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505
Czech J. Anim. Sci., 55, 2010 (11): 505–519 Original Paper
Effect of inorganic or organic selenium supplementation
on productive performance, egg quality and some
physiological traits of dual-purpose breeding hens
Y.A. A1, A.A. A2, H.S. Z3, F. B4, A.A. T E-D1,
M.A. A1
1Department of Animal and Poultry Production, Faculty of Agriculture,
Damanhour University, Egypt
2Department of Poultry Nutrition, Animal Production Research Institute, ARC,
Ministry of Agriculture and Land Reclamation, Egypt
3Department of Animal and Fish Production, Faculty of Agriculture-Saba Basha,
Alexandria University, Egypt
4Department of Animal Science and Food Conrol, Faculty of Veterinary Medicine,
University of Napoli Federico II, Italy
ABSTRACT: One hundred and twenty (100♀ + 20♂) 30-weeks-old dual-purpose breeding hens of Gimmi-
zah strain were housed in individual cages in a semi-open house. Birds were distributed randomly into five
treatments of 20♀ + 4♂. The 1st treatment was fed a control (unsupplemented) diet (17.5% CP and 11.4 MJ
per kg diet) containing 0.10 mg Se/kg (low level). The 2nd, 3rd, 4th and 5th treatments were fed the control diet
supplemented with 0.15 and 0.30 mg Se/kg from inorganic (sodium selenite) and organic (selenomethionine,
as Se-yeast Selplex® Alltech, Nicholasville, USA) sources, respectively. The total concentration of Se in experi-
mental diets was 0.25 (medium level) and 0.40 ppm (high level). Feed and water were provided ad libitum
throughout the experimental period (30–50 weeks of age). Different Se levels of the organic and inorganic
form and their interaction did not significantly (P > 0.05) affect egg production percentage, and most of egg
quality traits. Egg weight and egg mass significantly (P < 0.002) increased and the feed conversion ratio (FCR)
significantly (P < 0.04) improved due to Se supplementation compared with hens fed the control diet. Piped
embryos and spleen percentage significantly (P < 0.05) decreased due to Se supplementation. In addition,
the level of organic and inorganic Se and their interaction significantly (P < 0.0001) decreased the plasma
cholesterol concentration. Tibia Ca and P percentages and yolk selenium concentration significantly (P < 0.03;
P < 0.0001 and P < 0.0001, respectively) increased due to Se supplementation and the greatest increase was
recorded by a group fed diet with the high level (0.40) of organic Se. The duodenal and intestinal mucosa of
the ileum was negatively affected by the high level of inorganic Se while chickens fed the organic form showed
less toxic effects in hepatic and splenic tissues than those receiving the inorganic form. In conclusion, the
organic and inorganic Se supplementation at 0.15 and 0.30 mg/kg diet, which corresponded to a dietary level
of 0.25 and 0.40 mg/kg diet, improved the productive and reproductive performance of Gimmizah breeding
hens. A decrease in plasma total cholesterol and an improvement in the bone mineralization were observed.
The level of 0.25 mg/kg diet of organic Se was adequate to enrich eggs, which may be recommended for
practical application and which would improve the consumer health benefit.
Keywords: selenium; egg production; fertility; hatchability; egg quality
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Original Paper Czech J. Anim. Sci., 55, 2010 (11): 505–519
The role of trace elements to increase poultry
productivity is very important in the high-stress
production environment. Nutritionists realize that
both the level and the source of trace elements play
an important role in ration formulations and op-
timizing production level, product quality, health
status of birds and economic returns. Using chicken
eggs in the human diet leads to additional benefits
that can be derived from modifying the egg nutri-
tional profile, particularly egg fats and antioxidants.
In this regard, Kucharzewski et al. (2003) suggested
that the low concentrations of zinc and selenium
in the thyroid tissue confirm their participation in
the carcinogenic process.
Nowadays, there is a considerable interest in re-
placing inorganic trace minerals by the metal amino
acid complex that can meet the requirements of
animals for both the 1st or the 2nd limiting amino
acid and simultaneously improve the availability of
the metal to animals. The aim behind the applica-
tion of this new biotechnology in animal nutrition
is to protect the metals from dietary antagonists
such as phytate, non-starch polysaccharides, crude
fibre and interaction among minerals as well as to
reduce its negative effect on the availability of vita-
mins. It is clear that in some minerals, i.e. selenium,
chromium and iron, organic forms were more ef-
ficient utilized than inorganic forms (Hallberg and
Rossander-Hulthen, 1993; Skřivan et al., 2006).
Functional foods are nowadays of great interest
and producing poultry product modified foods may
be possible with the applications of the biotechnol-
ogy in trace mineral nutrition (Surai, 2000, 2006;
Bobcek et al., 2004; Skřivan et al., 2006; Gajčević
et al., 2009). The aim of this work was to study the
effect of different dietary levels and/or sources of
Se on productive and reproductive performance,
blood biochemical constituents and histopathology
of breeding hens as well as a means of producing
functional foods such as low cholesterol eggs and
Se-enriched eggs.
MATERIAL AND METHODS
Birds, management and experimental
design
A total number of 120, 30-weeks-old dual-pur-
pose breeding chickens of Gimmizah (Gallus gallus
f. domestica), a crossbred originated by crossing
of Dokki4 (Fayoumi × White Plymouth Rock) and
Barred Plymouth Rock) strain (100♀ + 20♂) were
weighed individually and housed in individual
wire laying cages until the end of the experiment
(50 weeks of age). Birds were randomly divided
into five groups, each consisting of 20 pullets and
4 cocks. Males were kept separately from females
for artificial insemination and fed the crosspend-
ing female experimental diets. The first group was
used as a control and fed the basal diet without
Se supplementation containing 0.1% Se by analy-
sis (Table 1). The second and the third treatment
groups were fed the basal diet supplemented with
0.15 and 0.30 inorganic Se mg/kg diet as sodium
Table 1. The composition and analysis of experimental
basal diet fed to Gimmizah laying hens during 30 to
50 weeks of age
Ingredient profiles (%)
Yellow maize 63.14
Soybean meal 44% CP 27.10
Limestone 7.60
Dicalcium phosphate 1.50
Sodium chloride (NaCl) 0.30
Vitamin + mineral premix10.30
DL-methionine 0.06
Total 100.00
Calculated and determined values2
ME MJ/kg diet 11.40
Lysine (%) 0.87
Calcium (%) 3.00
Av. phosphorus (%) 0.42
Chemical analyses
Se (ppm) 0.10
CP (%)317.45
1vitamin-mineral premix supplied per 1 kg of diet: vita-
min A 12 000 IU; vitamin D3 2 200 ICU; vitamin E10 mg;
vitamin K3 2 mg; vitamin B1 1 mg; vitamin B2 4 mg; vitamin B6
1.5 mg; vitamin B12 10 Ug; nicotinic acid 20 mg; folic acid
1 mg; pantothenic acid 10 mg; biotin 50 Ug; choline chloride
500 mg; copper 10 mg; iron 30 mg; manganese 55 mg; zinc
50 mg; iodine 1 mg; selenium 0.1 mg supplemented as sodium
selenite “Na2SeO3”,
2calculated values (NRC, 1994);
3determined values (AOAC, 1995)
507
Czech J. Anim. Sci., 55, 2010 (11): 505–519 Original Paper
selenite (Na2SeO3), respectively. The fourth and
the fifth groups were fed the basal diet supple-
mented with 0.15 and 0.30 organic Se mg/kg diet
as selenomethionine (Se-yeast Selplex® Alltech,
Nicholasville, USA), respectively.
Feed and water were provide d ad li bitum
throughout the experimental period (30–50 weeks
of age). Birds were illuminated with a 15:9 h light-
dark cycle. Vaccination and medical care were done
according to common veterinary care under vet-
erinarian’s supervision.
Measurements
Daily egg production and egg weight were re-
corded in each hen, and egg mass and hen day egg
production percentage were calculated. Feed intake
(FI) was recorded weekly. Egg production criteria
were calculated for monthly intervals during the
production period, then FCR was calculated as g
of feed required per each g of egg.
Eggs were collected for a 7-day period at 38, 42 and
46 weeks of age and were incubated in automatic
incubators. e removed eggs and eggs not hatched
on day 21 were broken to differentiate infertile eggs
from those containing dead embryos. Fertility was
calculated as the number of fertile eggs as relative
to the total number of eggs set while hatchability
was calculated as the number of hatched chicks as
relative to the total number of egg set.
Eggs laid on two successive days, from each
treatment at 40 and 48 weeks of age, were used
for measuring egg quality traits. Egg shell (SW),
yolk and albumen were weighed to the nearest
0.1 g (egg shells were washed, the inner egg shell
membrane was separated and air-dried for 72 h
before weighing). The following parameters were
also measured: egg shape index (ESI) according to
Ramanoff and Ramanoff (1949); yolk index (YI%)
as reported by Funk (1948); albumen height (AH);
Haugh unit score (HU) according to Haugh (1937);
shell weight per unit of surface area (SWUSA) ac-
cording to Attia et al. (1995); egg surface area ac-
cording to Carter (1975). SWUSA was calculated
by dividing the shell weight by the egg surface area
and presented as mg/cm2 of egg.
The content of Se in the basal diet and in egg
yolk was determined as follows: two grams of basal
diet or yolk mixture were digested by H2SO4 and
hydrogen peroxide H2O2 according to Black (1982).
Se was measured by the inductively coupled argon
plasma spectroscopy (ICP) in Agriculture Research
Center, Giza, Laboratories according to the method
of Cottenie et al. (1982). Feeds samples of experi-
mental diets were chemically analyzed according
to the official methods of AOAC (1995).
At the end of the experiment, blood samples
(3 ml) were collected from the brachial vein into
heparinized tubes of three birds/treatment. Plasma
was immediately separated by centrifugation for
10 minutes at 3 200 rpm. Plasma triglyceride (TG)
and total cholesterol (TC) were determined by
colorimetric methods using available commercial
kits (Diamond Diagnostics).
Two grams of yolk mixture (n = 5 per treatment)
was extracted with a mixture of chloroform: metha-
nol (2:1 v/v) using the procedure described by Folch
et al. (1957). Cholesterol determination was done in
triplicate using a commercial test kit for cholesterol
analysis (Sigma diagnostic cholesterol reagent proce-
dure No. 352, Sigma Chemical Co., St Louis, MO).
At the end of experiment, 5 females (50 weeks
of age) were randomly chosen, weighed after 12 h
fasting, slaughtered, feather picked and the total
inedible parts (head, legs and inedible viscera) were
taken aside and the remaining carcass (dressed
weight) was weighed. Liver, spleen, abdominal fat,
pancreas, spleen, intestine and ovary were sepa-
rated and individually weighed. Percentages of in-
ternal organs to live body weight were calculated.
The right tibia of slaughtered hens was removed,
cleaned from tissues, set in hexane for 48 h to re-
move fat and dried in an oven for 24 h until constant
weight (g), then ashed. Tibia Ca and phosphorus
contents were determined according to the meth-
ods of AOAC (1995).
Histopathological study
Tissue specimens were collected from the liver,
spleen and small intestine (duodenum, jejunum and
ileum) of both treated and control hens. Fixation
was done in bovine solution for specimens of the
intestine as well as in 10% neutral buffered formalin
solution for the other specimens. After washing in
tap water, specimens passed through the steps of a
routine paraffin embedding technique (dehydration
in series of alcohol, clearing in xylol and embedding
in melted paraffin wax). After blocking, paraffin
sections of 3–5 microns in thickness were obtained
with a microtome and later they were stained with
haematoxylin and eosin according to Bancroft and
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Original Paper Czech J. Anim. Sci., 55, 2010 (11): 505–519
Stevens (1990), and subjected to light microscopy
to record histopathological changes in the various
examined organs.
Statistical analysis
Data were analyzed by ANOVA using a two-way
model (SAS, 1990). The main effects were Se levels
and sources. The interaction between the two main
factors was tested. A 0.05 level of significance of
Student-Newman-Keuls test was used to test mean
differences. All the percentages were converted as
log 10 to normalize data distribution.
RESULTS AND DISCUSSION
Selenium concentration in basal diet
The chemical composition of basal diet (control)
showed that the Se concentration was 0.10 ppm
(Table 1). This value is within the acceptable range
of the recommendation for laying hens cited by
NRC (1994). Standing this result, the total concen-
tration of selenium in experimental diets was 0.10,
0.25 and 0.40 mg/kg diet both for either organic or
inorganic source.
Productive, quality and reproductive traits
Table 2 shows the effect of Se level and/or source
on egg production traits. The egg production per-
centage for the whole experimental period was not
significantly affected by the level and source of Se
and the interaction between these variables was
not significant either. The increasing Se level up to
0.40 ppm significantly increased both egg weight
and egg mass compared with those in hens fed the
control diet. A similar response was observed due
to Se supplementation when the inorganic or or-
ganic form was compared with the control diet. The
results of the interaction indicated that the high
Table 2. Effects of different Se sources and/or levels on egg production traits in Gimmizah hens from 30 to 50 weeks
of age (mean ± SD)
Level/source
of of selenium
Egg production
(%)
Egg weight
(g)
Egg mass
(g)
Feed intake
(g/hen/day)
FCR
(g feed/g egg)
Se level (ppm)
0.10 56.4 ± 8.94 54.3b ± 2.61 30.6b ± 4.72 134.5a ± 6.39 4.52a ± 0.78
0.25 61.8 ± 4.39 54.7b ± 2.30 33.8a ± 2.79 128.9c ± 6.71 3.84b ± 0.37
0.40 62.4 ± 6.33 56.0a ± 1.35 34.9a ± 3.71 131.9b ± 7.29 3.82b ± 0.48
P-value NS 0.002 0.002 0.008 0.04
Se source
Control 56.4 ± 8.94 54.3b ± 2.61 30.6b ± 4.72 134.5a ± 6.39 4.52a ± 0.78
Inorg 62.1 ± 6.86 55.4a ± 2.56 34.4a ± 4.23 126.1b ± 4.96 3.73b ± 0.51
Org 62.1 ± 3.53 55.4a ± 1.91 34.4a ± 2.10 134.7a ± 6.35 3.93b ± 0.29
P-value NS 0.002 0.002 0.0001 0.04
Se level × Se source
Control (0.10) 56.4 ± 8.94 54.3c ± 2.61 30.6c ± 4.72 134.5 ± 6.39 4.52a+ 0.78
Inorg (0.25) 62.9 ± 4.85 53.9c ± 2.82 33.9b ± 3.23 124.4 ± 3.53 3.70b ± 0.37
Inorg (0.40) 61.3 ± 8.47 56.8a ± 1.11 34.8ab ± 5.08 127.8 ± 5.63 3.76b ± 0.63
Org (0.25) 60.7 ± 3.68 55.5b ± 1.28 33.7b ± 2.36 133.4 ± 6.08 3.98b ± 0.33
Org (0.40) 63.6 ± 2.76 55.3b ± 1.12 35.1a ± 1.55 135.9 ± 6.50 3.88b ± 0.25
P-value NS 0.0003 0.002 NS 0.04
a,b,cmeans in the same column within similar treatments bearing different superscripts are significantly different at
P ≤ 0.05; NS = not significant
509
Czech J. Anim. Sci., 55, 2010 (11): 505–519 Original Paper
Table 3. Effects of different Se sources and/or levels on the quality of egg and shell in Gimmizah hens from 30 to 50 weeks of age (mean ± SD)
Level/source
of selenium
Yolk
(%) Yolk index Albumen
(%) HU Shell
(%)
SWUSA
(mg/cm2)
Shell thickness
(mm) Shape index
Se level
0.10 33.94 ± 1.69 41.74 ± 3.12 53.42 ± 1.63 74.16 ± 7.11 12.63 ± 0.90 105.5 ± 8.79 0.334 ± 2.88 76.76 ± 5.88
0.25 37.31 ± 3.72 42.22 ± 2.70 50.13 ± 4.17 70.98 ± 11.22 12.56 ± 1.30 103.9 ± 9.96 0.319 ± 3.81 78.88 ± 5.85
0.40 35.84 ± 3.76 42.07 ± 3.11 52.14 ± 3.93 68.14 ± 8.90 12.04 ± 0.91 100.4 ± 7.34 0.325 ± 2.66 77.11 ± 2.95
P-value NS NS NS NS NS NS NS NS
Se source
Control 33.94 ± 1.69 41.74 ± 3.12 53.42 ± 1.63 74.16 ± 7.11 12.63 ± 0.90 105.5 ± 8.79 0.334 ± 2.88 76.76b ± 5.88
Inorg 36.44 ± 3.08 41.62 ± 2.58 51.15 ± 3.31 67.65 ± 11.03 12.43 ± 1.21 103.9 ± 9.96 0.305 ± 3.81 79.58a ± 5.60
Org 36.71 ± 4.43 42.68 ± 3.12 51.12 ± 4.89 71.46 ± 8.96 12.17 ± 1.08 100.4 ± 7.34 0.323 ± 2.66 76.41b ± 2.82
P-value NS NS NS NS NS NS NS 0.02
Se level × Se source
Control (0.10) 33.94 ± 1.69 41.74 ± 3.12 53.42 ± 1.63 74.16 ± 7.11 12.63 ± 0.90 105.5 ± 8.79 0.334 ± 2.88 76.76b ± 5.88
Inorg (0.25) 36.91 ± 2.73 41.75 ± 2.38 50.09 ± 2.28 68.82 ± 13.08 13.00 ± 1.23 107.4 ± 9.91 0.317 ± 3.61 82.14a ± 6.42
Inorg (0.40) 35.96 ± 3.46 41.49 ± 2.87 52.20 ± 3.91 66.47 ± 9.01 11.85 ± 0.91 99.4 ± 7.22 0.324 ± 2.80 77.02b ± 3.20
Org (0.25) 37.72 ± 4.61 42.70 ± 3.01 50.16 ± 5.59 73.13 ± 9.12 12.13 ± 1.27 100.4 ± 9.13 0.292 ± 3.74 75.63b ± 2.72
Org (0.40) 35.71 ± 4.20 42.65 ± 3.37 52.08 ± 4.13 69.80 ± 8.89 12.22 ± 0.91 101.5 ± 7.65 0.320 ± 2.66 77.19b ± 2.82
P-value NS NS NS NS NS NS NS 0.01
a,b,cmeans in the same column within similar treatments bearing different superscripts are significantly different at P ≤ 0.05; NS = not significant; con = control; inorg = inorganic;
org = organic
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Original Paper Czech J. Anim. Sci., 55, 2010 (11): 505–519
level (0.40 ppm) of inorganic Se or the medium
level (0.25) and the high level (0.40 ppm) of or-
ganic Se significantly increased egg weight and egg
mass compared with those in hens fed the control
diet (Table 2). However, the high level (0.40 ppm)
of inorganic Se had the best effect on egg weight
and both the inorganic and organic form at the
high level (0.40 ppm) of Se positively affected egg
mass.
The increasing Se level to 0.25 and 0.40 ppm sig-
nificantly decreased FI and significantly improved
the FCR by 15 and 15.5%, respectively, compared
with those in hens fed the control diet, showing
no differences between the medium and the high
level. However, the inclusion of inorganic Se signifi-
cantly decreased FI by 6.7% and 6.8%, respectively,
compared with FI in hens fed the control diet and
organic Se. The FCR was significantly improved
by 17.5 and 13.1%, respectively, in hens receiving
organic or inorganic Se supplementations com-
pared with those fed the control diet. The interac-
tion between the Se level and source did not affect
FI, while it significantly affected the FCR. The lat-
ter indicates that Se supplementation at 0.25 or
0.40 ppm of inorganic or organic Se significantly
improved the FCR by 22.2, 16.8, 11.9 and 14.2%,
respectively, compared to the control diet.
In the literature, the effect of Se supplementation
on egg production traits is not clear and it is based
on Se content of the basal diet. Results reported by
Jiakui and Xialong (2004), Utterback et al. (2005)
and Leeson et al. (2008) indicated no differences
in egg production, egg weight and FI of laying hens
due to inorganic and organic Se supplementation.
Ganpule and Manjunatha (2003) demonstrated that
selenium yeast supplementation significantly im-
proved the FCR of laying hens compared with that
of hens fed the control diet. On the other hand,
Ševčíková et al. (2006) reported that the FCR was
not affected by Se supplementation. The above-
Table 4. Effects of different Se sources and/or levels on reproductive traits and tibia characteristics of Gimmizah
hens from 30 to 50 weeks of age (mean ± SD)
Level/source
of selenium
Fertility
(%)
Hatchability
(%)
Embryonic
mortality (%)
Piped
embryos (%)
Tibia
tibia (%) Ca (%) iP (%)
Se level
0.10 93.02 ± 2.77 76.02b ± 6.8 2.92 ± 3.56 14.09a ± 6.6 0.52 ± 0.03 13.55b ± 1.5 7.80 ± 0.73
0.25 92.81 ± 3.80 89.12a ± 2.5 0.00 ± 0.00 3.69b ± 4.5 0.50 ± 0.06 21.06a ± 4.3 6.90 ± 2.42
0.40 95.04 ± 4.40 88.94a ± 6.2 1.08 ± 2.76 5.02b ± 4.4 0.50 ± 0.03 21.23a ± 5.9 7.01 ± 1.13
P-value NS 0.02 NS 0.05 NS 0.03 NS
Se source
Control 93.02 ± 2.77 7 6.02c ± 6.8 2.92 ± 3.56 14.09a ± 6.6 0.52 ± 0.03 13.55c ± 1.5 7.80b ± 0.73
Inorg 94.05 ± 4.39 91.09a ± 4.1 0.00 ± 0.00 2.96b ± 3.1 0.50 ± 0.05 20.30a ± 4.9 8.58a ± 0.63
Org 93.80 ± 4.16 86.97b ± 4.4 1.08 ± 2.76 5.74b ± 5.1 0.50 ± 0.05 21.99a ± 5.4 5.33c ± 0.85
P-value NS 0.02 NS 0.05 NS 0.03 0.0001
Se level × Se source
Control (0.10) 93.02ab ± 2.77 76.02c ± 6.8 2.92 ± 3.56 14.09a ± 6.6 0.52 ± 0.03 13.55c ± 1.5 7.80b ± 0.73
Inorg (0.25) 90.66b ± 2.71 89.44ab ± 1.2 0.00 ± 0.00 1.22c ± 2.2 0.51 ± 0.05 24.90a ± 0.1 9.15a ± 0.23
Inorg (0.40) 97.44a ± 2.70 92.74a ± 5.4 0.00 ± 0.00 4.70bc ± 3.1 0.49 ± 0.05 15.70b ± 0.5 8.00b ± 0.08
Org (0.25) 94.96ab ± 3.68 88.80b ± 3.6 0.00 ± 0.01 6.16b ± 5.0 0.49 ± 0.07 17.22b ± 2.2 4.66d ± 0.37
Org (0.40) 92.64ab + 4.69 85.14b ± 4.7 2.17 ± 3.77 5.33b ± 5.7 0.51 ± 0.03 26.76a ± 1.1 6.01c± 0.58
P-value 0.007 0.02 NS 0.05 NS 0.0001 0.0001
a,b,cmeans in the same column within similar treatments bearing different superscripts are significantly different at P ≤ 0.05;
NS = not significantl; con = control; inorg = inorganic; org = organic
511
Czech J. Anim. Sci., 55, 2010 (11): 505–519 Original Paper
mentioned literature may support the results of
the present study regarding the positive effect of
Se on egg weight, egg mass and FCR and the lack
of effect on egg production percentage.
The level and source of Se and their interaction
had no significant effect on any traits of egg qual-
ity (Table 3), showing that Se content of the basal
diet was adequate to support egg production of
good quality. However, recent evidences by Payne
et al. (2005) and Gajčević et al. (2009) indicated
that eggs produced by hens fed a diet with organic
Se had higher HU values than eggs of hens fed the
recommended level of Se. Furthermore, Gajčević
et al. (2009) reported that the dietary supplementa-
tion of a higher amount of Se resulted in increased
GSH-Px activity in the hens’ blood (P < 0.05).
e level and source of Se had no significant ef-
fect on fertility and embryonic mortality percent-
age compared with those in hens fed the control
diet. On the other hand, the hatchability percent-
age improved significantly and the piped embryos
significantly decreased. The improvement in the
hatchability percentage was ~ 17% for the medium
(0.25) and high (0.40 ppm) level (Table 4). e re-
sults of the interaction indicated a significant ef-
fect with the greatest fertility percentage (97.4%)
in hens fed the high level (0.40 ppm) of inorganic
Se and the least significant one (90.7%) in hens fed
the medium (0.25 ppm) level of inorganic Se. e
organic Se groups exhibited intermediate values.
In addition, the medium (0.25) and the high (0.40
ppm) levels of inorganic and organic Se in layer diets
significantly improved the hatchability percentage
while the embryonic mortality percentages signifi-
cantly decreased compared with those in hens fed
the basal diet (0.10 ppm of Se). On the other hand,
the interaction between the level and the source of
Se did not significantly affect the embryonic mor-
tality percentage compared with that in hens fed
the control diet. Surai (2006) indicated that Se has
an important role in improved fertility, embryonic
development and hatchability of poultry. Moreover,
Se is deposited in the egg and distributed among
the developing tissues during embryogenesis (Surai,
2000; Paton et al., 2002). However, the present results
showed that sodium selenite had better hatchability
than the Selplex®, which needs further verification.
e improvement quoted herein could be due to
the ability of Se to remove oxygen free radicals and
lipid peroxidase and to alleviate the degree of tissue
damage caused by the oxygen and the free radicals
caused by hatching stress (Surai, 2006).
Tibia characteristics
Selenium level, source and the interaction be-
tween the level and the source of Se had no signifi-
cant effect on the tibia weight percentage compared
with that in hens fed the control diet (Table 4). The
increasing level of Se in the inorganic and organic
source significantly increased the calcium percent-
age in tibia compared with that in hens fed the
control diet. These results indicated that Se sup-
plementation improved the bone mineralization of
laying hens during 30–50 weeks of age (Table 4).
The Se level in layer diets had no significant effect
on the inorganic phosphorus percentage in tibia.
The phosphorus percentages in tibia significantly
decreased by organic Se but significantly increased
by inorganic Se compared with those in hens fed
the control diet. Although inorganic Se increased
tibia phosphorus, tibia Ca percentage and tibia
weight percentage did not differ between the two
sources.
It is worth noting that the medium level (0.25 ppm)
of inorganic Se resulted in the greatest Ca and phos-
phorus in tibia, nonetheless, the relative weight of
tibia was not changed. The mechanism by which Se
affects the bone formation is not known at present,
for example the Se presence in human bones is
about 16% of total body Se (Zachara et al., 2001). A
relationship between active vitamin D metabolites
and the Se-dependent enzyme thioredoxin reduct-
ase was established (Schutze et al., 1999). An effect
of thioredoxin reductase activity on 1.25 (OH)2D3
would be expected and this could be an important
link between Se and bone metabolism. On the other
hand, antioxidant properties of various selenopro-
teins could also be of importance in maintaining
the antioxidant protection of the oviduct during
eggshell formation (Surai, 2006).
Organs
The level and/or the source of selenium had no
significant effect on most of the organs except the
relative weight of spleen which significantly de-
creased compared with that in hens fed the control
diet. In addition, the relative weight of pancreas
significantly increased at both the medium (0.25)
and high (0.40 ppm) level of Se in respect of the
control group (Table 5). In agreement with the
present results, EL-Sebai (2000) and Ševčíková et
al. (2006) found that no significant effect due to
512
Original Paper Czech J. Anim. Sci., 55, 2010 (11): 505–519
supplementation of Se on liver weight of broiler
chickens.
Biochemical constituents
The level and the source of Se did not signifi-
cantly affect the albumin and triglyceride concen-
tration of the plasma compared with the control
treatment (Table 6). Similarly, Abaza (2002) found
that the plasma triglyceride was insignificantly
affected by Se or by the combination of Se and
vitamin E. However, Attia et al. (2006) found that
vitamin E and/or Se supplementation significantly
decreased triglycerides. The low dosage of inorgan-
ic Se and the high dosage of organic Se significantly
decreased the plasma triglyceride concentration
compared with the other Se treatments showing
a significant interaction between the level and the
source of Se.
Both the level and source of Se significantly
decreased the plasma cholesterol concentration
compared with that in hens fed the control diet
(Table 6). In accordance with the present obser-
vations Abd-El-Latif et al. (2004) reported that
additions of Zn, Se and vitamin E significantly al-
leviated the concentration of cholesterol in quails
fed dietary ochratoxin compared with quails fed
dietary ochratoxin without such feed additives. On
the other hand, Abaza (2002) observed that the
plasma cholesterol concentration was significantly
increased by Se or by the combination of Se and
vitamin E. However, Ljubic et al. (2006) suggested
that the organic Se supplementation influences
cholesterol metabolism in adipose tissue by de-
creasing the total cholesterol concentration during
the fattening period and increasing the free cho-
lesterol concentration after 48 h feed deprivation.
Changes in enzymes responsible for regulating cho-
lesterol synthesis, oxidation or elimination may be
Table 5. Effects of different Se sources and/or levels on the percentage of some organs in Gimmizah hens at 50 weeks
of age (mean ± SD)
Level/source
of selenium Spleen (%) Abdominal
fat (%) Ovary (%) Oviduct (%) Liver (%) Pancreas (%) Intestinal
weight (%)
Se level
0.10 0.162a ± 0.03 3.21 ± 1.82 1.72 ± 0.68 2.98 ± 0.34 0.52 ± 0.03 13.55b ± 1.5 7.80 ± 0.73
0.25 0.107b ± 0.03 5.09 ± 1.28 2.41 ± 0.83 2.58 ± 0.25 0.50 ± 0.06 21.06a ± 4.3 6.90 ± 2.42
0.40 0.081b ± 0.03 7.27 ± 1.69 2.13 ± 0.75 2.61 ± 0.18 0.50 ± 0.03 21.23a ± 5.9 7.01 ± 1.13
P-value 0.05 NS NS NS NS 0.03 NS
Se source
Control 0.162a ± 0.03 3.21 ± 1.82 1.72 ± 0.68 2.98 ± 0.34 2.20 ± 0.37 0.21 ± 0.04 2.02 ± 0.55
Inorg 0.090b ± 0.03 5.77 ± 1.97 1.96 ± 0.69 2.55 ± 0.20 1.86 ± 0.44 0.22 ± 0.02 2.15 ± 0.33
Org 0.098b ± 0.04 6.59 ± 1.71 2.57 ± 0.79 2.64 ± 0.23 2.09 ± 0.12 0.21 ± 0.01 2.44 ± 0.54
P-value 0.05 NS NS NS NS NS NS
Se level × Se source
Control (0.10) 0.162a ± 0.03 3.21 ± 1.82 1.72 ± 0.68 2.98 ± 0.34 2.20 ± 0.37 0.21 ± 0.04 2.02 ± 0.55
Inorg (0.25) 0.088c ± 0.01 4.66 ± 1.45 1.92 ± 0.02 2.52 ± 0.22 1.80 ± 0.22 0.21 ± 0.02 2.15 ± 0.11
Inorg (0.40) 0.092c ± 0.04 6.89 ± 1.91 2.01 ± 1.05 2.57 ± 0.20 1.93 ± 0.62 0.23 ± 0.02 2.16 ± 0.50
Org (0.25) 0.126b ± 0.03 5.52 ± 1.11 2.90 ± 0.99 2.64 ± 0.30 2.08 ± 0.17 0.21 ± 0.01 2.38 ± 0.82
Org (0.40) 0.070c ± 0.01 7.65 ± 1.61 2.24 ± 0.41 2.65 ± 0.18 2.10 ± 0.08 0.20 ± 0.02 2.50 ± 0.08
P-value 0.05 NS NS NS NS NS NS
a,b,cmeans in the same column within similar treatments bearing different superscripts are significantly different at P ≤ 0.05;
NS = not significant; con = control; inorg = inorganic; org = organic
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Czech J. Anim. Sci., 55, 2010 (11): 505–519 Original Paper
Table 6. Effects of different Se sources and/or levels on plasma total protein, albumin, globulin, Alb/Glb, triglyceride, cholesterol, HDL and selenium yolk concen-
trations of Gimmizah hens from 30 to 50week of age (mean ± SD)
Level/source of
selenium
Total protein
(g/dl)
Albumin
(g/dl)
Globulin
(g/dl) Alb/Glb Triglyceride
(mg/dl)
Cholesterol
(mg/dl)
HDL
(mg/dl)
Yolk Se (ppm
fresh yolk)
Se level
0.10 5.47 ± 0.4 4.06 ± 0.1 1.41 ± 0.4 3.25 ± 1.3 537.2 ± 39.5 195.0a ± 8.6 403.8b ± 71.0 0.209c ± 0.01
0.25 5.24 ± 0.7 3.73 ± 0.6 1.51 ± 0.6 3.03 ± 1.6 457.1 ± 99.9 131.6c ± 44.9 573.2a ± 45.1 0.223b ± 0.01
0.40 5.97 ± 1.4 3.81 ± 0.4 2.16 ± 1.7 3.62 ± 2.8 464.8 ± 79.9 163.1b ± 12.4 426.4b ± 43.2 0.356a ± 0.06
P-value NS NS NS NS NS 0.0001 0.0001 0.0001
Se source
Control 5.47b ± 0.4 4.06 ± 0.1 1.41b ± 0.4 3.25ab ± 1.3 537.2 ± 39.5 195.0a ± 8.6 403.8b ± 71.0 0.209c ± 0.01
Inorg 6.17a ± 1.2 3.58 ± 0.3 2.60a ± 1.3 1.83b ± 0.9 448.3 ± 97.5 169.6b ± 12.1 403.8b ± 170.9 0.261b ± 0.05
Org 5.03b ± 0.7 3.96 ± 0.6 1.07b ± 0.5 4.82a ± 2.2 473.6 ± 80.9 125.1c ± 38.2 595.9a ± 36.6 0.318a ± 0.09
P-value 0.02 NS 0.003 0.003 NS 0.0001 0.0001 0.0001
Se level × Se source
Control (0.10) 5.47b ± 0.4 4.06 ± 0.1 1.41b ± 0.4 3.25 ± 1.3 537.2a ± 39.5 195.0a ± 8.6 403.8b ± 71.0 0.209e ± 0.01
Inorg (0.25) 5.47b ± 0.8 3.60 ± 0.4 1.87b ± 0.5 2.03 ± 0.5 373.1b ± 63.8 173.5b ± 2.5 561.3a ± 44.7 0.219d ± 0.01
Inorg (0.40) 6.87a ± 1.3 3.55 ± 0.3 3.32a ± 1.6 1.63 ± 1.2 523.5a ± 20.9 165.8b ± 17.1 246.2c ± 1.8 0.303b ± 0.01
Org (0.25) 5.00b ± 0.6 3.86 ± 0.9 1.15b ± 0.5 4.03 ± 1.8 541.1a ± 20.9 89.7c ± 5.2 585.2a ± 48.7 0.227c ± 0.01
Org (0.40) 5.06b ± 0.9 4.07 ± 0.4 0.99b ± 0.6 5.61 ± 2.5 406.0b ± 51.7 160.5b ± 6.7 606.7a ± 20.9 0.408a ± 0.01
P-value 0.02 NS 0.003 NS 0.0001 0.0001 0.0001 0.0001
a,bmeans in the same column within similar treatments bearing different superscripts are significantly different at P ≤ 0.05; NS = not significant; con = control; inorg = inorganic;
org = organic
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Original Paper Czech J. Anim. Sci., 55, 2010 (11): 505–519
responsible for lowering the cholesterol synthesis
in mature as well as immature chickens (Konjufca
et al., 1997).
Regardless of Se source and the interaction be-
tween Se level and source, the Se level of 0.25 ppm
significantly increased the plasma HDL concentra-
tion compared with the other levels (Table 6). A
decrease in plasma cholesterol is associated with an
increase in plasma HDL. Organic Se significantly
increased plasma HDL compared with the other
treatments, regardless of the Se level and the in-
teraction between Se level and source. Indeed, the
decrease in plasma cholesterol of the organic Se
group may be a reflection of the increase in plasma
HDL. The interaction between Se level and source
significantly affected HDL that was increased due
to supplementation of 0.25 ppm of the inorganic
and organic Se source as well as the high dosage of
organic Se (0.40 ppm).
Yolk selenium
Table 6 shows the effect of Se level and/or source
on yolk selenium content. The increasing dietary
Se level significantly increased the yolk selenium
content linearly. The increases were 6.7 and 70.3%
due to diets containing the medium (0.25) and the
high (0.40 ppm) level of Se, respectively. The in-
clusion of inorganic and organic Se significantly
increased the yolk selenium content compared with
that in hens fed the control diet. However, hens fed
organic Se deposited significantly more Se in yolks
than those fed the inorganic source. This result
indicated that organic Se was more potent than
the inorganic source. Payne et al. (2005), Skřivan et
al. (2006) and Leeson et al. (2008) reported similar
results. The interaction results indicated that all
supplemented levels and both sources significantly
increased yolk Se content compared to the control
group. Moreover, there was a linear increase within
each source with increasing Se level. Furthermore,
both levels of organic Se had greater values than the
corresponding levels of inorganic source.
Research to produce Se enriched eggs for human
health benefits shows that organic Se supplemen-
tation (e.g. selenomethionine or Se-yeast) from
0.1 mg to 0.5 ppm increases the concentration of
Se in whole egg from ~ 0.1 to 0.4 mg Se/kg (Paton
et al., 2002) and in other animal tissues (Bobček et
al., 2004). Payne et al. (2005), Utterback et al. (2005)
and Skřivan et al. (2006) stated that the use of Se
yeast in laying hen diets was very effective from
the aspect of increasing the Se content of eggs. As
a result of dietary Se supplementation, the Se con-
centration in egg yolk was significantly increased
(Surai, 2006) included that in the albumen and
yolk (Gajčević et al., 2009). The reported Se yeast
(selenomethionine) improved product quality (re-
duced carcass drip loss, Se enrichment of meat and
eggs) and decreased intensity of lipid peroxidation
in yolks as shown by thiobarbituric acid reactive
substances (Gajčević et al., 2009) may be due to a
significant increase in GSH-Px activity in the blood
of hens (Gajčević et al., 2009). Paton et al. (2002)
concluded that a possible reason for the elevated
level of Se in yolk, albumen and egg contents after
supplementation of dietary Se-yeast can be due to
the fact that hens have additional metabolic path-
ways by which Se is transferred into the egg. For
example, increasing Se level in the egg albumen
of hens fed Se-yeast may be due to the incorpora-
tion of greater amounts of Se as selenomethionine
during albumen synthesis, selenomethionine could
replace methionine, thereby providing additional
Se. Surai (2006) reported that the Se-enriched quail
eggs (865.2 ng/g Se/egg yolk DM) could supply 50%
of the recommended daily allowance (RDA) of Se.
Previous studies showed that the production of Se-
enriched chicken eggs were a valuable option for
improving the Se status of the general population
in various countries (Yaroshenko et al., 2003). This
technology was successfully applied commercially
and Se-enriched eggs found their way to the super-
market shelves in more than 25 countries world-
wide (Surai, 2006). In addition, two eggs from the
group fed a diet containing 0.40 ppm of Se could
supply 100% of RDA according FAO/WHO (2002)
requirements.
Histopathological study
The administration of various levels of Se in
different forms, organic or inorganic ones, led to
nearly similar hepatic as well as splenic changes of
the treated chickens but with dose dependent ef-
fects that were smaller or milder in the low levels of
especially organic forms. The hepatic changes in se-
vere cases were characterized by fatty vacuolations
with some variable degrees that may be advanced
and somewhat serious and may led to the necrosis
of hepatic tissue in the case of administration at
high levels (Figures 1, 2, 3, 4 and 5).
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Czech J. Anim. Sci., 55, 2010 (11): 505–519 Original Paper
Figure 1. Liver of a control chicken shows normal hepato-
cytic acini (arrows); H and EX400
Figure 2. Liver of a chicken treated with low levels of
inorganic selenium shows one focus of severe hepatocytic
fatty vacuolations (asterisk) surrounded by mild or less
degenerated hepatocytic acini (arrows); H and EX250
Figure 3. Liver of a chicken treated with high levels of inorganic
selenium shows an area of severe fatty vacuolations (asterisk)
surrounded by either small hepatocytic fatty vacuolations
or necrosis (thick arrow) and another area of lymphocytic
infiltration (thin arrow); H and EX250
Figure 4. Liver of a chicken treated with low levels of organic
selenium shows an advanced degree of fatty vacuolations in
excess numbers of hepatocytic (arrows); H and EX400
Figure 5. Liver of a chicken treated with high levels of organic
selenium shows diffuse and severe sharply edged fatty
vacuolations (arrows); H and EX400
Figure 6. Spleen of a control chicken: normal splenic tissue
with small-sized germinal centres (arrows) surrounded by
various numbers of small lymphocytes; H and EX250
The spleen of the control group showed a nor-
mal histological structure where some small-sized
germinal centres appeared normally surrounded by
variable numbers of small lymphocytes (Figure 6).
On the other hand, microscopic splenic changes
were detected due to treatment with both levels and
sources of selenium (Figures 7, 8. 9 and 10).
The microscopic changes in the small intestine
were variable from part to another and from the ad-
ministered form to another. e duodenal mucosa
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Original Paper Czech J. Anim. Sci., 55, 2010 (11): 505–519
Figure 7. Spleen of a chicken treated with low levels of
inorganic selenium: small-sized follicular arterioles (arrow)
surrounded by areas of hyperplasia and congestion (asterisk);
H and EX400
Figure 8. Spleen of a chicken treated with high levels of
inorganic selenium: area of severe congestion (asterisk),
medium-sized follicular artery (arrow) surrounded by an
excess of mature small lymphocytes H and EX400
Figure 9. Spleen of a chicken treated with low levels of organic
selenium shows hyperplastic splenic tissue with an excess
of newly formed hyperplastic germinal centres (arrows); H
and EX400
Figure 10. Spleen of a chicken treated with high levels of
organic selenium shows well formed lymphoid follicles
(asterisk) and expanded germinal centre (artery); H and
EX400
Figure 11. Intestine of a control chicken shows the normal
duodenal wall with normal crypts of intestinal glands (arrows);
H and EX250
Figure 12. Duodenum of a chicken treated with a high
level of inorganic selenium shows vacuolar and hydropic
degeneration of the epithelial cells lining the intestinal crypts
(arrows); H and EX400
appeared to be affected only by the high levels of treat-
ment with the inorganic form of Se. It was noticeable
that the intestinal mucosa of the ileum was affected
by administration of the high levels of Se. e micro-
scopic ileal changes were similarly and obviously seen
at both high levels of organic and inorganic forms
of Se but with somewhat small differences in their
degrees (Figures 11, 12, 13, 14 and 15).
Although the nutritional supplements of Se are
beneficial for feed performance and digestion, the
517
Czech J. Anim. Sci., 55, 2010 (11): 505–519 Original Paper
high levels of administration of especially inorgan-
ic forms may lead to some adverse effects on the
liver functions as well as the absorption and FCR
in treated chickens.
CONCLUSIONS
It is possible to produce Se enriched eggs of
crossbred breeding hens by feeding a diet supple-
mented with organic Se at a medium (0.25) and
high (0.40 ppm) level with expected improvement
in the consumer health benefit. In addition, organic
Se improved the productive and reproductive per-
formance of laying hens, decreased the cholesterol
concentration, improved the tibia mineralization
and was less toxic than the inorganic form when
the histopathology of liver, spleen and intestine
was considered. Furthermore, the level and source
of Se in layer diets decreased total plasma choles-
terol. Moreover, Se increased percentage of Ca and
P in tibia compared to that in hens fed the control
diet. However, the medium level (0.25 ppm) of or-
ganic Se was adequate and can be recommended
to enrich eggs with less harmful effects on tissues
than the high level (0.40 ppm).
REFERENCES
Abaza M. (2002): Immune system and some physiologi-
cal aspects in Japanese quail affected by antioxidants.
Egyptian Poultry Science Journal, 22, 259–276.
Abd-El-Latif F.S.A., El-Ghamry A.A., El-yamany A.T.
(2004): Effect of using zinc, selenium and vitamin E
supplemen-tation on performance and metabolic re-
sponses of growing Japanese quail fed diets contami-
nated with ochratoxin. Egyptian Poultr y Science
Journal, 24, 447–463.
Association of Official Analytical Chemists (1995): Of-
ficial Methods of Analysis. 16th ed. AOAC, Arlington,
USA.
Figure 13. Ileum of a control chicken shows normal thickened
villi with lymphocytic elements (asterisk); H and E. X160
Figure 14. Ileum of a chicken treated with high levels of
inorganic selenium shows an excess of mononuclear cell
infiltration and aggregation (asterisk) in between degenerated
and necrotic intestinal glands (arrows); H and E X250
Figure 15. Ileum of a chicken treated with high levels of
organic selenium shows periglandular oedema and glandular
atrophy (arrows); H and E X250
518
Original Paper Czech J. Anim. Sci., 55, 2010 (11): 505–519
Attia Y.A., Burke W.H., Yamani K.A., Jensen L.S. (1995):
Energy allotments and performance of broiler breeders.
2- Females. Poultry Science, 74, 261–270.
Attia Y.A., Abd-El-Hamid A.E., Abd El-Ghany F.A., Ha-
biba H.I. (2006): Effect of oil source and antioxidant
supplementation on growth performance and meat
quality of Japanese quail males. In: Proceeding of XII.
European Poultry Conference. Verona, Italy, 10–14
September. Abstract: Wolds Poultry Journal, 62, 405.
Bancroft J.D., Stevens A. (1990): eory and Practice of
Histological Technique. 3rd ed. New York, USA.
Black C.A. (1982): Method of soil analysis. Soil Science
of America, Inc. Published Matison Wisconsin, USA.
Bobček B., Lahučký R., Mrázová J., Bobček R., Novotná
K., Vašiček D. (2004): Effects of dietary organic sele-
nium supplementation on selenium content, antioxida-
tive status of muscles and meat quality of pigs. Czech
Journal Animal Science, 49, 411–417.
Carter T.C. (1975): The hen’s egg. Estimation of shell
superficial area and egg volume using measure-
ments of fresh egg weight and shell length and breadth
alone or in combination. British Poultry Science, 16,
541–543.
Cottenie A., Verloo M., Kaikan L., Vlghe G., Comerlynch
R. (1982): Chemical analysis of plants and soils. Lab,
Anal Agrochem. State University, Ghent, Belgium.
EL-Sebei A. (2000): Influence of selenium and vitamin E
as antioxidants on immune system and some physio-
logical aspects in broiler chickens. Egyptian Poultry
Science Journal, 20, 1065–1082.
FAO/WHO (2002): Selenium. In: Human Vitamin and
Mineral Requirements. Report of a Joint FAO/WHO
Expert Consulation. FAO, Rome, Italy, 235–255.
Folch J., Lees M., Sloane-Slanley G.S. (1957): A simple
method for the isolation and purification of total lipids
from animal tissues. Journal of Biological Chemistry,
226, 497–509.
Funk E.M. (1948): e relation of yolk index determined
in natural position to the yolk index as determined
after separating the yolk from the albumen. Poultry
Science, 27, 367.
Gajčević Z., Kralik G., Has-Schön Elizabeta, Pavić V.
(2009): Effects of organic selenium supplemented to
layer diet on table egg freshness and selenium content.
Italian Journal Animal Science 8, 189–199.
Ganpule S.P., Manjunatha B.P. (2003): Antioxidant nutri-
tion starts with breeders. Feed Mix 11, 14–16.
Hallberg L., Rossander-Hulthen L. (1993): Factors influ-
encing the bioavailability of iron in man. In: Schlemmer
U. (ed.): Bioavailability ‘93-Nutritional, Chemical and
Food Processing Implications of Nutrient Availability.
Ettlingen, Germany, 23–32.
Haugh R.R. (1937): e haugh units for measuring egg
quality. US Egg and Poultry Magazine, 43, 552–555.
Jiakui L., Xiaolong W. (2004): Effect of dietary organic
versus inorganic selenium in laying hens on the pro-
ductivity, selenium distribution in egg and selenium
content in blood, liver and kidney. Journal of Trace
Elements in Medicine and Biology, 18, 65–68.
Konjufca V.H., Pesti G.M., Bakalli R.I. (1997): Modulation
of cholesterol levels in broiler meat by dietary garlic
and copper. Poultry Science, 76, 1264–1274.
Kucharzewski M., Braziewicz J., Majewska U., Gozdz S.
(2003): Copper, Zinc and Selenium in whole blood and
thyroid tissue of people with various thyroid diseases.
Biological Trace Element Research, 93, 9–18.
Leeson S., Namkung H., Caston L., Durosoy S., Schlegel
P. (2008): Comparison of selenium levels and sources
and dietary fat quality in diets for broiler breeders and
layer hens. Poultry Science, 87, 2605–2612.
Ljubic B., Milinkovic-Tur S., Pirsljin J., Zdelar-tuk M.,
Filipovic N. (2006): Effect of organic selenium food
supplementation and fasting on adipose tissue lipid
concentration and lipoprotein lipase activity in broiler
chickens. In: Proceeding of European Poultry Confer-
ence. Verona, Italy.
NCR (1994): National Research Council. Nutrient re-
quirements of poultry. 9th ed. National Academy Press.
Washington, USA.
Paton N.D., Cantor A.H., Pescatore A.J., Ford M.J., Smith
C.A. (2002): e effect of dietary selenium source and
level on the uptake of selenium by developing chick
embryos. Poultry Science, 81, 1548–1554.
Payne R.L, Lavergne T.K., Southern L.L. (2005): Effect of
inorganic versus organic selenium on hen production
and egg selenium concentration. Poultry Science, 84,
232–237.
Ramanoff A.I., Ramanoff A.J. (1949): e Avian Egg. John
Wiley and Sons, Inc. New York, USA.
SAS Institute (1990): SAS/STAT User’s Guide: Statistics.
Version 6, Cary, NC, USA.
Schutze N., Fritsche J., Ebert-Dumig R., Schneider D.,
Kohrle J., Andreesen R., Kreutz M., Jkob F. (1999): e
selenoprotein thioredoxin reductase is expressed in
peripheral blood monocytes and THP1 human myeloid
leukemia cells-regulation by 1.25-dihydroxyvitamin D3
and selenite. Biofactors, 10, 329–338.
Ševčíková S., Skřivan M., Dlouhá G., Koucký M. (2006):
e effect of selenium source on the performance and
meat quality of broiler chickens. Czech Journal of
Animal Science, 51, 449–457.
Skřivan M., Simane J., Dlouhá G., Doucha J. (2006): Effect
of dietary sodium selenite, Se-enriched yeast and Se-
enriched Chlorella on egg Se concentration, physical
519
Czech J. Anim. Sci., 55, 2010 (11): 505–519 Original Paper
parameters of eggs and laying hen production. Czech
Journal of Animal Science, 51, 163–167.
Surai P.F. (2000): Effect of selenium and vitamin E content
of the maternal diet on the antioxidant system of the
yolk and the developing chick. British Poultry Science,
41, 235–243.
Surai P.F. (2006): Selenium in Nutrition and health. Not-
tingham University Press, Nottingham, UK.
Utterback P.L., Parasons C.M., Yoon I., Butler J. (2005):
Effect of supplementing selenium yeast in diets of lay-
ing hens on egg selenium content. Poultry Science, 84,
1899–1901.
Yaroshenko F.A., Dvorska J.E., Surai P.F., Sparks N.H.C.
(2003): Selenium-enriched eggs as a source of selenium
for human consumption. Applied Biotechnology, Food
Science and Policy, 1, 13–23.
Zachara B.A., Pawluk H., Bloch-Boguslawska E., Sliwka
K.M., Korenkiewicz J., Skok Z., Ryc K. (2001): Tissue
level, distribution, and total body selenium content in
healthy and diseased humans in Poland. Archives of
Environmental Health, 56,461–466.
Received: 2009–07–07
Accepted after corrections: 2010–01–06
Corresponding Author
Youssef A. Attia, Faculty of Agriculture, Damanhour University, Egypt
Tel. +0020 103 753 095, e-mail: yfat_alexu40@hotmail.com
