Previous Article in Journal
Extended-Spectrum Beta-Lactamases (ESBLs) Gene Mutations in Kuwait: How Much Do We Know? Not Much!
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Bacteria
Volume 4
Issue 2
10.3390/bacteria4020023
bacteria-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Dietary Dill Weed (Anethum graveolens) Stimulated Disease Resistance of African Catfish (Clarias gariepinus) Against Edwardsiellosis Infection

by
Lee Seong Wei
1,*,
Vui Kien Liew
1,
Albaris B. Tahiluddin
2,3,
Ramasamy Harikrishnan
4,
Md. Eilious Hosain
5,
Mohamad Nor Azra
6 and
Wendy Wee
7,*
1
Department of Agricultural Sciences, Faculty of Agro-Based Industry, Universiti Malaysia Kelantan, Jeli Campus, Jeli 17600, Kelantan, Malaysia
2
College of Fisheries, Mindanao State University-Tawi-Tawi College of Technology and Oceanography, Sanga-Sanga, Bongao 7500, Philippines
3
Department of Aquaculture, Institute of Science, Kastamonu University, Kastamonu 37200, Türkiye
4
Department of Zoology, Pachaiyappa’s College for Men, Kanchipuram 631501, Tamil Nadu, India
5
Fisheries Biotechnology Division, National Institute of Biotechnology, Ganakbari, Ashulia, Savar, Dhaka 1349, Bangladesh
6
Institute of Climate Adaptation and Marine Biotechnology (ICAMB), Universiti Malaysia Terengganu, Kuala Nerus 21030, Terengganu, Malaysia
7
Centre for Fundamental and Continuing Education, Universiti Malaysia Terengganu, Kuala Nerus 21030, Terengganu, Malaysia
*
Authors to whom correspondence should be addressed.
Bacteria 2025, 4(2), 23; https://doi.org/10.3390/bacteria4020023
Submission received: 22 January 2025 / Revised: 19 February 2025 / Accepted: 17 April 2025 / Published: 3 May 2025
Browse Figures
Versions Notes

Abstract

:
This study evaluated the effects of dietary dill weed (DW) on growth, hematological profile, digestive enzyme activities, antioxidative response, heat tolerance, gut microbiota composition, and disease resistance in African catfish (Clarias gariepinus). A control diet (basal diet) was compared to three DW diets (DW5, DW10, and DW15) with increasing DW levels (0.5, 1.0, and 1.5%, respectively). After eight weeks, fish fed DW diets exhibited significantly higher growth performance (p < 0.05) compared to the control group, as evidenced by increased final weight (FW), specific growth rate (SGR), and weight gain (WG). Conversely, the feed conversion ratio (FCR), hepatosomatic index (HSI), and visceral somatic index (VSI) were significantly lower (p < 0.05) in fish fed DW diets compared to the control. Dietary DW supplementation significantly enhanced (p < 0.05) hematological profiles, including red blood cell (RBC), white blood cell (WBC), hematocrit (HCT), and hemoglobin (HBG), compared to the control group. Similarly, antioxidant responses, including superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activity, significantly increased (p < 0.05) in fish fed DW diets before or after the heat tolerance assay. Fish fed DW diets displayed a higher relative abundance of beneficial gut microbiota, including Cetobacterium spp., Akkermansia muciniphila, Phocaeicola spp., and Niameybacter massiliensis. Furthermore, dietary DW supplementation stimulated disease resistance against Edwardsiella tarda infection in African catfish. Regression analysis indicated that the optimal DW inclusion level for promoting growth performance and health status in African catfish ranged from 0.229 to 0.433%.

1. Introduction

African catfish, Clarias gariepinus, emerges as a star in aquaculture due to its consumer appeal and affordability in Malaysia. This popular freshwater fish entices investors with its rapid growth cycle to reach marketable size (200–300 g) (1–2 months), high stocking density tolerance, and strong market demand [1]. However, this intensive farming approach, while lucrative, can compromise fish health and growth due to stress. Stress negatively affects fish physiology and immune responses. Stressed fish have been reported to suffer immunocompetence depletion, such as reduced chemiluminescence and cytotoxicity activity. At the same time, stress elevates cortisol and reduces complement proteins [2]. Subsequently, stressed fish become more susceptible to infectious diseases, ultimately jeopardizing aquaculture production.
Edwardsiella tarda, a bacterium causing Edwardsiellosis, poses a significant threat to diverse aquatic animals [3]. This ubiquitous pathogen has been isolated from a vast array of brackish and freshwater organisms [4,5]. E. tarda infections are linked to high mortality rates in aquaculture, leading to farm closures in some cases [3]. To counter this challenge, proactive measures are being implemented. These strategies include the use of prebiotics, probiotics, phytobiotics, and vaccines [6]. Phytobiotics are defined as plant-based materials, such as herbs, vegetables, fruits, agricultural wastes, plant-based bioactive compounds, etc., which have beneficial effects on growth and health. They were reported to enhance feed palatability, increase digestive enzymes, promote antioxidative enzymes, stimulate disease resistance, modulate gut microbiota, and mitigate stress in various species of aquatic animals [3].
Recently, the application of phytobiotics as feed additives in aquafeeds has garnered significant attention due to the promising results in various aquatic species. Studies have shown that specific plant materials can be used as feed additives, such as Zingiber officinale (ginger) [7] and Curcuma longa leaves [1], which can enhance growth performance, digestive enzyme activity, and antioxidative responses in African catfish cultured in the laboratory at doses of 2–3% and 1.5% of the feed, respectively. Similar positive effects on growth, digestive enzyme activity, and antioxidative responses were observed in striped catfish, Pangasianodon hypophthalmus, farmed in an earthen pond and fed ginger rhizome as a feed additive at 1% of the feed [8]. Furthermore, research suggests that fermented water spinach and natural spirulina, used as fish meal replacement at doses of 50% and 5% of the feed, respectively, can positively impact the growth and health of stinging catfish, Heteropneustes fossilis, cultured in the laboratory [9,10]. The potential benefits extend beyond these examples, with studies indicating the efficacy of papaya, Carica papaya, leaves (2% of feed) [11], pineapple waste (30% of feed) [12], and Peperomia pellucida leaves (0.01% of feed) [13] as feed additives in promoting the growth, digestive enzyme activity, and antioxidative responses of tilapia cultured in the laboratory. These findings collectively highlight the immense potential of utilizing phytobiotics in aquaculture.
Dill weed (DW) (Anethum graveolens), a well-known culinary herb, has emerged as a promising phytobiotic for animal production based on recent studies. For instance, research has demonstrated the positive effects of dill leaf as a feed additive on broiler growth and health [14,15]. This herb is in the order Apiales and grouped in the Apiaceae family, known to possess bioactive compounds like camphene, limonene, carvone, α-pinene, α-phellandrene, and β-cymene [14]. Additionally, DW essential oil exhibits inhibitory activity against various microorganisms [16]. Moreover, dill has been traditionally used for its antioxidant properties and to enhance digestibility [14], as well as to manage diabetes [17]. Therefore, these bioactive compounds might benefit aquatic animals, such as through antimicrobial activity, improved digestive activity, and enhanced health status. While some research has explored the application of DW in aquatic animals, particularly in species like common carp (Cyprinus carpio), research on its application in African catfish farming remains largely unexplored. To this end, the present study aimed to investigate the beneficial effects of dietary dill weed on the growth, health, and stress tolerance of African catfish. This was achieved through a feeding trial, analysis of digestive enzyme activity (protease, lipase, and amylase activities), evaluation of antioxidative responses (superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities) before and after heat tolerance stress, and an E. tarda challenge assay.

2. Materials and Methods

2.1. Experimental Feed Preparation

Dried dill weed obtained from a local market was ground into a powder using a grinder (Panasonic, Japan). A commercially available catfish feed (Dindings, Malaysia) containing 34% crude protein, 4% fat, and 11% moisture served as the basal diet and control. The basal diet was then ground and homogenously mixed with 0.5, 1.0, and 1.5% (w/w) DW to create three experimental diets (DW5, DW10, and DW15). The experimental diets were pelletized (2 mm diameter), oven-dried at 50 °C, and stored at −20 °C until further use.

2.2. Feeding Trial Condition

A total of 1000 catfish juveniles with an average weight of 5 g/fish were procured from a commercial farm located in Tanah Merah, Kelantan, Malaysia. The fish were then transported to the Aquaculture Laboratory at the Universiti Malaysia Kelantan Jeli Campus. Upon arrival, the fish were acclimatized in a 500 L tank for one week. During this period, they were fed with a commercial pellet diet (Dindings, Malaysia) to satiation once daily (3% of body weight). Following the acclimatization period, 600 fish with an average weight of 10.5 g were randomly distributed into 12 tanks with a 200 L capacity, resulting in a final density of 50 fish per tank. All 4 treatments (control, DW5, DW10, and DW15) were conducted in triplicate (n = 3). Experimental fish were fed the designated feed to satiation once daily, in the morning from 8 am to 10 am, followed by a complete (100%) water exchange using aged tap water in the afternoon to maintain water quality, as water quality deteriorates after feeding activity. The water quality parameters in the experimental unit were monitored weekly using a ProQuatro multiparameter meter (YSI, USA) and an ammonia kit (API, Malaysia). Throughout the feeding trial, pH ranged from 6.4 to 6.8, dissolved oxygen ranged from 5.1 to 6.3 ppm, ammonia was <0.1 ppm, and temperature ranged from 25.5 to 27.9 °C.

2.3. Sampling

Following a feeding trial, three fish per replicate (n = 3) were euthanized with 100 ppm clove oil and weighed [18]. Blood was collected from the caudal vessels and stored in heparinized tubes. The fish were then dissected to isolate the liver and intestines and preserved in phosphate-buffered saline (PBS). Both samples were kept in a freezer for further analysis. The liver was used for subsequent evaluation of antioxidative response, while the intestine was used for digestive enzyme activity testing and gut microbiota analyses.

2.4. Growth Performance Calculation

At the end of the feeding trial, experimental fish were sampled for growth performance analysis. Growth performance was evaluated based on final weight (FW), weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR), hepatosomatic index (HSI), and visceral somatic index (VSI). The formulae for the calculation of growth parameters were as follows:
Total weight gain = Final weight (FW) − Initial weight (IW)
Weight gain (WG) = (Total weight gain/Initial weight) × 100
Feed conversion rate (FCR) = Total feed intake/Total weight gain
Hepatosomatic index (HSI) = Total liver weight/Total body weight
Viscerosomatic index (VSI) = Total viscera weight/Total body weight

2.5. Hematological Profiling

Blood collected from the fish (n = 3) sampled from each treatment was analyzed using an automated hematology analyzer (Mythic 18 Vet, USA) to determine the comprehensive hematological profile. This profile included white blood cell (WBC) count, differential leukocyte counts for monocytes (MON) and lymphocytes (LYM), red blood cell (RBC) count, hematocrit (HCT), hemoglobin (HGB) concentration, mean corpuscular hemoglobin concentration (MCHC), and mean corpuscular hemoglobin (MCH).

2.6. Digestive Enzyme Activity Assay

A homogenate was prepared from the sampled intestine. Briefly, the intestine was dissected into small pieces and homogenized in PBS (pH 7.5) on ice for 1 min [19]. The homogenate was then centrifuged at 10,000 rpm for 10 min. The resulting supernatant was stored at a cold temperature for subsequent analysis.
The activity of total protease, amylase, and lipase in the samples was measured using specific substrates and established protocols. A standard curve was constructed for the detection of each enzyme’s activity. Protease activity was measured using Na-benzoyl-DL-arginine-p-nitroanilide (BAPNA) as a substrate [20]. One unit of protease activity was defined as the amount of enzyme required to release 1 µmol of nitroanilide per min at 37 °C. Similarly, amylase activity was quantified using soluble starch as the substrate [21], with one unit defined as the amount hydrolyzing 10 mg of starch in 30 min at 37 °C. Lipase activity was evaluated using p-nitrophenyl palmitate (pNPP) [22], with one unit defined as the amount releasing 1 µmol of pNPP per min at 37 °C. All enzyme activities were expressed as units per mg of protein.

2.7. Antioxidant Enzyme Activity Assay

A liver homogenate was prepared for the analysis of antioxidant enzyme activity. Briefly, the liver sample was dissected into small pieces and homogenized in ice-cold PBS. The homogenate was then centrifuged at 8000 rpm for 10 min, and the supernatant was collected for subsequent assays of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities, conducted immediately. A standard curve was constructed for the detection of each enzyme’s activity. The activities of these antioxidant enzymes were determined using a commercially available colorimetric assay kit (Elabscience, USA) according to the manufacturer’s instructions. Absorbance was measured at 560 nm using a spectrophotometer (Bio-Rad, USA). The results were expressed as units per mg of protein (U/mg prot).

2.8. Heat Stress Assay

Following the completion of the feed trial, ten fish per replicate (n = 10) were randomly selected for the heat stress assay, which was conducted simultaneously with the bacterial challenge assay. A replicate of fish without exposure to heat stress served as the control group. These fish were housed in 50 L tanks equipped with electrical heaters. The water temperature was gradually increased at a rate of 2 °C per h until reaching a final temperature of 32 °C [23]. The heat stress exposure lasted for 72 h at the final temperature [23]. Subsequently, the livers of the experimental fish were sampled for analysis of antioxidative response.

2.9. Bacterial Challenge Assay

At the end of the feed trial, the experimental fish (n = 20) were randomly selected from each replicate for the bacterial challenge assay. E. tarda was administered via the intraperitoneal route at a dose of 1 × 108 colony-forming units (CFU)/mL. The bacterial strain was sourced from an earlier study, and its LD50 was 1 × 108 CFU/mL [24]. Fish infected with E. tarda continued to receive the designated feed for four consecutive weeks. The cumulative survival rate was then recorded.

2.10. Gut Microbiota Analysis

2.10.1. DNA Preparation

Three fish intestines per replicate were sampled for microbiota analysis. Intestines from the same treatment were pooled. DNA extraction involved the following steps. First, the samples were washed with sorbitol buffer and resuspended in homogenization buffer in a 1.5 mL microcentrifuge tube containing silica beads [25]. The samples were then vortexed at 4000 rpm for 30 min. Following homogenization, saturated NaCl was added, and the mixture was incubated on an ice block for 5 min to facilitate protein precipitation. This was followed by centrifugation at 10,000× g for 10 min. The supernatant was collected and mixed with isopropanol, followed by another centrifugation step at 10,000× g for 10 min to pellet the DNA. The isolated DNA pellet was then stored in TE buffer for subsequent sequencing analysis.

2.10.2. DNA Sequencing

The primers 341F (CCTACGGGNGGCWGCAG) and 518R (ATTACCGCGGCTGCTGG) were used for bacterial 16S rRNA gene amplification [26,27]. Polymerase chain reaction (PCR) assays were performed as described in previous studies [26,27]. The amplified PCR products were visualized using agarose gel electrophoresis. The purified and pooled PCR products were processed with the NEB Ultra II library. The library was then quantified and sequenced on an iSeq 100 (Illumina, San Diego, CA, USA).

2.10.3. DNA Sequencing Analysis

Raw sequence reads were processed using Fastp v0.21 and joined/merged for further analysis in QIIME2 v.2021.4. DADA2 was employed to analyze the data [28,29,30]. QIIME2 plugins were then used to assess bacterial diversity and generate relative abundances of taxa within the gut microbiota. These relative abundance results were used to construct a bar chart depicting the taxonomic composition of the gut microbiota.

2.11. Statistical Analysis

The effects of dietary treatments on growth performance, hematological profiling, digestive enzyme activity, antioxidative response, and cumulative survival rate were analyzed using one-way ANOVA, followed by Tukey’s post hoc multiple comparison test, to identify significant differences between groups (p < 0.05). Statistical analyses were performed using IBM SPSS Statistics (Version 23.0). Additionally, a regression analysis was employed to determine the optimal range for selected growth and health parameters of the experimental fish.

3. Results

3.1. Growth Performance

This study observed a significant increase (>10-fold) in the FW of all experimental fish following the feeding trial (Table 1). Dietary DW inclusion in African catfish diets significantly impacted (p < 0.05) FW, WG, SGR, and FCR compared to the control group. For instance, fish fed DW10 and DW15 diets demonstrated the best performance in FW, WG, and SGR. This was followed by fish fed DW5 diet. Conversely, African catfish fed DW diets exhibited significantly lower values (p < 0.05) for VSI and HSI compared to the control. For example, fish that received DW10 and DW15 diets showed the lowest VSI and HSI, followed by fish fed the DW5 diet.

3.2. Hematological Profiling

African catfish fed DW diets exhibited significantly higher (p < 0.05) WBC, RBC, HCT, and HGB levels compared to the control. The greatest increases in these parameters were observed in fish fed diets containing 1% and 1.5% DW (Table 2). This was followed by fish fed the DW5 diet. The fish in the control group showed significantly lower WBC, RBC, HCT, and HGB levels. No significant differences were detected in MON, LYM, MCH, or MCHC among all treatments.

3.3. Digestive Enzyme Activity

African catfish fed diets containing DW exhibited a significant increase (p < 0.05) in the activity of all digestive enzymes assayed, including protease, amylase, and lipase. The highest activity levels were observed in fish fed diets with 1% and 1.5% DW inclusion (Figure 1). This was followed by fish fed the DW5 diet, which showed the second-highest protease, amylase, and lipase activities. By contrast, fish in the control group demonstrated the lowest digestive enzyme activity.

3.4. Antioxidant Enzyme Activity

Dietary inclusion of DW significantly enhanced (p < 0.05) the activities of antioxidant enzymes (SOD, GPx, and CAT) in the liver of African catfish, both before and after heat stress. Fish fed diets containing 1% and 1.5% DW exhibited the highest enzyme activity levels (Figure 2). This was followed by fish fed DW5 diet. By contrast, fish in the control group showed the lowest antioxidant enzyme activities. No mortality of the experimental fish was observed after the heat stress assay.

3.5. Cumulative Survival Rate of Post-Bacterial Infection

The cumulative survival rate of African catfish infected with E. tarda was significantly higher (p < 0.05) in fish fed diets containing DW compared to the control group (3.3%). High survival rates of 66.7% and 70% were observed in fish fed diets with 1% and 1.5% DW inclusion, respectively (Figure 3). By contrast, fish fed DW5 had the second-highest cumulative survival rate (26.7%).

3.6. Gut Microbiota Analysis

Analysis of the gut microbiota revealed that fish fed DW diets harbored a distinct bacterial community dominated by Cetobacterium spp. (10.2–11.1%), Bacteriodales spp. (7.8–8.8%), Akkermansia muciniphila (9.9–10.8%), Phocaeicola spp. (12.4–13.1%), and Niameybacter massiliensis (Figure 4). By contrast, the control group exhibited a high relative abundance of Bacteroides spp. (11.1%), Proteus mirabilis (5.3%), Anaerorhabdus furcosa (5.6%), Parabacteroides spp. (7.8%), Clostridium paraputrificum (4.8%), Escherichia coli (3.2%), and Clostridium spp. (6.5%). Notably, all fish groups displayed a similar relative abundance of E. tarda.

3.7. Regression Analysis

Regression analysis identified optimal dietary DW inclusion levels of 0.262, 0.224, 0.229, 0.289, 0.277, 0.295, 0.433, and 0.311 for maximizing the FW, WG, SGR, FCR, RBC, protease activity, CAT activity, and survival rate in African catfish, respectively (Table 3).

4. Discussion

This study revealed that dietary inclusion of DW can promote growth performance, feed utilization, and digestive enzyme activity in African catfish. Furthermore, DW supplementation enhanced the antioxidative responses of these fish both before and after heat stress induction. Dietary DW also significantly increased the cumulative survival rate of African catfish challenged with E. tarda compared to the control group. Finally, this study suggests a positive impact of DW on gut microbiota composition.
In the current study, dietary DW supplementation significantly promoted final weight, SGR, and WG. Furthermore, it improved feed utilization efficiency, as evidenced by significantly low FCR, HSI, and VSI values compared to the control group. These findings align with previous research by Bilen et al. (2018), who reported enhanced growth performance in common carp (C. carpio) fed a 0.1% dietary methanolic extract of DW. Similar growth-promoting effects of DW have also been observed in broilers [14,15]. One potential explanation for this observation is that DW may improve palatability due to its reportedly pleasant flavor, thereby stimulating feed intake in fish [31].
Dietary DW also significantly increased the activities of digestive enzymes, including protease, lipase, and amylase, in African catfish. This finding suggests a possible link between DW supplementation and improved feed utilization efficiency. Oni et al. [31] reported that DW contains vitamin A, vitamin C, and fiber, all of which are essential nutrients for digestive enzyme activation. These enzymes play a crucial role in promoting feed digestion and nutrient absorption in fish [8].
Interestingly, dietary DW supplementation significantly increased RBC count, HBG concentration, and hematocrit in African catfish. This finding suggests that the DW diet may promote hemosynthesis and erythropoiesis activities in these fish [32]. Dill weed possesses phytoestrogens, non-steroidal compounds [33] that boost hemosynthesis and erythropoiesis activities [34]. Phytoestrogens help activate estrogen receptors (ERs). ERs play an important role in regulating RBC production [34]. Furthermore, the significantly higher WBC count in the DW-fed group might indicate improved health status [32]. Nevertheless, it is important to acknowledge that WBC values can be influenced by various factors, including gender, season, environmental pollutants, and feeding regime [32]. The absence of significant differences in MCH and MCHC between the experimental groups suggests that the fish were not anemic [32].
Dietary DW diet supplementation appeared to alleviate stress caused by heat and bacterial infection in African catfish. The finding is supported by the significantly higher activities of antioxidative enzymes (SOD, CAT, and GPx) observed in fish fed DW diets. Similar results were reported by Bilen et al. [35] in common carp fed a 0.1% dietary methanolic extract of DW. Their study demonstrated that common carp receiving DW extract displayed significantly higher SOD, CAT, and GPx activities compared to the control group. Furthermore, significantly higher survival rates were recorded following infection with E. tarda and Aeromonas hydrophila in fish fed DW extract diets. Additionally, previous research suggested that dietary DW can mitigate heat stress in broilers at a level of 0.4–0.6% of the feed [31]. Moreover, DW supplementation has been shown to alleviate stress caused by high-fat, high-cholesterol diets in rats [36], nicotine exposure [37], and carbon tetrachloride exposure [38], likely through the enhancement of antioxidative enzyme activity. The high antioxidant properties of DW are attributed to the presence of bioactive compounds, such as camphene, limonene, carvone, α-pinene, α-phellandrene, and β-cymene [31].
Supplementation of DW in the diet positively impacted the gut microbiota composition of African catfish. Fish fed DW diets exhibited a higher abundance of beneficial microorganisms, including Cetobacterium spp., Akkermansia muciniphila, and Phocaeicola spp., compared to the control group. Cetobacterium spp., commonly found in freshwater fish [39], contribute to vitamin B12 production [40], potentially supporting the health of fish in the current study. Furthermore, Cetobacterium somerae has been investigated as a promising probiotic in various aquaculture species, such as largemouth bass, Micropterus salmoides [41], crucian carp, Carassius carassius [42,43], and common carp, C. carpio [44]. A. muciniphila, another beneficial microorganism, has been shown to modulate the immune system and alleviate oxidative stress [45,46,47]. In addition, a high abundance of Phocaeicola in the gut may significantly enhance the fish’s immune system, as this bacterium produces antimicrobial substances like succinate [48]. Furthermore, Phocaeicola spp. may act as a liver protector and enhance lipid metabolism [49]. Therefore, these findings suggest that dietary DW can alter the gut microbiota of African catfish toward a composition that is potentially beneficial for their health.

5. Conclusions

This study revealed that dietary DW inclusion at 1.5% significantly improved growth performance (FW, WG, and SGR) and feed utilization efficiency in African catfish. In addition, DW supplementation enhanced hematological profiles, potentially mitigated heat stress, and promoted disease resistance against E. tarda. Our findings also demonstrated a positive impact of dietary DW on African catfish gut microbiota composition. Future research is warranted to elucidate the underlying mechanisms by which dietary DW exerts these beneficial effects in African catfish.

Author Contributions

L.S.W.: Conceptualization, Methodology, Investigation: V.K.L., A.B.T., R.H., M.E.H., M.N.A. and W.W.: Resources, Data Curation, Visualization. All authors: Writing—original draft, Supervision. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Universiti Malaysia Kelantan Matching Grant (R/MTCH/A0700/00387A/009/2023/01161) and the Ministry of Higher Education, Malaysia, under the Niche Research Grant Scheme (NRGS) (R/NRGS/A0.700/00387A/006/2014/00152).

Institutional Review Board Statement

The animal study protocol was approved by the Animal Care and Use Committee of the Faculty of Agro-Based Industry, Universiti Malaysia Kelantan (UMK/FIAT/ACUE/PG/020/2023).

Informed Consent Statement

Not applicable.

Data Availability Statement

The supporting data can be obtained from the corresponding authors upon reasonable request.

Conflicts of Interest

The authors declare no conflicts of interest in relation to this work.

References

  1. Wei, L.S.; Kon Yeu, H.; Khoo, M.I.; Mn, A.; Wee, W. Effect of dietary supplementation of turmeric, Curcuma longa leaf on growth and health status of African catfish, Clarias gariepinus. Vet. Integr. Sci. 2024, 22, 907–920. [Google Scholar] [CrossRef]
  2. Yada, T.; Tort, L. 10-Stress and Disease Resistance: Immune System and Immunoendocrine Interactions. In Fish Physiology; Schreck, C.B., Tort, L., Farrell, A.P., Brauner, C.J., Eds.; Academic Press: Cambridge, MA, USA, 2016; Volume 35, pp. 365–403. [Google Scholar]
  3. Goh, K.W.; Abdul Kari, Z.; Wee, W.; Zakaria, N.N.A.; Rahman, M.M.; Kabir, M.A.; Abdul Hamid, N.K.; Tahiluddin, A.B.; Kamarudin, A.S.; Téllez-Isaías, G.; et al. Exploring the roles of phytobiotics in relieving the impacts of Edwardsiella tarda infection on fish: A mini-review. Front. Vet. Sci. 2023, 10, 1149514. [Google Scholar] [CrossRef] [PubMed]
  4. Janda, J.M.; Duman, M. Expanding the Spectrum of Diseases and Disease Associations Caused by Edwardsiella tarda and Related Species. Microorganisms 2024, 12, 1031. [Google Scholar] [CrossRef]
  5. Leung, K.Y.; Wang, Q.; Zheng, X.; Zhuang, M.; Yang, Z.; Shao, S.; Achmon, Y.; Siame, B.A. Versatile lifestyles of Edwardsiella: Free-living, pathogen, and core bacterium of the aquatic resistome. Virulence 2022, 13, 5–18. [Google Scholar] [CrossRef]
  6. Wee, W.; Abdul Hamid, N.K.; Mat, K.; Khalif, R.I.A.R.; Rusli, N.D.; Rahman, M.M.; Kabir, M.A.; Wei, L.S. The effects of mixed prebiotics in aquaculture: A review. Aquac. Fish. 2024, 9, 28–34. [Google Scholar] [CrossRef]
  7. Wei, L.S.; Kari, Z.A.; Kabir, M.A.; Khoo, M.I.; Azra, M.N.; Wee, W. Promoting Growth and Health of African Catfish, Clarias gariepinus, Through Dietary Novel Supplement, Ginger, Zingiber officinale Rosc, Leaf Powder. Aquac. Stud. 2024, 24, AQUAST1719. [Google Scholar] [CrossRef]
  8. Ashry, A.M.; Habiba, M.M.; El-Zayat, A.M.; Badreldeen, A.H.; Younis, N.A.; Ahmed, H.A.; El-Dakroury, M.F.; Ali, M.A.M.; Dawood, M.A.O. Effects of ginger (Zingiber officinale) on the growth performance, digestive enzyme activity, antioxidative response, and antibacterial capacity of striped catfish (Pangasianodon hypophthalmus) reared in outdoor conditions. Aquac. Rep. 2023, 33, 101760. [Google Scholar] [CrossRef]
  9. Rahman, M.; Mamun, M.A.A.; Rathore, S.S.; Nandi, S.K.; Abdul Kari, Z.; Wei, L.S.; Tahiluddin, A.B.; Rahman, M.M.; Manjappa, N.K.; Hossain, A.; et al. Effects of dietary supplementation of natural Spirulina on growth performance, hemato-biochemical indices, gut health, and disease resistance to Aeromonas hydrophila of Stinging catfish (Heteropneustes fossilis) fingerling. Aquac. Rep. 2023, 32, 101727. [Google Scholar] [CrossRef]
  10. Nandi, S.K.; Suma, A.Y.; Rashid, A.; Kabir, M.A.; Goh, K.W.; Abdul Kari, Z.; Van Doan, H.; Zakaria, N.N.A.; Khoo, M.I.; Seong Wei, L. The Potential of Fermented Water Spinach Meal as a Fish Meal Replacement and the Impacts on Growth Performance, Reproduction, Blood Biochemistry and Gut Morphology of Female Stinging Catfish (Heteropneustes fossilis). Life 2023, 13, 176. [Google Scholar] [CrossRef]
  11. Hamid, N.K.A.; Somdare, P.O.; Md Harashid, K.A.; Othman, N.A.; Kari, Z.A.; Wei, L.S.; Dawood, M.A.O. Effect of papaya (Carica papaya) leaf extract as dietary growth promoter supplement in red hybrid tilapia (Oreochromis mossambicus × Oreochromis niloticus) diet. Saudi J. Biol. Sci. 2022, 29, 3911–3917. [Google Scholar] [CrossRef]
  12. Anis Mohamad Sukri, S.; Andu, Y.; Tuan Harith, Z.; Sarijan, S.; Naim Firdaus Pauzi, M.; Seong Wei, L.; Dawood, M.A.O.; Abdul Kari, Z. Effect of feeding pineapple waste on growth performance, texture quality and flesh colour of nile tilapia (Oreochromis niloticus) fingerlings. Saudi J. Biol. Sci. 2022, 29, 2514–2519. [Google Scholar] [CrossRef] [PubMed]
  13. Lee, S.W.; Sim, K.Y.; Wendy, W.; Zulhisyam, A.K. Peperomia pellucida leaf extract as immunostimulator in controlling motile aeromonad septicemia due to Aeromonas hydrophila in red hybrid tilapia, Oreochromis spp. farming. Vet. World 2016, 9, 231–234. [Google Scholar] [CrossRef]
  14. Hammod, A.J.; Abd El-Aziz, A.H.; Areaaer, A.H.; Alfertosi, K.A. Effect of Dill Powder (Anethum graveolens) as a Dietary Supplement on Productive Performance, Mortality and Economic Figure in Broiler. IOP Conf. Ser. Earth Environ. Sci. 2020, 553, 012018. [Google Scholar] [CrossRef]
  15. Jangali, A.; Hedayati, M.; Khalaji, S.; Manafi, M. Oxidative stress and effects of dill (Anethum graveolens dhi) powder on the performance and health status of broilers. S. Afr. J. Anim. Sci. 2021, 51, 700–714. [Google Scholar] [CrossRef]
  16. Milenković, L.; Ilić, Z.S.; Stanojević, L.; Danilović, B.; Šunić, L.; Kevrešan, Ž.; Stanojević, J.; Cvetković, D. Chemical Composition and Bioactivity of Dill Seed (Anethum graveolens L.) Essential Oil from Plants Grown under Shading. Plants 2024, 13, 886. [Google Scholar] [CrossRef]
  17. Haidari, F.; Zakerkish, M.; Borazjani, F.; Ahmadi Angali, K.; Amoochi Foroushani, G. The effects of Anethum graveolens (dill) powder supplementation on clinical and metabolic status in patients with type 2 diabetes. Trials 2020, 21, 483. [Google Scholar] [CrossRef]
  18. Wei, L.S.; Adrian Susin, A.A.; Tahiluddin, A.B.; Kien, L.V.; Wee, W. Exploring the potential of black fungus, Auricularia auricula, as a feed additive in African catfish, Clarias gariepinus, farming. Heliyon 2024, 10, e33810. [Google Scholar] [CrossRef] [PubMed]
  19. Jiang, M.; Xiao, W.; Ye, J.; Xu, L.; Peng, R.; Han, Q.; Lü, Z.; Shi, H.; Jiang, X. Effects of feed transition on digestive tract digestive enzyme, morphology and intestinal community in cuttlefish (Sepia pharaonis). Front. Mar. Sci. 2022, 9, 941488. [Google Scholar] [CrossRef]
  20. Erlanger, B.F.; Kokowsky, N.; Cohen, W. The preparation and properties of two new chromogenic substrates of trypsin. Arch. Biochem. Biophys. 1961, 95, 271–278. [Google Scholar] [CrossRef]
  21. Robyt, J.; Whelan, W. The β-Amylases, Starch and Its Derivates; Academic press: London, UK, 1968; pp. 477–497. [Google Scholar]
  22. Winkler, U.K.; Stuckmann, M. Glycogen, hyaluronate, and some other polysaccharides greatly enhance the formation of exolipase by Serratia marcescens. J. Bacteriol. 1979, 138, 663–670. [Google Scholar] [CrossRef]
  23. Dawood, M.A.O.; Noreldin, A.E.; Sewilam, H. Blood biochemical variables, antioxidative status, and histological features of intestinal, gill, and liver tissues of African catfish (Clarias gariepinus) exposed to high salinity and high-temperature stress. Environ. Sci. Pollut. Res. 2022, 29, 56357–56369. [Google Scholar] [CrossRef] [PubMed]
  24. Lee, S.W.; Liew, V.K.; Kari, Z.A.; Kabir, M.A.; Azra, M.N.; Khoo, M.I.; Wee, W. Protective Effects of Dietary Etlingera elatior (Jack) Bud Flower Powder against Edwardsiella tarda Infection in African Catfish, Clarias gariepinus. Aquac. Res. 2024, 2024, 1754005. [Google Scholar] [CrossRef]
  25. Inglis, P.W.; Pappas, M.d.C.R.; Resende, L.V.; Grattapaglia, D. Fast and inexpensive protocols for consistent extraction of high quality DNA and RNA from challenging plant and fungal samples for high-throughput SNP genotyping and sequencing applications. PLoS ONE 2018, 13, e0206085. [Google Scholar] [CrossRef] [PubMed]
  26. Klindworth, A.; Pruesse, E.; Schweer, T.; Peplies, J.; Quast, C.; Horn, M.; Glöckner, F.O. Evaluation of general 16S ribosomal RNA gene PCR primers for classical and next-generation sequencing-based diversity studies. Nucleic Acids Res. 2012, 41, e1. [Google Scholar] [CrossRef]
  27. García-López, R.; Cornejo-Granados, F.; Lopez-Zavala, A.A.; Sánchez-López, F.; Cota-Huízar, A.; Sotelo-Mundo, R.R.; Guerrero, A.; Mendoza-Vargas, A.; Gómez-Gil, B.; Ochoa-Leyva, A. Doing More with Less: A Comparison of 16S Hypervariable Regions in Search of Defining the Shrimp Microbiota. Microorganisms 2020, 8, 134. [Google Scholar] [CrossRef]
  28. Bolyen, E.; Rideout, J.R.; Dillon, M.R.; Bokulich, N.A.; Abnet, C.C.; Al-Ghalith, G.A.; Alexander, H.; Alm, E.J.; Arumugam, M.; Asnicar, F.; et al. Reproducible, interactive, scalable and extensible microbiome data science using QIIME 2. Nat. Biotechnol. 2019, 37, 852–857. [Google Scholar] [CrossRef]
  29. Callahan, B.J.; McMurdie, P.J.; Rosen, M.J.; Han, A.W.; Johnson, A.J.A.; Holmes, S.P. DADA2: High-resolution sample inference from Illumina amplicon data. Nat. Methods 2016, 13, 581–583. [Google Scholar] [CrossRef]
  30. Parks, D.H.; Chuvochina, M.; Chaumeil, P.-A.; Rinke, C.; Mussig, A.J.; Hugenholtz, P. A complete domain-to-species taxonomy for Bacteria and Archaea. Nat. Biotechnol. 2020, 38, 1079–1086. [Google Scholar] [CrossRef]
  31. Oni, A.I.; Adeleye, O.O.; Adebowale, T.O.; Oke, O.E. The role of phytogenic feed additives in stress mitigation in broiler chickens. J. Anim. Physiol. Anim. Nutr. 2024, 108, 81–98. [Google Scholar] [CrossRef] [PubMed]
  32. Wei, L.S.; Hooi, K.Y.; Khoo, M.I.; Azra, M.N.; Wee, W. Effects of dietary kaffir lime, Citrus hystrix DC, leaf powder on the growth performance, digestive enzyme, hematology, antioxidative response, and disease resistance against Edwardsiella tarda infection in African catfish, Clarias gariepinus. Aquac. Int. 2024, 32, 7469–7485. [Google Scholar] [CrossRef]
  33. Mesripour, A.; Rafieian-Kopaei, M.; Bahrami, B. The effects of Anethum graveolens essence on scopolamine-induced memory impairment in mice. Res. Pharm. Sci. 2016, 11, 145–151. [Google Scholar] [PubMed]
  34. Bhukhai, K.; Fouquet, G.; Rittavee, Y.; Tanhuad, N.; Lakmuang, C.; Borwornpinyo, S.; Anurathapan, U.; Suksamrarn, A.; Piyachaturawat, P.; Chairoungdua, A.; et al. Enhancing Erythropoiesis by a Phytoestrogen Diarylheptanoid from Curcuma comosa. Biomedicines 2022, 10, 1427. [Google Scholar] [CrossRef]
  35. Bilen, S.; Özkan, O.; Alagöz, K.; Özdemir, K.Y. Effect Of dill (Anethum graveolens) and garden cress (Lepidium sativum) dietary supplementation on growth performance, digestive enzyme activities and immune responses of juvenile common carp (Cyprinus carpio). Aquaculture 2018, 495, 611–616. [Google Scholar] [CrossRef]
  36. Abbasi, E.; Goodarzi, M.T.; Tayebinia, H.; Saidijam, M.; Khodadadi, I. Favorable effects of Anethum graveolens on liver oxidative stress and cholesterol 7 alpha-hydroxylase levels in non-alcoholic fatty liver disease (NAFLD) rat models. Metab. Open 2021, 12, 100140. [Google Scholar] [CrossRef] [PubMed]
  37. Ajarem, J.S.; Maodaa, S.N.; El-Serehy, H.A.; Altoom, N.; Allam, A.A.; Hernandez-Bautista, R.; Mahmoud, A.M. Anethum graveolens Prevents Liver and Kidney Injury, Oxidative Stress and Inflammation in Mice Exposed to Nicotine Perinatally. Coatings 2021, 11, 838. [Google Scholar] [CrossRef]
  38. Oshaghi, E.A.; Khodadadi, I.; Tavilani, H.; Goodarzi, M.T. Effect of dill tablet (Anethum graveolens L) on antioxidant status and biochemical factors on carbon tetrachloride-induced liver damage on rat. Int. J. Appl. Basic Med. Res. 2016, 6, 111–114. [Google Scholar] [CrossRef]
  39. Ramírez, C.; Coronado, J.; Silva, A.; Romero, J. Cetobacterium Is a Major Component of the Microbiome of Giant Amazonian Fish (Arapaima gigas) in Ecuador. Animals 2018, 8, 189. [Google Scholar] [CrossRef]
  40. Tsuchiya, C.; Sakata, T.; Sugita, H. Novel ecological niche of Cetobacterium somerae, an anaerobic bacterium in the intestinal tracts of freshwater fish. Lett. Appl. Microbiol. 2008, 46, 43–48. [Google Scholar] [CrossRef]
  41. Zhang, Y.; Qi, X.; Zhang, Z.; Jin, Z.; Wang, G.; Ling, F. Effects of dietary Cetobacterium somerae on the intestinal health, immune parameters and resistance against Nocardia seriolae of largemouth bass, Micropterus salmoides. Fish Shellfish Immunol. 2023, 135, 108693. [Google Scholar] [CrossRef]
  42. Zhao, Y.; Li, S.; Lessing, D.J.; Chu, W. The attenuating effects of synbiotic containing Cetobacterium somerae and Astragalus polysaccharide against trichlorfon-induced hepatotoxicity in crucian carp (Carassius carassius). J. Hazard. Mater. 2024, 461, 132621. [Google Scholar] [CrossRef]
  43. Zhao, Y.; Li, S.; Lessing, D.J.; Guo, L.; Chu, W. Characterization of Cetobacterium somerae CPU-CS01 isolated from the intestine of healthy crucian carp (Carassius auratus) as potential probiotics against Aeromonas hydrophila infection. Microb. Pathog. 2023, 180, 106148. [Google Scholar] [CrossRef] [PubMed]
  44. Xie, M.; Zhou, W.; Xie, Y.; Li, Y.; Zhang, Z.; Yang, Y.; Olsen, R.E.; Ran, C.; Zhou, Z. Effects of Cetobacterium somerae fermentation product on gut and liver health of common carp (Cyprinus carpio) fed diet supplemented with ultra-micro ground mixed plant proteins. Aquaculture 2021, 543, 736943. [Google Scholar] [CrossRef]
  45. Calvo, A.; Pastor, Y.; Rosas-Val, P.; Gamazo, C. Unveiling the immunomodulatory effect of the novel probiotic Akkermansia muciniphila and its protective effect in vitro. Microbiol. Res. 2024, 283, 127677. [Google Scholar] [CrossRef] [PubMed]
  46. Teng, Y.; Zhao, D.; Yan, C.; Ren, X.; Wang, A.; Xia, X. Pasteurized Akkermansia muciniphila improves immunity and relieves other toxic effects in 5-fluorouracil treated BALB/c mice. Food Biosci. 2024, 59, 103918. [Google Scholar] [CrossRef]
  47. Cheng, J.; Lei, Z.; Fang, C.; Jia, W.; Xu, Y. Pasteurized Akkermansia muciniphila and its outer membrane protein Amuc_1100 alleviate alcoholic liver disease through modulating gut microbiota and host metabolism. Food Biosci. 2024, 59, 104072. [Google Scholar] [CrossRef]
  48. Keitel, L.; Miebach, K.; Rummel, L.; Yordanov, S.; Büchs, J. Process analysis of the anaerobe Phocaeicola vulgatus in a shake flasks and fermenter reveals pH and product inhibition. Ann. Microbiol. 2024, 74, 7. [Google Scholar] [CrossRef]
  49. Jin, S.; Chen, P.; Yang, J.; Li, D.; Liu, X.; Zhang, Y.; Xia, Q.; Li, Y.; Chen, G.; Li, Y.; et al. Phocaeicola vulgatus alleviates diet-induced metabolic dysfunction-associated steatotic liver disease progression by downregulating histone acetylation level via 3-HPAA. Gut Microbes 2024, 16, 2309683. [Google Scholar] [CrossRef]
Bacteria 04 00023 g001aBacteria 04 00023 g001b
Figure 1. Digestive enzyme activities for (a) protease, (b) amylase, and (c) lipase in African catfish fed 0% (control), 0.5%, 1%, and 1.5% dietary dill weed after an eight-week feeding trial. DW5: 0.5% dietary dill weed; DW10: 1% dietary dill weed; DW15: 1.5% dietary dill weed. Data expressed as mean ± SD. Different letters (a–c) on each bar show significant differences (p < 0.05) among the treatments.
Figure 1. Digestive enzyme activities for (a) protease, (b) amylase, and (c) lipase in African catfish fed 0% (control), 0.5%, 1%, and 1.5% dietary dill weed after an eight-week feeding trial. DW5: 0.5% dietary dill weed; DW10: 1% dietary dill weed; DW15: 1.5% dietary dill weed. Data expressed as mean ± SD. Different letters (a–c) on each bar show significant differences (p < 0.05) among the treatments.
Bacteria 04 00023 g001aBacteria 04 00023 g001b
Bacteria 04 00023 g002aBacteria 04 00023 g002b
Figure 2. Antioxidant enzyme activities for (a) superoxide dismutase (SOD), (b) glutathione peroxidase (GPx), and (c) catalase (CAT) in the liver of African catfish fed 0% (control), 0.5%, 1%, and 1.5% dietary dill weed, before and after heat stress. DW5: 0.5% dietary dill weed; DW10: 1% dietary dill weed; DW15: 1.5% dietary dill weed. Data expressed as mean ± SD. Different letters (a–c) on each bar show significant differences (p < 0.05) among the treatments. Asterisks (*) indicate a significant effect of heat stress (p < 0.05).
Figure 2. Antioxidant enzyme activities for (a) superoxide dismutase (SOD), (b) glutathione peroxidase (GPx), and (c) catalase (CAT) in the liver of African catfish fed 0% (control), 0.5%, 1%, and 1.5% dietary dill weed, before and after heat stress. DW5: 0.5% dietary dill weed; DW10: 1% dietary dill weed; DW15: 1.5% dietary dill weed. Data expressed as mean ± SD. Different letters (a–c) on each bar show significant differences (p < 0.05) among the treatments. Asterisks (*) indicate a significant effect of heat stress (p < 0.05).
Bacteria 04 00023 g002aBacteria 04 00023 g002b
Bacteria 04 00023 g003
Figure 3. Cumulative survival rate of African catfish fed 0% (control), 0.5%, 1%, and 1.5% dietary dill weed in the four weeks after challenge with E. tarda. DW5: 0.5% dietary dill weed; DW10: 1% dietary dill weed; DW15: 1.5% dietary dill weed.
Figure 3. Cumulative survival rate of African catfish fed 0% (control), 0.5%, 1%, and 1.5% dietary dill weed in the four weeks after challenge with E. tarda. DW5: 0.5% dietary dill weed; DW10: 1% dietary dill weed; DW15: 1.5% dietary dill weed.
Bacteria 04 00023 g003
Bacteria 04 00023 g004
Figure 4. Relative abundance of microbial taxa representing the gut microbiome of African catfish fed with 0% (control), 0.5%, 1%, and 1.5% dietary dill weed after an eight-week feeding trial. DW5: 0.5% dietary dill weed; DW10: 1% dietary dill weed; DW15: 1.5% dietary dill weed.
Figure 4. Relative abundance of microbial taxa representing the gut microbiome of African catfish fed with 0% (control), 0.5%, 1%, and 1.5% dietary dill weed after an eight-week feeding trial. DW5: 0.5% dietary dill weed; DW10: 1% dietary dill weed; DW15: 1.5% dietary dill weed.
Bacteria 04 00023 g004
Table 1. Growth performance parameters of experimental fish fed 0% (control), 0.5%, 1%, and 1.5% dietary DW for eight weeks.
Table 1. Growth performance parameters of experimental fish fed 0% (control), 0.5%, 1%, and 1.5% dietary DW for eight weeks.
Treatments
ParametersControlDW5DW10DW15
Initial weight (IW) (g)10.5 ± 0.0610.5 ± 0.0610.6 ± 0.1210.5 ± 0.153
Final weight (FW) (g)143.3 ± 1.66 c158.0 ± 1.10 b171.0 ± 1.79 a172.9 ± 2.46 a
Weight gain (WG) (%)1260.7 ± 9.38 c1409.9 ± 4.88 b1518.8 ± 30.38 a1541.5 ± 4.06 a
Specific growth rate (SGR) (%/day)2.02 ± 0.005 c2.11 ± 0.003 b2.16 ± 0.015 a2.17 ± 0.002 a
Feed conversion ratio (FCR)1.36 ± 0.016 c1.22 ± 0.009 b1.12 ± 0.013 a1.11 ± 0.016 a
Hepatosomatic index (HSI)2.86 ± 0.122 d2.26 ± 0.088 c1.73 ± 0.079 a1.60 ± 0.083 b
Visceral somatic index (VSI)5.26 ± 0.169 c4.18 ± 0.301 b3.43 ± 0.222 a3.40 ± 0.232 a
DW5: 0.5% dietary dill weed; DW10: 1% dietary dill weed; DW15: 1.5% dietary dill weed. Data expressed as mean ± SD. Values in the same row with different superscripts (a–d) show significant differences at p < 0.05.
Table 2. Hematological analysis of African catfish fed with 0 (control), 0.5%, 1%, and 1.5% of dietary DW after eight-week feeding trial.
Table 2. Hematological analysis of African catfish fed with 0 (control), 0.5%, 1%, and 1.5% of dietary DW after eight-week feeding trial.
Treatments
ParametersControlDW5DW10DW15
WBC/µL91.0 ± 1.71 c97.7 ± 1.96 b104.8 ± 3.00 a108.7 ± 3.40 a
LYM (%)80.8 ± 0.6083.2 ± 2.5380.5 ± 2.0980.5 ± 3.46
MON (%)10.4 ± 0.5710.0 ± 0.2110.2 ± 0.5110.1 ± 0.25
RBC (103/µL)2.3 ± 0.17 c3.00 ± 0.12 b3.5 ± 0.15 a3.5 ± 0.15 a
HGB (g/dL)4.7 ± 0.20 c5.2 ± 0.12 b6.1 ± 0.25 a5.9 ± 0.25 a
HCT (%)20.7 ± 1.10 c26.3 ± 2.57 b32.3 ± 1.93 a32.3 ± 1.72 a
MCH (pg)30.0 ± 0.9230.6 ± 1.2331.2 ± 1.4530.8 ± 0.83
MCHC (g/dL)21.9 ± 1.3122.3 ± 1.2722.2 ± 1.3121.9 ± 1.31
DW5: 0.5% dietary dill weed; DW10: 1% dietary dill weed; DW15: 1.5% dietary dill weed. WBC: white blood cell; LYM: lymphocytes; MON: monocytes; RBC: red blood cell; HGB: hemoglobin; HCT: hematocrit, MCH: mean corpuscular hemoglobin; MCHC: mean corpuscular hemoglobin concentration. Data expressed as mean ± SD. Values in the same row with different superscripts (a–c) show significant differences at p < 0.05.
Table 3. Regression analysis of African catfish fed dietary DW for eight weeks.
Table 3. Regression analysis of African catfish fed dietary DW for eight weeks.
ParametersEquationR2Dill Weed (%)
Final weight (FW)y = 0.0010x2 − 0.2694x + 18.21510.91740.2624
Weight gain (WG)y = 0.0000x2 − 0.0356x + 21.96940.93960.2244
Specific growth rate (SGR)y = 67.7596x2 − 274.8743x + 278.76660.95800.2290
Feed conversion ratio (FCR)y = 17.5727x2 − 48.6238x + 33.6320.89940.2895
Red blood cell (RBC)y = 0.7008x2 − 3.0165x + 3.23860.90780.2772
Protease activity y = 20.3318x2 − 16.7621x + 3.37730.77490.4331
Catalase (CAT) activityy = 0.0013x2 − 0.2032x + 7.42010.89560.2950
Cumulative survival ratey = 0.0000x2 + 0.0018x − 0.04020.98830.3115
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Wei, L.S.; Liew, V.K.; Tahiluddin, A.B.; Harikrishnan, R.; Hosain, M.E.; Azra, M.N.; Wee, W. Dietary Dill Weed (Anethum graveolens) Stimulated Disease Resistance of African Catfish (Clarias gariepinus) Against Edwardsiellosis Infection. Bacteria 2025, 4, 23. https://doi.org/10.3390/bacteria4020023

AMA Style

Wei LS, Liew VK, Tahiluddin AB, Harikrishnan R, Hosain ME, Azra MN, Wee W. Dietary Dill Weed (Anethum graveolens) Stimulated Disease Resistance of African Catfish (Clarias gariepinus) Against Edwardsiellosis Infection. Bacteria. 2025; 4(2):23. https://doi.org/10.3390/bacteria4020023

Chicago/Turabian Style

Wei, Lee Seong, Vui Kien Liew, Albaris B. Tahiluddin, Ramasamy Harikrishnan, Md. Eilious Hosain, Mohamad Nor Azra, and Wendy Wee. 2025. "Dietary Dill Weed (Anethum graveolens) Stimulated Disease Resistance of African Catfish (Clarias gariepinus) Against Edwardsiellosis Infection" Bacteria 4, no. 2: 23. https://doi.org/10.3390/bacteria4020023

APA Style

Wei, L. S., Liew, V. K., Tahiluddin, A. B., Harikrishnan, R., Hosain, M. E., Azra, M. N., & Wee, W. (2025). Dietary Dill Weed (Anethum graveolens) Stimulated Disease Resistance of African Catfish (Clarias gariepinus) Against Edwardsiellosis Infection. Bacteria, 4(2), 23. https://doi.org/10.3390/bacteria4020023

Article Metrics

Back to TopTop