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Journal homepage: www.fia.usv.ro/fiajournal
Journal of Faculty of Food Engineering,

Ştefan cel Mare University of Suceava, Romania

Volume XVI, Issue 4 - 2017, pag. 239 - 244

THE INFLUENCE OF REGULAR AND GENETICALLY MODIFIED SOYBEANS

ON POSTNATAL DEVELOPMENT OF RATS

N. N. Omelchenko1, G. V. Dronik2, *І. А.Winkler3, М. S. Rogozynskyi1, V. А. Kucheriava1

1 Chernivtsi Faculty, National Technical University “Kharkiv Polytechnic Institute”, Chernivtsi, Ukraine
2 Bucovina State Agricultural Research Station, NAAS of Ukraine, Chernivtsi, Ukraine

3 Bucovina State Medical University, Chernivtsi, Ukraine

*Corresponding author: winkler@bsmu.edu.ua

Received 19th October 2017, accepted 21th December 2017

Abstract: Ukraine is one of the European and world leaders in soybean cultivation. According to

some estimation, 30-90 % of the crops area is used currently for cultivation of genetically modified

varieties. As modified soybean areas are expanding, the potential nutritional threats related to this

product should be thoroughly assessed.

The influence of nutrition ration consisting of 20 % of the thermo-treated genetically modified soy-

beans on postnatal development of rats has been investigated over two generations in comparison with

nutrition by regular thermo-treated beans. The number of alive and dead newborns, average number

of offspring and the survival rate has been calculated as well as general estimation of physical devel-

opment of the newborn rats was made.

The experimental results prove that the reproductive function of rats and the offspring development

are not seriously influenced by nutrition with genetically modified soybeans within the first and second

generations. No statistically reliable difference was found between the characteristic parameters of

the experimental and control groups, which remained within their regular physiological limits. How-

ever, some decrease in the suckling age rats’ number was registered in the experimental group.

Keywords: regular soybean, genetically modified soybean, rats, postnatal development, survival rate.

1. Introduction

As molecular biology, biotechnology and

gene engineering reach new advance, con-

struction of new plants varieties and cattle

breeds becomes easier and more available

for agricultural and industrial users avoid-

ing traditional selection methods and pro-

cedures. Moreover, it is quite feasible now

to construct even the genotypes that never

existed before by introducing the alien

genes into DNA of a given variety. This

way new functions or characteristics of the

variety can be obtained. Such genetically

modified organisms (GMO) are becoming

more and more popular in many fields of

medicine, agriculture, cattle breeding, food

production and processing. The widest in-

troduction of GMO in crop production is

known for soybean, maze, cotton, rape,

sugar beet, papaya, pumpkin, paprika, to-

mato, rice, potato, plum, haricot bean, al-

falfa, wheat, groundnuts, mustard, cauli-

flower and chili pepper [1, 2].

Soya is extensively used in many fields of

food production and agriculture because of

its useful merits. Soybean consists of 36-48

% of proteins, 13-27 % of oils, 17-34 % of

carbohydrates and brings other useful

components like vitamins (thiamin, ribo-

flavin, pyridoxine, folic acid, choline, vit-

amin E and C), macro- and micro elements

(K, Р, Ca, Mg, Fe, Zn, Mn and Se) and bi-

oactive compounds (phospholipids, to-

copherols, phytoestrogens and some oth-

ers) [3-5]. High nutritional values and op-

timal composition ensure wide distribution

of soybeans as a component of various

http://www.fia.usv.ro/fiajournal
mailto:winkler@bsmu.edu.ua

Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava

Volume XVI, Issue 4 – 2017

N.N. OMELCHENKO, G.V. DRONIK, І.А.WINKLER, М.S. ROGOZYNSKYI, V.А. KUCHERIAVA, An influence of

regular and genetically modified soybeans on postnatal development of rats, Food and Environment Safety, Volume XVI,

Issue 4 – 2017, pag. 239 – 244

240

foods and food additives. Soya is used in

human nutrition directly as well as soybean

oil, milk, tofu cheese and as an additive for

a wide variety of food such as chocolate

and sausage. It is reported that about 60 %

of regular food consist of some soybean

products [4].

Some gene modifications (GM) are being

made in order to achieve higher crop

productivity and better resistance of soya

against diseases, pests, herbicides, abiotic

stresses and other negative influences. First

commercial GM soya varieties have been

introduced in 1996 while according to the

estimation of International Service for the

Acquisition of Agri-Biotech Applications

[6], current crop area occupied by various

GM plants has reached 185.1 mln ha in

2016. More than 50 % of this area is occu-

pied by four cultures: soybean, cotton,

maze and rape). More than 30 countries are

involved in the GM crops cultivation while

more than 60 countries – in the consump-

tion.

Ukraine is one of world leaders and the

European leader in GM soya cultivation.

Current estimation shows that 30-90 % of

all soya crops in Ukraine is occupied by

the GM varieties [7] still remaining beyond

strict government control of the seed grain

quality and amount. This estimation has

also been proven by independent analysis

of the cattle forage and additives per-

formed in 2013-2015 [8]. Further uncon-

trolled spreading of GMO can provoke

more or less deeper ingression of the modi-

fied soya in human food.

There are still vivid discussions on possi-

ble threats and food safety of GMO. As

seen from analysis of hundreds scientific

papers dealing with this problem reviewed

in [9], there is still no doubtful evidence of

distinct negative effects of GMO or GMO-

containing food on human health. There is

still no correlation found between con-

sumption of the GMO-containing food and

digestion, kidney diseases, diabetes, can-

cer, autism, obesity and various allergy

symptoms.

On the other hand, the idea of potential

threat of genetically engineered products is

also popular and has many supporters stat-

ing that these components should be con-

sidered as dangerous as long as no indis-

putable safety evidences are found. More-

over, some primary deviations were found

in the viscera morphogenesis as a result of

nutrition with GMO components. Chronic

intoxications and some diseases have also

been reported for next generations of the

lab animals [10-18].

That is why the discussion of possible safe-

ty/unsafety of GMO is still open and re-

quires more data and evidences.

This work deals with investigation of pos-

sible influence of nutrition with traditional

and genetically modified soybeans on

postnatal development in the first and sec-

ond generations of rats.

2. Experimental

All experiments were carried out with

three generations of the Wistar line rats:

parents (F0), first (F1) and second (F2).

The source population consisted of males

and females aged 3-3.5 months. The exper-

iment lasted for 9 months. The animals

were kept in a vivarium, in the standard

plastic boxes with thermo-treated wood

shavings substrate at 20-22 0C, relative

humidity 50-60 % and under the standard

day/night regime.

All rats were divided into three groups: one

control and two experimental. All the

groups were formed by random selection

of the animals with the only account of the

body weight. Each group consisted of 12

rats: 8 females and 4 males. The control

group animals were fed according to the

standard vivarium ration. The second

group animals were fed with the food con-

taining 20 % of thermo-treated soybeans of

variety Chernivetska 9. Unlikely to the tra-

ditional procedure, the soybeans were

Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava

Volume XVI, Issue 4 – 2017

N.N. OMELCHENKO, G.V. DRONIK, І.А.WINKLER, М.S. ROGOZYNSKYI, V.А. KUCHERIAVA, An influence of

regular and genetically modified soybeans on postnatal development of rats, Food and Environment Safety, Volume XVI,

Issue 4 – 2017, pag. 239 – 244

241

steeped in water during 12 hours then

boiled during 60 minutes and finally dried

at 115-125 0C. The third group animals

were fed using the above procedure but

with the genetically engineered soya

Roundup Ready, line GTS 40-3-2: 20 % of

their ration consisted of this GM material.

All rations were optimized according to the

standard norms and requirements and pro-

vided to the respective groups throughout

the entire experimental period.

The reproduction capacity characteristics

and some postnatal development data dur-

ing first two months of life were investi-

gated in all the groups. Following postnatal

development characteristics were con-

trolled: ratio between alive and dead

youngs, average offspring value, visual

estimation of general physical develop-

ment, body weight and survival rate. Fur-

ther development of the rats was assessed

by the auricle opening time, body hair

eruption time, teething and eyes opening

time.

Male and female rats were combined for

the fertilization with ratio 2:1 for a single

estrous period (5 days). The baby rats were

put apart from their mothers on the 30th

day and provided with the same adult ra-

tion. Further experiments were carried out

with the descendants obtained from differ-

ent mothers in order to randomize the in-

vestigation and avoid incest.

3. Results and discussion

Investigation of reproductive capaci-

ty/fertility is one of integral indicators for

the hygienic evaluation of various poten-

tially unsafe or threatening processes or

phenomena. This capacity is very sensitive

function that can be disordered under in-

fluence of many unfavorable impacts and

effects. On the other hand, evaluation of

reproductive capacity is very labor and

time demanding procedure, which puts ob-

stacles on wide introduction of this method

to the food and food additives safety analy-

sis. This approach is recommended only

for an optional usage in case its necessity

is obvious. Even after more than 20 years

long efforts in investigation of possible

adverse effects of GMO on the human and

cattle health, there is still not enough evi-

dence to support or reject this assumption.

That is why results of investigation of re-

productive capacity should shed more light

on this problem.

It has been found that the pregnancy time

was unchanged in both experimental

groups comparing to the value of the con-

trol group. All baby rats were delivered

after 21-23 days of pregnancy.

An average offspring number was 9.4 ± 2.4

individuals in the control group F1 genera-

tion; 8.0 ± 2.1 individuals – in the second

group and 8.5 ± 1.5 individuals in the third

group. No deviations were found in physi-

cal development of young rats from all the

groups [19]: the auricle opening time was

3-4 days; body hair erupted after 5-6 days;

teething time was 9-10 days and eyes

opening time was 15-16 days. No visible

mutilations were registered.

Survival rate of the F1 rats was quite high

in all the groups (see Table 1). It is easy to

see that the corresponding values for dif-

ferent groups are rather close. Death rate

for the first five days was 5.3 % (control

group), 6.2 % (second group) and 7.3 %

(third group). Same rates for the next 25

days period were correspondingly 4.2 %,

8.3 % and 12.7 %.

Gender ratio in the control group was bal-

anced while insignificant prevalence of the

young males was registered in both exper-

imental groups.

It has been shown [20] that physical condi-

tion of the female rats is the key factor

governing reproductive capacity of the ro-

dent. Fat deposits and body weight are

growing during the pregnancy time to store

enough metabolic resource to be used for

lactation.

Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava

Volume XVI, Issue 4 – 2017

N.N. OMELCHENKO, G.V. DRONIK, І.А.WINKLER, М.S. ROGOZYNSKYI, V.А. KUCHERIAVA, An influence of

regular and genetically modified soybeans on postnatal development of rats, Food and Environment Safety, Volume XVI,

Issue 4 – 2017, pag. 239 – 244

242

Table 1.

Survival rate indexes for the F1 offspring

Group
Number of baby rats,

individuals

First 5 days survival rate Next 25 days survival rate

Individuals % Individuals %

І 75 71 94.7 68 95.8

ІІ 64 60 93.8 55 91.7

ІІІ 68 63 92.7 55 87.3

Gaining body weight during pregnancy is

the key factor for the successful pregnancy

ratio, fertility, offspring gender balance,

baby rats’ survival ratio, the rate of their

development and overall reproductive ca-

pacity in the population. Insufficiently fed

females bring more male babies. This gen-

der regulation occurs due to the embryonic

mortality and results in lowering of the fe-

male number in the population, which de-

creases its reproductive potential.

It has been found that the body weight in-

crease rate stayed within normal values for

all three groups over early postnatal time

and mixed feeding period. No difference

has been found between the first genera-

tion of rats raised under traditional and ge-

netically modified soybean feeding. All

indexes of their development didn’t exceed

corresponding normal values.

Survival rate parameters remained high for

the F2 generation animals as well (see Ta-

ble 2). For instance, the initial five days

death percentage was 6.7 % (control

group); 6.1 % (second group) and 8.9 %

(third group) while the next 25 days death

percentages were correspondingly 7.1 %,

8.1 % and 16. 4 %.

Table 2.

Survival rate indexes for the F2 offspring

Group
Number of baby

rats, individuals

First 5 days survival rate Next 25 days survival rate

Individuals % Individuals %

І 60 56 93.3 52 92.9

ІІ 66 62 93.9 57 91.9

ІІІ 67 61 91.1 51 83.6

It is seen that postnatal death rate for the

third group F2 animals was somewhat

higher than that in the second and control

group. This effect can be caused by a long

term influence of phytoestrogens and other

bioactive compounds coming to the organ-

ism from GM soybeans. Normal embryo-

nal development can be disturbed by these

compounds resulting in the birth of debili-

tated or unviable individuals. This effect is

especially dangerous for the reproductive

hormones balance both for males and fe-

males [21] and, according, to some recent

data affects primarily normal functioning

of hypothalamus and hypophysis through

the regime of growth hormone generation

[22]. All adverse effects of phytoestrogens

disappear after stopping of feeding with

GM materials.

An average F2 offspring number in the

control group was 7.5 ± 1.7 individuals; in

the second group – 8.3 ± 1.8 and in the

third group – 8.4 ± 1.9. As seen from these

data, the F2 offspring number in the con-

trol group was somewhat lower than that in

the other groups but these values remained

comparable and within the physiological

norms.

No relevant difference has been found be-

tween the groups in the F1 baby rats’

weight. This parameters also stayed within

physiological norms for the corresponding

age (m (group I) = 5.7 ± 0.54 g; m (II) =

5.2 ± 0.49 g; m (III) = 5.3 ± 0.52 g). Same

Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava

Volume XVI, Issue 4 – 2017

N.N. OMELCHENKO, G.V. DRONIK, І.А.WINKLER, М.S. ROGOZYNSKYI, V.А. KUCHERIAVA, An influence of

regular and genetically modified soybeans on postnatal development of rats, Food and Environment Safety, Volume XVI,

Issue 4 – 2017, pag. 239 – 244

243

pattern was registered also for the F2 ani-

mals’ weight after 28 days (see Fig. 1).

No statistically relevant disturbances in the

offspring gender balance have been regis-

tered. Besides, overall physical develop-

ment of all F2 baby rats was found satis-

factory: the auricle opening time was 3-4

days; body hair eruption time was 4-6

days; teething time was 9-10 days and eyes

opening time was 15-17 days. All these

values also lay within corresponding phys-

iological norms [19]. No difference was

found between animals’ development for

the control and experimental groups.

0 5 10 15 20 25 30

age, day

m
a
s
s
,

control

II group

III group

Fig. 1. Body weight dynamics for the F2 baby rats

4. Conclusions

No relevant evidence of negative or posi-

tive effect of feeding the rats with a food

containing 20 % of thermo-treated genet-

ically modified soya on reproductive ca-

pacity and physical conditions of the rats

were found. All the animals showed simi-

lar rates and indexes of physical shape and

postnatal development parameters despite

different feeding regimes over the experi-

mental and control groups. The parameters

remained within physiological norms with

the exception of some decrease in the suck-

ling age rats number in the population fed

with the genetically engineered soybean

ration.

5. References

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Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava

Volume XVI, Issue 4 – 2017

N.N. OMELCHENKO, G.V. DRONIK, І.А.WINKLER, М.S. ROGOZYNSKYI, V.А. KUCHERIAVA, An influence of

regular and genetically modified soybeans on postnatal development of rats, Food and Environment Safety, Volume XVI,

Issue 4 – 2017, pag. 239 – 244

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1. Introduction
It is seen that postnatal death rate for the third group F2 animals was somewhat higher than that in the second and control group. This effect can be caused by a long term influence of phytoestrogens and other bioactive compounds coming to the organis...
An average F2 offspring number in the control group was 7.5 ± 1.7 individuals; in the second group – 8.3 ± 1.8 and in the third group – 8.4 ± 1.9. As seen from these data, the F2 offspring number in the control group was somewhat lower than that in th...
No relevant difference has been found between the groups in the F1 baby rats’ weight. This parameters also stayed within physiological norms for the corresponding age (m (group I) = 5.7 ± 0.54 g; m (II) = 5.2 ± 0.49 g; m (III) = 5.3 ± 0.52 g). Same pa...
No statistically relevant disturbances in the offspring gender balance have been registered. Besides, overall physical development of all F2 baby rats was found satisfactory: the auricle opening time was 3-4 days; body hair eruption time was 4-6 days;...
Fig. 1. Body weight dynamics for the F2 baby rats
4. Conclusions