Average Daily Growth Rate Research Articles

Effect of mineral-phytobiotic supplement on mass growth and meat productivity of crossbred sheep

The article presents data on the effect of a mineral-phytobiotic supplement on the age dynamics of the live weight of sheep obtained from crossbred ewes. The age dynamics of absolute, relative, and average daily growth rates were analyzed. The results of slaughter and the morphological composition of carcasses of 5-month-old lambs were studied. As a result of the research, it was found that in the first 2 months after birth, the mass of the lambs was higher by 12.5 %, and in lambs by 18.65 %, which was 15.58 % on average. In the following age periods, the live weight of gilts and lambs of the experimental group was also higher than the sheep of the control group by 17.68, respectively; 20.64; 12.45 and 17.08 %, while in the lambs of the experimental group, the intensity of increase compared to the control group was slightly lower and amounted to 14.92, respectively; 14.22; 12.89 and 9.56 %. The highest average daily growth in both groups of experimental sheep was in the period from birth to 2 months of age. By the age of 6 months, lambs and gilts of both groups had a live weight higher than 50 % compared to 18-month-old sheep. The slowdown in absolute growth is observed starting from 49 months of age, which in our opinion is related to weaning and transition to pasture. According to the results of the slaughter of 5-month-old lambs, it was established that the weight of the cartridge carcass, the slaughter weight, and the slaughter yield of the sheep of the experimental group was higher by 26.58, respectively; 22.75 and 7.89 %. The morphological composition of the carcasses of the 5-month-old lambs of the experimental group was higher by 32.69 and 22.26 %, respectively, in terms of pulp yield and fleshiness ratio.

Application of brown seaweed-derived agro biostimulant to the commercial farming of the red seaweed Kappaphycus alvarezii in India: Growth enhancement and production of quality raw material

Currently global seaweed industries are facing issue with availability of raw material for processing of carrageenan due to low growth of current planting material. Use of biostimulants in seaweed cultivation is recently paid more attention due to their proven biostimulatory effect, of which, Ascophyllum marine plant extract powder (AMPEP) is a well proven biostimulant to improve the growth and quality of Kappaphycus alvarezii biomass. Hence, 500 kg of AMPEP was purchased and studied its impact on the commercial farming of K. alvarezii from April 2018 to January 2022 in India. Vegetative propagule of K. alvarezii were dipped in an AMPEP with concentration range of: 0.025, 0.05, 0.10, 0.15, 0.20 and 0.25 % for 30, 60, 90 and 120 min. Before out-planting on rafts in shallow coastal water and found that K. alvarezii responded well to a 0.1 % solution with dipping time of 60 min. The percentage of average daily growth rate (ADGR%) of AMPEP-treated plant in a 45 d grow out period was 3.50 ± 0.50 % vs a control of 1.75 ± 0.25 % for the summer and pre-monsoon months (p < 0.05) but no statistically significant differences between the treated and control plants were found during the rainy and winter seasons. Treated plants were found with low incidence of epiphytes, and disease as compared to control plants. The general appearance and health of treated Kappaphycus was good with significant differences in the yield and quality of semi-refined carrageenan (SRC) and dry weed quality (p < 0.05). The cost of AMPEP for producing of additional 1 kg of dry Kappaphycus was 0.066USD. Results of the present study is very encouraging and AMPEP can be used for the production of K. alvarezii biomass for industrial and biorefinery processing as it has been witnessed that there was 16.66 % increase in biomass production in 2021in India.

EFFECT OF REPLACEMENT OF MAIZE FODDER WITH MAIZE SILAGE ON DRY MATTER INTAKE, WEIGHT GAIN &amp; FEED EFFICIENCY IN BUFFALO MALE CALVES

The experiment was conducted to examine the replacement of maize fodder withmaize silage on dry matter intake, weight gain and feed efficiency in male buffalo calves. Total of 18no. of young male buffalo calves with body weight of 250 + 20 kg and having age around 24 monthswere randomly distributed into three groups containing 6 in each group.A diet of 16% Crude Proteinand 2.1 Mcal/kg energy was prepared and fed to calves at the rate of 1% of live body weight in allexperimental groups. Apart from concentrate, 16 kg of maize fodder was offered to each calves ofgroup A, 08 kg of maize fodder and 08 kg of maize silage to animals of group. Whereas 16kg of maizesilage was individually given to buffalo calves of group C. The experiment was continued for 90 daysfollowed by 10 days which were served for adjustment period. The group A, B and C had dry matterintake (DMI) of 4.82, 4.83 and 4.27 kg respectively. They posed a significant difference (P&lt;0.0001)among three groups. Whereas the difference was non significant difference (P=0.39) in terms of dailyweight gain. The average daily growth rate was 0.90, 0.92 and 0.91 kg for groups A, B and Crespectively. The feed efficiency (feed intake per unit gain) of group C was the lowest i.e. 5.18followed by group B 5.54 and highest feed efficiency value was 6.13, observed in group A. Thedifference was significant (P&lt;0.0001) for feed efficiency

Modeling the growth dynamics of water lettuce, Pistia stratiotes L. in wastewater

This study was aimed at assessing water lettuce (Pistia stratiotes L.) biomass growth, which was tested at the Faculty of Civil Engineering and Architecture of Nis under partially controlled conditions during a 70-day-long test, with a mixture of communal wastewater and water from the shaft at the hydraulic engineering demonstration facility as a source of nutrient matter. The biomass measured after the 70-day experiment ranged from 4.31 to 4.71 kg WW/m2 (average 4.48 kg WW/ m2). The daily absolute growth rate (AGR) was 58.81 g/m2 day, the daily increase rate (DIR) was 16.16 %/day, the average daily relative growth rate (RGR) was 0.0359 g/g day, and the biomass doubling time (DT) was 32.94 days. The following models were used to model the dynamics of water lettuce biomass growth: the exponential model (average MSE 0.0485, average coefficient of determination (R2) to 0.9757); the logistic model (mean squared error (MSE) 0.0049, R2 0.9976), and the sigmoidal model (average MSE 0.0003, average R2 0.9999). All models have a high accuracy; however, the exponential models give a continuous increase in biomass over time, practically to infinity, without taking into account that under conditions of increased plant density and reduced availability of resources, biomass growth slows down and, therefore, they are not suitable for application in real conditions. The logistic model (environmental capacity 6.1680 kg/m2 after about 150 days, ti 53.8587 days, ta 32.8295 days, tb 74.8879), and sigmoidal model (environmental capacity 5.2903 kg/m2 after about 150 days, ti 50.2972 days, ta 34.3072 days, tb 66.2872 days) adequately describe the biomass growth of the growth phase of water lettuce with high precision, which is essential for planning appropriate preventive and active measures to control the spread of water lettuce as an invasive plant and minimize negative impacts on waterbodies in Serbia.

Effects of Blood Meal Inclusion Diet on Growth Performance, Feed Utilization and Survival Rate of Clarias gariepinus (Burchell 1822) in Concrete Pond

The inclusion of blood meal as a substitution for commercial fishmeal in the practical fish diets was evaluated in Clarias gariepinus juveniles (initial weight: 11.45±0.25g and initial length: 9.00±0.91cm) for a period of 39 weeks. The proximate analysis of blood meal had 50.04%, 4.95%, 0.98%, 3.05%, 16.51% and 19.00% representing value of crude protein, lipid, fibre, ash, moisture and nitrogen free extract, respectively. Five isonitrogenous diets (40% crude protein) containing fishmeal which was replaced by blood meal at graded level of 0% as control, 25%, 50%, 75% and 100% were formulated. A total of 300 juveniles were used and randomly distributed into five treatments with each having triplicates of 20 fish per pond respectively. Fish were fed twice daily at 5% body weight in equal proportions at 8.00 am and 4.00 pm. At the end of the feeding trial, the results showed that growth performance were significant higher (p&lt;0.05) in fish fed control diet (1263.55g) and 25% BM diet (1068.67 g), mean length gain (54.16 cm and 50.85 cm), protein efficiency ratio (31.59% and 24.22%) and percentage weight gain (11035.3% and 8476.03%) compared to other treatments diets with the lowest values of (675.35 g, 46.86 cm, 11.73% and 4190.63%, respectively) recorded in fish fed 100% BM diet. However, Feed conversion ratio, specific growth rate, average daily growth and survival rate were not significantly difference (p&gt;0.05) in all the dietary treatments. The water quality parameters monitored were within recommended ranged and were not affected by the supplemented diets. It can be concluded that inclusion of blood meal up to 25% can efficiently replace fish meal without any deleterious effects on growth, feed utilization and survival rate. The use of blood meal as an alternative protein source in diets of farmed fish species will reduce the cost of feeds; boost the profitability and sustainability of the fish production.

Age, Growth and Population Structure Analyses of the Purpleback Flying Squid Sthenoteuthis oualaniensis in the Northwest Indian Ocean by the Statolith Microstructure

A total of 1177 Sthenoteuthis oualaniensis were randomly collected from the northwest Indian Ocean from February between May 2019 and 2020 by lighting falling-net vessels. The age, growth, and population structure of S. oualaniensis were studied based on the statolith microstructure. The results showed that the range of mantle length (ML) was 123–562 mm for females and 88–273 mm for males, and the range of body weight (BW) was 78–6268 g for females and 82–518 g for males in 2019 and 2020, respectively. The hatching date extended from May to December, with the 2019 samples mainly composed of the autumn population, while the 2020 samples were mostly composed of the summer population. The analysis of covariance (ANCOVA) showed that there were significant differences in the growth of ML–age and BW–age between sexes. In the growth model of the ML–age relationship, both females and males in 2019 were best described by s linear model, and 2020 was best described by a logarithmic model. The growth model of the BW–age relationship of females and males in 2019 was best described as linear and the growth model of the BW–age relationship of females and males in 2020 was described logarithmically and exponentially, respectively. The average absolute daily growth rate (AGR) and instantaneous growth rate (IGR) for ML of the 2019 samples were 0.85 mm/d and 0.40%/d, and the average AGR and IGR for ML of the 2020 samples were 0.65 mm/d and 0.18%, respectively. The growth of S. oualaniensis samples in 2019 was faster than that in 2020. This study provided basic information on the age, growth, and population of S. oualaniensis, which will supply a scientific basis for stock assessment and sustainable development.

Ultra-early weaning alters growth performance, hematology parameters, and fecal microbiota in piglets with same genetic background

Piglets with the same genetic background were used to investigate the effects of different lengths of suckling period on growth performance, hematology parameters, and fecal microbiota. All piglets were born by a sow (Landrace×Yorkshire). On day 14 postpartum, a total of 16 piglets [Duroc×(Landrace×Yorkshire)] with a similar initial body weight (2.48 ± 0.25 kg) were randomly assigned into two groups with four replicates per group, two pigs per replicate pen (one barrow and one gilt). On day 14 of age, experiment started, piglets from the first group were weaned (14W), whereas the others continued to receive milk until day 28 of age (28W). The experiment completed on day 70 of age, last 56 days. Growth performance parameters including body weight, average daily gain, feed intake, feed efficiency, and growth rate and hematology parameters including immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), albumin, globulin, and total protein were measured in this study. Additionally, a technique of 16S rRNA gene sequencing was used to analyze fecal microbiota for revealing how the changes in the lengths of suckling period on intestinal microbiota. We found that ultra-early weaning impaired growth performance of piglets, whose worse body weight, average daily gain, feed intake, feed efficiency, and growth rate were observed in 14W group at all measured timepoints in comparison with those in 28W group (P < 0.05). Moreover, higher contents of serum IgA (P = 0.028), IgG (P = 0.041), and IgM (P = 0.047), as well as lower contents of serum albumin (P = 0.002), albumin-to-globulin ratio (P = 0.003), and total protein (P = 0.004), were observed in 14W group in comparison with those in 28W group on day 28 of age, but not on day 70 of age. High-throughput pyrosequencing of 16S rRNA indicated that the intestinal microbiota richness in 14W group was lower than that in 28W group (P < 0.05); moreover, in comparison with 28W group at all sampling timepoints, fecal microbiota in 14W group showed more beneficial bacteria and fewer pathogenic bacteria (P < 0.05). Therefore, we considered that ultra-early weaning had positive effects on immune status and fecal microbiota composition in piglets, but negative effects on growth performance and fecal microbiota abundance.

Wastewater Treatment Efficiency by a Freshwater Phylactolaemate Bryozoan and Experimental Feeding with Protozoa

The wastewater treatment ponds of the King’s Royally Initiated Laem Phak Bia Environmental Research and Development (LERD) Project in west-central Thailand provide habitats for freshwater bryozoans, which are colonial invertebrate animals. Bryozoans sieve food particles out of the water using a retractable lophophore and can play an important ecological role in wastewater treatment. In this unique environment, we: (1) investigated the efficiency of a phylactolaemate bryozoan (Plumatella casmiana) in wastewater treatment, measured by BOD5, chlorophyll a and turbidity; and (2) determined the role of protozoans in the diet of the bryozoan P. casmiana. Comparison of growth rate and fecal pellet characteristics between protozoan-fed bryozoans and phytoplankton-fed bryozoans was investigated. At the end of our wastewater treatment experiment, water quality parameters were markedly improved in the treatment with bryozoans compared to the control (without bryozoans). The treatment efficiency levels for BOD5, turbidity, and chlorophyll a were 24.04%, 59.21%, and 55.13%, respectively. The growth rates of bryozoans in the experimental treatment increased over time. Our study also revealed that this bryozoan can feed on a diet of protozoans under experimental conditions. However, the average daily growth rate of protozoan-fed bryozoans -20 zooids per day was lower than that of phytoplankton-fed bryozoans 19 zooids per day. This may have been due to incomplete digestion of protozoans or insufficient nutrition in the bryozoans. The results from this study provide better understanding of bryozoan ecology and their role in wastewater treatment systems.

Comparison of Growth of Common Carp, Cyprinus carpio Cultivated in and outside Cages in Earthen Ponds in Basrah, Iraq

The current experiment was conducted in one earthen pond (2500 m2) at Agricultural Research Station of the Aquaculture Unit, College of Agriculture at the University of Basrah, Al-Hartha District from 17 February to 10 June 2021. This experiment aims to investigate growth differences between common carp cultivated in small cages (2 x 3 x 2 meter) located inside earthen pond and those were released in the same pond. Effects of fish stocking density inside small cages were also investigated. Four stocking densities were used [100 fishes in cages 1 and 2 (T1); 150 fishes in cages 3 and 4 (T2); 200 fishes in cages 5 and 6 (T3); 250 fishes in cages 7 and 8 (T4); while 1600 fishes were stocked in the earthen pond (T5)]. Fishes were fed daily 3% of fish weight on commercial sinking pellets manufactured by Agricultural Consultant Office of the College of Agriculture. Total length and weight of fishes were measured at the beginning and at the end of the experiment, while subsamples of fishes were weighed periodically and daily feed changed after each weighing. Daily feed was divided into three meals, the first one was given early at the morning, the second one at mid-day and the third one at afternoon. Results of current experiment revealed best growth criteria in T1 where average final weight was 750.5 g, average weight increment was 454.6 g, average daily growth rate was 4.33 g/day and average feed conversion rate was 2.77. Some of these criteria showed significant differences (P≤0.05) between T1 and other treatments, while feeding conversion rate (3.33) was achieved by fishes reared outside cages in the pond. As a conclusion, it can be pointed out that growth criteria of fishes reared inside cages were better than fishes reared outside cages and fish stocking densities were not affecting growth criteria of fishes reared inside cages.

Effects of Diet Supplemented with Morinda citrifolia Fermented Extract on the Growth Performance and Feed Conversion Ratio of Oreochromis niloticus

The use of additives in feeds to promote the growth of farmed fish has been rapidly expanding; among these are supplements derived from indigenous plants. Here, we analyzed the effects of satiation feeding of diet supplemented with noni (Morinda citrifolia) fermented extract on the feeding rate, growth performance and feed conversion ratio of Tilapia, Oreochromis niloticus. Fish with an initial average weight of 2.83 ± 0.01 g were fed with diets supplemented with noni fermented extract at 0 (control), 100-, 200- and 300-ml kg-1 for 12 weeks. Subsequent results showed that growth rate was correlated with or dependent on the concentration of noni fermented extract in the diet. The best result for growth performance, such as weight gain, average daily growth rate and specific growth rate, was found in a fish-fed diet supplemented with noni fermented extract at 200 ml kg-1. However, the feed conversion ratio (FCR) is still higher than the control. The high FCR compared to control may be due to the anthraquinone in noni fermented extract, which decreases nutrient absorption. Fish fed with a 300 ml kg-1 noni fermented extract supplemented diet was the lowest growth performance and highest in FCR, suggesting that concentrations over 200 ml kg-1 might be detrimental to fish. Taken together, noni fermented extract can be a natural source of feed supplement to improve fish growth performance and may act as an appetite stimulant. However, due to its laxative effect, noni fermented extract supplementation should be given at appropriate levels and effective feeding management.

COVID-19 outbreak trends in South Africa: A comparison of Omicron (B.1.1.529), Delta (B.1.617.2), and Beta (B.1.351) variants outbreak periods

ObjectivesWe provided COVID-19 outbreak trends in South Africa during the Omicron (B.1.1.529), Delta (B.1.617.2), and Beta (B.1.351) variants outbreak periods from November 2020 to March 2022. MethodsWe used the time series summary data of the COVID-19 outbreak for South Africa available in the COVID-19 data repository created by the Center for System and Science and Engineering at Johns Hopkins University and the Our World in Data database by the University of Oxford from January 2020 to March 2022. We used the joinpoint regression model with a data-driven Bayesian information criterion method for analyzing the outbreak trends. In addition, we used density ellipses and partition modeling on the outbreak data. ResultsDuring the Omicron outbreak period, COVID-19 cases in South Africa significantly jumped by 4.7 times from December 01 to December 08, 2021. The average daily growth rate of incidence peaked at 23,000 cases/day until December 16, 2021, which was 18.6 % higher than the peak growth during the Delta outbreak period. South Africa experienced peak growth in COVID-19 cases with 18,611 cases/day (January 04 to January 14, 2021) during the Beta outbreak period and with 19,395 cases/day (July 01 to July 11, 2021) during the Delta outbreak period. Density ellipsoid showed a significant correlation between daily cases and daily death count during the Beta and Delta outbreak period which was not prominent in the Omicron outbreak period. Comparatively higher daily death tolls were reported in days with a recovery rate of less than 89.1 % and 91.9 % in the Beta and Delta outbreak period respectively. The backlog counts may be one of the reasons for the significant increase in daily death tolls during the Omicron period. ConclusionsDuring the Omicron period, COVID-19 cases peaked growth was 18.6 % higher than the peak growth during the Delta outbreak period. Despite that fact, growth in death trends in the Omicron outbreak period was found low which might be due to the low mortality rate and case fatality proportion. The emergence of the Omicron variant once again reminds us that- “no one is safe until everyone is safe”.

Evaluation of Growth, Haematological, Biochemical and Oxidative Stress Parameters of Clarias gariepinus Fed with Alstonia boonei and Mitracarpus scaber

Synthetic agents as growth promoters in aquaculture has become unpopular, hence, the need for better alternatives. This study was conducted to investigate the effects of dietary plants on growth performance, haematological, biochemical and oxidative stress parameters in African catfish. Fish were fed on basal diets for 84 days, the control and six other experimental diets containing different levels of Alstonia boonei (0.5%,1.0% and 1.5%) and Mitracarpus scaber (0.5%,1.0% and 1.5%) of the basal diets. Fish were weighed bimonthly, blood samples were collected and analyzed. At the end of the experiment, the final weight (FW), weight gain (WG), Average Daily Growth Rate (ADGR) and Specific Growth Rate (SGR) of fish fed with A. boonei and M. scaber were significantly higher than that of control (P&lt;0.05). The values of RBC and haemoglobin of the M. scaber (0.5%) group were significantly higher than the other groups including the control. The values of Heterophil-Lymphocyte Ratio (HLR) and Platelet-Lymphocyte Ratio (PLR) in the control group were significantly higher than those of the treatment groups. Biochemical parameters and oxidative stress markers did not show any significant difference between the treatment groups and the control (P&gt;0.05). The findings clearly indicated that the plants enhanced growth performance in fish with little or no deleterious effects.

Dynamics of growth and spawning in the Indian squid Uroteuthis duvaucelii (Cephalopoda: Loliginidae) from the tropical Arabian Sea

The dynamics of age, growth, maturation and spawning of the Indian squid Uroteuthis duvaucelii, were determined by statolith analysis in the tropical southeastern Arabian Sea. In the samples, the smallest male (30 mm Dorsal Mantle Length) was 63 days old and the largest (350 mm DML) 170 days old. The smallest female (32 mm DML) was 62 days old and the largest female (207 mm DML) was 146 days old. The maximum life span was estimated at 6 months. Recruitment to the trawl fishery occurred approximately after two months of age. The average daily growth rates were estimated as 1.22 mm DML/day for females and 1.48 mm DML/day for males. The age at first maturity was estimated as 98 days for males and 106 days for females. Hatch dates were distributed throughout the whole year with two peaks indicating the presence of two cohorts with varying growth dynamics. The best-fitting growth models were the Gompertz growth model for females and the Linear model for the male populations based on the Akaike Information Criterion (AIC). This study suggests that fast growth and a short life span associated with a rapid population turnover may facilitate continuous recruitment to the fishery. From a conservation and management perspective, a closed fishing season during the peak spawning and hatching period (October–November) or in the subsequent recruitment period may prove beneficial to U. duvaucelii population in the Arabian Sea. This study further improves the overall understanding of the life-cycle of multiple spawning tropical squids.

Impact of feeding strategies on the growth and nutrient discharge in the polyculture of carps using farm ponds

The present study aimed at evaluating appropriate feeding strategies to obtain maximum fish production from farm ponds at low/minimum investment costs was carried out under the Tamil Nadu-Irrigated Agriculture Modernization Project financed by the World Bank. The study was carried out for 180 days at the Directorate of Sustainable Aquaculture, Thanjavur, in four, equal-sized, farm ponds with two treatments in duplicates by stocking5 species (Catla catla, Labeo rohita, Cirrhinus mrigala, Ctenopharyngodon idella and Cyprinus carpio) in theratio of 1:1:1:1:2. Treatment 1 (T1) involved the feeding strategy of pelleted feed with 20% CP (crude protein)broadcast twice a day whereas in Treatment 2 (T2), the same feed was provided four times a day as feed ballsusing feed trays. Among the five species, C. carpio (779±189.01 g) and C. mrigala (670±121.38 g) stocked inT2 attained the maximum weight. Production parameters such as gross production, net production, average dailygrowth rate were not significant between the treatments, however T2 showed comparatively better results than T1.Survival rate of fishes was recorded significantly higher in T1 (35.54±2.60%) than in T2 (29.6±2.36%). Nutrientssuch as total phosphorus, total nitrogen and total potassium were significant and highly discharged in T1 than inT2. Experiment revealed that feeding fishes in trays helped to monitor the weight gain and feed intake with reducednutrient discharge, thereby proper feed management was obtained in T2 when compared to T1

Variability in foodscapes and fish growth across a habitat mosaic: Implications for management and ecosystem restoration

Riverine ecosystems in their natural state are complex mosaics of habitats whose conditions vary across space and time as landscape features filter prevailing hydrologic forcing. Yet, through anthropogenic alteration many large river systems have become simplified through the construction of levees and dams that reduce lateral connectivity and flow variability. The extent to which shifts in habitat mosaics create conditions that support different trophic responses that manifest in differences in fish growth across the landscape remains largely untested. This is primarily due to limitations in linking habitat features, dynamic physical processes, and trophic transfer of energy to higher taxa at the landscape scale. Here, we conducted large-scale enclosure experiments across varying habitats on a fluvial floodplain as a model system to measure factors that influence habitat-specific growth rates in multiple Chinook Salmon (Oncorhynchus tshawytscha) stocks important to fisheries and of conservation concern. Using an ecosystem approach, we reveal that landscape context, water residence time, and habitat type (agricultural, wetland, river channel) result in different hot-spots of primary and secondary food production. This variation in the aquatic foodscape resulted in significant variation in salmon growth rates and ultimate size and morphology across the landscape. Floodplain habitats generally exhibited higher water residence times as highlighted by higher specific conductance, salinity, and chlorophyll-a values. Pelagic invertebrate abundance was 10 to 100 times more abundant in the off-channel habitats compared to the river channels. The average daily growth rates of the juvenile Chinook Salmon ranged from 0.15 mm day−1 and 0.01 g day−1 in the riverine habitat to 0.55 mm day−1 and 0.07 g day−1 in the off-channel habitat. These data were used to build mixed effects models that showed the influence of chlorophyll-a concentration, water temperature and pelagic invertebrate composition on fish growth across locations throughout the experiment. As landscapes become increasingly simplified there is increased risk of losing the mosaic of habitats necessary to achieve enhanced fish growth and phenotypically diverse and sustainable salmon populations. This in-situ experimental and modeling approach can be applied to other systems to develop ecosystem indicators such as habitat-specific fish growth rates to manage landscapes and processes to support resilient fish populations.

Retracted] Application of Nanoscaffold Material Combined with Exercise Rehabilitation Therapy in the Treatment of Athletes with Hip Injuries

A nanoscaffold is a porous scaffold. It injects antibiotics, cells, and polymer particles into damaged cavities in the form of injectables and forms hydrogels after the molecules self‐assemble at the injection site. Sports rehabilitation is a new frontier field integrating sports, health, and medicine, also known as physical therapy. It is the use of various sports methods for the injured or disabled, so that they can fully recover their physical functions and spirits, and can make them reintegrate into society. It mainly studies the relationship between sports and health. Among the tissue engineering scaffolds used as seed cell carriers, nanomaterials are playing an increasingly important role in the study of joint injury and repair due to their unique effects such as cell adhesion and proliferation. The purpose of this paper is to study a reliable nanoscaffold material for the treatment of patients with hip injuries in athletes and to observe its actual effect in combination with sports rehabilitation therapy. In this paper, an electrospinning method was proposed to prepare nanoscaffold materials, and the nanoscaffold materials were applied to the exercise rehabilitation process of two groups of hip patients, and the data of the patients’ rehabilitation were calculated. The results showed that the OD value of the cells in the exercise rehabilitation therapy using nanofiber scaffolds increased significantly, and the average daily growth rate of the OD value was 0.112. And the rehabilitation after 5 months was 19.8 points higher in hip range of motion score, 11.3 points higher in overall function score, and 6.2% lower in complication rate compared with ordinary exercise rehabilitation therapy. Therefore, it can be concluded that the therapy of the nanofiber scaffold material combined with exercise rehabilitation can more efficiently help patients with hip joint injury to recover, and the probability of complications is lower compared with the traditional exercise rehabilitation therapy.

Pertumbuhan Trepang Holothuria scabra yang dipelihara dalam kurungan dengan substrat berbeda di Perairan Pantai Bahoi

This research was conducted to examine the effect of different substrates on the growth of Sea Cucumber Holothuria scabra reared in cages in Bahoi Coastal waters. This research was conducted from April to June 2021 in Bahoi Coastal Waters, West Likupang, North Minahasa. The method used in this research is the observation method with three treatments: A (sand), B (mud), C (seagrass), and three replications. The cages are made of nets size 100 cm x 100 cm x 50 cm as many as 9 cages. The sea cucumber size data was collected every two weeks. Samples of sea cucumber were taken randomly from each cage, left for ± 10 minutes, photographed, weighed, then recorded. Data collection for water quality is carried out every week during the day at the lowest tide, between 12:00 to 14:00. Water quality parameters were measured using a thermometer, refractometer, and litmus paper. Based on the research results, the average absolute weight growth and daily growth rate of sea cucumber reared with mud substrate showed the best results, that is 0.55 g and 0.72%, while the sand and seagrass substrates showed negative values. The results of ANOVA (analysis of variance) showed that there was no significant difference between absolute growth and daily growth rate of Sea Cucumber H. scabra reared on sand, mud, and seagrass substrates.

Effects of light source and photoperiod on growth of duckweed Landoltia punctata and its water quality

This study investigated the effects of light source [LED white (LW), fluorescent white (T5) and LED blue (LB)] and photoperiod (12:12, 16:08, 24:00 light/dark) on growth of duckweed Landoltia punctata and the resulting effects on its water quality for 16 days. The average daily relative growth rate (RGR) reached about 0.519 g d−1. Both light source and photoperiod had no significant difference on the mean RGR; however, their interaction had significant effects on duckweed's growth (p ≤ 0.05). Moreover, except T5 (24:00) > [T5 (12:12) ≥ T5 (16:08) ≥ LB (24:00)], LW (12:12) > [T5 (16:08) ≥ LB (24:00)], and LB (12:12) > LB (24:00), there were no differences in RGR in all pair-comparisons of treatment (p ≤ 0.05). Nitrate (NO3−) mostly influenced weight increment (WI), 70%. For light source and photoperiod effects on water quality, no total ammonia nitrogen (TAN) was detected in all treatments after 16 days, while NO3− increased gradually. In addition, results show that most of the total nitrogen (TN) was contributed from NO3− (R2 = 0.9999). Overall, our findings could contribute on producing duckweed in a controlled and programmed condition for maximum production and quality. Constructed models and practical application contribute in predicting nutrients sensitivity and proven useful in water management or water quality assessments.

Comparative study of zootechnical parameters between two species of salmonids; Oncorhynchus aguabonita and Oncorhynchus mykiss

The main objective of this study is to compare the zootechnical parameters of two species of rainbow trout; Oncorhynchus aguabonita (mutant trout) and Oncorhynchus mykiss (wild trout) subjected to the same ecological and dietary conditions during the fry phase. The results showed that the alevins of mutant trout have better growth performance compared to the alevins of wild trout. The average weight gain, average daily growth rate, and food conversion efficiency during the experimental period are 6.67 g, 0.071 g/d, and 0.76, respectively, compared to only 3.47 g, 0.036 g/d, and 0.86 for wild trout. The results obtained during the experimental period are encouraging to give greater importance to the mutant variety Oncorhynchus aguabonita, which will contribute to the increased demand for animal protein and essential fatty acid for cardiovascular diseases.

ЭКОЛОГИЧЕСКИЙ ПОДХОД В ПОВЫШЕНИИ ЭФФЕКТИВНОСТИ ИНДУСТРИАЛЬНОГО МЕТОДА ПОЛУЧЕНИЯ АКВАКУЛЬТУРНОЙ ПРОДУКЦИИ

The article considers using the latest technologies with recirculation aquaculture systems (RAS), which allows growing aquaculture objects at high seeding densities all year round. However, it has a number of difficulties and, first of all, the need to purify water from metabolites. An alternative to RAS technology is an ecological approach to growing aquaculture products, which is implemented by us using the artificial eco-systems or, otherwise, agrohydroecosystems based on RAS. An experiment was carried out on the joint cultivation of a sterlet × beluga hybrid with tilapia in an aquaponic module of an integrated storey unit (IED); an increase in the mass accumulation coefficient and average daily growth rate of fish was noted. Due to the right choice of parameters that satisfy the conditions for growing all experimental objects application of IED technology allows obtaining a high increase in the mass of aquatic organisms and additional products per unit area (lettuce, strawberries). The introduction of a hydroponics block into the system reduces the amount of nitrogenous substances in the medium, while an even greater effect can be achieved by adding a microbiological preparation (culture liquid) into the system. When using an IED, raw materials and energy are consumed most efficiently, with a minimum impact on the envi-ronment.