RESEARCH OF SELECTED PHYSICAL INDICATORS OF TABLE EGGS IN THE SMALL-SCALE BREEDINGS FROM THE ASPECT OF HEALTH SAFETY

The purpose of this study was to investigate selected indicators of the table eggs in small-scale breedings, focusing mainly on the eggshell and its contamination and damage. Our object of study was eggs, shell, damage, and contamination of table eggs. Four small-scale breedings were randomly selected in Slovakia. These breeds were alternatively with an outdoor freerange. Laying hens Dominant was bred under conditions small-scale breeds No.1, No. 2 and No. 3 in the 1 st laying cycle, and No. 4 in the 2 nd laying cycle. Egg weight was balanced in three small-scale breedings. Egg weight was significantly higher in the fourth small-scale breeding, statistically significant (p <0.05) compared to egg weight in the studied 3 smallscale breedings. Shell weight and shell thickness in the equatorial plane of the egg were balanced in three small-scale breedings and in the fourth small-scale breedings were significantly higher, statistically significant (p <0.05). The higher egg weight per breeding is related to the higher laying hens age that was in the 2 nd laying cycle compared to laying hens 3 small-scale breedings in the 1 st laying cycle. Higher eggshell weight in three farms may be related to improved conditions in breeding hygiene, as confirmed by the results of investigations into contamination and damage to table eggs. These differences may also be related to nutrition.


INTRODUCTION
Improved animal welfare is the sum of physical and mental well-being. Many factors affect the welfare of laying hens. The results obtained from research into improved living conditions may be contradictory. In this context, experts agree that a suitable approach to assessing the welfare of laying hens is to integrate the information across disciplines, using several different methodologies (Scientific Panel on Animal Health and Welfare, 2005).
The assessment of the indicators of egg external quality raised laying hens in the system of alternative environments, such as on litter, is fundamental for the promotion of this rearing system. To determine the effects of the rearing environment on the performance and welfare of hen laying, the analysis of productive parameters and egg quality and safety are examples of some measures adopted (Alves, Silva and Piedade, 2007).
According to the knowledge previously published, it is known that laying hens kept in domestic conditions (smallscale breeding) they largely preserve kinds of natural behavior, generally according to their wild ancestor (Fraser and Broom, 1990).
Laying hens have been bred for several thousand years in some properties. Domestication and selection took place. Some types of behavior originate in genetics and persist in the environment, that it requires to prepare conditions for satisfying hen laying needs. This type of behavior is known as instinct. Ethologists (scientists who specialize in animal behavior studies) explain that, in terms of motivation and ethological needs, strongly motivated behavior is largely controlled by internal factors (such as changes in hormone levels), which are available regardless of the type of outdoor environment (Duncan, 1998).
Behavior identified as important for improved welfare laying hens includes nesting, examination, perch, raking and nutritional behavior, dusting, engaging in comfortable behavior (such as over lighting, etc.) (Petherick and Rushen, 1997).
Laying hens are biologically able to adapt to environmental conditions when the environment is appealing to them. At that time, they increase interest in such an environment, which in turn increases the quality of their living conditions. The environment is engaging, increases interest, and adds to the quality of animal life. A rich and diverse environment stimulates exploratory behavior and allows pecking and raking (Knierim, 2006).
According to Baer (1998), an enriched environment has a positive impact on the physical, mental, and social wellbeing of animals, including laying hens and can improve their health. European Food Safety Authority, Panel on Animal Health and Welfare (AHAW), an independent an advisory body providing the scientific basis for European policy and legislation, based on the processing of scientific literature, it has come to the following conclusion: stabling systems differ in the possibilities for laying hens to show species-specific behavior, such as raking, dusting, exploring and selecting a suitable nest. Sufficient space must be provided for laying hens, to carry out the above-mentioned natural activities. A free-range breeding system in nature can pose a risk of laying hens and endanger their health. Layers in outdoor free-range may be exposed to wild birds, insects, and other potentially infectious agents (Scientific Panel on Animal Health and Welfare, 2005).
The laying hens may come into contact with bacteria and intestinal parasites and coccidia (McDougald, 2003; Scientific Panel on Animal Health and Welfare, 2005).
The object of social interest in the context of the welfare of laying hens, it is largely focused on farm conditions, most for breeding systems, conditions for natural behavior, and limited conditions associated with stress and mutilation. However, the impact of genetics on the welfare of laying hens is clear, with strong genetic effects on traits including immune function ( Bacteria belong to the main cause of human foodborne diseases v worldwide and infected poultry flocks are the most common cause of human infection through the storage of foods. Human salmonellosis is more often associated with the consumption of poultry and poultry products, including eggs, than with the consumption of food from other animals. All producers of table eggs, regardless of the type of breeding system, are subject to strict safety requirements (Gast, 2003 For extensive implementation, comprehensive risk reduction programs and testing of laying hens in flocks intended for the production of table eggs are attributed to a reduction in the incidence of human S. enteritidis infections (Wright et al., 2016).
Verhallen-Verhoef and Rijs (2003) reported that hygiene in breeding conditions is one of the most important factors for laying hens. If there is a large number of laying hens in a small area, it is a great problem to maintain hygiene and then the hens are exposed to a lot of stress.
Otter (2015) notes that in the conditions of the smallscale breedings there is common breeding with a freerange system, which has proved its worth. In the breeding area, it is very appropriate to provide the facilities necessary for carrying out the natural activities of the laying hens, e.g. such as perch for rest, litter material for raking, and others. Hygiene and cleanliness in the breeding environment are the basis for the good health of laying hens, but also for the laying of non-harmful eggs concerning the consumer. The application of welfare aspects is also important for laying hens under small-scale conditions. These aspects support the healthy development of laying hens and the production of quality and healthsafe table eggs.
In the Council of the European Union (2006) it was noted that table eggs are sold worldwide. On the European Union market, eggs are classified in quality class A or quality class B. Quality class A is classified for direct human consumption. On the contrary, class B eggs are marked as technical and are not intended for direct human consumption. Laying hen nutrition and post-laying egg handling are factors that play a very important role in determining the safety and quality of table eggs. The eggshell is characterized by being a natural external packing table of laying hens, the task of which is to prevent the penetration of contaminants into the internal egg content. The system of rearing, but also the type of feed administered by laying hens, affects egg composition to a very large extent.
Surai and Sparks (2001) report that there is a lack of knowledge about factors of the table egg chemical composition concerning a free-range or a range consisting of grassland.
Eggshell quality has a major economic impact on quality egg production because broken and cracked eggs mean an economic loss for farmers (Yoho et al., 2008).
The abnormalities can be observed sometimes on the egg surface, on the shell. Eggshell surface abnormalities are assessed by altered shell surface, shell dilution, increased translucence, cracks, and cracks in the eggshell. These abnormalities, changes in quality and ultrastructure have been observed in flocks of hen laying in the experiment by (Kursa et al., 2019).
The purpose of this study was to investigate selected indicators of the table eggs in small-scale breedings, focusing mainly on the eggshell and its contamination and damage.

Scientific hypothesis
Scientific hypothesis: balanced results selected indicators of table eggs in small-scale breedings, due to the small numbers of animals in breeding and outdoor free-range for carrying out natural activities.

MATERIAL AND METHODOLOGY Object of research
Our object of study was eggs, shell, damage, and contamination of table eggs. Four small-scale breedings were randomly selected in Slovakia. These breeds were alternatively with an outdoor free-range.

Rearing conditions of the laying hens
Laying hens Dominant was bred in conditions of 4 smallscale breeders in Slovakia. Breeding conditions as well as nutritional conditions were ensured in these small-scale breedings of small-scale breeds in accordance with laying hens needs. Laying hens Dominant was reared in smallscale breedings No. 1,No. 2,and No. 3 in the 1 st laying cycle, and No. 4 in the 2 nd laying cycle. Henhouse with deep litter and free-range was a breeding house for laying hens. Laying hens had the opportunity to run daily in the summer from 6:00 am to about 7:00 pm. pm and in winter until 5:00 pm. The hen house equipment consisted of a watering-place, a feeder, a nest, and perch. To lay eggs, a nest was made for them to be made by hand collection. Drinking water and feed were part of the free-range. Laying hens were fed with a conventional feed mixture intended for laying hens, which was replenished at least 2 times a day. Sometimes laying hens were fed with food from the kitchen or crushed eggshells. Drinkers and feeders were washed daily. The eggs produced were harvested once a day in the summer in the afternoon and twice a day in the winter in the morning and afternoon.
Egg samples of 80 pieces were obtained from four selected small-scale breeders, i.e. 20 eggs from each smallscale breeder. Investigation of egg samples was carried out in a laboratory at the Department of Food Hygiene and Safety.

Statistical analysis
The results in the study are presented as meanarithmetic mean (x ̅), variance range (R), which determines the difference between the minimum value (Min) and the maximum value (Max), the standard deviation (SD), and the coefficient of variation (cv, %).
Hypotheses about equality of mean values were tested using a one-factor analysis of variance (F) at significance levels α = 0.05, α = 0.01 and α = 0.001. One-factor variance analysis (ANOVA) is the simplest form of ANOVA that examines the relationship between interval and nominal variables. It tests the null hypothesis of the mean equivalence, assuming that the selections have the same variance. The null hypothesis indicates that there is no relation between the interval and the nominal variable. If the calculated statistical value F is greater than the corresponding character value that divides the statistical set of a group with the same number of Fisher-Snedecor distribution elements FI-1, n-I, the hypothesis of equality of mean values is rejected.
Scheffe's test was used at a significance level of α = 0.05 to compare the difference in the indicator between smallscale breedings. The Pearson correlation coefficient (r) reflects the relation between the two egg variable variables. The Pearson correlation coefficient (r) reflects the degree of the linear relation between the data of the two egg indicators. Its value is between -1 and +1. A +1 indicates that there is a high positive linear relationship between the two indicator data. A value of -1 means that there is a high negative linear relation, and value of 0 means that there is no linear relation between the two indicator data. The interpretation of the size of the correlation coefficient is given by Cohen (1988).
Values of correlation coefficient (r) and strength of dependence between two variables: below 0.1 trivial (simple, light), 0.1 -0.3 weak, 0.3 -0.5 medium, above 0.5 strong. It is often reported in the publications that the correlation coefficient values of 0.7 -0.9 represent a very strong relation and 0.9 -1 as an almost perfect relation between two variables. The correlation coefficient results are statistically significant at α = 0.05, α = 0.01 and α = 0.001. The SAS statistical package, version 8.2, was used to statistically evaluate the results.

RESULTS AND DISCUSSION Egg weight
Average egg weight in individual small-scale breedings is given in Figure 3. Statistically evaluation of egg weight in individual small-scale breedings is given in Table 1.  Huber-Eicher and Sebö (2001) took the view that they showed a higher weight of eggs and their egg components, which were in a negative correlation with the stocking intensity (r = -0.27, p <0.01). The authors pointed out that if laying hens produced more eggs under industrial conditions, the lower the egg weight was recorded. At the end of their investigation, the authors concluded that laying hens that were kept under organic farming conditions, they laid eggs which were generally heavier due to the lower production intensity.

Eggshell weight
Average eggshell weight in individual small-scale breedings is given in Figure 4. Statistically, evaluation of eggshell weight in individual small-scale breedings is given in Table 2.
Egg colour is also an important factor in egg production, in our case brown. Colour shell of eggs can affect consumer choice due to regional or national cultural preferences for different colours, directly affecting eggs' production (Wei and Bitgood, 1990;Joseph et al., 1999).
Thus, the determination of egg colour and eggshell strength is of importance. The average weight of eggshell was found to be either the same or relatively balanced in small-   Such contradictory aspects may also be related to ensuring that laying hens are kept in line with their needs. Therefore, in our research, we focused on characterizing the laying hens and compared them with four small-scale breeders in Slovakia with a focus on selected indicators of the table eggs. Avian eggshells are commonly used in studies focusing on bioindication and environmental monitoring (

Shell thickness in the equatorial plane of egg
The average thickness in the equatorial plane of egg in individual small-scale breedings is given in Figure 5.
Statistically evaluation of shell thickness in equatorial plane of egg is given in Table 3.
The average thickness in equatorial plane of egg was found to be either the same or relatively balanced in small-  0.31 -0.43 Note: nmultiplicity; SDstandard deviation; c vcoefficient of variation; Rvariation range as the difference between the smallest and the largest value of the data distribution; +++: statistically significant difference among group means by analysis of variance (p <0.001); +: statistically significant difference among groups by Sheffe´s test (p <0.05); -: no statistically significant difference among groups by Sheffe´s test (p >0.05).

Correlation relation between egg indicators in small-scale breedings
Correlation relation between indicators of the eggs in small scale breedings and statistically significant difference between the two variables are given in Table 4. Middle, a positive linear relation (small-scale breeding No. 1 and at the lower limit a strong positive linear relation (small-scale breeding No. 4) was found between egg weight and eggshell weight, statistically significant (p <0.05). A very strong relationship in all small-scale breedings (p <0.01, p <0.001) was found between eggshell weight and shell thickness in the equatorial plane of the egg.
Shell thickness in individual parts of the equatorial plane of the egg in small-scale breedings Average shell thickness in individual parts of the equatorial plane of the egg in small-scale breedings is given in Figure 6. A statistically significant difference between the two variables is given in Table 5. The average thickness in equatorial planes 1, 2, and 3 of the egg was found to be either the same or relatively balanced in smallscale breedings 1, No. 2, and No. 3. The measured values in the three parts of the equatorial plane of egg were largely balanced in small-scale breeding No. 4. The values of the equatorial planes of the egg in this small-scale breeding were statistically significant (p <0.05) higher compared to the values of the equatorial planes of the egg of small-scale breedings No. 1,No. 2,and No. 3. The eggshell is a natural protection for the egg, and thus it is significant to get a high value of eggshell strength (Bain, 1990).
The eggshell strength, reflecting the resistance ability to equatorial plane 1 equatorial plane 2 equatorial plane 3

Figure 6
Average shell thickness in individual parts of the equatorial plane of the egg according to small-scale breedings No. 1, 2, 3, and 4, mm. 0.31 -0.43 Note: nmultiplicity; SDstandard deviation; c vcoefficient of variation; Rvariation range as the difference between the smallest and the largest value of the data distribution; +++: statistically significant difference among group means by analysis of variance (p <0.001); +: statistically significant difference among groups by Sheffe´s test (p <0.05); -: no statistically significant difference among groups by Sheffe´s test (p >0.05). damage, can protect eggs when they are in collecting, packaging, storage, and transportation. It can be found the higher the eggshell strength, the stronger the resistance to damage. Cracked eggs can finally cause economic loss in two ways, one is that they cannot be sold at a high price, another is cracked eggs may raise the risk of bacterial contamination to intact eggs, which can even produce food quality and safety problems (

Correlation relation between shell thicknesses in individual parts of the equatorial plane of the egg according to small-scale breedings
Correlation relation between shell thickness in individual parts of the equatorial plane of the egg according to smallscale breedings and statistically significant difference between the two variables are given in Table 6.
In shell thickness between individual parts of the equatorial plane of the egg in small-scale breedings, No. 1,No. 2,No. 3,and No. 4, an almost perfect positive linear relation was found, statistically very highly significant (p <0.001).

Correlation relation between shell thicknesses in individual parts of the equatorial plane of the egg together for all small-scale breedings
Correlation relation between shell thickness in individual parts of the equatorial plane of the egg together for all small-scale breedings and statistically significant difference between the two variables is given in Table 7.
Almost perfect positive linear relation, statistically very high significant (p <0.001), was found in the shell thickness between the individual parts of the equatorial plane of the egg in all examined small-scale breedings together.

Contamination and damage of table eggs
The percentage and number of eggs with damaged egg surface but also deformed and contaminated on the eggshell are given in Table 8. Table eggs obtained from a small-scale breeder were subjected to an assessment of the hygiene aspect of the breeding environment. Table eggs can be considered as naturally packaged food. The eggshell serves to contain the egg contents. It is also the first barrier against bacterial penetration and must be free from defects in the order to optimize the safety of human consumption (Mabe et al., 2003). We found that table eggs were contaminated with blood (from 5 to 45%) and dropping (from 20 to 60%). We found sediments, pigment dots and calcium deposits on the surface of table eggs. Also table eggs from two farms had a deformed shape.
Solomon (2010) reported that the coated eggshell, it is common surface defect observed on the eggshell. There are observed additional calcium deposits or extra-cuticular coverings and possibly reflects the timing and magnitude of the stress or disturbance experienced by the flock. It is commonly observed an incidence of this defect of 1% and could be caused by the age of the laying hens, often younger flocks coming into production (Coutts and Graham, 2007). 0.99 ++ Note: S-C B -Small-scale breeding; numeric valuevalue r; +++: statistically significant difference between the two variables (p <0.001); +: statistically significant difference between the two variables (p <0.05); -: no statistically very highly significant difference between the two variables (p >0.05). Table 7 Correlation relation between shell thickness in individual parts of the equatorial plane of the egg together for all small-scale breedings and statistically significant difference between the two variables and statistically significant difference between the two variables.

Indicator of shellegg
Shell thickness in equatorial plane of egg 2 Shell thickness in equatorial plane of egg 3 Shell thickness in equatorial plane of egg 1 0.97 +++ 0.98 +++ Shell thickness in equatorial plane of egg 2 0.99 +++ Note: numeric valuevalue r; +++: statistically significant difference between the two variables (p <0.001).
These damaged table eggs, but also deformed and contaminated on the surface, are related both to internal factors and to external factors, which the farmer can influence and take measures to improve laying hens living conditions. Hincke et al. (2000) reported that there are multiple factors affecting eggshell quality like the genetics of the hen, nutrition, and management of feed intake, disease, and environment challenge, and also equipment insult. A decline in eggshell quality is detected as hens approach the end of a laying period (Mazzuco and Hester, 2005). In this way, the condition of the eggshell at the oviposition time can influence the incidence of shell breakage. An interesting insight presents Alves et al. (2007). When the laying hens are raised in conditions of greater thermal comfort, it can promote eggshell quality and decrease egg losses through cracks.
Hulzebosch (2004) states in his study that eggshell plays a very important role. It must form a good barrier against the intrusion of microorganisms into the internal egg content. Many research results confirm increased microbial contamination in alternative breeding compared to laying hens.
In alternative breeding, laying hens lay eggs more extensively outside the nest, into the litter. Such eggs show excessive contamination of their surface. Such eggs have a damaged shell, which can lead to the deterioration of the internal content of the egg and its contamination. There are two ways in which the contents of a table egg can be infected. It can be infected by an endogenous route and an exogenous route. Engelmaierová, Tůmová and Charvátová (2010) state that endogenous contamination occurs through sick laying hens, which affect the egg through the bloodstream. Exogenous contamination of table eggs is caused by microorganisms that are in the outdoor environment. Görner and Valík (2004) in the study point out that there is a large number of spores on the surface of the eggshell that are highly permeable to air. The cuticle is an outer layer whose main function is to prevent microorganisms from entering the egg. When the eggs are brought into contact with the air, the cuticle is drawn into the spores, changing its shape, which results in deformation, causing penetration of the microorganisms through the shell into the internal contents of the egg. An important protective barrier is also represented by the membrane membranes. Their fibrous structure acts as a filter.
Their protective properties are associated with the chemical action of lysozyme and ovotransferrin. Microorganisms, by means of proteolytic enzymes, disrupt the membranes and penetrate the whites. The main role of egg white is to protect the egg yolk from contamination. Gram-positive bacteria are affected by egg white due to their antimicrobial and bactericidal effects. Egg yolk that has no antimicrobial properties is the perfect breeding ground for the reproduction of microorganisms. If a high incidence of contamination has been observed on the surface of the eggshell, there is a higher risk of contaminants penetrating the egg content. Křepelka (2012) points out that contaminated eggs are a major problem in terms of consumer protection, which must be constantly eliminated. In most cases, gram-negative bacteria, e.g. Pseudomonas spp., Alcaligenes spp. Salmonella enteritidis and Escherichia coli and grampositive bacteria such as e.g. Bacillus spp. and Staphylococcus.

CONCLUSION
Table eggs from small-scale breeding are preferred by the consumer. Literary sources are poor and inconsistent in the knowledge of laying hens breeding conditions in smallscale breeding, and the quality and safety of table eggs. Because the food consumer likes table eggs from smallscale breeders, we have researched this issue. Based on the obtained and statistically evaluated results there were formulated the following conclusion: (a) The average egg weight was equalized in three smallscale breedings and the fourth small-scale breeding was significantly higher. Higher egg weight is related to the higher age of laying hens. (b) The average eggshell weight and shell thickness in the equatorial plane of the egg was balanced in three smallscale breedings and the fourth small-scale breeding was significantly higher. Higher eggshell weight may be related to improved conditions in breeding hygiene, as confirmed by the results of the investigation of contamination and damage of table eggs. These differences may also be related to nutrition.