https://doi.org/10.52973/rcfcv-e34459
Received: 27/05/2024 Accepted: 11/07/2024 Published: 15/10/2024
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Revista Científica, FCV-LUZ / Vol. XXXIV, rcfcv-e34459
ABSTRACT
The interplay between dietary components and antioxidant systems
in sh physiology is crucial for aquaculture. Citrus fruits, renowned for
their high content of bioactive antioxidants, have attracted attention
for their antioxidant features in sh. The purpose of this study was to
investigate the dietary effects of using essential oil from macerated
oils of lemon peel (Citrus limon) (MOL), orange peel (Citrus sinensis)
(MOO) and grapefruit peel (Citrus paradisi) (MOG) on growth, proximate
composition, hematological, antioxidant parameters of rainbow trout
(Oncorhynchus mykiss) subjected to high stocking density stress. Fish
(110 ± 10.95 g) were randomly introduced to three trial groups (1% of
MOL, MOO and MOG). At the end of feeding period (42-day), the results
showed that the three trial groups had signicant effects on the feed
conversion ratio (FCR), especially in the MOG (P<0.05). The FCR value in
MOG was remarkably 0.81. In the study, the lowest dry matter and ash
levels were detected in MOO, moisture content in MOL, but the highest
fat (6.82 ± 0.82) and protein (15.85 ± 0.74) levels were found in MOG. There
were signicant differences in proximate composition and red blood
cell (RBC) (1.73 ± 0.07 in MOG), hemoglobin (Hgb) (8.97 ± 0.43 in MOL),
hematocrit (Hct) (23.92 ± 1.09 in MOL), mean corpuscular hemoglobin
concentration (MCHC) (38.22 ± 0.34 in MOG) between the control and
all groups (P<0.05). The results showed that glutathione peroxidase
(GPx), catalase (CAT) and glutathione reductase (GR) activities in all
treatment groups were decreased and malondialdehyde (MDA) level
was increased in the MOO group activity (P>0.05).
Key words: stress on fish; herbal oils; food supplements; fish
physiology
RESUMEN
La interacción entre los componentes de la dieta y los sistemas
antioxidantes en la siología de los peces es crucial para la acuicultura.
Los cítricos, conocidos por su alto contenido en antioxidantes
bioactivos, han llamado la atención por sus características
antioxidantes en los peces. El propósito de este estudio fue
investigar los efectos dietéticos del uso de aceites esenciales de
aceites macerados de cáscara de limón (Citrus limon) (MOL), cáscara
de naranja (Citrus sinensis) (MOO) y cáscara de pomelo o toronja
(Citrus paradisi) (MOG) sobre el crecimiento, composición próximal,
parámetros hematológicos y antioxidantes de la trucha arcoíris
(Oncorhynchus mykiss) sometida a estrés por alta densidad. Para el
estudio se introdujeron aleatoriamente peces (110 ± 10,95 g) en tres
grupos de prueba (1 % de MOL, MOO y MOG). Al nal del período de
alimentación (42 días), los resultados mostraron que los tres grupos
de prueba tuvieron efectos signicativos en el factor de conversión
alimentcia (FCR), especialmente en el MOG (P<0,05). El valor del FCR en
MOG fue notablemente de 0,81. En el estudio, los niveles más bajos de
materia seca y cenizas se detectaron en MOO, el contenido de humedad
en MOL, pero los niveles más altos de grasa (6,82 ± 0,82) y proteína
(15,85 ± 0,74) se encontraron en MOG. Hubo diferencias signicativas
en la composición proximal y en los glóbulos rojos (RBC) (1,73 ± 0,07
en MOG), hemoglobina (Hgb) (8,97 ± 0,43 en MOL), hematocrito
(Hct) (23,92 ± 1,09 en MOL), concentración corpuscular media de
hemoglobina. (MCHC) (38,22 ± 0,34 en MOG) entre el control y todos
los grupos (P<0,05). Los resultados mostraron que las actividades
de la glutatión peroxidasa (GPx), catalasa (CAT) y glutatión reductasa
(GR) en todos los grupos de tratamiento disminuyeron y el nivel de
malondialdehído (MDA) aumentó en la actividad del grupo MOO (P>0.05).
Palabras clave: estrés sobre el pescado; aceites vegetales;
complementos alimenticios; siología del pez
Effects of several macerated citrus oils on health parameters of rainbow
trout (Oncorhynchus mykiss) under high stocking density
Efectos de varios aceites cítricos macerados sobre los parámetros de salud de la
trucha arco iris (Oncorhynchus mykiss) bajo alta densidad de población
Basar Altinterim
Malatya Turgut Ozal University, Agriculture Faculty, Fisheries Department. Battalgazi, Malatya, Türkiye.
*Corresponding author: basar.altinterim@ozal.edu.tr
Effects of citrus fruits on fish health / Altinterim ____________________________________________________________________________________
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INTRODUCTION
Citrus fruits, including oranges (Citrus sinensis), lemons (Citrus
limon), limes, and grapefruits (Citrus paradisi), are renowned for their
rich content of bioactive compounds such as avonoids, phenolic
acids, and vitamin C. Additionally, citrus avonoids, such as hesperidin
and naringin, have been shown to possess anti-inflammatory,
antimicrobial, and antiviral properties [1]. These compounds exhibit
potent antioxidant properties, which have been linked to various
health benefits, including protection against oxidative stress-
related diseases.
Furthermore, citrus essential oils, extracted from the peels or
leaves of citrus plants, contain a myriad of volatile compounds with
documented antimicrobial and immunomodulatory effects. These
natural compounds have demonstrated a sustainable alternative to
conventional chemotherapeutic agents and antibiotics [2]. There has
been a growing interest in exploring natural remedies for promoting
fish antioxidant system and enhancing aquaculture practices.
Citrus species have emerged as a promising avenue due to their
rich phytochemical ingredients and diverse biological activities [3].
The potential health benets of citrus species on sh have garnered
attention for their application in aquaculture. Studies have suggested
that incorporating citrus extracts or by-products for examples oils
or pulp etc. into fish diets can confer various physiological and
immunological advantages, ultimately improving growth performance,
antioxidant capacity, and overall well-being [4].
Citrus species can aid in combating infectious diseases commonly
encountered in aquaculture settings. Despite the promising ndings
from experimental studies, there remains a need for comprehensive
reviews that synthesize the existing literature and provide insight into
the mechanisms underlying the health-promoting effects of citrus
species in sh [5]. Macerated oils are oils obtained by keeping certain
parts of plants in carrier oils such as sunower or olive oil for 15-20
days (d). Macerated oils contain both therapeutic and nutritional
properties. In the extraction method, only small molecules are
transferred to the oil, while in the macerated method, large molecules
are transferred to the oil. Thus, it becomes a complex consisting of
the majority of the fat-soluble therapeutically effective substances in
the plant. For these reasons, macerated oils are seen as a whole [6].
Essential oils and pressed oils were generally used as food additives
in aquaculture. Studies on macerated oils were quite limited. In this
study, the aim to provide a comprehensive overview of the current
state of knowledge regarding the benefits of citrus species on
sh health (7, 8). Through an analysis of relevant research articles,
macerated citrus oils will explored the antioxidant and hematologic
parameters of sh as well as their potential applications in aquafeed
formulations. By consolidating this information, we hope to stimulate
further research efforts and facilitate the integration of citrus-derived
products into sustainable aquaculture practices.
MATERIALS AND METHODS
Fish material and experimental design
The investigation took place within the sheries Department of
Malatya Turgut Ozal University. macerated oils of lemon peel (MOL),
macerated oils of orange peel (MOO), and macerated oils of grapefruit
peel (MOG) oils were generated utilizing the maceration technique.
After the dried peels of Citrus species were crushed in a grinder
(EMIR, YB-30 BL, Turkey), they were kept in glass jars at 100 g·L
-1
for 15 d. At the end of the waiting period, it was ltered with lter
paper and stored in lightproof bottles and kept in a cool place. The
macerated oils were incorporated into trout feed at a rate of 1%.
The experiment was executed following a completely randomized
design comprising ve treatments, each replicated twice, control
group (normal, unstress): 10 sh, control stress group (high density):
50 fish, three citrus groups (high density): 50, totaling 210 fish
for each replicationwere used. The average weight (TEM scales,
Ns6200, Türkiye) of rainbow trout in the experiment was 110 ± 10.95
g. Throughout the trial, sh were fed with feed equal to 2% of their
total body weight twice daily for 42 d. Key water parameters, including
average temperature (8.3 ± 0,1°C), conductivity (16.2 ± 0,01 µS·cm
-1
),
hardness (10.52 ± 0,01 mg·L
-1
), salinity (8.6 ± 0,1 ppt o g·L
-1
), pH (8.2 ± 0,2),
and dissolved oxygen (7.49 ± 0,02 mg·L
-1
), were assessedusing pH
meter with multiprobe (EZDO – Waterproof Handheld pH Tester 6011,
China) during the experiment.
Hematologic and antioxidant analysis
Upon completion of the experiment, blood was sampled from the
caudal vein of individual sh subsequent to their sedation with benzocaine
(25 mg·L
-1
water) [9]. Blood samples were procured from the tail veins
of the anesthetized sh and transferred to ethylenediaminetetraacetic
acid (EDTA) containing tubes. Hematological analysis was conducted
using the Fully Auto Hematology Analyzer (PROCAN PE–6800VET, China).
The blood samples were refrigerated for one day at 4
o
C. For plasma
extraction, samples underwent centrifugation at 1000 G for 15 min.
Glutathione peroxidase (GPx), glutathione reductase (GR), catalase
(CAT) activities and malondialdehyde (MDA) level were assessed in
plasma using commercial kits (SunLong Biotech Co., LTD, China).
Plasma homogenates were analyzed following kit instructions, and
absorbance values were measured at 450 nm using a microplate reader
(DR–200Bc Microplate Reader, Prokan Electronics, China, Shanghai YL).
The results were computed as per the provided instructions.
Growth parameters
The parameters assessing growth performance, including weight
gain (WG) percentage, specic growth rate (SGR), and feed conversion
ratio (FCR), were computed following the methodology outlined by [10].
The formula for weight gain (%) is:
Weight gain
Final weight Initialweight
Initialweight
(%)
100
SGR is calculated as:
SGR
Final weight Initialweight
days
100
FCR is determined by dividing the feed offered by the weight gain
in grams. The determination of the FCR occurred at the conclusion
of the 42-d feeding period, with each sh in the respective tanks
individually weighed, and the FCR calculated as per the method
described by Gultepe in 2018 [11].
FCR
TotalFeed Consumed
TotalWeight Gain
=
TABLE I
Growth performance of rainbow trout fed diets containing
dierent macerated citrus oils concentrations for 42 days
Variable
Groups
Control Control stress MOL MOO MOG
IW 122 ± 1.45 107.5± 1.15 107.0 ±1.05 106.5 ± 1.15 107.5 ± 1.10
FW 228 ± 3.10 188.8 ± 2.70 201.1 ± 2.90 164.0 ± 2.15 190.4 ± 2.40
WG 106 ± 3.10 81.3 ± 2.30 94.1 ± 2.10 57.5 ± 1.00 82.9 ± 1.35
FCR 1.16 ± 0.13 1.12 ± 0.10 0.93 ± 0.08 1.04 ± 0.11 0.81 ± 0.06
SGR 2.71 ± 0.09 2.08 ± 0.12 2.41± 0.09 1.47 ± 0.13 2.12 ± 0.08
IW: initial weight, FW: nal weight, WG: weight gain, FCR: feed conversion ratio, SGR:
specic growth rate is expressed in % per day
-1
, MOL: macerated oil of lemon peel,
MOP: macerated oil of orange peel, MOG: macerated oil of grapefruit peel
TABLE II
Proximate composition of the musculature of control and
experimental groups (Mean ± Standard Deviation)
Variable
Groups
Control Control stress MOL MOO MOG
Dry matter 24.28 ± 0.35
a
24.71 ± 0.25
a
24.99 ± 0.12
a
23.14 ± 0.19
b
24.19 ± 0.80
ab
Moisture 75.71 ± 0.54
ab
75.29 ± 0.21
a
75.05 ± 0.21
a
76.86 ± 0.37
bc
75.80 ± 0.43
ac
Ash 1.16 ± 0.15
a
1.55 ± 0.11
ab
1.49 ± 0.05
a
1.09 ± 0.35
a
1.26 ± 0.12
a
Fat 6.26 ± 0.75
a
6.45 ± 1.02
a
6.82 ± 0.82
a
6.59 ± 0.69
a
6.18 ± 0.56
a
Protein 15.76 ± 0.57
a
15.82 ± 0.67
ab
15.85 ± 0.74
ab
14.45 ± 0.44
ab
15.71 ± 0.36
b
MOL: macerated oil of lemon peel, MOP: macerated oil of orange peel, MOG:
macerated oil of grapefruit peel
TABLE III
Hematological parameters (Mean ± Standard Deviation)
Parameters
Groups
Control
Control
stress
MOL MOO MOG
WBC (10
3
·µL
-1
)
47.80 ± 5.24
a
56.37 ± 1.26
a
52.50 ± 2.62
a
53.43 ± 0.90
a
53.12 ± 2.01
a
LYM (%)
94.02 ± 0.21
a
84.93 ± 9.03
a
93.12 ± 0.30
a
93.28 ± 0.55
a
93.37 ± 0.45
a
MID (%)
3.98 ± 0.24
a
4.10 ± 0.19
a
4.43 ± 0.18
a
4.38 ± 0.36
a
4.45 ± 0.28
a
GRAN (%)
2.00 ± 0.09
a
1.97 ± 0.11
a
2.45 ± 0.14
a
2.33 ± 0.20
a
2.18 ± 0.07
a
RBC (10
6
·µL
-1
)
1.53 ± 0.18
a
1.87 ± 0.07
b
1.72 ± 0.08
ab
1.69 ± 0.04
ab
1.73 ± 0.07
ab
Hgb (g·dl
-1
)
7.90 ± 0.94
a
9.72 ± 0.36
b
8.97 ± 0.43
ab
8.72 ± 0.12
ab
8.90 ± 0.48
ab
Hct (%)
21.32 ± 2.46
a
26.03 ± 0.88
b
23.92 ± 1.09
ab
23.28 ± 0.33
ab
23.23 ± 1.14
ab
MCV (fL)
139.43 ± 1.52
a
139.35 ± 1.42
a
139.55 ± 1.18
a
138.32 ± 1.27
ab
134.65 ± 1.25
b
MCH (pg)
51.35 ± 1.11
a
51.85 ± 0.91
a
52.17 ± 0.87
a
51.65 ± 0.77
a
51.38 ± 0.71
a
MCHC (g·dl
-1
)
36.87 ± 0.44
a
37.25 ± 0.36
ab
37.43 ± 0.39
ab
37.38 ± 0.34
ab
38.22 ± 0.34
b
MOL: macerated oil of lemon peel, MOP: macerated oil of orange peel, MOG: macerated
oil of grapefruit peel, WBC: white blood cell, LYM: lymphocyte, MID: monocyte, GRAN:
granulocyte, RBC: red blood cell, Hgb: hemoglobin, Hct: hematocrit, MCV: mean
corpuscular volume, MCH: mean corpuscular hemoglobin, MCHC: mean corpuscular
hemoglobin concentration
Antioxidant parameters
MOO treatment alone caused signicant increase in the GPX activity
of the plasma (P<0.05). All treated groups showed no signicant
change in the GR and CAT activities compared with the control
(P>0.05). It was found that the MDA activities were higher compared
with the control group in all examples (P<0.05, FIGURE 1).
Optimizing feed efficiency is a critical aspect of aquaculture
management, directly impacting production costs and environmental
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Proximate composition
The composition of sh muscle, in terms of dry matter, moisture,
fat, total proteins and ash of the muscle samples of sh was analyzed
following the procedure outlined in reference [12]. Moisture was
assessed using a gravimetric technique, in which the sample was
dried at 105°C until it achieved a constant weight. Crude protein levels
were determined using the Micro Kjeldahl method (6.2 × N) (EFLAB,
MGD1000X, Türkiye). Total lipid content was quantied by extracting
(Soxhlet system) with light petroleum ether, with subsequent removal
of the solvent through distillation. Ash content was determined from
the residue remaining after incineration in a mue furnace at 550°C
for approximately 20 hours.
Statistical analyses
Prior to analysis, data underwent normalization using the Kolmogorov–
Smirnov method and were subsequently subjected to two-way analysis
of variance (ANOVA). Mean comparisons were conducted using Duncan’s
statistical test at a signicance level of 95%. Statistical analyses were
performed using SPSS 25 software, while graphical representations
were created using Excel 2016 software, as referenced [13, 14, 15].
RESULTS AND DISCUSSION
Growth indices
Although the highest weight gain among the groups and the SGR
were highest in the control group, FCR values were strikingly more
ecient in the citrus groups according to control groups. FCR in
treatments containing MOG showed the most signicant difference in
comparison with control treatment after exposure to MOG. In addition,
second and third signicant differences in FCR values were observed
in MOL and MOO groups (TABLE 1).
Proximate muscle analysis
Statistical differences were detected in dry matter, moisture,
ash, protein levels except lipid level in the application groups
(TABLEII). Muscle dry matter content of sh in treatment containing
MOO decreased signicantly compared to other groups (P<0.05).
The amount of ash in the MOO group was decreased among three
treatments (P<0.05). The fat level in muscle was not signicantly
different treatments (P>0.05).The amounts of muscle protein declined
signicantly in MOG group compared to the control (P<0.05).
Blood and serum parameters
According to the blood parameters data in TABLE III; red blood
cell (RBC), hemoglobin (Hgb), hematocrit (Hct), mean corpuscular
hemoglobin concentration (MCHC) counts signicantly dropped in
all treatments (P<0.05). But white blood cell (WBC) count decreased
and lymphocyte (LYM), monocyte (MID), granulocyte (GRAN) levels
elevated considerably in all treatments groups compared to the
control stress group.
Control Control Stress MOL MOO MOG
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Activity
GPx GR CAT MDA
FIGURE 1. The values of GPx, GR, CAT activities and MDA level of experimental groups
(Mean ± Standard Deviation). MOL: macerated oil of lemon peel, MOP: macerated oil
of orange peel, MOG: macerated oil of grapefruit peel, GPx: glutathione peroxidase,
GR: glutathione reductase, CAT: catalase, MDA: malondialdehyde
Effects of citrus fruits on fish health / Altinterim ____________________________________________________________________________________
4 of 6
sustainability. Citrus fruits, renowned for their rich nutritional prole
and bioactive compounds, have been explored as potential dietary
supplements to improve fish performance and feed utilization
eciency. Several studies have been conducted recently to assess the
impact of citrus products on the growth performance of several sh
species. They found that WG, FCR and SGR values increased in rainbow
trout fed with feed supplemented with Ferulago angulata extract,
similar to our study [16].In another study conducted on rainbow trout
of mavigreek, the best FCR value was found in the control group, while
in our study, MOG (0.81) < MOL (0.93) < MOO (1.04) < control (1.12) values
gave better results than the control group [17]. Supplementing diets
with lemon and orange essential oils enhanced growth performance
of tilapia [18]. In the same context, the addition of grapefruit (Citrus
paradise) peel extract to caspian white sh (Rutilus kutum) diets
increased sh growth performance [19]. Adel et al. investigated the
impact of dietary supplementation with lemon verbena (LV) (Aloysia
citrodora) extract on growth performance and feed eciency in
Siberian sturgeon (Acipenser baerii). They reported a signicant
improvement in the growth performance and feed utilization [20].
Ebtehal et al., reported a signicant increase in protein content and
a decrease in lipid content in sh fed with citrus peel meal compared
to the control group. The authors attributed this improvement to the
high ber content and bioactive compounds present in citrus peels,
which positively inuenced nutrient digestibility and utilization in sh
[21].This is similar to the positive results on the FCR value of citrus oils.
Resketi et al. [22] examined the inuence of dietary supplementation
with citrus extracts on the proximate composition of rainbow trout.
They observed a signicant increase in the protein content and a
decrease in lipid content in sh fed with citrus extracts compared to
the control group; in that study, there was no statistically signicant
effect of the citrus oils given on the proximate analysis.
It has been observed that blood production in sh is stimulated
as a result of stress due to intensive stocking. In our study, it was
observed that citrus macerated oils suppressed blood production
caused by stress in RBC, Hgb, Hct and MCHC values. This suggested
that this situation provided a negative feedback. Similar to this
ndings, extracts of orange and lemon had no marked effects on the
haematological indices including Hgb and RBC of the cultured sh [18].
In another study, orange essential oil and lemon essential oil has
not affected on the haematological indices including Hb and RBC of
the cultured sh [23]. In a study conducted on rainbow trout using
macerated tomato and carrot oils, significant differences were
detected in MCH, RBC, HGB, HCT, LYM values [6]
Vicente et al. found that RBC, Hgb, Hct and MCHC values did not
change in Nile tilapia when orange peel was applied [24]. Sgarro etal.
[25] investigated the impact of dietary supplementation with orange and
lemon extracts on Nile tilapia. They observed a signicant increase in RBC
count, Hgb concentration, and Hct levels in sh fed with citrus extracts
compared to the control group. Our similar results were attributed to the
antioxidant properties of citrus bioactive compounds, which potentially
enhance erythropoiesis and oxygen-carrying capacity in sh.
In an another trial on hematologic parameters in rainbow trout,
Macedo et al. investigated the effects of dietary supplementation
with citrus peel extract. They reported a signicant increase in
WBC and LYM levels in sh fed with citrus peel extract compared
to the control group. In our application, it was suggested that the
immunomodulatory properties of citrus bioactive compounds
might enhance the immune response of sh, leading to alterations
in hematologic proles [26].
Most applications on citrus species involved peels, essential
oils, and extracts. In our study conducted in plasma, a lower or no
antioxidant effect was observed. However, the increase in GPx values
in the MOL and the MOO groups attracted attention.
The interplay between dietary components and antioxidant systems
in sh physiology is crucial for maintaining cellular homeostasis and
mitigating oxidative stress. Citrus fruits, renowned for their high
content of antioxidants, have attracted attention for their potential
to modulate antioxidant parameters in sh.
In the study conducted by Altinterim [27] in rainbow trout with
macerated sesame oil, an increase in GPx level was detected, similar to
that in our macerated lemon group. Chekani et al. [28] investigated the
inuence of dietary supplementation with citrus peel extract on blood
antioxidant parameters in African catsh. They reported a signicant
increase in total antioxidant capacity (TAC) and GPx activity in the blood
of sh fed with citrus peel extract compared to the control group.
Similar to present study, increasing GPx level by bioactive compounds
from citrus enhanced the sh’s antioxidant defense system, thereby
reducing oxidative stress and improving overall health.
Several studies have investigated the effects of dietary
supplementation with citrus extracts or bioactive compounds on the
antioxidant status of sh. For example, research by Mohammady etal. [18]
demonstrated that feeding Nile tilapia with a diet containing fed essential
oils extracted from sweet orange (C. sinensis) and lemon (C. limon) peels,
signicantly increased the activities of SOD, CAT, and GPx in the liver.
Furthermore, the research of Harikrishnan etal. [29] investigated
the effects of dietary supplementation with dried lemon peel on the
antioxidant enzyme activities of grass carp. Results showed that lemon
peel extract supplementation signicantly upregulated the expression
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5 of 6
of SOD, CAT and GPx levels, suggesting a potential enhancement of
antioxidant defense mechanisms in Rohu (Labeo rohita).
CONCLUSIONS
In this study, it was observed that dietary supplementation with
citrus species increased feed eciency and growth performance
by positively affecting the fish FCR. The beneficial effects of
citrus-derived compounds on FCR were attributed to their ability to
enhance nutrient digestibility, metabolic eciency, hematologic and
antioxidant status in sh. Harnessing the nutritional and bioactive
properties of citrus fruits through dietary supplementation offers a
potential strategy to improve feed utilization eciency and mitigate
production costs. According to the results of this study, the bioactive
compounds present in citrus macerated oils, such as avonoids
and polyphenols, might enhance nutrient absorption and metabolic
eciency, leading to improved feed conversion in sh.
Current evidence suggests that citrus species have the potential
to modulate the antioxidant system of sh through their bioactive
compounds. Further research is needed to elucidate the mechanisms
underlying these effects and to investigate the potential application
of citrus-derived supplements in aquaculture practices aimed at
improving sh health and welfare. It is especially important to adjust
the appropriate doses of the macerated oils to be given according
to the sh to be bred. Extracts, which are pharmaceutical precursor
raw materials, are products that are not suitable for practical use, as
they have a high probability of side effects and are costly as essential
oils. Maceration products stand out as a desired feed additive product
because they carry fat-soluble bioactive compounds, provided that the
dose adjustment is made according to the sh species. In addition, being
cost-effective is also a reason for preference for the manufacturer.
Conicts of interest
The authors declare that I have no conict of interest.
BIBLIOGRAPHIC REFERENCES
[1] Hai NV. The use of probiotics in aquaculture. J. Appl. Microbiol.
[Internet]. 2015; 119(4):917–935. doi: https://doi.org/f8dwc3
[2] Mohanty BP, Ganguly S, Mahanty A, Sankar TV, Anandan R,
Chakraborty K, Paul BN, Sarma D, Syama Dayal J, Venkateshwarlu
G, Mathew S, Asha KK, Karunakaran D, Mitra T, Chanda S, Shahi N,
Das P, Das P, Akhtar Md S, Vayagopal P, Sridhar N. DHA and EPA
content and fatty acid prole of 39 food shes from India. BioMed
Res. Int. [Internet]. 2016; 2016:4027437. doi: https://doi.org/gnf8ck
[3] Mohamed RA, Yousef YM, El-Tras WF, Khalafallaa MM. Dietary
essential oil extract from sweet orange (Citrus sinensis) and bitter
lemon (Citrus limon) peels improved Nile tilapia performance and
health status. Aquac. Res. [Internet]. 2021; 52(4):1463–1479. doi:
https://doi.org/g7nktw
[4] Abdel Rahman AN, ElHady M, Shalaby SI. Efficacy of the
dehydrated lemon peels on the immunity, enzymatic antioxidant
capacity and growth of Nile tilapia (Oreochromis niloticus) and
African catsh (Clarias gariepinus). Aquaculture [Internet]. 2019;
505:92–97. doi: https://doi.org/gp95z5
[5] Ringo E, Olsen RE, Gifstad TO, Dalmo RA, Amlund H, Hemre GI,
Bakke AM. Prebiotics in aquaculture: A review. Aquac. Nutr.
[Internet]. 2010; 16(2):117–136. doi: https://doi.org/dhb32j
[6] Altınterim B, Aksu Ö. Effect of macerated tomato (Lycopersicon
esculentum) and carrot (Daucus carota) oils on hematological
parameters of rainbow trout (Oncorhynchus mykiss) at high
stocking density. Int. J. Pure Appl. Sci. [Internet]. 2019; 5(2):85–90.
doi: https://doi.org/g7nktx
[7] Souza CF, Baldissera MD, Baldisserotto B, Heinzmann BM,
Martos-Sitcha JA, Mancera JM. Essential oils as stress-reducing
agents for sh aquaculture: A review. Front. Physiol. [Internet].
2019; 10:785. doi: https://doi.org/ggmdzj
[8] Ogunkalu O. Effects of feed additives in sh feed for improvement of
aquaculture. Eurasian J. Food Sci. Technol. [Internet]. 2019 [cited
20 May 2024]; 3(2):49–57. Available in: https://goo.su/NXrMUD
[9] Altınterim B, Aksu Ö. inuence of macerated and cold press
wheat germ (Triticum vulgare) oils added at different rates to
trout feed on the feed rate (FCR), haemotology parameters
and NBT (Nitroblue tetrazolium) values of rainbow trout
(Oncorhynchus mykiss). Int. J. Pure Appl. Sci. Technol. [Internet].
2019; 5(2):72–77. doi: https://doi.org/g7nktz
[10] Ricker WE. Growth Rates and Models. In: Hoar WS, Randall DJ,
Brett JR, editors. Bioenergetics and Growth. Fish Physiology.
Vol.8. New York: Academic Press; 1979. p. 677-743. ( Fish
Physiology Book series).
[11] Gültepe N. How the use of orange (Citrus sinensis) Peel
Essential oil affected the growth performance of rainbow trout
(Oncorhynchus mykiss)? Bull. Univ. Agric. Sci. Vet. Med. Cluj-
Napoca, Anim. Sci. Biotechnol. [Internet]. 2018; 75(1):16–20.
doi: https://doi.org/g7nkt3
[12] AOAC International. Official methods of analysis of AOAC
International. 16
th
ed. Gaithersburg (MD, USA): AOAC International;
1995. 1015 p.
[13] Cimen M. Fen ve Saglık Bilimleri Alanlarinda SPSS Uygulamali Veri
Analizi. Ankara (Türkiye): Palme Yayinlari; 2015. 314 p. Turkish.
[14] Kalayci S. SPSS uygulamali cok değiskenli istatistik teknikleri. 9.
Baski. Ankara (Türkiye): Dinamik Akademi; 2019. 426 p. Turkish.
[15] Karagöz Y. SPSS 22 Uygulamali biyoistatistik – Tip, eczacilik,
dis hekimliği ve saglik bilimleri için. Ankara: Nobel Akademik
Yayıncılık; 2015. 760 p. Türkish.
[16] Bohlouli S, Sadeghi E. Growth performance and haematological
and immunological indices of rainbow trout (Oncorhynchus
mykiss) ngerlings supplemented with dietary Ferulago angulata
(Schlecht) Boiss. Acta Vet. Brno. [Internet]. 2016; 85(3):231–238.
doi: https://doi.org/g7nkt6
[17] Altinterim B. Inuence of macerated fenugreek (Trigonella foenum
graecum) oil added to trout feed at the different rates on the feed
conversion rate (FCR), body length, blood parameters and nitroblue
tetrazolium (NBT) values of rainbow trout (Oncorhynchus mykiss,
Walbaum, 1792). Cell. Mol. Biol. [Internet]. 2019; 65(3):89–93. doi:
https://doi.org/g7nkt8
[18] Mohammady EY, Soaudy MR, Abdel-Rahman A, Abdel-Tawwab
M, Hassaan MS. Comparative effects of dietary zinc forms on
performance, immunity, and oxidative stress-related gene
expression in Nile tilapia, Oreochromis niloticus. Aquaculture
[Internet]. 2021; 532(1):736006. doi: https://doi.org/g68fcg
Effects of citrus fruits on fish health / Altinterim ____________________________________________________________________________________
6 of 6
[19] Samavat Z, Shamsaie-Mehregan M, Jamili S, Soltani M, Hosseini-
Shekarabi SP. Determination of grapefruit (Citrus paradisi) peel
extract bio-active substances and its application in Caspian white
sh (Rutilus frisii kutum) diet: Growth, haemato-biochemical
parameters and intestinal morphology. Aquac. Res. [Internet].
2019; 50(9):2496–2504. doi: https://doi.org/g7nkt9
[20] Adel M, Dawood MAO, Gholamhosseini A, Sakhaie F, Banaee M.
Effect of the extract of lemon verbena (Aloysia citrodora) on the
growth performance, digestive enzyme activities, and immune-
related genes in Siberian sturgeon (Acipenser baerii). Aquaculture
[Internet]. 2021; 541:736797. doi: https://doi.org/g7nkvc
[21] Hussein E, Goda AMA, Saad Y. Impact of orange (Citrus sinensis)
peel meal as feed additive in the diets for mono-sex Nile tilapia
(Oreochromis niloticus) fries. Menoua J. Anim. Poult. Fish Prod.
[Internet]. 2022; 6(10):157–169. doi: https://doi.org/g7nkvf
[22] Resketi MA, Yeganeh S, Khalili KJ. Dietary sour lemon (Citrus
limon) peel essential oil supplementation for reduction of
deltamethrin-induced stress in rainbow trout (Oncorhynchus
mykiss). J. World Aquac. Soc. [Internet]. 2021; 52(1):105–123.
doi: https://doi.org/g7nkvg
[23] Acar Ü, Kesbiç OS, Inanan BE, Yilmaz S. Effects of dietary
Bergamot (Citrus bergamia) peel oil on growth, haematology
and immune response of European sea bass (Dicentrarchus
labrax) juveniles. Aquac. Res. [Internet]. 2019; 50(11):3305–3312.
doi: https://doi.org/g7nkvh
[24] Vicente IS, Fleuri LF, Carvalho PLPF, Guimarães MG, Naliato RF,
Müller HDC, Sartori MMP, Pezzato LE, Barros MM. Orange peel
fragment improves antioxidant capacity and haematological prole
of Nile tilapia subjected to heat/dissolved oxygen-induced stress.
Aquac. Res. [Internet]. 2019; 50(1):80–92. doi: https://doi.org/g7nkvj
[25] Sgarro MF, Maggiolino A, Forte L, Matera R, Bifulco G, Claps S,
Natrella G, De Palo P. Effect of dietary administration of red
orange and lemon extract on volatile compounds: prole and
sensory parameters of lamb meat. Ital. J. Anim. Sci. [Internet].
2024; 23(1):101–113. doi: https://doi.org/g7nkvm
[26] Macedo JDS, Copatti CE, Costa EV, da Silva FMA, Dutra LM,
Santos VLA, Almeida JRGS, Tavares-Dias M, Melo JFB. Effects
of Citrus limon extract on growth performance and immunity in
striped catsh (Pangasius hypophthalmus). Aquac. Int. [Internet].
2023; 31:719–738. doi: https://doi.org/g7nkvp
[27] Altinterim B. Effects of macerated and cold pressed sesame
(Sesamum indicum, L.) oil on antioxidant enzyme activities,
hematological parameters, nitro blue tetrazolium (Nbt) activity and
proximate composition of rainbow trout (Oncorhynchus mykiss,
Walbaum, 1792) at high stocking density. Int. J. Pure Appl. Sci.
[Internet]. 2023; 9(2):231–239. doi: https://doi.org/g7nkvq
[28] Chekani R, Akrami R, Ghiasvand Z, Chitsaz H, Jorjani S. Effect of
dietary dehydrated lemon peel (Citrus limon) supplementation on
growth, hemato-immunolological and antioxidant status of rainbow
trout (Oncorhynchus mykiss) under exposure to crowding stress.
Aquaculture [Internet]. 2021; 539:736597 doi: https://doi.org/g7nkvr
[29] Harikrishnan R, Thamizharasan S, Devi G, Van Doan H, Ajith
Kumar TT, Hoseinifar SH, Balasundaram C. Dried lemon peel
enriched diet improves antioxidant activity, immune response
and modulates immuno-antioxidant genes in Labeo rohita
against Aeromonas sorbia. Fish Shellsh Immunol. [Internet].
2020; 106:675–684. doi: https://doi.org/g6knqg