Preface

When discussing animal species, it is fundamental to consider the quantity and size of the usable products that come from them. Domestication of the goat began at the border of the Neolithic Period and the Stone Age, about 10,000 years ago. The goat has become a co-ani‐ mal in the past few years but is mainly kept for its meat, milk and hair, as well as fur pro‐ duction. Accordingly, we use a wide variety of "products". Goats are bred in large numbers of varieties and breeds, and are kept in a wide range of environmental conditions on Earth. Different breeds are also crossed to reach specific goals.

The number of goats kept in the world is slightly smaller than that of sheep (about 1.2 bil‐ lion heads), but still, more than 1 billion heads offer meat and milk for almost 3 billion peo‐ ple. According to the data of FAOSTAT (2018), 1,002,810,368 heads of goats were kept in the world in 2016, from which more than half were produced in *Asia* (55.45% – 556,019,726 heads). *Africa* was ranked in second place (38.66% – 387,667,193 heads), followed by the *Americas* (3.78% – 37,866,521 heads), *Europe* (1.69% – 16,965,650 heads) and *Oceania* (0.34% – 4,291,278 heads).

*China* was the biggest (14.87% – 149,091,143 heads) goat-keeper country (as in the case of sheep) in 2016, and the following countries were also part of the top 10 goat-keeper coun‐ tries: *India* (13.35% – 133,874,637 heads), *Nigeria* (7.37% – 73,879,561 heads), *Pakistan* (7.01% – 70,300,000 heads), *Bangladesh* (5.59% – 56,083,240 heads), *Sudan* (3.12% – 31,325,105 heads), *Ethiopia* (3.01% – 30,200,226 heads), *Kenya* (2.67% – 26,745,916 heads), *Mongolia* (2.55% – 25,574,861 heads) and *Mali* (2.21% – 22,141,497 heads).

Research and development carried out so far and summarised under "goat science" has an enormous number of fields covering large or small results, some of which have been select‐ ed for this book. They concern a wide range of knowledge and provide good summaries of results reached in different fields of goat science.

#### **Genetics**

The genetic characteristics of goats determine the reproductive and production characteris‐ tics of the individuals and varieties, the quality of the products (milk and meat composition, hair length and fines, etc.), as well as the environment in which varieties can be successfully bred. Several publications have already reported on the inheritability and repeatability of each quality trait. Recently, research has increasingly focused on the appearance of certain attributes of molecular, DNA and gene levels, and their level of applicability.

In the first chapter the utility of cross-reactive regents to understand the molecular genetics and genome biology of the goat and the importance of dietary modulators as avenues for immune modulation and maintenance of homeostasis in the goat are the targets of study. Several kinds of treatment (such as added probiotics, mushroom extracts, etc.) are studied and their effects are summarised in this chapter.

To meet the increasing demands for goat's milk and meat products, production and repro‐ duction efficiency has to be improved. The need for these products continues throughout the world, and in the traditional system of production may offer only seasonal supplies. The utilisation of new reproduction methods and reproductive biotechnological technics is more and more important in the case of females but is also important in male goats too. In the seventh chapter the main knowledge regarding oestrus synchronisation and manipulation,

Preface XI

Goat's milk is not as popular as cow's milk among consumers; however, goat's milk has several benefits and nutritional values, which are missing from cow's milk. Over the last couple of decades the rearing of dairy goats became an economic activity, which is rather concentrated in certain regions and countries of the world. In addition, goat's milk and milk products have become rather significant parts of foods for more than 1 billion people.

According to the FAOSTAT (2018) data, 15,262,116 tons of goat's milk was produced in the world in 2016, from which *Asia* had the biggest share (55.70% – 8,043,749 tons), followed by *Africa* (25.74% – 3,928,719 tons), *Europe* (16.63% – 2,537,787 tons), the *Americas* (4.93% –

Studying the 10 biggest goat's milk-producing countries (FAOSTAT, 2018), the following or‐ der was determined for the year 2016: *India* (24.69% – 3,767,866 tons), *Sudan* (7.24% – 1,104,620 tons), *Bangladesh* (6.89% – 1,051,493 tons), *Pakistan* (5,40% – 824,098 tons), *France* (3.95% – 603,040 tons), *South Sudan* (3.06% – 466,672 tons), *Spain* (2.69% – 410,977 tons), *Greece* (2.52% –

In 2016 (FAOSTAT, 2018) there were 202,004,520 milking goats registered, from which the biggest herd was milked in *Asia* (52.11% – 105,619,554 heads), followed by *Africa* (39.60% – 80,272,622 heads), *Europe* (4.32% – 8,748,735 heads), the *Americas* (3.97% – 8,047,754 heads)

Concerning the order of the countries having milking goats (FAOSTAT, 2018) the following order could be observed in the year 2016: *India* (14.40% – 29,180,066 heads), *Bangladesh* (14.01% – 28,400,285 heads), *Sudan* (9.31% – 18,878,691 heads), *Mali* (8.19% – 16,606,239 heads), *Pakistan* (4.05% – 8,212,610 heads), *Indonesia* (3.79% – 7,686,690 heads), *South Sudan* (3.43% – 6,943,044 heads), *Somalia* (3.12% – 6,327,494 heads), *Niger* (2.72% – 5,514,053 heads)

The composition of the goat's milk produced is the target of various scientific studies.

The protein content of goat's milk is one of the most important values in its utilisation. The main groups of proteins are the caseins, whey proteins, and milk fat globule membranes. De‐ termination of these components in detail and the possible experimental and industrial meth‐ ods, as well as the equipment used, is the target of much research and development work.

One of the important animal health problems in milk production is mastitis (udder inflam‐ mation) and in relation to this are the somatic cell counts of various milk items. Mastitis could have a deep impact on protein composition and the processability of the milk. The progress of proteomics applications and an overview of developments in the field of goat's

384,903 tons), *Somalia* (2.47% – 377,733 tons) and *Indonesia* ( 2.46% – 375,453 tons).

artificial insemination, and the use of the male effect are summarised.

**Milk production**

751,823 tons) and *Oceania* (0.00 – 39 tons).

and *Oceania* (0.00% – 1351 heads).

and *Turkey* (2.31% – 4,687,028 heads).

milk are provided in the eighth chapter of this book.

In South Africa, many goat breeds are bred for hair, meat and milk production. The genetic development of imported and indigenous varieties has been going on for decades, but un‐ fortunately the development of breeding stock is historically limited. The limited degree of individual marking and production control and the participation in development pro‐ grammes, except angora goats, resulted in poor genetic development.

Molecular genetic research has opened up a new opportunity to define certain properties and to preserve the genetic resources represented by these goat varieties. The results of this research are summarised in the second chapter.

#### **Nutrition**

It is well known that goats are mainly "browsers", preferring the leaves of trees, bushes and shrubs instead of grazing pastures. In general, if they are allowed to follow their genetic determinations, 80% of goats feed from browsing and only 20% feed from grazing. This mainly happens in extensive goat farming, but in intensive dairy goat production systems, goat nutrition is very similar to that of dairy cattle to reach as high a milk production as possible – in addition to the higher reproduction characteristics.

Based on genetic determinations a question arises: do goats have different passage rates compared to other ruminants? Several factors affect rumen fill levels and the rates of pas‐ sage through the rumen. These are the animal species and feeding types, stage of reproduc‐ tive cycle and physiological state, ambient temperature, level of nutrition and feed intake, forage-to-concentrate ratio in the diet, practical size and functional gravity. Taking all these effects into consideration the authors of the third chapter state that despite several differen‐ ces, goats are not different from other ruminants with respect to passage rate because it is largely due to dietary quality.

Many kinds of mineral deficiency can occur in goats depending on the pastures they graze and the feed they are supplied with. Among others, iodine deficiency could cause several problems in goats, and its symptoms are recognised rather easily. These symptoms and pos‐ sible and necessary treatments are summarised in the fourth chapter.

#### **Reproduction**

The reproduction of goats is quite well known, and most goat keepers are well versed in the details. Goats kept in traditional extensive systems have one oestrus season and one kidding season during the year, which is simple to handle compared to those animals being kept under intensive indoor systems. To be able to modify the reproduction traits of goats it is useful to summarise the most important details from folliculogenesis via physiology and endocrinology of the oestrual cycle, the methods of oestrus synchronisation, artificial in‐ semination and use of the male effect in oestrus induction. An overview of this knowledge can be read in the fifth chapter.

There are many effects on the reproductive performance of male animals. Among others, in‐ sulin-like factor 3 (INSL3) is essential for testis descent during foetal development, and has been implicated in testicular and sperm functions in adult males. In the sixth chapter, up-todate knowledge of the development and impact of these factors has been summarised.

To meet the increasing demands for goat's milk and meat products, production and repro‐ duction efficiency has to be improved. The need for these products continues throughout the world, and in the traditional system of production may offer only seasonal supplies. The utilisation of new reproduction methods and reproductive biotechnological technics is more and more important in the case of females but is also important in male goats too. In the seventh chapter the main knowledge regarding oestrus synchronisation and manipulation, artificial insemination, and the use of the male effect are summarised.

#### **Milk production**

Several kinds of treatment (such as added probiotics, mushroom extracts, etc.) are studied

In South Africa, many goat breeds are bred for hair, meat and milk production. The genetic development of imported and indigenous varieties has been going on for decades, but un‐ fortunately the development of breeding stock is historically limited. The limited degree of individual marking and production control and the participation in development pro‐

Molecular genetic research has opened up a new opportunity to define certain properties and to preserve the genetic resources represented by these goat varieties. The results of this

It is well known that goats are mainly "browsers", preferring the leaves of trees, bushes and shrubs instead of grazing pastures. In general, if they are allowed to follow their genetic determinations, 80% of goats feed from browsing and only 20% feed from grazing. This mainly happens in extensive goat farming, but in intensive dairy goat production systems, goat nutrition is very similar to that of dairy cattle to reach as high a milk production as

Based on genetic determinations a question arises: do goats have different passage rates compared to other ruminants? Several factors affect rumen fill levels and the rates of pas‐ sage through the rumen. These are the animal species and feeding types, stage of reproduc‐ tive cycle and physiological state, ambient temperature, level of nutrition and feed intake, forage-to-concentrate ratio in the diet, practical size and functional gravity. Taking all these effects into consideration the authors of the third chapter state that despite several differen‐ ces, goats are not different from other ruminants with respect to passage rate because it is

Many kinds of mineral deficiency can occur in goats depending on the pastures they graze and the feed they are supplied with. Among others, iodine deficiency could cause several problems in goats, and its symptoms are recognised rather easily. These symptoms and pos‐

The reproduction of goats is quite well known, and most goat keepers are well versed in the details. Goats kept in traditional extensive systems have one oestrus season and one kidding season during the year, which is simple to handle compared to those animals being kept under intensive indoor systems. To be able to modify the reproduction traits of goats it is useful to summarise the most important details from folliculogenesis via physiology and endocrinology of the oestrual cycle, the methods of oestrus synchronisation, artificial in‐ semination and use of the male effect in oestrus induction. An overview of this knowledge

There are many effects on the reproductive performance of male animals. Among others, in‐ sulin-like factor 3 (INSL3) is essential for testis descent during foetal development, and has been implicated in testicular and sperm functions in adult males. In the sixth chapter, up-to-

date knowledge of the development and impact of these factors has been summarised.

and their effects are summarised in this chapter.

research are summarised in the second chapter.

largely due to dietary quality.

can be read in the fifth chapter.

**Reproduction**

**Nutrition**

X Preface

grammes, except angora goats, resulted in poor genetic development.

possible – in addition to the higher reproduction characteristics.

sible and necessary treatments are summarised in the fourth chapter.

Goat's milk is not as popular as cow's milk among consumers; however, goat's milk has several benefits and nutritional values, which are missing from cow's milk. Over the last couple of decades the rearing of dairy goats became an economic activity, which is rather concentrated in certain regions and countries of the world. In addition, goat's milk and milk products have become rather significant parts of foods for more than 1 billion people.

According to the FAOSTAT (2018) data, 15,262,116 tons of goat's milk was produced in the world in 2016, from which *Asia* had the biggest share (55.70% – 8,043,749 tons), followed by *Africa* (25.74% – 3,928,719 tons), *Europe* (16.63% – 2,537,787 tons), the *Americas* (4.93% – 751,823 tons) and *Oceania* (0.00 – 39 tons).

Studying the 10 biggest goat's milk-producing countries (FAOSTAT, 2018), the following or‐ der was determined for the year 2016: *India* (24.69% – 3,767,866 tons), *Sudan* (7.24% – 1,104,620 tons), *Bangladesh* (6.89% – 1,051,493 tons), *Pakistan* (5,40% – 824,098 tons), *France* (3.95% – 603,040 tons), *South Sudan* (3.06% – 466,672 tons), *Spain* (2.69% – 410,977 tons), *Greece* (2.52% – 384,903 tons), *Somalia* (2.47% – 377,733 tons) and *Indonesia* ( 2.46% – 375,453 tons).

In 2016 (FAOSTAT, 2018) there were 202,004,520 milking goats registered, from which the biggest herd was milked in *Asia* (52.11% – 105,619,554 heads), followed by *Africa* (39.60% – 80,272,622 heads), *Europe* (4.32% – 8,748,735 heads), the *Americas* (3.97% – 8,047,754 heads) and *Oceania* (0.00% – 1351 heads).

Concerning the order of the countries having milking goats (FAOSTAT, 2018) the following order could be observed in the year 2016: *India* (14.40% – 29,180,066 heads), *Bangladesh* (14.01% – 28,400,285 heads), *Sudan* (9.31% – 18,878,691 heads), *Mali* (8.19% – 16,606,239 heads), *Pakistan* (4.05% – 8,212,610 heads), *Indonesia* (3.79% – 7,686,690 heads), *South Sudan* (3.43% – 6,943,044 heads), *Somalia* (3.12% – 6,327,494 heads), *Niger* (2.72% – 5,514,053 heads) and *Turkey* (2.31% – 4,687,028 heads).

The composition of the goat's milk produced is the target of various scientific studies.

The protein content of goat's milk is one of the most important values in its utilisation. The main groups of proteins are the caseins, whey proteins, and milk fat globule membranes. De‐ termination of these components in detail and the possible experimental and industrial meth‐ ods, as well as the equipment used, is the target of much research and development work.

One of the important animal health problems in milk production is mastitis (udder inflam‐ mation) and in relation to this are the somatic cell counts of various milk items. Mastitis could have a deep impact on protein composition and the processability of the milk. The progress of proteomics applications and an overview of developments in the field of goat's milk are provided in the eighth chapter of this book.

So far, many scientists have dealt with the secret of the goat mammary gland and tried to model its establishment, characterisation and the application of primary goat mammary cell culture to understand the details of its functioning. In the ninth chapter the authors provide a good summary of the knowledge in this field.

Goat's meat serves as a major source of meat in less developed countries, but it is less popu‐ lar in developed countries. This situation is forecast to change because of the health benefits

Preface XIII

Besides the huge differences in consumption trends among less developed and western countries, many factors modify the value of goat's meat and the marketability of the carcass. These are not only the breed, type, age, weight of slaughter and gender of slaughtered ani‐ mals, but also the production system, nutrition, type of suckling, as well as ageing of the

The factors that affect parasitic infection in livestock may be divided into three groups, which co-exist and overlap each other. Members of first group are highly dependent on the animal itself: genetics, ageing, reproduction phases (like pregnancy, etc.), immune status, nutrition status and hypobiosis. The second group is dominantly based on farm manage‐ ment: grazing, co-grazing, alternate grazing, housing system and drenching, as well as han‐ dling the animals. The third group of factors originated from the environment: temperature, moisture, sunlight, grass composition and the varieties of worm species. At the same time, the effects of all these are highly dependent on gut immunity and various kinds of therapeu‐ tics, as well as resistance of various kinds of worms against the different agents of the drugs used. Several parts of this matrix are evaluated in the fourteenth chapter, including the vari‐ ous kinds of plants that could be used as natural treatments against internal parasites.

Because the use of huge amounts of various kinds of medicines was noticed a new approach to reducing the quantity of medicines – especially antibiotics – has become more and more important. Homeopathy, meaning that one should use different agent molecules in various levels of dilutions, has caught the attention of several scientific teams. However, many sci‐ entists doubt the real benefits of highly diluted molecule agents, and a wide range of infor‐

However, the goat is one of the most adaptable animal species and its production level is highly dependent on environmental circumstances. Along with global warming, heat stress is becoming more and more important even in the case of goats. There are serious physio‐ logical and metabolic consequences of heat stress, which have strong impacts on milk and meat production and even reproduction characteristics, as well asmilk composition. It is necessary to have a more exact understanding of the genetic background of heat tolerance and the complexity of an animal's reaction to thermal stress. The most up-to-date informa‐

Goats were traditionally kept mainly in extensive production systems, so-called traditional grazing. In spite of this and especially as a reason to increase the demand for milk and milk products, traditional goat keeping has been converted to intensive indoor systems; however, several kinds of semi-intensive systems are also used. The intensification of goat's milk pro‐ duction started mainly in Europe (especially in France, Spain, the Netherland and Greece) and then started to spread to other parts of the world. This process became so successful that intensive dairy goat breeds (Alpine, Saanen, Toggenburg, Nubian, etc.) and the produc‐ tion system (including housing, feeding, milking, and reproduction) were needed for their

tion is summarised and evaluated in the sixteenth chapter of this book.

meat. These effects are evaluated in detail in the thirteenth chapter of this book.

of consuming lean meat with limited fat and cholesterol contents.

mation is summarised in the fifteenth chapter.

**Animal health**

**Heat stress**

**Production systems**

The short- and medium-length fatty acid content gives a specific taste and odour to goat's milk and milk products. Medium fatty acid synthesis in the goat mammary gland still has a number of unknown details, which are summarised and evaluated in the tenth chapter.

#### **Milk and health**

There are many publications reporting the health benefits of goat's milk, and a number of them give new reasons why the consumption of goat's milk is highly advantageous. Accord‐ ing to the statements of many scientific publications and promotional announcements, the advantages of goat's milk could be summarised as follows. The frequent and systematic consumption of goat's milk helps to build strong bones, it has significant anti-inflammatory properties, it increases nutrient uptake efficiency, it can be used as a metabolism booster and at the same time can boost the immune system as well as protect the heart. It can help one's growth and development at various stages of life, and in several cases could give a "helping hand" in weight loss. In addition, goat keeping possesses serious environmental protection qualities by preventing bush fires and exterminating unwanted weeds and plants simply through grazing.

However, goats produce red meat, but this meat is very lean, and because of its composi‐ tion, vitamins, proteins, minerals, as well as fat content, goat's meat could be considered an essential part of human nutrition.

Keeping these positive effects at the forefront, nutritional and health profiles of goat prod‐ ucts are presented in the eleventh chapter where the focus is on goat's milk. In the twelfth chapter the relationships between feeding systems and various breeds as well as the bioac‐ tive compounds of goat's milk and cheeses are summarised and evaluated.

#### **Goat's meat**

World goat's meat production consisted of 5,621,133 tons in 2016 according to FAOSTAT (2018) data. Among the continents, *Asia* (73.18% – 4,113,646 tons) dominated goat's meat pro‐ duction. *Africa* took the second stage (22.13% – 1,244,109 tons) with slightly more than onethird of the *Asian* data. The *Americas* were in third place (2.26% – 127,041 tons). *Europe* was in fourth place with limited data (1.76% – 98,934 tons) and *Oceania* was last (0.67% – 37,603 tons).

Concerning the 10 biggest goat's meat-producing countries, *China*'s leadership was obvious (40.33% – 2,266,998 tons). *India* took second place (8.99% – 505,371 tons) but provides less than one-quarter of goat's meat in compare with *Chin*a. The following countries were also in the top 10: *Pakistan* (5.37% – 301,589 tons), *Nigeria* (4.33% – 243,230 tons), *Bangladesh* (3.71% – 208,719 tons), *Sudan* (1.98% – 111,532 tons), *Mali* (1.70% – 95,415 tons), *Islamic Republic of Iran* (1.48% – 82,958 tons), *Myanmar* (1.41% – 79,418 tons), *Mongolia* (1.37% – 76,903 tons) and *Yemen* took eleventh place with 65,872 tons.

Many scientists have declared that goats are resilient and prolific small ruminants with the ability to adapt to a wide range of ecological circumstances. Comparing the possibilities and values of this kind of meat, production and consumption are still not as great as other meats.

Goat's meat serves as a major source of meat in less developed countries, but it is less popu‐ lar in developed countries. This situation is forecast to change because of the health benefits of consuming lean meat with limited fat and cholesterol contents.

Besides the huge differences in consumption trends among less developed and western countries, many factors modify the value of goat's meat and the marketability of the carcass. These are not only the breed, type, age, weight of slaughter and gender of slaughtered ani‐ mals, but also the production system, nutrition, type of suckling, as well as ageing of the meat. These effects are evaluated in detail in the thirteenth chapter of this book.

#### **Animal health**

So far, many scientists have dealt with the secret of the goat mammary gland and tried to model its establishment, characterisation and the application of primary goat mammary cell culture to understand the details of its functioning. In the ninth chapter the authors provide

The short- and medium-length fatty acid content gives a specific taste and odour to goat's milk and milk products. Medium fatty acid synthesis in the goat mammary gland still has a number of unknown details, which are summarised and evaluated in the tenth chapter.

There are many publications reporting the health benefits of goat's milk, and a number of them give new reasons why the consumption of goat's milk is highly advantageous. Accord‐ ing to the statements of many scientific publications and promotional announcements, the advantages of goat's milk could be summarised as follows. The frequent and systematic consumption of goat's milk helps to build strong bones, it has significant anti-inflammatory properties, it increases nutrient uptake efficiency, it can be used as a metabolism booster and at the same time can boost the immune system as well as protect the heart. It can help one's growth and development at various stages of life, and in several cases could give a "helping hand" in weight loss. In addition, goat keeping possesses serious environmental protection qualities by preventing bush fires and exterminating unwanted weeds and plants simply

However, goats produce red meat, but this meat is very lean, and because of its composi‐ tion, vitamins, proteins, minerals, as well as fat content, goat's meat could be considered an

Keeping these positive effects at the forefront, nutritional and health profiles of goat prod‐ ucts are presented in the eleventh chapter where the focus is on goat's milk. In the twelfth chapter the relationships between feeding systems and various breeds as well as the bioac‐

World goat's meat production consisted of 5,621,133 tons in 2016 according to FAOSTAT (2018) data. Among the continents, *Asia* (73.18% – 4,113,646 tons) dominated goat's meat pro‐ duction. *Africa* took the second stage (22.13% – 1,244,109 tons) with slightly more than onethird of the *Asian* data. The *Americas* were in third place (2.26% – 127,041 tons). *Europe* was in fourth place with limited data (1.76% – 98,934 tons) and *Oceania* was last (0.67% – 37,603 tons). Concerning the 10 biggest goat's meat-producing countries, *China*'s leadership was obvious (40.33% – 2,266,998 tons). *India* took second place (8.99% – 505,371 tons) but provides less than one-quarter of goat's meat in compare with *Chin*a. The following countries were also in the top 10: *Pakistan* (5.37% – 301,589 tons), *Nigeria* (4.33% – 243,230 tons), *Bangladesh* (3.71% – 208,719 tons), *Sudan* (1.98% – 111,532 tons), *Mali* (1.70% – 95,415 tons), *Islamic Republic of Iran* (1.48% – 82,958 tons), *Myanmar* (1.41% – 79,418 tons), *Mongolia* (1.37% – 76,903 tons) and

Many scientists have declared that goats are resilient and prolific small ruminants with the ability to adapt to a wide range of ecological circumstances. Comparing the possibilities and values of this kind of meat, production and consumption are still not as great as other meats.

tive compounds of goat's milk and cheeses are summarised and evaluated.

a good summary of the knowledge in this field.

**Milk and health**

XII Preface

through grazing.

**Goat's meat**

essential part of human nutrition.

*Yemen* took eleventh place with 65,872 tons.

The factors that affect parasitic infection in livestock may be divided into three groups, which co-exist and overlap each other. Members of first group are highly dependent on the animal itself: genetics, ageing, reproduction phases (like pregnancy, etc.), immune status, nutrition status and hypobiosis. The second group is dominantly based on farm manage‐ ment: grazing, co-grazing, alternate grazing, housing system and drenching, as well as han‐ dling the animals. The third group of factors originated from the environment: temperature, moisture, sunlight, grass composition and the varieties of worm species. At the same time, the effects of all these are highly dependent on gut immunity and various kinds of therapeu‐ tics, as well as resistance of various kinds of worms against the different agents of the drugs used. Several parts of this matrix are evaluated in the fourteenth chapter, including the vari‐ ous kinds of plants that could be used as natural treatments against internal parasites.

Because the use of huge amounts of various kinds of medicines was noticed a new approach to reducing the quantity of medicines – especially antibiotics – has become more and more important. Homeopathy, meaning that one should use different agent molecules in various levels of dilutions, has caught the attention of several scientific teams. However, many sci‐ entists doubt the real benefits of highly diluted molecule agents, and a wide range of infor‐ mation is summarised in the fifteenth chapter.

#### **Heat stress**

However, the goat is one of the most adaptable animal species and its production level is highly dependent on environmental circumstances. Along with global warming, heat stress is becoming more and more important even in the case of goats. There are serious physio‐ logical and metabolic consequences of heat stress, which have strong impacts on milk and meat production and even reproduction characteristics, as well asmilk composition. It is necessary to have a more exact understanding of the genetic background of heat tolerance and the complexity of an animal's reaction to thermal stress. The most up-to-date informa‐ tion is summarised and evaluated in the sixteenth chapter of this book.

#### **Production systems**

Goats were traditionally kept mainly in extensive production systems, so-called traditional grazing. In spite of this and especially as a reason to increase the demand for milk and milk products, traditional goat keeping has been converted to intensive indoor systems; however, several kinds of semi-intensive systems are also used. The intensification of goat's milk pro‐ duction started mainly in Europe (especially in France, Spain, the Netherland and Greece) and then started to spread to other parts of the world. This process became so successful that intensive dairy goat breeds (Alpine, Saanen, Toggenburg, Nubian, etc.) and the produc‐ tion system (including housing, feeding, milking, and reproduction) were needed for their expected level of production and can now be found in almost every goat-keeper country; however, these breeds are mainly dominant in Europe. This is the main reason why goat's milk production is much higher in Europe – considering the number of goats kept – than in other continents of the world.

The relationship between the environment and production systems used and the products made is summarised in the seventeenth chapter of this book. There are several advantages and some disadvantages to the animals, the environment and especially to the farmers.

In Jordan, goats are kept mainly for meat production and less for milk, skin and fibre, and the production system is based on the utilisation of low-quality roughage. The eighteenth chapter shows how the extensive production system is being gradually shifted toward a more intensive way of production using feeds grown on arable lands.

 The changing production system and the traditional way of goat keeping in Lebanon are summarised in the nineteenth chapter of this book. There is a rising demand for traditional goat's milk products, but this demand could not be served from the goat's milk produced using traditional systems.

**Sándor Kukovics**

**Genetics**

**Section 1**

General Director of Sheep and Goat Products' Board and Inter-professional Organisation President of Hungarian Sheep- and Goat Dairying Public Utility Association Hungary

**Section 1**
