Objective: In the context of the fast-expanding shrimp farming industry in Sri Lanka, this study aimed to evaluate the distribution and understanding of BMPs, examine the relationship between BMPs and disease outbreaks, and analyze the current antibiotic usage trends through a fact-finding survey. Materials and Methods: A questionnaire survey was conducted in 131 shrimp farms located in Puttalam District in North Western Province, where shrimp farming is thriving in Sri Lanka. The survey was conducted from September to October 2021. In addition, in August 2022 and August 2023, interviews were conducted with shrimp farms in Puttalam district and Batticaloa district, shrimp hatcheries, and export companies. Data were analyzed using descriptive statistics, Probit, and Tobit regression analysis. Results: The item-count technique revealed a significant (p < 0.05) difference in the use of antibiotics without consulting experts, signifying inappropriate use. No aquaculture farmer reported being unaware of BMPs, and among the 45 farmers who attended a BMPs seminar, 30 claimed to possess a good understanding of BMPs. Probit and Tobit regression results revealed that the rate of understanding of BMPs, education level, and obtaining information on the sanitation management of shrimp farming from extension and guidance organizations were inversely associated with both disease incidence in shrimp farming and shrimp discards. Conclusion: Although the use of antibiotics is prohibited in BMPs, the analysis results suggest inappropriate use of antibiotics. The findings indicate that enhanced BMP understanding can reduce disease incidence and shrimp discards, emphasizing the need for incentives to promote BMP adoption and reduce the necessity for antibiotics. Adv. Vet. Anim. Res., 11(1): 33-39, March 2024 http://doi.org/10.5455/javar.2024.k744

Objective: In the context of the fast-expanding shrimp farming industry in Sri Lanka, this study aimed to evaluate the distribution and understanding of BMPs, examine the relationship between BMPs and disease outbreaks, and analyze the current antibiotic usage trends through a fact-finding survey. Materials and Methods: A questionnaire survey was conducted in 131 shrimp farms located in Puttalam District in North Western Province, where shrimp farming is thriving in Sri Lanka. The survey was conducted from September to October 2021. In addition, in August 2022 and August 2023, interviews were conducted with shrimp farms in Puttalam district and Batticaloa district, shrimp hatcheries, and export companies. Data were analyzed using descriptive statistics, Probit, and Tobit regression analysis. Results: The item-count technique revealed a significant (p < 0.05) difference in the use of antibiotics without consulting experts, signifying inappropriate use. No aquaculture farmer reported being unaware of BMPs, and among the 45 farmers who attended a BMPs seminar, 30 claimed to possess a good understanding of BMPs. Probit and Tobit regression results revealed that the rate of understanding of BMPs, education level, and obtaining information on the sanitation management of shrimp farming from extension and guidance organizations were inversely associated with both disease incidence in shrimp farming and shrimp discards. Conclusion: Although the use of antibiotics is prohibited in BMPs, the analysis results suggest inappropriate use of antibiotics. The findings indicate that enhanced BMP understanding can reduce disease incidence and shrimp discards, emphasizing the need for incentives to promote BMP adoption and reduce the necessity for antibiotics. [J Adv Vet Anim Res 2024; 11(1.000): 33-39]

Objective: The experiment evaluated how Aloe vera gel (AVG) extract supplementation affected immune responses and physiological performances in broiler chickens. Materials and Methods: 90-day-old Cobb 500 broiler chicks were reared for 38 days without the addition of antibiotics, either through feed or water. At 10 days, chicks were allocated into three groups: A, B, and C (n = 30). Group A served as non-supplemented control. Groups B and C were administered aqueous extracts of AVG at 1.0% and 2.0%, respectively, with drinking water. Results: The supplementation of AVG potentiated the chicken immune response to Newcastle disease- vaccinated birds and sheep red blood cell-treated birds, which detected the highest antibody titers against Newcastle disease virus and sRBC. The cellular immune response evaluated through a cutaneous basophilic hypersensitivity test using phytohemagglutinin-P demonstrated a significant increase in skin thickness in AVG-supplemented birds. The relative sizes of lymphoid organs (bursa, spleen, and thymus) were significantly enhanced (p < 0.05) among the groups. Broilers given AVG-1 and AVG-2 exhibited significantly greater (p < 0.01) live body weight, dressing percentages, and serum protein and serum albumin levels. The supplemented groups experienced a significant reduction in total serum cholesterol, triglycerides, and low-density lipoprotein–cholesterol values, while the levels of high-density lipoprotein-cholesterol remained unchanged. The dietary aqueous extracts of AVG are effective in enhancing innate and specific immunity. Conclusion: This work strengthens the perspective of the use of AVG as an immune stimulant to facilitate recovery from immune suppression states, enhance innate and specific immunity, and improve broiler growth performance. Adv. Vet. Anim. Res., 11(1): 40-46, March 2024   http://doi.org/10.5455/javar.2024.k745

Objective: The experiment evaluated how Aloe vera gel (AVG) extract supplementation affected immune responses and physiological performances in broiler chickens. Materials and Methods: 90-day-old Cobb 500 broiler chicks were reared for 38 days without the addition of antibiotics, either through feed or water. At 10 days, chicks were allocated into three groups: A, B, and C (n = 30). Group A served as non-supplemented control. Groups B and C were administered aqueous extracts of AVG at 1.0% and 2.0%, respectively, with drinking water. Results: The supplementation of AVG potentiated the chicken immune response to Newcastle disease-vaccinated birds and sheep red blood cell-treated birds, which detected the highest antibody titers against Newcastle disease virus and sRBC. The cellular immune response evaluated through a cutaneous basophilic hypersensitivity test using phytohemagglutinin-P demonstrated a significant increase in skin thickness in AVG-supplemented birds. The relative sizes of lymphoid organs (bursa, spleen, and thymus) were significantly enhanced (p < 0.05) among the groups. Broilers given AVG-1 and AVG-2 exhibited significantly greater (p < 0.01) live body weight, dressing percentages, and serum protein and serum albumin levels. The supplemented groups experienced a significant reduction in total serum cholesterol, triglycerides, and low-density lipoprotein–cholesterol values, while the levels of high-density lipoprotein-cholesterol remained unchanged. The dietary aqueous extracts of AVG are effective in enhancing innate and specific immunity. Conclusion: This work strengthens the perspective of the use of AVG as an immune stimulant to facilitate recovery from immune suppression states, enhance innate and specific immunity, and improve broiler growth performance. [J Adv Vet Anim Res 2024; 11(1.000): 40-46]

Objective: This study was conducted to evaluate the prevalence of total aflatoxin (AF) and ochratoxin A (OTA) in poultry feed ingredients under different environmental conditions during the summer and winter seasons, while the hygiene quality of the feed ingredient was assessed through viable fungal count (VFC). Materials and Methods: A total of 288 poultry feed ingredients (n = 96 each) samples were collected from different poultry shops, which were initially analyzed for the presence of AF and OTA through thin layer chromatography (TLC) and then confirmed the contamination concentration through the enzyme-linked immunosorbent assay method. Results: The results of the current study confirmed the incidence of contamination with AF and OTA by TLC and ELISA methods. The contamination level of AF ranged from 26.09 to 50.56 (mean = 41.22 ± 9.45) μg/kg, whereas the contamination level of OTA ranged from 50.13 to 6.21 (mean 42.60 ± 6.21) μg/kg. The contamination level of AF was found to be above the permissible level set by the Food and Drug Administration (20 μg/kg), whereas the contamination level of OTA was below the permissible limits. Moreover, the VFC values were also below the recommended level. The results showed that the association between AF, OTA, and moisture content was significant (p < 0.05). Conclusion: Mycotoxin contamination was significantly (p < 0.05) highest in the winter season. These findings suggested that continuous monitoring regimes might prevent mycotoxin contamination in poultry feed ingredients. Adv. Vet. Anim. Res., 11(1): 107-113, March 2024 http://doi.org/10.5455/javar.2024.k754

Objective: This study was conducted to evaluate the prevalence of total aflatoxin (AF) and ochratoxin A (OTA) in poultry feed ingredients under different environmental conditions during the summer and winter seasons, while the hygiene quality of the feed ingredient was assessed through viable fungal count (VFC). Materials and Methods: A total of 288 poultry feed ingredients (n = 96 each) samples were collected from different poultry shops, which were initially analyzed for the presence of AF and OTA through thin layer chromatography (TLC) and then confirmed the contamination concentration through the enzyme-linked immunosorbent assay method. Results: The results of the current study confirmed the incidence of contamination with AF and OTA by TLC and ELISA methods. The contamination level of AF ranged from 26.09 to 50.56 (mean = 41.22 ± 9.45) μg/kg, whereas the contamination level of OTA ranged from 50.13 to 6.21 (mean 42.60 ± 6.21) μg/kg. The contamination level of AF was found to be above the permissible level set by the Food and Drug Administration (20 μg/kg), whereas the contamination level of OTA was below the permissible limits. Moreover, the VFC values were also below the recommended level. The results showed that the association between AF, OTA, and moisture content was significant (p < 0.05). Conclusion: Mycotoxin contamination was significantly (p < 0.05) highest in the winter season. These findings suggested that continuous monitoring regimes might prevent mycotoxin contamination in poultry feed ingredients. [J Adv Vet Anim Res 2024; 11(1.000): 107-113]

Objective: The purpose of this study was to select the active fraction of red ginger (Zingiber officinale var. Rubrum) for its antioxidant and antibacterial activities against Staphylococcus aureus (AMC 6934), Bacillus subtilis (AMC 7923), Pseudomonas aeruginosa (AMC 8973), and Escherichia coli (AMC 5761). Materials and Methods: A total of 2 kg of dry red ginger rhizome powder was macerated in stages with different levels of solvent polarity to extract the chemical composition within the red ginger powder sample. The extraction process begins with a non-polar solvent (n-hexane) by soaking the red ginger powder sample for 3 × 24 h. Results: The red ginger extract fractionated with methanol produced alkaloids, phenolics, flavonoids, and coumarins, while the fractionation using n-hexane produced alkaloids and triterpenoids only. The fractionation with ethyl acetate produced alkaloids, phenolics, flavonoids, triterpenoids, saponins, and coumarins. The antioxidant activity test was 49.261 mg/l for the ethyl acetate fraction, 146.648 mg/l for the methanol fraction, and 300.865 mg/l for the n-hexane fraction. Conclusion: The ethyl acetate fraction was effectively powerful in inhibiting the growth of Grampositive and Gram-negative bacteria. All fractions had moderate antibacterial activity; however, the performance of ethyl acetate in the red ginger extract was better than that of methanol and n-hexane. Adv. Vet. Anim. Res., 11(1): 114-124, March 2024 http://doi.org/10.5455/javar.2024.k755

Objective: The purpose of this study was to select the active fraction of red ginger (Zingiber officinale var. Rubrum) for its antioxidant and antibacterial activities against Staphylococcus aureus (AMC 6934), Bacillus subtilis (AMC 7923), Pseudomonas aeruginosa (AMC 8973), and Escherichia coli (AMC 5761). Materials and Methods: A total of 2 kg of dry red ginger rhizome powder was macerated in stages with different levels of solvent polarity to extract the chemical composition within the red ginger powder sample. The extraction process begins with a non-polar solvent (n-hexane) by soaking the red ginger powder sample for 3 × 24 h. Results: The red ginger extract fractionated with methanol produced alkaloids, phenolics, flavonoids, and coumarins, while the fractionation using n-hexane produced alkaloids and triterpenoids only. The fractionation with ethyl acetate produced alkaloids, phenolics, flavonoids, triterpenoids, saponins, and coumarins. The antioxidant activity test was 49.261 mg/l for the ethyl acetate fraction, 146.648 mg/l for the methanol fraction, and 300.865 mg/l for the n-hexane fraction. Conclusion: The ethyl acetate fraction was effectively powerful in inhibiting the growth of Gram-positive and Gram-negative bacteria. All fractions had moderate antibacterial activity; however, the performance of ethyl acetate in the red ginger extract was better than that of methanol and n-hexane. [J Adv Vet Anim Res 2024; 11(1.000): 114-124]

Objective: This research aimed to assess the effects of dried plantain herb, lemongrass, and their combination on milk yield, immunological, liver enzymatic, serum, and milk mineral status in dairy cows. Materials and Methods: Twenty cows were arbitrarily assigned to 4 diets. Cows were given a basal ration considered as control diet (CL-D) having 14.93% crude protein (CP)and 10.96 MJ ME per kg dry matter (DM). Each cow was given 100 gm plantain, 100 gm lemongrass, and 50 gm plantain + 50 gm lemongrass with CL-D and taken as plantain diet (PT-D), lemongrass diet (LG-D), and plantain-lemongrass diet (PL-D), daily for 63 days, respectively. Blood and milk samples were taken four times at an interval of 14 days. Data were analyzed using a two-way repeated measures analysis of covariance. Results: Better DM consumption and milk yield were observed in the PT-D and LG-D compared to the CL-D (p ≤ 0.05). LG-D improved the milk’s total solids, protein, and fat compared to CL-D (p < 0.05). Substantially, herbal groups improved serum albumin and reduced globulin concentrations compared to CL-D. LG-D had the highest serum immunoglobulin G, while herbal groups effectively reduced the liver enzymes compared to CL-D. Herbal groups did not affect serum and milk’s calcium and phosphorus concentrations, while LG-D and PL-D substantially improved serum and milk zinc concentrations. Conclusions: Both plantain and lemongrass improved dairy cows’ DM consumption and milk yield. Plantain and/or lemongrass enhanced the immune system and liver health, but not serum and milk calcium and phosphorus level. Lemongrass and a combination of plantain and lemongrass increased the serum and milk zinc concentrations. Adv. Vet. Anim. Res., 11(1): 185-193, March 2024 http://doi.org/10.5455/javar.2024.k764

Objective: This research aimed to assess the effects of dried plantain herb, lemongrass, and their combination on milk yield, immunological, liver enzymatic, serum, and milk mineral status in dairy cows. Materials and Methods: Twenty cows were arbitrarily assigned to 4 diets. Cows were given a basal ration considered as control diet (CL-D) having 14.93% crude protein (CP)and 10.96 MJ ME per kg dry matter (DM). Each cow was given 100 gm plantain, 100 gm lemongrass, and 50 gm plantain + 50 gm lemongrass with CL-D and taken as plantain diet (PT-D), lemongrass diet (LG-D), and plantain-lemongrass diet (PL-D), daily for 63 days, respectively. Blood and milk samples were taken four times at an interval of 14 days. Data were analyzed using a two-way repeated measures analysis of covariance. Results: Better DM consumption and milk yield were observed in the PT-D and LG-D compared to the CL-D (p ≤ 0.05). LG-D improved the milk's total solids, protein, and fat compared to CL-D (p < 0.05). Substantially, herbal groups improved serum albumin and reduced globulin concentrations compared to CL-D. LG-D had the highest serum immunoglobulin G, while herbal groups effectively reduced the liver enzymes compared to CL-D. Herbal groups did not affect serum and milk's calcium and phosphorus concentrations, while LG-D and PL-D substantially improved serum and milk zinc concentrations. Conclusions: Both plantain and lemongrass improved dairy cows' DM consumption and milk yield. Plantain and/or lemongrass enhanced the immune system and liver health, but not serum and milk calcium and phosphorus level. Lemongrass and a combination of plantain and lemongrass increased the serum and milk zinc concentrations. [J Adv Vet Anim Res 2024; 11(1.000): 185-193]

Objective: The present work aimed to determine the impact of various cooking methods on sensory attributes, microbial safety, and physicochemical characteristics of ostrich meat to specify the best cooking method that guarantees the microbial safety of the meat as well as maintains nutritional values and is highly attractive to consumers. Materials and Methods: One hundred fresh leg muscles of ostriches were divided into five groups. Different cooking techniques were used for each group, as follows: roasting, boiling, grilling, frying, and microwaving. Each method was examined by evaluating the impact of various cooking methods on sensory attributes, proximate chemical analysis, protein and fat oxidation parameters, microbial load, changes in color, and the shear force of ostrich meat. Results: The oven-roasting and grilling methods are highly recommended and more appealing to consumers since they produce tenderer and juicier meat, cause less cooking loss (CL), and maintain the nutritive value of ostrich meat; however, they have the highest protein and fat oxidation rates. On the other hand, boiling and frying methods revealed good fat oxidation parameters, the highest CL, and preserved nutritional value, but unfortunately, they were not highly preferred by consumers. From a hygienic point of view, grilling and microwave cooking are the methods that ensure the microbiological safety of cooked ostrich meat, as they significantly reduce Enterobacteriaceae and psychrotrophic bacterial counts, among other cooking methods. Conclusion: The oven roasting and grilling methods were the most preferable thermal cooking techniques, as they achieved the highest acceptability to consumers and maintained the nutritive values of ostrich meat. Adv. Vet. Anim. Res., 11(1): 194-202, March 2024 http://doi.org/10.5455/javar.2024.k765

Objective: The present work aimed to determine the impact of various cooking methods on sensory attributes, microbial safety, and physicochemical characteristics of ostrich meat to specify the best cooking method that guarantees the microbial safety of the meat as well as maintains nutritional values and is highly attractive to consumers. Materials and Methods: One hundred fresh leg muscles of ostriches were divided into five groups. Different cooking techniques were used for each group, as follows: roasting, boiling, grilling, frying, and microwaving. Each method was examined by evaluating the impact of various cooking methods on sensory attributes, proximate chemical analysis, protein and fat oxidation parameters, microbial load, changes in color, and the shear force of ostrich meat. Results: The oven-roasting and grilling methods are highly recommended and more appealing to consumers since they produce tenderer and juicier meat, cause less cooking loss (CL), and maintain the nutritive value of ostrich meat; however, they have the highest protein and fat oxidation rates. On the other hand, boiling and frying methods revealed good fat oxidation parameters, the highest CL, and preserved nutritional value, but unfortunately, they were not highly preferred by consumers. From a hygienic point of view, grilling and microwave cooking are the methods that ensure the microbiological safety of cooked ostrich meat, as they significantly reduce Enterobacteriaceae and psychrotrophic bacterial counts, among other cooking methods. Conclusion: The oven roasting and grilling methods were the most preferable thermal cooking techniques, as they achieved the highest acceptability to consumers and maintained the nutritive values of ostrich meat. [J Adv Vet Anim Res 2024; 11(1.000): 194-202]

Objective: The methodology employed in this research was designed to identify and characterize the infectious bursal disease virus (IBDV) at the molecular level, originating from recent outbreaks in Bangladesh. Materials and Methods: The IBDV outbreak farm was investigated, and bursa of fabricius (BF) specimens were acquired from infected chickens. Initially, viruses in the processed samples were detected in chicken embryo fibroblast (CEF) cells, and the RT-PCR method was used to confirm IBDV. The positive samples were injected through chorioallantoic membrane route into the embryo of a 10-day-old specific pathogen-free (SPF) egg for virus isolation and pathogenicity testing. Finally, we sequenced the VP2 gene to identify phylogenetic relationships and detect mutations. Results: From the 77 collected samples, 42.85% (33/77) were found positive for cytopathic effects in CEF cells, and IBDV was detected in 31.16% (24/77) of the samples by RT-PCR. IBDV was isolated in SPF chicken embryos. In the pathogenicity test, infectious bursal disease was evident in seronegative chickens with visible signs of disease. Sequence analysis shows that the broiler-isolated viruses clustered with genotype A3B2 and backyard chickens with genotype A1B1. The presence of amino acid motifs for virulence markers was revealed in the partially sequenced VP2 gene with a mutation at S254G in four IBDV isolates from broilers. However, amino acids for virulence markers were absent in two isolates from backyard chickens, which shows sequence homology with IBDV classic strains. Conclusion: In this study, we identified and characterized circulating reassorted IBDV from vaccinated broilers, which may be one of the major causes of vaccination failure in broilers. J. Adv. Vet. Anim. Res., 11(3): 534–543, September 2024 http://doi.org/10.5455/javar.2024.k803

Objective: The methodology employed in this research was designed to identify and characterize the infectious bursal disease virus (IBDV) at the molecular level, originating from recent outbreaks in Bangladesh. Materials and Methods: The IBDV outbreak farm was investigated, and bursa of Fabricius (BF) specimens were acquired from infected chickens. Initially, viruses in the processed samples were detected in chicken embryo fibroblast (CEF) cells, and the RT-PCR method was used to confirm IBDV. The positive samples were injected through chorioallantoic membrane route into the embryo of a 10-day-old specific pathogen-free (SPF) egg for virus isolation and pathogenicity testing. Finally, we sequenced the VP2 gene to identify phylogenetic relationships and detect mutations. Results: From the 77 collected samples, 42.85% (33/77) were found positive for cytopathic effects in CEF cells, and IBDV was detected in 31.16% (24/77) of the samples by RT-PCR. IBDV was isolated in SPF chicken embryos. In the pathogenicity test, infectious bursal disease was evident in seronegative chickens with visible signs of disease. Sequence analysis shows that the broiler-isolated viruses clustered with genotype A3B2 and backyard chickens with genotype A1B1. The presence of amino acid motifs for virulence markers was revealed in the partially sequenced VP2 gene with a mutation at S254G in four IBDV isolates from broilers. However, amino acids for virulence markers were absent in two isolates from backyard chickens, which shows sequence homology with IBDV classic strains. Conclusion: In this study, we identified and characterized circulating reassorted IBDV from vaccinated broilers, which may be one of the major causes of vaccination failure in broilers. [J Adv Vet Anim Res 2024; 11(3.000): 534-543]

Objective: This research was conducted to analyze the effect of cryopreservation of sperm using modified cryoprotectants on embryo development through in vitro fertilization (IVF). In this research, three types of cryoprotectant combinations were compared, including Nakagata, modified cryoprotectant, and commercial (Kitazato). Materials and Methods: Several parameters, namely sperm concentration, motility, morphology, plasma membrane integrity, cryo-survival rate, and viability rate, were measured and compared before vitrification and warming. Embryo development was also observed on the first and third days of development based on the cell number, cell size, and fragmentation rate. Results: Sperm cryopreservation exhibited a negative influence on embryo quality. Both Nakagata cryoprotectants and modified cryoprotectants attained good-quality embryos. In terms of embryonic development, this research revealed a modified cryoprotectant superior to Nakagata’s cryoprotectant, although Kitazato was superior to the Nakagata cryoprotectant and modified cryoprotectant. Significant differences were found in the three cryoprotectants on observations on day 1 and day 3, all of them with p-value < 0.05. Conclusion: Modified cryoprotectant was found to be better than Nakagata but less significant than Kitazato in terms of embryonic development quality. Therefore, modified cryoprotectants could be a better alternative compared to commercial (Kitazato) cryoprotectants for improving embryo quality. J. Adv. Vet. Anim. Res., 11(3): 554–552, September 2024 http://doi.org/10.5455/javar.2024.k804

Objective: This research was conducted to analyze the effect of cryopreservation of sperm using modified cryoprotectants on embryo development through in vitro fertilization (IVF). In this research, three types of cryoprotectant combinations were compared, including Nakagata, modified cryoprotectant, and commercial (Kitazato). Materials and Methods: Several parameters, namely sperm concentration, motility, morphology, plasma membrane integrity, cryo-survival rate, and viability rate, were measured and compared before vitrification and warming. Embryo development was also observed on the first and third days of development based on the cell number, cell size, and fragmentation rate. Results: Sperm cryopreservation exhibited a negative influence on embryo quality. Both Nakagata cryoprotectants and modified cryoprotectants attained good-quality embryos. In terms of embryonic development, this research revealed a modified cryoprotectant superior to Nakagata's cryoprotectant, although Kitazato was superior to the Nakagata cryoprotectant and modified cryoprotectant. Significant differences were found in the three cryoprotectants on observations on day 1 and day 3, all of them with p-value < 0.05. Conclusion: Modified cryoprotectant was found to be better than Nakagata but less significant than Kitazato in terms of embryonic development quality. Therefore, modified cryoprotectants could be a better alternative compared to commercial (Kitazato) cryoprotectants for improving embryo quality. [J Adv Vet Anim Res 2024; 11(3.000): 544-552]

Objective: This study was conducted to isolate and identify probiotic bacteria from wild stinging catfish (Heteropneustes fossilis), a very popular high-valued aquaculture species of Bangladesh. The isolates were identified through conventional culture-based and molecular techniques. Materials and Methods: Stinging catfish harvested from natural sources of three sampling sites under two districts (Kishoreganj and Netrakona) were collected, dissected for gut content, and cultured onto Lactobacillus MRS Agar plates. Out of 60 bacterial isolates obtained, 10 were chosen for an in vitro evaluation of their probiotic potentials through pH and bile tolerance tests. The 16S rRNA gene sequences of the selected isolates were searched against the NCBI database using the Basic Local Alignment Search Tool for Nucleotides (BLASTNs). Results: The isolates were identified as Staphylococcus arlettae, Bacillus subtilis, Staphylococcus succinus, Bacillus velezensis, Kocuria subflava, Macrococcus caseolyticus, Lysinibacillus sphaericus, Glutamicibacter mysorens, Bacillus cereus, and Acinetobacter lwoffii. Among them, B. subtilis, S. succinus, B. velezensis, M. caseolyticus, G. mysorens, and B. cereus exhibited notable growth across all tested pH levels (pH 2, 3, and 4) and bile salt concentrations (0.3%, 0.5%, and 1.0%) suggesting that they have strong potential as probiotic bacteria. In addition, S. arlettae also indicated promising growth except at pH 2. L. sphaericus and K. subflava exhibited limited growth at low pH but tolerated bile salt concentrations. A. lwoffii did not show any growth at pH tests but minimal growth at the lower concentrations of bile salts. Conclusion: According to the potentiality assessments and previous literature reviews, five isolates such as B. subtilis, S. succinus, M. caseolyticus, G. mysorens, and B. cereus were identified as potential probiotic bacteria. As species-specific probiotics are considered to perform more effectively and efficiently than unknown-sourced commercial probiotics, the findings of this study will be applicable in enhancing the aquaculture production of stinging catfish. J. Adv. Vet. Anim. Res., 11(3): 560-572, September 2024 http://doi.org/10.5455/javar.2024.k806

Objective: This study was conducted to isolate and identify probiotic bacteria from wild stinging catfish (Heteropneustes fossilis), a very popular high-valued aquaculture species of Bangladesh. The isolates were identified through conventional culture-based and molecular techniques. Materials and Methods: Stinging catfish harvested from natural sources of three sampling sites under two districts (Kishoreganj and Netrakona) were collected, dissected for gut content, and cultured onto Lactobacillus MRS Agar plates. Out of 60 bacterial isolates obtained, 10 were cho¬sen for an in vitro evaluation of their probiotic potentials through pH and bile tolerance tests. The 16S rRNA gene sequences of the selected isolates were searched against the NCBI database using the Basic Local Alignment Search Tool for Nucleotides (BLASTNs). Results: The isolates were identified as Staphylococcus arlettae, Bacillus subtilis, Staphylococcus succinus, Bacillus velezensis, Kocuria subflava, Macrococcus caseolyticus, Lysinibacillus sphaeri¬cus, Glutamicibacter mysorens, Bacillus cereus, and Acinetobacter lwoffii. Among them, B. subtilis, S. succinus, B. velezensis, M. caseolyticus, G. mysorens, and B. cereus exhibited notable growth across all tested pH levels (pH 2, 3, and 4) and bile salt concentrations (0.3%, 0.5%, and 1.0%) sug¬gesting that they have strong potential as probiotic bacteria. In addition, S. arlettae also indicated promising growth except at pH 2. L. sphaericus and K. subflava exhibited limited growth at low pH but tolerated bile salt concentrations. A. lwoffii did not show any growth at pH tests but minimal growth at the lower concentrations of bile salts. Conclusion: According to the potentiality assessments and previous literature reviews, five iso¬lates such as B. subtilis, S. succinus, M. caseolyticus, G. mysorens, and B. cereus were identified as potential probiotic bacteria. As species-specific probiotics are considered to perform more effec¬tively and efficiently than unknown-sourced commercial probiotics, the findings of this study will be applicable in enhancing the aquaculture production of stinging catfish. [J Adv Vet Anim Res 2024; 11(3.000): 560-572]