Statistical indicators of milk consumption in Slovakia

The aim of the paper is to analyse the total milk consumption, consumption of selected types of milk in Slovakia. The consumption of fresh cheese and cottage cheese is also presented in comparison with selected types of milk in Slovakia. The paper presents data from the Statistical Office of the Slovak Republic. The data consist of milk and dairy products, cow's milk and dairy products, goat's milk, sheep's milk, drinking milk, drinking cow's milk, drinking goat's milk, fresh cheese, and cottage cheese. The analysis was carried out using basic mathematical statistics; other values of mathematical statistics were examined: skewness expression, sample variance, z - test etc. The results of the research indicated a behaviour change in consumption (an increase in the consumption of the last dairy product)


INTRODUCTION
Dairy products represent nutritionally rich foods in the diet and contain essential building nutrients necessary for life such as calcium, potassium, protein, fat, and vitamin D. They are very important in a balanced diet.Dairy products reduce the risk of osteoporosis and cardiovascular disease and are an addition to a healthy diet.Dairy products are characterised by their limited storage capacity, instability, and difficulty in storage and transport.Milk is a perishable product that requires rapid handling at a set low temperature (up to 4 °C), transport to its destination as quickly as possible and processing within 24 hours.Over time, the bacterial count increases and the metabolism of the milk intensifies.Tukker et al. (2006) pointed out that dairy products are the second most consumed food and beverages in the  Mgr.Vladimír Matušek, PhD., Institute of Statistics, Operations Research and Mathematics, Faculty of Economics and Management, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia, e-mail: vladimir.matusek@uniag.skworld.Dairy processing is also very important for the EU economy.The EU exports milk and dairy products all over the world and is the largest milk producer in the world.
Based on the results obtained, Kubicová et al. (2021) found that milk consumption in Slovakia and Hungary is very low, while in the Czech Republic and Poland, milk consumption is recorded within the range of recommended rations, i.e. it is sufficient.Looking to the future, the consumption trend described above suggests that the situation in the Slovak Republic will follow an unfavourable trend.Research has shown that Slovakia consumes the least milk and dairy products per capita compared to neighbouring V4 countries.Over the last 10 years, increased attention has been paid to the impact of dairy consumption on health.
Healthy nutrition and eating habits are the main pillars of a healthy lifestyle.The well-known Hippocratic dictum: 'let your food be your medicine' is still relevant at the beginning of the third millennium.Diet has been shown to have a significant impact on health.The European Union's fundamental objective is to achieve the highest possible level of consumer health protection and to improve the availability of healthy food.Statistics from the World Health Organisation (WHO) testify to the deteriorating health status of the Slovak population.According to them, the most common cause of mortality is incorrect eating habits (Krivánek, 2004).
Alfred Adler, an Austrian psychologist, originally addressed the idea of lifestyle around the beginning of the 20th century.From his point of view, a lifestyle was a kind of defence mechanism, a pattern of behaviour that an individual adopted at a young age.He considered it as one of the dynamic components of personality (Hayward, 2004).According to Kulčáková and Richterová (2010), lifestyle represents the way a person lives.In terms of consumer behaviour, it examines what products the consumer is interested in, the way they are used, and what the consumer thinks about them.A healthy lifestyle is primarily a set of behavioural patterns of an individual whose role is to maintain and improve their own health.When examining it, it is possible to come across the basic categories of these behaviours, which include: a regular regime, nutrition, drinking, physical activity, protective elements -obtained through the intake of a varied and balanced diet; sometimes it is necessary to supply it to the body, for example in the form of food supplements.Bakke et al. (2016) others report that consumer consumption behaviour of conventional milk in relation to skimmed milk, low-fat milk and whole milk has received attention at the beginning of the third millennium; relatively few studies have examined the consumption of unprocessed and processed liquid milk.This study aimed to analyse the consumption and preferences of fluid milk consumers in Turkey using data from a cross-sectional national survey.The results indicate that consumption of unprocessed liquid milk is positively related to household size, number of children in the family, household income and age of the female householder, and negatively related to education level.
The authors also discussed goat's milk.Zine-Eddine et al. (2018) considers goat farming in Morocco as a strategic manufacturing sector.This activity is of particular importance.Goat rearing plays an important socio-economic role for farmers and women in rural areas; for example, in 2018, the number of goats reached 5,731,000 head and 44,618 tons of goat milk was produced in the same year.However, a small amount of this milk is practically consumed in conventional form.However, a small amount of this milk is practically consumed in liquid form, after which most of the product is processed into cheese.2019) investigated the impact of dairy products on health and examined the association between dairy consumption and the risk of mortality from multiple causes.The findings show that dairy consumption is not associated with an increased risk of mortality.This study has been registered in PROSPERO as CRD42018091856.Wang et al. (2020) have also investigated the associations of milk consumption with mortality risk in a population with low milk consumption.They enrolled 18,214 participants from China over the age of 50 years.The results showed that nearly 70% of the respondents did not consume milk, 15% consumed milk no more than 3 times per week, and 15% had high milk consumption.There were 2697 deaths over 12 years, high consumption was associated with a higher risk of overall cancer mortality.In a sample of Chinese individuals with significantly lower milk consumption compared to the Western population, it was observed that moderate milk consumption is associated with a lower risk of mortality.However, high milk consumption was found to be associated with an increased risk of overall cancer mortality.

MATERIAL AND METHODS
In the research we used data obtained from the website of the Statistical Office of the Slovak Republic.Basic descriptive mathematical statistics were used to evaluate the data.The name of the Z-test is derived from the Z-score of the normal distribution.Z-tests are the most commonly used statistical tests in various scientific fields such as economics, medicine and others.Tables 1 and 2 present statistical data on the consumption of milk and selected dairy products between 2001 and 2021.We analyse milk consumption in the third millennium and compare the consumption of cow's, goat's and sheep's milk, as well as the consumption of fresh cheese and cottage cheese.

RESULTS AND DISCUSSION
Based on Tables 1 and 2, it can be observed that in recent years, Slovaks have developed a greater preference for curds and cheeses.According to the recommendations of the World Health Organisation, each of us should consume 220 kg of milk and milk products per year.In Slovakia, the average annual consumption is only 173.6 kg per person per year.It is a lower number; however, it is positive that it has been increasing over the years.Ten years ago, the consumption of milk and milk products was 20 kg lower per person per year.
Consumption of cheese and cottage cheese, for example, has risen significantly by four kilograms per person per year since 2009.The support for increasing interest in Slovak milk and dairy products has been a long-standing effort of the Dairy Fund, to which Slovak primary milk producers and processors have been contributing since its establishment in 2008.
While the interest in the consumption of milk and dairy products in Slovakia is slowly growing, the self-sufficiency of Slovakia in production, especially of raw cow's milk, is decreasing, according to dairy farmers.According to them, the reason for this is the decline of both dairy cows and entire farms, which have been unable to continue to function in the rather difficult competition with foreign producers.The latter are often at an advantage due to higher national subsidies.This is why dairy farmers and dairy processors are calling on the state, when preparing the next common agricultural policy, to also focus on support for livestock production, dairy farms and investment in processing plants.In the table 3 is statistical analyse milk consumption between 2001 and 2021.The values presented in Table 1 and Table 2 were used as baselines to compare dairy consumption in each year.Based on this, the research objective was to determine whether dairy consumption differs significantly when comparing the periods 2002-2010 and 2011-2021.
The research hypotheses were proposed based on theoretical knowledge and economic practice.In the research, we test the hypothesis: H0: The difference in dairy consumption is not statistically significant when comparing the periods 2002 -2010 and 2011 -2021.
H1: There is a statistically significant difference in dairy consumption is not statistically significant when comparing the periods 2002 -2010 and 2011 -2021.
In Table 4 is results of F-test.In Table 4 we see that the z-test value is 0.039 for 2012 -2022 and 2002 -2011 and the critical value is 0.272 at the significance level.We found that the value of the F-test is greater than the critical value, equality of variances is not rejected.
In Table 5 is results of z-test.In Table 5 we see that the z-test value is -4.57for 2012 -2022 and 2002 -2011 and the critical value is 1.64 at the significance level.We found that the value of the z-test is greater than the critical value, so we reject the null hypothesis.That is, we accept the alternative hypothesis that there is a significant difference in the milk consumption.
Figure 1 compares the consumption of milk and milk products in Slovakia and the Czech Republic.Compared to the Slovak Republic, dairy consumption is 60 per cent higher.In Slovakia, the average consumption of cow's milk is 50 litres per year, which is 11 percent less than in the Czech Republic.The consumption of milk and dairy products is incomparably lower in comparison with the Czech Republic.

CONCLUSIONS
The paper presented the consumption of milk and dairy products in the Slovak Republic over the last 20 years.Current milk consumption is 160 kg per capita per year, which is below the recommended consumption allowance of 220 kg per capita.For comparison with the Czech Republic, research has confirmed that Czech consumers consume on average up to 250 kg of milk and milk products per year, which exceeds the recommended consumption level by 30 kg.Dairy producers are adapting their production to demand, but it is important to point out the problems associated in particular with the introduction of new technologies in production, the rising cost of input investments and the growing disinterest of consumers in consuming milk and milk products.
Neves et al. (2021) and Baker et al. (2021) have considered time trends in the consumption of different types of milk (breast milk, formula milk and animal milk) among children under 2 years of age from 2000 to 2019 at the global level.The consumption of formula milk in the first 6 months of life increased in higher-middle-income countries and in East Asia and the Pacific, while it remained below 8% in Central Africa and South Asia.The consumption of animal milk among children under 6 months of age has decreased significantly in less developed African and Asian countries.

Figure 1
Figure 1 Consumption of milk and milk products (kg annual per capita averages)

Table 1
Statistical data on the consumption of milk and selected dairy products between 2002 and 2011 Source: http://datacube.statistics.sk/

Table 2
Statistical data on the consumption of milk and selected dairy products between 2012 and 2021.

Table 3
Development of milk consumption -mathematical statisticKurtosis expresses the distribution of data in a file.In Table3, only two values of kurtosis are positive, that is, only milk for drinking and cow milk for drinking had values close to the mean.Skewness expresses the skewness of the file, that is, simply whether high values or low values prevail in the file.In Table3, all skewness values are positive, that is, it is a leftskewed distribution (more smaller values and few larger ones).Sample Variance was lowest for goat and sheep milk.We will use the z -test to see if there is a significant difference in dairy consumption.The ztest is used to see if the difference between the sample means is statistically important.The name of the Z-test is derived from the Z-score of the normal distribution.According to Chen (2011), Eden and Yates (2009) z-tests are the most commonly used statistical tests in various scientific fields such as economics, medicine and others.Using the F test, we found that the research samples have a normal distribution.The variance and the mean of the population are known.We will divide the research samples into two groups: Sample A -from 2002 to 2010, and Sample B -from 2011 to 2021.