratio (P = 0.003). Feeding pullets twice a day yielded the highest average BW uniformity, while the pullets fed once a day had the lowest BW uniformity (P = 0.003). Total mortality was lower in the 20-TW and 30-TW pullets than in the 20-ON pullets, which was primarily caused by fewer dead and graded pullets. The pullets fed twice a day showed overall more eating, more drinking and less sitting, object pecking, and aggressive pecking. The behavior pattern during the daylight period was different for the pullets fed twice a day. Pullets on the diluted feeding strategies were less eager to approach the novel feeder and ate less feed (P = 0.002). In conclusion, feeding pullets with adjusted feeding strategies (feeding twice a day and up to 30% diluted diets) resulted in improved behavior and welfare expressed in decreased stereotypic pecking behavior, and lower eagerness to approach the novel feeder with lower feed intake, with improved BW uniformity and decreased mortality., Competing Interests: DISCLOSURES The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The transmission and incidence of vector-borne diseases rely on vector distribution and life history traits such as survival, fecundity, and feeding. Since arthropod disease vectors are ectotherms, these vital rates are strongly influenced by temperature. Chagas disease is a neglected tropical disease caused by the protozoan parasite, Trypanosoma cruzi. This parasite is transmitted when the feces of the infected triatomine enter the bloodstream of the host. One of the most important vector-species of this disease in the Southern Cone region of South America is Triatoma infestans. In this study, we evaluated the role of constant and variable environmental temperature on the feeding behavior of T. infestans. Fifth-instar nymphs were acclimatized to 4 thermal treatments comprising 2 temperatures (27 °C and 18 °C) with and without diurnal thermal variability (27 ± 5 °C and 18 ± 5 °C). Individuals were fed weekly for 7 wk to quantify their feeding. Our results showed lower feeding frequency in nymphs acclimatized to cold temperature compared to those from warmer temperature treatments. However, treatments with thermal variability presented a nonlinear effect on feeding, with an increased feeding rate in the cold, variable treatment and a decreased feeding rate in the warm, variable treatment. Individuals maintained under cold treatments, the variable temperature exhibited a higher feeding rate and the lowest amount of ingested blood among all treatments. Thus, natural diurnal temperature variation cannot be ignored if we are to make more accurate T. cruzi transmission risk predictions now and in the future., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

This study examined the influence of feeding frequency on the morphology of the reproductive tract in broiler breeder hens, with a focus on the liver, ovary, and oviduct. A total of 364 hens and 52 roosters, starting at 31 wk of age and continuing until the end of their 38th week, were divided into 13 groups with varying feeding frequencies (1, 2, or 3 times daily). Significant changes in reproductive and metabolic parameters were observed, where feeding hens twice or thrice daily resulted in significantly reduced ovary weight and follicle counts (P < 0.001), while liver weight increased (P < 0.05). These findings suggesting complex interactions between feeding practices and reproductive efficiency., Competing Interests: DISCLOSURES The authors declares no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Numerous dietary studies have shown that European vipers (genus Vipera) present low feeding frequency and a specialist diet, which is characterised by a marked ontogenetic shift. However, how eco-geographic factors shape species' feeding ecology remains scarcely addressed. We investigated the feeding ecology of the Iberian adder, Vipera seoanei , examining 402 specimens distributed across its distributional range and addressing how biological, temporal and eco-geographic factors relate to the species feeding activity and dietary consumption. Our results indicated a low feeding frequency in the species, higher in juveniles than in adults. Adult females showed higher rates of prey consumption than adult males, which match to the distinct reproductive demands of both sexes, although no differences between reproductive and non-reproductive females were found. V. seoanei preyed on a varied taxa spectrum, but showed a rather specialist diet based on small mammals. Amphibians and reptiles were also an important part of its diet, particularly in the juveniles. Body size was found as the single biological trait related to the consumption of major prey groups, supporting the occurrence of an ontogenetic shift in the diet. Two habitat and two climatic factors correlated to the consumption of major prey groups, reflecting the ecological requirements of prey across the viper's range. Overall, this study extends the existing knowledge on the feeding ecology of European vipers, signalling how energy intake and allometric constraints shape the feeding activity and dietary consumption of the species across the geography, leading to distinct feeding strategies in juveniles and adults. [ABSTRACT FROM AUTHOR]

This study examined the rate and course of gastric evacuation (GE) in rainbow trout Oncorhynchus mykiss in relation to meal size, body size and temperature. The GE experiments were performed on small (mean ± 95% C.I., 17.7 ± 0.5 cm total length), medium (22. 9 ± 0.2 cm) and large (28.3 ± 0.3 cm) rainbow trout fed meals of different sizes using commercial food pellets at water temperatures T ranging from 7.8°C to 19.2°C. Estimating the shape parameter of a general power function suggested that the square root function adequately described the GE in rainbow trout independently of meal size. The effects of total body length L and weight W on gastric evacuation rate (GER) were described by simple power functions. The square root function was further expanded by a temperature function with temperature optimum to describe the effect of temperature. The expanded square root function revealed a considerable effect of body size and temperature on the GER of rainbow trout. The GER increased exponentially with rising temperature, reached an optimum at c. 18.5°C and then declined abruptly to zero at c. 21°C. The GER of rainbow trout could thus be described by dStdt=−0.00152L0.75e0.08T1−e1.18T−20.9St (g h−1) or dStdt=−0.00440W0.26e0.08T1−e0.97T−21.1St (g h−1), where St is the current stomach content mass (g), and at post‐prandial time t (h). These functions should prove useful to calculate total GE time as well as stomach fullness at different post‐prandial times and therefore provide valuable information to develop optimal feeding strategies for farming of rainbow trout. [ABSTRACT FROM AUTHOR]