Stocking Density Research Articles

Influence of different stocking densities of pearlspot (Etroplus suratensis) on plankton diversity indices of biofilm-based rearing system

Aim: Biofilm-based aquaculture systems, proven cost-effective, reduce the need for expensive supplementary feed. The biofilm acts as a natural planktonic food source for reared organisms. Previous research highlighted the influence of fish stocking density and biomass on plankton diversity in different aquaculture settings, underscoring the significance of these factors in biofilm-based systems. Hence, the present study attempted to understand how varying stocking densities of pearlspot (Etroplus suratensis) influence plankton diversity indices in the biofilm-based aquaculture system. Methodology: The present experiment was designed in 5 Practical Salinity Unit (PSU) brackishwater with soil-bottomed FRP circular (500 L) tanks for 60 days. The sugarcane bagasse was used as a substrate forbiofilm production after fertilization with cow dung, urea, and lime. Fries of pearlspot (4.67 ± 0.04 mm 1.71 ± 0.03 g-1) were stocked at four different stocking densities in triplicates viz T1 (50 nos); T2 (100 nos), T3 (150 nos) and T4 (200 nos) fish fry m-3 in the biofilm-based rearing system. Plankton samples were collected from water and biofilm deposited on the substrate and analyzed for diversity indices. The Shannon Diversity Index, Simpson Diversity Index, Simpson Dominance Index, and Margalef Richness Index were used to compute the plankton diversity indices in different treatments using standard equations. Results: In the current investigation, lower stocking densities with lower fish biomass were associated with significantly higher (P≤0.05) Shannon Diversity Index, Simpson Diversity Index, and Margalef Richness Index in water. In contrast, the Simpson Dominance Index in water showed a significantly lower (P≤0.05) value for treatments with lower fish biomass than for treatments with higher biomass. Interpretation: The values obtained for various diversity indices indicated that a biofilm-rearing system with lower E. suratensis biomass produced more planktonic abundance, evenness, and species richness. Key words: Biofilm, Pearlspot, Plankton diversity, Stocking density

The influence of different stocking density on growth rate and survival rate koi larvae (Cyprinus carpio)

Abstract Stocking density has an important role in the survival and growth of fish larvae. The purpose of this study was to determine the optimal stocking density level for larval rearing with improved feed. Tubifex sp. which has a high protein content of about 57% and fat as much as 13%. The method used was the experimental method with a completely randomized design (CRD) on 4 different treatments of stocking density with 3 replications. The treatments given were P0/Control (1 individual/L), P1 (2 individuals/L), P2 (3 individuals/L), and P3 (4 individuals/L) maintained for 49 days. The results obtained during the study were the growth rate values of P0 (0.021 gram/day), P1 (0.017 gram/day), P2 (0.016 gram/day), and P3 (0.017 gram/day). The survival rates are P0 (90.00%), P1 (91.00%), P2 (90.33%), and P3 (87.50%). Absolute length values P0 (1.94cm ), P1 (1.70cm ), P2 (1.70cm), and P3 (1.77 cm) The quality of the water obtained is that the temperature ranges from 26–29, the pH is 6.8–8.1, and the DO is 5–6. The results showed that different stocking densities had no significant effect (p > 0.05) on the survival and growth rate of koi fish.

Long-term effects of pre-weaning social housing on response to a social and housing transition in pregnant heifers

Dairy cattle are routinely managed in social groups and subject to various management and social transitions, yet conventional approaches to rearing dairy calves limit social experience during early weeks of life. The objective of this study was to evaluate long-term effects of dairy calf social housing, with calves housed individually or in pairs, on long-term behavioral responses observed in pregnant heifers following social regrouping and introduction to a novel housing environment. Holstein heifers were raised during the milk-feeding period (provided 8 L/d milk replacer) in either individual pens (n = 20 heifers) or paired pens (n = 20 pens; 1 focal heifer/pen) and subsequently identically managed in groups on pasture from 9 weeks of age. At 30 d before expected calving, pregnant heifers were moved from pasture to a free stall barn, which represented introduction to a novel social group and an unfamiliar housing environment. Behavior was continuously recorded from video for 24 h, beginning at 0000 h on the day after introduction, to characterize feeding behavior, locomotor activity, and stall usage, as well as social proximity and competitive behavior surrounding the feed bunk and stall. Stocking density of the free stall barn fluctuated and was categorized as low (≤75%, 100 × animals in pen/available stalls), medium (>75%, 100%), or high (≥100%). Body weights obtained following calving indicated that previously PH heifers were heavier (632.3 vs. 593.4 kg; PH vs. IH), and body weight was included as a covariate in analysis of feeding behavior. Upon introduction to the free stall pen, previously PH heifers spent more time walking (1.9 vs. 1.3 min/h) with no effect of calf social housing on duration of lying time. However, stall use was subject to an interaction between previous housing treatment and stocking density and differed overall between previous housing treatments; previously PH heifers spent less time in the stall, particularly at high stocking density (29.4 vs. 48 min/h), due to shorter (29.6 vs. 95.7 min/visit) but marginally more frequent stall visits. Previously pair-housed heifers were also less likely to be displaced from a stall (44 vs. 85% of heifers replaced; PH vs. IH). Feeding behavior was similarly influenced by previous housing treatment particularly at high stocking density, with previously PH heifers spending more time feeding (8.2 vs. 4.2 min/h) and visiting the feed bunk more frequently (1.5 vs. 0.8 visits/h). These results suggest that preweaning social housing had long-term effects on behavior and ability to adapt to a novel environment which became most apparent under heightened competitive pressure.

Stocking density at feeders and drinkers and temporal feed restriction affects dairy cows' drinking behavior

Water is an essential resource for dairy cows and its consumption is closely linked to feed intake. Social competition can lead to changes in drinking behavior, especially for subordinate cows. We studied how changes in stocking density at the feeder (varied between 1 or 2 cows per feeder), and drinker (varied between 6 or 12 cows per drinker) and a temporal feed restriction (14 or 24 h access) impacts drinking in 4 groups of 6 cows each, following a Latin Square design. Within each group of 6 focal cows, we recorded drinking behavior and 2 were identified as most dominant, 2 as most subordinate, and the 2 others as intermediate, based on success in agonistic interactions at the drinker. Cows drank less water when feed availability was restricted (on average 5.3 L/d less ± 3.4; 4.5% average difference). Subordinate cows also spent less time drinking when overstocked (9.3 min/d less ± 6.7; 24.3% difference). During treatments with more competition, cows were more likely to be observed drinking in the hours after the peak in drinking observed for the control treatment. A high level of competition among group-housed animals is considered a welfare problem and can lead to injuries and reduced production. Our findings provide evidence that feed restriction and higher stocking density of cows at the drinker and feeders changes the drinking behavior of cows, with subordinate animals experiencing more pronounced effects.

High species richness of sheep-grazed sand pastures is driven by disturbance-tolerant and weedy short-lived species.

We selected 15 sheep-grazed sand pastures along a gradient of increasing grazing intensity to study the fine-scale patterns of main biomass fractions (green biomass, litter) and that of plant species and functional groups (life forms and social behaviour types). We classified them into five grazing intensity levels based on stocking density, proximity to drinking and resting places and the number of faeces. We aimed to answer the following questions: (i) How does increasing intensity of sheep grazing affect the amount of green biomass, the species richness and their relationship in sand pastures? (ii) How does increasing intensity of sheep grazing affect the biomass of perennial and short-lived graminoids and forbs? (iii) How does the disturbance value-expressed in the biomass ratio of disturbance-tolerant and ruderal species-change along the gradient of grazing intensity? A unimodal relationship between green biomass and species richness was detected; however, the ordination (canonical correspondence analysis, CCA) showed no clustering of pastures subjected to the same levels of grazing intensity. Along the grazing intensity gradient we found an increasing trend in species richness and significant differences in green biomass (decreasing trend), litter (decreasing trend), graminoids (decreasing trend) and short-lived forbs (increasing trend). We found an increasing amount of disturbance-tolerant and ruderal species with increasing grazing intensity. We suggest that we might need to use multiple scales for sampling and a fine-scale assessment of grazing intensity. Our findings might be instructive for pastures in densely populated regions, which are prone to the encroachment of disturbance-tolerant and ruderal species.

Effect of Stocking Density on the Growth of the Endangered Amazonian Fish Hypancistrus zebra (Siluriformes: Loricariidae)

ABSTRACTStocking density has a significant influence on animal homeostasis, and so is a crucial factor in the management of organisms in captivity and an important role in ex situ conservation of endangered species. Hypancistrus zebra is an endemic fish species from the Xingu River, Brazil—considered Critically Endangered since the early 2000s due to fishing pressure and, more recently, due to habitat changes resulting from the construction of the Belo Monte Hydroelectric Dam. The implementation of appropriate management in captivity is of utmost importance for its conservation, particularly in enhancing ex situ breeding techniques. This study aimed to evaluate the growth of juvenile H. zebra in aquaria with three different stocking density levels. The juveniles were distributed between three treatments, each with three replicates. We found no correlation between biomass and aquarium volume. The highest correlation coefficients were found between growth rates and densities related to the number of individuals per shelter area. Mortality rate was directly related to the initial number of fish in the aquariums, with larger populations showing higher mortality rates. The treatment with lower stocking density displayed the highest growth rate, while the treatment with higher density had the lowest growth rate, with a 23.38% difference between them.

The Effect Of Stocking Densities On Growth And Survival Rate Of Thai Mahseer (Tor Tambroides) During Nursery Stage.

Abstract Tor Fish are freshwater fisheries resources that have the potential to be found in Indonesia. Tor fish has been in high demand among entrepreneurs and the broader public. Tor tambroides (Sapan fish or Thai mahseer fish seed fish), Tor douronensis (Semah or Garing fish), Tor soro (Soro, Lempon, or Dewa fish), and Tor tambra are the four kinds of Tor fish native to Indonesia. Tor fish is a native indigenous freshwater fish from Indonesia that is on the verge of extinction. The Tor tambroides fish population in nature has declined and is on the verge of extinction as a result of widespread poaching for eating and trade as an ornamental fish. Thai mahseer fish seed fish cultivation activities include hatchery, nursery and enlargement. To protect populations of Thai mahseer fish seed fish from scarcity, Thai mahseer fish seed fish cultivation needs to do to prevent the scarcity of Thai mahseer fish seed fish in their natural habitat and Thai mahseer fish seed fish have high potential as freshwater fish in the aquaculture sector. This research aims to determine the impact of various stocking densities on growth and survival rates for Thai mahseer fish seeds, as well as the optimal density to support growth and survival rates. The study used a Random Design Complete (RDC) with four treatments and five replications. Feeding was provided ad libitum in the morning and evening. Given differences in the stocking density of Thai mahseer fish seeds, the results revealed a significant impact on all treatments. Treatment 1 had the greatest daily growth rate with a stocking density of 2 seeds/L and a yield of 0.015±0.003; specific growth rate. The highest absolute weight growth obtained was in Treatment 1 with a yield of 1.01gr; the highest absolute length growth obtained was in Treatment 1 with a yield of 2.9cm; and the highest survival rate for Thai mahseer fish seeds was obtained in Treatment 1 with a yield of 80%.

Effects of Stocking Density and Palm Oil Additive on Water Quality and Blood Parameters of the African Catfish, Clarias gariepinus During Transportation

Effects of Stocking Density and Palm Oil Additive on Water Quality and Blood Parameters of the African Catfish, Clarias gariepinus During Transportation

Characteristics of Morphological Changes in Fins according to Larval Growth of Red Spotted Grouper, Epinephelus akaara.

This study investigated the fin development and morphological characteristics according to larval growth in order to obtain information on behavioral characteristics and optimal stocking density during red seed grouper seed production. To examine the growth and fin development process of the larvae, we randomly sampled at 1, 3, 5, 7, 9, 10, 11, 13, 15, 17, 19, 20, 25, 30, 39, 45, 51, and 72 days after hatching. External morphology was observed and measured using an optical microscope. To observe skeletal development, larvae at 13, 20, 30, and 72 days after hatching were fixed in formalin and stained for cartilage and bone examination. At 9-10 DAH, red spotted grouper larvae (2.74±0.1 to 3.0±0.2 mm TL) exhibited a second dorsal fin spine and pelvic fin spine, which subsequently elongated. At 19-20 DAH, the larvae (5.7±0.1 to 6.1±0.1 mm TL) have the lengths of the second dorsal fin spine and pelvic fin spine average 34% and 31% to total length, respectively. From 30 to 72 DAH (12.6±0.4 to 56.0±0.2 mm TL), the length of the second dorsal fin spine and pelvic fin spine to total length decreased from 27% to 8% for the dorsal fin and 21% to 14% for the pelvic fin, respectively. At 30 DAH (12.6±0.4 mm TL), the larvae reached the complete count of fin rays in each fin. At 39 DAH (20.28±3.07 mm TL), the larvae had fin shapes similar to those of adults. At 13-30 DAH (4.2±0.1 to 12.6±0.9 mm TL), barbs and spinules were distributed along the ridges of the second dorsal and pelvic fin spines. However, at 72 DAH, these barbs and spinules were no longer observed on the fins. During the seed production process, red spotted grouper larvae tend to cluster in the morning, and during this time, entanglement of barbs and spinules on the second dorsal and pelvic fin spines can lead to mortality. Therefore, it is considered essential to focus on managing the behavioral patterns and appropriate rearing density of red spotted grouper larvae from the emergence of barbs and spinules on the second dorsal and pelvic fin spines until they regress and metamorphosis is completed.

Modulation of Intestinal Histology and Immune Functions Using Different Level of Salvia Indica Supplementations with Stocking Density in Local Quails

Under the direction of Salahaddin University in Erbil's College of Agricultural Engineering Sciences, study was carried out to investigate how local quail performed biochemically, histologically, and immune-wise when varied levels of Salvia indica (SI) additive were added at high stocking density. For a 42-day trial, 216 one-week-old local quails were divided into four treatments at random, with three replicates for each treatment, in cages measuring 60 by 30 by 25 centimeters. The following was the design of the feed treatments: Positive control (12 birds/replicate), Negative control 20 birds per replicate at a high stocking density, 20 birds per replicate plus 0.2% of SI additive, and 20 birds per replicate plus 0.4% of SI additive. When compared to a negative control, the results indicated that 0.4% SI supplements with high stocking density produced the best live body weight and weight gain. When compared to positive and negative controls, the cholesterol level of female quails considerably (P<0.05) decreased in both SI with high stocking density; however, no significant variations were seen with either of the SI additives with high stoking density. Furthermore, when compared to the positive control, the LDL content in female quails was considerably (P<0.05) reduced by both supplements of SI with high stocking density and negative control. When treated with SI, the height of the jejunum villus was significantly (P<0.05) higher than when treated with both positive and negative controls. The size of Fabricius follicles was significantly (P<0.05) enhanced by the addition of SI treatments, but no significant difference was seen between the two SI additives with high stocking density. In summary, adding Salvia indica to a diet with high stocking density enhanced the quail population's biochemical markers, immunological response, and jejunum histology.

Fish production, water quality, and the role of nitrification as an ammonia removal process in intensively aerated hybrid catfish ponds

AbstractSix 0.1‐ha earthen ponds with 45 kW/ha of aeration capacity were stocked with hybrid catfish (Ictalurus punctatus x I. furcatus) ranging from 15,000 to 90,000 fish ha−1 in 15,000 fish ha−1 increments to analyze the effect of nitrogen loading on ammonia accumulation and fish production. Minimum dissolved oxygen (DO) concentration was maintained above 3.0 mg O2 L−1 to prevent hypoxia‐induced appetite reduction. Stocking density did not impact survival but decreased average fish harvest weight and increased food conversion ratio (FCR). Gross production increased with stocking density and ranged from 7249 to 35,674 kg ha−1. Average total (TAN) and un‐ionized ammonia (NH3) were not different among stocking densities despite greater nitrogen inputs in ponds with higher feeding rates. Nitrite () and nitrate () concentrations were significantly higher in ponds with higher stocking densities, suggesting that nitrification increased with nitrogen loading. Phytoplankton assimilation of ammonia is the primary ammonia removal process in traditional catfish ponds with modest fish densities and feeding rates. However, in intensively aerated ponds with high feeding rates, nitrification can become an important process for ammonia removal. These data indicate that small earthen hybrid catfish ponds with high aeration capacities can increase catfish production without ammonia accumulating.

Sodium butyrate suppresses stress, immunosuppression and oxidative stress in common carp, Cyprinus carpio, reared at high stocking density

Sodium butyrate suppresses stress, immunosuppression and oxidative stress in common carp, Cyprinus carpio, reared at high stocking density

Effects of Stocking Density of Filter-Feeding Fishes on Water Quality and Bacterial Community in Rice–Crayfish Polyculture System

To evaluate the effects of filter-feeding fishes on water quality and bacterial community in the rice–crayfish coculture system, four different stocking densities of bighead carp (0, 500, 1000, 1500 ind./200 m2) were set up in rice–crayfish coculture systems. Water samples in the systems were collected biweekly to detect dissolved oxygen (DO), temperature (T), potential of Hydrogen (pH), ammonia nitrogen (NH4+-N), nitrite nitrogen (NO2−-N), nitrate nitrogen (NO3−-N), total nitrogen (TN), total phosphorus (TP), and Chlorophyll-a (Chl-a); the bacterial community in the water was analyzed simultaneously, then the correlation between water quality and microorganisms were studied. The results showed that concentrations of TN, TP, NO2−-N, and NH4+-N decreased while DO and NO3−-N increased along with the breeding process. NO2−-N, NO3−-N, TN, and NH4+-N were important environmental factors affecting the bacterial community structure in water (p < 0.05). Bighead carp stocking had an impact on the diversity, richness, and evenness of the bacterial communities in the systems. The dominant bacteria in the four different carp density groups were Proteobacteria, Actinomycetes, Bacteroidetes, and Cyanobacteria. Bighead carp increased the abundance of Bacteroidea but reduced that of Actinomycetes, Cyanobacteria, and Proteobacteria. The introduction of bighead carp promoted the conversion of nitrogen and phosphorus, reducing the risk of cyanobacterial blooms. Group 1000 ind./200 m2 exhibited the best effect on the removal of nitrogen and phosphorus from the water body.

Rice-fish coculture: Enhancing resource management and food security

Rice-fish coculture is an age-old nature-based practice that effectively utilizes land and water resources and promises to be a viable alternative to rice monoculture for sustainable joint production of rice and fish with socioeconomic and ecological advantages in rural areas. However, qualitative and quantitative studies on such practices to evaluate their socioeconomic vulnerability based on primary data of farmers' opinions are sparse. In this study, we attempted to identify the factors responsible for the success and lapses in rice-fish coculture in five villages of Ziro Valley in the lower Subansiri district of Arunachal Pradesh. We conducted an exhaustive field survey to collect primary data through questionnaires survey, focus group discussions, and interviews. Then, we analyzed the data by applying artificial intelligence and machine learning algorithms to identify the stresses and recommend guidelines to improve farmers' management and decision-making for sustainable rice-fish coculture. The results of the general linear regression, considering fifteen variables, Akaike information criterion, and the decision tree on three important responses of the farmers indicate that the the current practice of rice-fish coculture in the Ziro Valley yields poor returns. We identified that mismanagement of inputs, unwillingness to invest, nonavailability of adequate funds and formal training, and limited involvement of youths in the culture are crucial factors behind poor returns. However, institutional support in managing stocking density, feed, and rice type, along with human resource training, can address these gaps, thereby improving the production and livelihoods of a significant section of the Apatani tribe.

A new dataset for video-based cow behavior recognition

A new video based multi behavior dataset for cows, CBVD-5, is introduced in this paper. The dataset includes five cow behaviors: standing, lying down, foraging,rumination and drinking. The dataset comprises 107 cows from the entire barn, maintaining an 80% stocking density. Monitoring occurred over 96 h for these 20-month-old cows, considering varying light conditions and nighttime data to ensure standardization and inclusivity.The dataset consists of ranch monitoring footage collected by seven cameras, including 687 video segment samples and 206,100 image samples, covering five daily behaviors of cows. The data collection process entailed the deployment of cameras, hard drives, software, and servers for storage. Data annotation was conducted using the VIA web tool, leveraging the video expertise of pertinent professionals. The annotation coordinates and category labels of each individual cow in the image, as well as the generated configuration file, are also saved in the dataset. With this dataset,we propose a slowfast cow multi behavior recognition model based on video sequences as the baseline evaluation model. The experimental results show that the model can effectively learn corresponding category labels from the behavior type data of the dataset, with an error rate of 21.28% on the test set. In addition to cow behavior recognition, the dataset can also be used for cow target detection, and so on.The CBVD-5 dataset significantly influences dairy cow behavior recognition, advancing research, enriching data resources, standardizing datasets, enhancing dairy cow health and welfare monitoring, and fostering agricultural intelligence development. Additionally, it serves educational and training needs, supporting research and practical applications in related fields. The dataset will be made freely available to researchers world-wide.

Herbal extract dietary supplementation effect on growth performance and meat quality in broiler raised under two stocking densities

The number of birds or their total live weight in relation to a given area is known as stocking density; higher stocking densities will cause more stress to the birds, which may have an impact on their physiological state, productivity, carcass quality, growth performance, immunity, metabolism, and meat quality. The present study aimed to investigate the potential impact of 2 different stocking densities on growth performance, carcass characteristics, meat quality, serum, and expression of Insulin like growth factor-1 (IGF-1), muscle regulatory genes expression and serum biochemical indicators of broilers supplemented with essential oils (EO). In total, 784-day-old chicks of Ross 308 were randomly assigned into 4 different groups with 7 replicates for each: Normal feed (no essential oils [EO] added) and normal stocking as 9 bird/m2, (NSD). Normal feed (no essential oils [EO] added) and high stocking as 14 bird/m2, (HSD). Feed with essential oils (Digestarom DC® 150 g/Ton of feed) and normal stocking as 9 birds/m2, (NSD + EO). Feed with essential oils (Digestarom DC® 150 g/Ton of feed) and high stocking as 14 birds/m2, (HSD + EO) for 35 days. Bodyweight was recorded at the beginning of the trial and then at the end of each week, feed intake was recorded at the end of each week as well. A total of 28 birds (7 birds per treatment) birds were slaughtered at 35 days of age to evaluate each parameter. The HSD group had the lowest (P < 0.05) feed intake. The NSD groups showed the highest (P < 0.05) body weight gain compared to HSD groups. The HSD + EO had lower adjusted FCR (P < 0.05) compared to HSD. The legs % was the highest (P < 0.05) for NSD group, while HSD + EO had the highest (P < 0.05) Fat Pad percentage. Moreover, HSD had the highest CL%, and the lowest WHC and Warner–Bratzler shear force. For biochemical indicators, (IGF-1) was the lowest (P < 0.05) HSD group. Also, Mammalian Target of Rapamycin (mTOR) and Aspartate Aminotransferase (AST) were higher (P < 0.05) in the EO supplemented groups. Regarding gene expression, the results showed that Myogenin (MyoG) and IGF-1 were lower in HSD while MSTN was higher in the same group, (P < 0.05). In brief, essential oil supplement has improved the performance of broilers under high stocking density situation.

Broiler flocks in production systems with slower-growing breeds and reduced stocking density receive fewer antibiotic treatments and have lower mortality

In the Netherlands, the number of broiler production systems with higher welfare standards, using slower-growing broilers and decreased stocking densities, has increased over the last decade. This study aimed to investigate the effect of this change on antibiotic treatments, mortality, and footpad lesions. Data from national monitoring databases from 2013 to 2021 were used, resulting in 113,380 included flocks from 917 farms. Flocks were divided into conventional (CONV), medium-growing (MED), and slow-growing (SLOW), based on breed and slaughter age (median age: CONV 42 d; MED 50 d; SLOW 56 d). Generalized mixed-effect models were created to compare antibiotic treatments in and after the first week, total on-farm mortality, and footpad lesion scores between these 3 production systems. Year, quarter, flock size, thinning, number of houses, and regional density of poultry farms were included as fixed effects. Random effects were farm and veterinary practice in all models, with an additional random slaughterhouse effect to describe footpad lesions. Probability of treatment in the first week of age in CONV flocks overall years (7.2%, 95% CI [5.9, 8.7]) was higher than in MED (2.0%, 95% CI [1.6, 2.5]) and SLOW flocks (1.3%, 95% CI [1.0, 1.7]). Treatment probability after the first week was similarly higher in CONV flocks (14.7%, 95% CI [12.1, 17.6]) than in MED (3.2%, 95% CI [2.5, 4.0]) and SLOW flocks (2.2%, 95% CI [1.7, 2.9]). CONV flocks had a higher mean mortality (3.2%, 95% CI [3.0, 3.4]) than MED (2.0%, 95% CI [1.9, 2.1]) and SLOW flocks (1.9%, 95% CI [1.8, 2.0]). Regarding footpad lesions, CONV flocks had the highest mean scores (range 0-200) over all years, whereas SLOW flocks had the lowest scores (CONV: 46.1, 95% CI [42.1, 50.6]; MED: 21.3, 95% CI [18.9, 24.0]; SLOW: 13.2, 95% CI [11.5, 15.1]). This analysis of data from flocks over a 9-yr period indicates that switching from conventional to alternative production systems with higher welfare standards could positively affect broiler health and antibiotic use.

Effect of Natural Feeding Capacity of Dengue Mosquito (Aedes aegypti) Larvae and Different Stocking Densities of Gold Molly Panda Fish (Poecilia spp) on the Feeding Speed and Function of Natural Predators in Gold Molly Panda Fish (Poecilia spp)

Effect of Natural Feeding Capacity of Dengue Mosquito (Aedes aegypti) Larvae and Different Stocking Densities of Gold Molly Panda Fish (Poecilia spp) on the Feeding Speed and Function of Natural Predators in Gold Molly Panda Fish (Poecilia spp)

Growth performance of eel fish (Anguilla bicolor) which are maintained in containers of different colors

Performance of Eel (Anguilla bicolor) maintened in containers of different colors. Growth is the main driver in increasing the profitability of aquaculture. In addition to maintenance management the color of the container is also a factor supporting the growth of eels. This study aims to determine the effect of the color of different rearing containers on the growth and appetite response of eel. The test fish used were elver stage eels with an average weight (129 ±131g). The method used is an experiment with two treatments they are grey and green. The test fish were placed in a container measuring 19x4 m2 and a water level of 1m with a stocking density of 1100 individuals each, 30 days of rearing. The variables observed were growth performance including SR (Survival Rate), ADG (Average Daily Growth), FCR (Food Conversion Ratio), SGR (Specific Growth Rate). The results obtained indicated that there was a significant difference in the average growth of fish reared in grey and green containers. Grey container treatment was proven to get higher yields with average final weight values (192.4 ± 4.5 g), FCR (1.01 ± 0.02), ADG (2.01g/day ± 0.06), SGR (1 .25%BW/day±0.02). Based on the results of the study it can be concluded that there is a significant difference in the growth of eels reared in ash and green containers. The color of the ash container proved to be better in supporting growth performance.Keywords: Elver; Green; Grey; Nocturnal

Utilization of Indigofera zollingeriana leaves meal in feed formulation to color brightness and growth in koi fish (Cyprinus carpio)

This study aims to determine the effect of the addition of Indigofera zollingeriana in feed formulations with different doses on the color brightness of koi fish. The research design was Completely Randomized Design (CRD) with five treatments and three replications. Treatment P0 was control (without the use of Indigofera leaf meal), P1 was the addition of 5% indigofera meal, P2 was the addition of 10% indigofera meal, P3 was the addition of 15% indigofera meal, and P4 was the addition of 20% indigofera meal. Fingerlings measuring 6 ± 1 cm with a stocking density of 1 fish for 2 L were reared for 30 days in this study. The results showed that P2 with a percentage of 10% Indigofera zollingeriana meal was the best treatment for the brightness of koi fish color (27.23). Still, they had no significant effect on the growth of absolute length (1.04 cm) and absolute weight (1.05 g), feed efficiency (23.08%), and survival rate (100%). The water quality obtained during maintenance was temperature 26-27oC, pH 6.1-7.2, dissolved oxygen 5.2-6.3 mg/L, and ammonia 0.02-0.036 mg/L.Keywords: Fish Color Brightness; Indigofera zollingeriana; Koi Fish