Daily Growth Rate Research Articles

Masculinization of Tilapia (Oreochromis Niloticus) by Oral Method Using Senggani Fruit Extract (Melastoma Malabathricum L.)

Introduction: Tilapia have different growth rates in male and female fish where the growth of male fish is faster than female. Therefore, in tilapia farming activities, the production of tilapia weighing >100g/head is difficult to achieve due to uncontrolled spawning. Method: This study was designed using a completely randomized design (CRD) with 5 treatments and 4 replicates, namely treatment A (control), B (Senggani fruit extract 0.75 g/kg feed), C (extract 1.5 g/kg feed), D (extract 2.25 g/kg feed), E (extract 3 g/kg feed). The organisms used in the study were 7-day-old tilapia larvae. Tilapia larvae were given feed that had been added with Senggani fruit extract according to the treatment dose. Tilapia were reared for 62 days, and given artificial feed containing 41% protein, each feeding was given with a frequency of 3 times a day (morning, afternoon, evening). Results and Discussion: The results showed that the highest percentage of male sex was found in treatments A, B, C, D and E, which amounted to 50; 56.25; 57.5; 58.75; and 60%, respectively. Daily growth rate, survival and feed conversion ratio obtained during the study in each treatment amounted to 7.49, 7.45; 7.44; 7.46; and 7.40. for survival 73.75; 72.5; 72.5; 70; and 68.75 then the results of feed conversion ratio respectively 1.86; 1.88; 1.89; 1.86; and 1.91. The analysis showed that the highest percentage of male sex was found in the treatment of 3 g/kg feed which amounted to 60% (P>0.05). Daily growth rate, survival rate and feed conversion ratio did not significantly affect the treatment given (p>0.05). Conclusion: The results of water quality measurements obtained are still within the optimum limits for tilapia rearing. Conclusion: Feeding using Senggani fruit extract to masculinize tilapia did not have a significant effect (p>0.05) on the percentage of male tilapia, daily growth rate and feed conversion ratio.

Impact of Nutritional Tea Polyphenols on Growth, Feed Efficiency, Biochemical Traits, Antioxidant Capacity, Haematological Parameters and Immunity in Coho Salmon (Oncorhynchus kisutch).

To evaluate the impact of nutritional tea polyphenols (TPs) on body composition, growth, biochemical markers, antioxidant capacity, and hemato-immunological levels, a ten-week feeding experiment was carried out on coho salmon (Oncorhynchus kisutch, 180.51 ± 0.15 g). The control group was fed a basal diet; the T1, T2, T3, and T4 groups were fed 0.005%, 0.01%, 0.02%, and 0.04% TPs, respectively. These results demonstrate that adding TPs significantly (p < 0.05) increased the coho salmon fish's weight gain (WG), relative growth rate (RGR), condition factor (CF), feed efficacy (FE), daily growth rate (DGR), and specific growth rate (SGR). There was no discernible difference in the body compositions of the treated TPs and the control group (p > 0.05). In addition, the T3 group showed a significant (p < 0.05) decrease in GPT, LDL, HDL, TC, and CAT. Fish given a 0.02% diet containing TPs had significantly lower levels of malondialdehyde (MDA) in their liver; yet, the TP-treated groups had higher levels of SOD and CAT than the control (p < 0.05). The data analysis shows a significant rise in lysozyme, respiratory burst activity, bactericidal activity, and blood hematological parameters in the 0.01-0.04% TP groups. According to these findings, TPs could be a useful dietary supplement for raising the antioxidant status, growth parameters, haemato-immunological response, and whole-body composition of coho salmon fish.

Seasonal coordination of aboveground vegetative and reproductive growth and storage in apple trees subjected to defoliation, flower and fruit thinning

Key messageThe growth rates of current-year shoots, fruits and trunks in apple trees peak sequentially during the growing season. The period of most intense growth coincided with the lowest NSC reserves.Vegetative and reproductive growth and storage are major carbon sinks in fruit trees; however, little is known about their mutual seasonal coordination. In this study, we monitored growth dynamics of trunks, fruits and current-year shoots together with the concentration of non-structural carbohydrates (NSC) in trees subjected to defoliation, early season flower thinning, mid-season fruit thinning and their respective combinations across the season. We found that defoliation had a negative effect on both trunk radial growth and annual fruit yield. Flower and fruit thinning caused lower fruit number per tree, but the individual fruits were larger resulting in a similar annual fruit yield among the treatments. Shoot extension growth was not significantly affected by the defoliation and flower and fruit thinning treatments. The concentration of non-structural carbohydrates was also similar across treatments. Modelled daily growth rates of shoots, fruits and trunks peaked sequentially one after another throughout the growing season with a delay of 15 and 18 days, respectively. The period of most intense growth of tree’s organs corresponded well with the lowest NSC reserves and a temporary depletion of starch in 1-year-old branches. Taken together, our study illustrates a tight temporal coordination of major carbon sinks and improves our understanding of sink/source relations of commercially important apple trees.

Effectiveness of viterna addition to feed on survival and growth rate of freshwater pomfret (Colossoma macropomum)

Pomfret (Colossoma macropomum) is one of the freshwater fish commodities that is widely cultivated and widely consumed by Indonesian people. This research aims to determine the effectiveness of doses of viterna addition on feed to the survival and growth rate of pomfret. The method used in this study was an experimental method with four treatments and repeated three times. Viterna doses were PI: 0 ml (control), P2: 10 ml, P3: 15 ml and P4: 20 ml. The result showed that there was a significant effect on absolute length growth, absolute weight growth, and daily growth rate. While the survival and feed conversion rate did not have a significant effect. The highest absolute length growth result was P4=3.82 cm, while the lowest absolute length growth result was P1 3.01 cm. The highest absolute weight growth result was P4 9.88 g, while the lowest absolute weight growth was P1 6.40 g. The highest daily growth rate was P4 2.35%, while the lowest daily growth rate was P1 1.77%. From the results of adding viterna with different doses to the feed, the higher the dose of viterna given, the resulting growth has a better category.

Assessing the nitrate and phosphate uptake kinetics potential and growth performance of Gracilaria corticata var. cylindrica in shrimp farm water (SFW)

Gracilaria corticata var. cylindrica (GCC) was studied as a biofilter in shrimp farm water (SFW) and its growth and biochemical attributes in the medium were evaluated. GCC showed significant nutrient absorption from SFW, with maximum nitrate and phosphate uptake observed after the first 48 h. Nitrate depletion happened faster than phosphate, thus showing a higher affinity for nitrate uptake (78.4% removal) by GCC. Nutrient uptake kinetics followed the Michaelis–Menten curve, with Vmax values of 43.16 μM g dw−1 h−1 for nitrate and 67.50 μM g dw−1 h−1 for phosphate. Also, GCC’s low Km values (12.53 µM for nitrate, 1.91 µM for phosphate) indicated efficient nutrient utilization. GCC showed rapid growth in SFW, with a daily growth rate of 2.93 ± 0.19% d−1, comparable to the commercial MP1 media (3.54 ± 0.19% d−1) and greater to seawater (2.23 ± 0.13% d−1). Proximate analysis revealed consistent biochemical compositions across all three media, with carbohydrate and protein contents of 2.24 ± 0.41% and 0.76 ± 0.12%, respectively, in SFW. Pigment analysis revealed that pigment concentrations varied, with SFW having the greatest R-PE concentration (182.25 ± 32.77 µg g−1), followed by MP1 media and saltwater. R-PC concentrations followed a similar pattern, with SFW having the greatest concentration (85.73 ± 19.33 µg g−1). These findings highlight GCC’s potential as an efficient biofilter for reducing nitrate and phosphate levels in SFW, therefore offering a sustainable solution for aquaculture effluent management and the potential integration of GCC into shrimp farming practices.

The effects of solar radiation on daily and seasonal stem increment of canopy trees in European temperate old-growth forests.

It is well established that solar irradiance greatly influences tree metabolism and growth through photosynthesis, but its effects acting through individual climate metrics have not yet been well quantified. Understanding these effects is crucial for assessing the impacts of climate change on forest ecosystems. To describe the effects of solar irradiance on tree growth, we installed 110 automatic dendrometers in two old-growth mountain forest reserves in Central Europe, performed detailed terrestrial and aerial laser scanning to obtain precise tree profiles, and used these to simulate the sum of solar irradiance received by each tree on a daily basis. Generalized linear mixed-effect models were applied to simulate the probability of growth and the growth intensity over seven growing seasons. Our results demonstrated various contrasting effects of solar irradiance on the growth of canopy trees. On the one hand, the highest daily growth rates corresponded with the highest solar irradiance potentials (i.e. the longest photoperiod). Intense solar irradiance significantly decreased tree growth, through an increase in the vapor pressure deficit. These effects were consistent for all species but had different magnitude. Tree growth is the most effective on long rainy/cloudy days with low solar irradiance.

Effect of Different Feeds on Growth Rate and Survival of Common Carp (Cyprinus carpio L.) Larvae

The present study was conducted to evaluate the growth and survival rates of common carp (Cyprinus carpio) larvae fed different diets levels in laboratory Two-day-old larvae were transferred from the University of Basrah Marine Science Center hatchery to the Abi Al-Khaseeb district's experiment laboratory. The larvae were distributed into four treatments 450 larvae each treatment (150 larvae per replicate and three replicates per treatment) at a stock density of 3.33 larvae /L. The treatments were as follows: T1 was given boiling egg yolks; T2 was given a processed diet with 45% protein; T3 was given Redi-Lac milk powder; and T4 was given ground Artemia eggs. The experiment ran for 20 days, beginning on April 17, 2022.The results showed that larvae fed on diet containing ground Artemia eggs (T4) produced the highest final weight (39.667mg), followed by a diet containing 45% protein processed diet (T2), , Redi-Lac milk powder food (T3), and boiled egg yolks food (T1) produced the lowest final weight ( 27.333 and 24.667 mg, respectively) Statistical analysis revealed a significant difference (P≤0.05) in the final weight, weight gain, daily growth rate, relative growth rate and specific growth rate between T4 and T1, but not between T4 and T2 and between T4 and T3. The survival rate showed a significant difference (P≤0.05) between T4 (0.71%) and other treatments. Our results suggest that ground Artemia eggs is the most suitable and optimal meal for common carp fish larvae.

Seasonal to interannual variations of daily growth rate of a Tridacna shell from Palau Island, western Pacific, and paleoclimatic implications

Seasonal-interannual climate change is an important component of Earth's climate system and has a significant impact on ecosystems and social systems. However, the short-run of modern observational data limits our understanding of the seasonal-interannual climates on long-term timescales. The natural archives can provide information on climate change before the industrial period, but most of their temporal resolution is too low to capture the seasonal-interannual climate signals. Tridacna spp. is the largest marine bivalve, and its shell has the potential to trace climatic/environmental changes on a daily to interannual scale. In this study, we investigated the daily growth pattern of a modern Tridacna gigas shell (PL-1) from Palau based on laser scanning confocal microscopy images. The results showed that the growth pattern of PL-1 was affected by effective solar radiation primarily, followed by nutrients on the seasonal timescale. On the interannual timescale, the growth rate of the shell was modulated by ENSO, which affected the effective solar radiation and nutrients accepted by Tridacna. The growth rate of Tridacna PL-1 was accelerated during the ENSO positive phase, and vice versa. However, due to a lack of situ observations, the effects of nutrients on Tridacna and the symbiotic zooxanthella in detail need to be further investigated. This study indicates that the daily growth rate of Tridacna shells in equatorial regions may have the potential to reconstruct seasonal-interannual climate/environment variations.

17 Effect of branched-chain amino acids on lactating sow and piglet performance

Abstract Sows (n = 360 PIC 1050 and Genesus) were used to investigate the effect of various branched-chain amino acid (BCAA) levels on sow lactation and litter growth performance. Upon entering the farrowing room, sows were blocked by parity group (P0, P2, P3+) and randomly assigned to one of six dietary treatments containing various levels of BCAA. Experimental diets were formulated to various standardized ileal digestible (SID) leucine, isoleucine, and valine levels by replacing cornstarch with L-leucine, L-isoleucine, and L-valine. Levels of the BCAA were expressed as ratios to SID lysine and were formulated at 114 or 180 for Leu, 56 or 64 for Ile, and 64 or 120 for Val. Diets were formulated to be isocaloric (3.23 Mcal ME/kg) and met or exceeded all other NRC (2012) essential amino acid and vitamin and mineral recommendations. Sow body weight (BW), backfat, and body condition score were recorded at the time of entry into the farrowing room and at the time of weaning. Piglet litter weights were recorded after cross-fostering and at weaning to determine litter growth rate. Data were analyzed using generalized linear mixed models with fixed effects of dietary treatment and parity group and a random effect of lactation group. The models were fit using R version 4.3.1 (R Core Team, 2023). The sow and her litter were the experimental unit, and results were considered significant if P ≤ 0.05 and a tendency if 0.05 &amp;lt; P ≤ 0.10. Sows nursed piglets for 21.3 d (P = 0.998). The mean parity by treatment ranged from 3.8 to 3.9 (P = 0.999). After farrowing, the mean estimated sow BW was 219 kg, with a range between treatments of 216 to 221 kg (P = 0.651). On average, sows gained 2.82% of their BW (P = 0.696) with an average daily feed intake (ADFI) of 8.75 kg/d (P = 0.932). However, as expected, sow Leu, Ile, Val, and total BCAA intakes were different across treatments (P ≤ 0.001). Sows entered the farrowing house with an average of 11.50 mm of backfat (P = 0.919) and lost 6.04% backfat through lactation (P = 0.667). Sows started the trial with an average of 14.1 piglets/sow (P = 0.967) and weaned 12.6 piglets per sow (P = 0.981) with a piglet average daily gain of 0.22 kg/d (P = 0.193) and a daily litter growth rate of 2.89 kg/d (P = 0.291). In conclusion, there was no evidence of an effect of the various leucine, isoleucine, and valine levels evaluated in this study on lactating sow and piglet performance.

An approach to optimizing dietary protein to growth and body composition in walking catfish, Clarias batrachus (Linneaeus, 1758).

Clarias batrachus is a commercially important food fish. In the present study, effect of varying dietary protein levels was evaluated on the survival, growth parameters and proximate composition of C. batrachus. Diets comprising 25%, 30%, 35%, 40%, 45%, and 50% crude protein (CP) were supplied to fish in T1, T2, T3, T4, T5, and T6, respectively, at the rate of 5% of fish body weight for the entire 90 days, twice daily. Size of each stocked C. batrachus was recorded after 15 days. Results revealed 100% survival rate of C. batrachus in all treatments. Significantly highest (P<0.001) mean value of weight gain (g/fish), percent weight gain, daily growth rate, specific growth rate and protein efficiency ratio (PER) in C. batrachus were recorded, reared in T4 by feeding 40% CP in diet. The best FCR value (1.90±0.02) for C. batrachus was obtained in T4 by feeding 40%CP in diet. Mean value of water, ash, fat and protein contents (wet mass) were ranged 74.10-79.23%, 3.12-4.68%, 3.90-4.43% and 13.09-16.79% for C. batrachus in the studied treatment groups. Water content (%) was found significantly (P<0.05) higher in the body of C. batrachus for T1, T2, T3 and T6 than for T4 and T5. Ash was found significantly (P<0.05) higher in the fish reared in T4 and T5. Fat content in the wet body mass of C. batrachus was found significantly higher in T4 and T1. While, significant higher (P<0.05) values of mean protein content was noted in C. batrachus reared in T4 and T5. Body composition of C. batrachus was also categorically affected by body size, however, condition factor showed non-significant correlation in most of the relationships in the present study. Overall, results indicated that feeding appropriate diet (containing 40% CP) to the fish resulted good growth performance, lower FCR and higher protein content in the fish. Present study provides valuable knowledge of optimal dietary protein level in C. batrachus which will help in commercial success of aquaculture.

The effect of different lighting times on survival and growth rate of gurami seeds (Oshpronemus gouramy)

This study aims to determine the effectiveness of different photoperiods on maturity and the effect of different light durations on survival and growth of gourami (Ospronemus gouramy) fry. The study was conducted on August 22th - September 22th in the Green House Samudra University.Test fish used is seed of gouramy measuring 5-6 cm. The methods used in this study was Completely Randomized Design (CRD) with 4 treatments and 3 replications. The treatments in this study were P1 (4 hours light, 20 hours dark), P2 (8 hours light, 16 hours dark), P3 (12 jam hours light, 12 hours dark), and P4 (16 hours light, 18 hours dark). Seeds of fish was put in a containing 20 liters of water volume with a stocking density of 10 tails each container. The frequency of feeding is done 4 times a day at 06.00 am, 12.00 am, 18 pm and 24.00 pm. The results showed that different natural feeding teratments had a significant effect on the absolute weight, absolute length growth, daily growth rate, survival, FCR, and water quality. The best treatment in this study was P1 treatment (4 hours light, 20 hours dark) because it had a high value compared to other treatments.Keywords: Gouramy; Growth; Photoperiod; Survival; Weight

Rapid flight feathers moult and fat stores in the Common Snipe Gallinago gallinago in the early stage of autumn migration

We analysed primary and secondary feather moult and fat reserves in 539 Common Snipes captured in the middle Pripyat River Valley, an important stopover site for waders in Central Europe, between 2002 and 2022. The average daily rate of feather growth was 1.89% in primaries and 2.27% in secondaries, being one of the highest documented in waders. The estimated duration of growth for a single flight feather varied from 11 to 21 days in primaries and from 8 to 11 days in secondaries. Moreover, multiple flight feathers (up to 14) were replaced simultaneously. As a result, the wing moult in Common Snipes was rapid with the mean primary moult duration estimated at 53 days (28 June–20 August) according to the Underhill–Zucchini model, and only 20 days in secondaries (31 July–20 August) based on moult estimates of individual secondaries. Hence, although secondary feathers began to grow when primary moult was already advanced, moulting of both flight feather groups was completed in most birds at almost the same time. Our study shows that Common Snipe in the middle Pripyat River Valley exhibit very rapid wing moult with large wing gaps. Fat reserves and thus body mass of Common Snipes were the lowest when the wing gap was greatest, compensating for their reduced wing area. Late and slow movement towards wintering grounds, allows them to moult rapidly at the early stage of autumn migration, which is likely to occur only in sites with abundant food resources.

Photoprotection by photoinhibitory and PSII-reaction centre quenching controls growth of Ulva rigida (Chlorophyta) and is a pre-requisite for green tide formation

Main ConclusionThe combined photoinhibitory and PSII-reaction centre quenching against light stress is an important mechanism that allows the green macroalga Ulva rigida to proliferate and form green tides in coastal ecosystems.Eutrophication of coastal ecosystems often stimulates massive and uncontrolled growth of green macroalgae, causing serious ecological problems. These green tides are frequently exposed to light intensities that can reduce their growth via the production of reactive oxygen species (ROS). To understand the physiological and biochemical mechanisms leading to the formation and maintenance of green tides, the interaction between inorganic nitrogen (Ni) and light was studied. In a bi-factorial physiological experiment simulating eutrophication under different light levels, the bloom-forming green macroalga Ulva rigida was exposed to a combination of ecologically relevant nitrate concentrations (3.8–44.7 µM) and light intensities (50–1100 µmol photons m−2 s−1) over three days. Although artificial eutrophication (≥ 21.7 µM) stimulated nitrate reductase activity, which regulated both nitrate uptake and vacuolar storage by a feedback mechanism, nitrogen assimilation remained constant. Growth was solely controlled by the light intensity because U. rigida was Ni-replete under oligotrophic conditions (3.8 µM), which requires an effective photoprotective mechanism. Fast declining Fv/Fm and non-photochemical quenching (NPQ) under excess light indicate that the combined photoinhibitory and PSII-reaction centre quenching avoided ROS production effectively. Thus, these mechanisms seem to be key to maintaining high photosynthetic activities and growth rates without producing ROS. Nevertheless, these photoprotective mechanisms allowed U. rigida to thrive under the contrasting experimental conditions with high daily growth rates (12–20%). This study helps understand the physiological mechanisms facilitating the formation and persistence of ecologically problematic green tides in coastal areas.

Mapping the Potential Development of Soybenas Crops Based on Growing Degree Days

The main factors affecting plant growth and yield are soil, climate, and plants. The influence of clime is more than soil on plant growth under certain conditions. The evidence is that some cover vegetation growth conditions are much different even though they grow on the same land. In each distinct place, the harvest time of one type of plant is not the same. One crucial factor that affects this is the daily growth rate or the degree of Growing Degree Days (GDD). Know parameters such as soil type, slope, land use, rainfall, and GDD temperature by using geographic information systems in determining the suitability of agricultural commodity development areas. The study aims to determine the suitability of soybean cropland in West Sumatra based on GDD value. Conducting land suitability analysis using the GDD method through several stages, namely, the classification of soybean land suitability parameters, making a map of soybean plant land suitability in physical characteristics, classifying the GDD value of soybean plants for the West Sumatra region, and making a soybean cropland suitability map based on GDD value. The potential land for soybean cultivation in West Sumatra based on land suitability class, physical characteristics, and GDD value is 555,791.66 hectares in class S1 (very suitable) and an area of 2,313,796.44 hectares in class S2 (appropriate enough). The most optimal planting time for soybean cultivation is in August. Lima Puluh Kota Regency, Pasaman Regency, Sijunjung Regency, and Solok Regency have land suitable for soybean cultivation with more than 200 thousand hectares of areas and are in areas with growing degree days suitable for soybean growth.

Optimized Nitrogen Application Rate Significantly Increases Total Economic Value and Quality of Flue-Cured Tobacco due to the Improvement of Superior Tobacco Yield

Summary With the improvement of irrigation and transportation infrastructures, single tobacco cultivation has been converted into tobacco–vegetable double cultivation in Yunnan Province. High residual nitrogen (N) levels in soil before tobacco transplanting induced by the excessive N input during the vegetable cultivation season resulted in a reduction of economic income and the quality of flue-cured tobacco. Therefore, the objective of this paper is to describe the optimization of N management and to provide a better understanding of the mechanism of optimal N application rate on the economic benefit and quality of tobacco. A field experiment with six N application rates (0, 45, 60, 75, 90, and 105 kg N ha−1) was carried out with a randomized block design in 2021 and 2022 in Yunnan Province. The economic value and yield, intrinsic chemical and processing quality, leaf growth rate and agronomic characters were determined. Compared with the currently recommended 105 kg N ha−1 rate, 75 kg N ha−1 significantly increased the total economic value and superior tobacco yields, improved the integrated grade of chemical compounds and resulted in leaf midrib proportions in an appropriate range. The total economic value positively correlated with the superior tobacco leaf yields (R2 = 0.91, p &lt; 0.001), while not with medium and inferior leaf yield. The daily leaf growth rate in prosperous growth stage significantly correlated with the yield of superior tobacco and reached its maximum at a N rate of 75 kg N ha−1. The sum of N application rate and soil residual N before transplanting correlated with the total economic value (R2 = 0.66, p &lt; 0.05) and superior leaf yield (R2 = 0.64, p &lt; 0.05), respectively. Based on the amount of soil residual N before transplanting, the optimal N application rate was 66 kg N ha−1 which was 39 kg N ha−1 lower than the currently recommended N rate (105 kg N ha−1). Our results highlighted that the technical consultants and farmers should adjust the N application rate appropriately according to the residual N amount before transplanting and optimize the water and fertilizer management especially in the prosperous growth stage. An optimized N rate is not only of economic benefit and the improvement of quality of tobacco cultivation, but also environment friendly.

Потенціал росту стерляді прісноводної (Acipenser ruthenus Linnaeus, 1758) в ювенальний період за використання пробіотичного препарату «Емпробіо»

Purpose. To study the effect of the complex probiotic “Emprobio” on the survival and growth rates of larvae and fry of the sterlet (Acipenser ruthenus) as well as to assess its effect on the morphological structure of the intestine and liver. Methodology. The study of the effect of the probiotic was carried out on larvae and fry of sterlet. 6-hour enrichment of live feed organisms was carried out in 2 variants. In the variant 1, the concentration of the probiotic preparation was 0.4 cm3/dm3 of the incubation mixture. In the variant 2, similarly, the preparation concentration was 4.0 cm3/dm3. Larvae and fry were fed with Artemia nauplii, which were the transfer of the probiotic. Every 7 days, the average fish weight, the growth and survival rates were analyzed. Determination of the number of colonies of lactic acid bacteria in the intestines of fish was carried out by the method of deep seeding in Petri dishes. Determination of unicellular fungi was carried out by the method of serial dilutions of intestinal contents in a peptone-buffer solution with subsequent inoculation on a sterile wort-agar medium. Light-optical examination of cells and tissues was carried out in penetrating light using the equipment “E. Leitz “diaplan” Wetzlan” (Germany), halogen illuminator “Linvatec-2” (USA). General morphometric studies of tissue structures were performed with the help of a built-in eyepiece-micrometer as well as with the use of an eyepiece-micrometer overlay grid (eyepiece 7x (Huygens). In-depth studies of individual tissue areas were carried out using a 100x objective, “I-Plan” with a built-in iris diaphragm of 5.5 units of a compensation 20x eyepiece “K. Zeiss”. The data were statistically processed in MS Excel. Findings. During the 1st 7 days of the experiment, there were no significant differences in the growth rate of larvae between the groups.In the 2nd week of the experiment, an increase in the average daily weight gain of fish was observed in the experimental groups, which exceeded the control by 47.0% and 24.7%, respectively.At the end of the experiment, the average weight of fry of the 1st group was higher by 26.9%, and of the 2nd — by 27.9%, compared to the control group. As a result of the use of the probiotic preparation for 28 days, the survival rate of sterlet juveniles in the 1st experimental group was 75.0%. That is, it was 47.1% higher than the results of the control group. In the 2nd experimental group, the survival rate of sterlet juveniles was 80.1%, which was 6.8% higher than in the 1st group, and 57.1% higher than in the control group. The use of “Emprobio” in the feed at a concentration of 4.0 cm3/dm3 contributed to a faster process of microflora redistribution in the intestine. Therefore, already after the 1st 5 days of exogenous feeding, the average daily growth rates of the juveniles in this experimental group had higher values (by 8.8%) compared to the control group. The results of inoculation the intestine contents in the experimental groups showed that the use of the probiotic preparation in the incubation mixture in the amount of 0.4 cm3/dm3 ensured the inoculation of probiotic lactic acid bacteria in the intestines of sterlet juveniles. Their functioning was reflected in fish productive parameters, starting from the 14th day of the experiment. However, the lack of intestinal inoculation by one of the components of the preparation, namely saccharomycetes, indicated the insufficiency of such a concentration to show the full potential of the probiotic. In the 2nd experimental group, positive growth dynamics of the entire microbiome can be seen. Histological studies showed a positive effect of the probiotic preparation at a concentration of 4.0 cm3/dm3 on the morphological structure of the liver. In particular, the area of hepatocytes, which increased by 42.9% after 7 days of the experiment and by 63.0% after 21 days of the experiment. The sizes of the nuclei and the ratio of the diameter of the nucleolus/nucleus of hepatocytes also increased. At the same time, the probiotic did not cause probable changes in the morphological structure of the intestinal wall. Originality. For the first time, the possibility of using the complex probiotic “Emprobio”, introduced by enrichment in live feed for growing sterlet in the juvenile period was analyzed.A positive effect of probiotics at a concentration of 4.0 cm3/dm3 on growth processes and survival of starlet juveniles was shown. The effect of microorganisms on the histostructure of the intestine and liver of the sterlet was clarified. Practical value. The obtained results will be useful for improving the technology of growing sturgeon larvae and fry. Keywords: sterlet, growth rate, survival, enrichment, probiotic, Emprobio, intestine, liver.

Alizarin Red S Marking in Otoliths: A Study on the Growth Dynamics of Diplodus vulgaris Juveniles

This study investigates the age and growth rates of juvenile Diplodus vulgaris in the Çanakkale Strait, utilizing Alizarin Red S (ARS) marking to analyze otoliths for daily growth increments. The research aimed to validate the daily deposition of growth rings in otoliths as a reliable method for age determination in young fish. A total of 65 specimens were subjected to ARS immersion at varying concentrations to identify the optimal marking conditions that would not adversely affect the survival rates of the juveniles. Post-treatment, the fish were released into controlled environments and monitored over a period to assess the incorporation and visibility of ARS marks in the otoliths. The results demonstrated a clear correlation between fish size and age, with a consistent daily growth rate that supports the hypothesis of daily increment formation in otoliths. The mortality rate associated with ARS treatment was within acceptable limits, confirming the method's viability for non-lethal age and growth studies. This research not only underscores the effectiveness of ARS marking in studying juvenile fish growth patterns but also contributes to a better understanding of the life history of D. vulgaris in the Çanakkale Strait, offering valuable insights for fisheries management and conservation efforts.

An analysis of the welfare of fast-growing and slower-growing strains of broiler chicken

Due to concerns about the welfare of fast-growing (FG) strains of broiler chicken, animal welfare organisations have advocated the use of certain slower-growing (SG) strains that meet key welfare targets under test conditions. However, a widespread transition to SG strains could negatively affect sustainability because these birds tend to have higher feed conversion ratios and longer production cycles. It is important therefore to review the extent and limits of SG welfare improvements under test conditions and on commercial farms, to support the best policy decisions. Following a systematic literature search, 63 source papers were identified. Most reported comparative welfare outcomes for at least one SG strain with at least one FG counterpart, whilst a minority examined the suitability of various SG strains for niche production. The literature review considered different types of study design and accounted for confounding factors such rearing environment and diet. Additionally, a quantitative analysis of effect size for mortality, gait score and contact dermatitis was conducted across studies that had compared birds under similar rearing conditions and that had used SG strains with an average daily growth rate of at least 40g/day. Modern, commercial SG strains performed better on most relevant welfare traits than FG strains. This was the case even when the ‘fairest’ comparisons were made at equivalent bodyweights (when SG birds were older), under matched-environmental conditions, experimentally or on farm. The quantitative analysis found that FG strains had a higher estimated incidence rate ratio for mortality (risk of death over a given period of time) of between 1.69 and 2.16, contact dermatitis affecting 15-25% more birds, and a mean gait score 0.65 points higher than SG strains. FG strains were also less active but other differences in behaviour were inconsistent with some behaviours (e.g. dustbathing) often absent altogether. Growth rate was generally, but not always, predictive of welfare problems. Alternative strategies, such as the slaughter of birds prior to the onset of any welfare decline, could be evaluated in future in terms of welfare improvement and efficiency of production.

Early-Life Population Parameters and Hatch-Date Analysis of Sharpsnout Seabream (Diplodus puntazzo Walbaum, 1792) Juveniles in the Sea of Marmara, Türkiye

This research aims to determine early-life population parameters and hatch date of sharpsnout seabream (Diplodus puntazzo Walbaum, 1792) juveniles using microstructure analyses of sagittal otoliths collected from the Sea of Marmara, Türkiye. Specimens were collected using an experimental beach seine at 12 stations from November 2021 to March 2022. The mean catch per unit effort (CPUE) was 1.1 individuals per haul, with 44.4% of the total D. puntazzo specimens collected at the Erdek Station. A negative allometric growth was calculated from the length-weight relationship equation (W=0.0178L2.698). The daily age ranged between 39 days-1 and 141 days-1, with a mean of 78.9 ± 2.29 days-1. The daily growth rate and mortality ratio were calculated as 0.213 mm/day and 4.38%, respectively. The hatching mainly occurred in September and October.

Initial Biomass Effect of Azolla caroliniana Culture on Performance in the Southern Kyrgyzstan Conditions

The object of the study was Azolla caroliniana Willd., collected from reservoirs of collector-drainage networks in the vicinity of Osh (Ak-Buura river basin), and also grown in laboratory conditions. To determine the initial biomass of the culture, Azolla caroliniana was grown outdoors in tray units with an area of 1 m2 of water surface, a capacity of 500 l, a depth of 50 cm and a nutrient medium prepared from chicken manure (5 g/l), which was renewed every 5 days. The initial biomass of the Azolla culture added to the trays in option I was 100 g/m2, in option II 200 g/m2, option III 300 g/m2, option IV 400 g/m2, option V 500 g/m2, option VI 600 g/m2, VII option 700 g/m2. The A. caroliniana high performance in variants III and IV is the result of its daily growth rate. As a result, the daily increase was 129.0±0.4 g/m2in option III, and 112.4±0.3 in option IV. With a low biomass (in options I and II), azolla does not have time to fully use the available nutrient medium; due to the excess nutrient medium, other aquatic plants and algae develop strongly. In this regard, the growth and development of Azolla shoots and rhizoids slows down. In the III and IV variants of the Azolla experiment, due to the complete absorption of nutrients, normal development of the root structure and shoots occurs; accordingly, the daily growth rate of raw biomass was higher than in the other variants. Thus, when growing Azolla caroliniana in field conditions or in greenhouses, it is advisable to use 300-400 g of initial biomass per 1 m2 of water surface.