Animal husbandry – животноводство
Reproductive physiology – репродуктивная физиология
Graduates – выпускники
ВАРИАНТ №2
ANIMAL PHYSIOLOGY
The word "physiology" originated from the Greek language and it consists of two parts: physis which means "nature" and logos which is "word". In general, physiology is the study of mechanical, physical, and biochemical functions of living organisms. Physiology has traditionally been divided into plant physiology, animal physiology and human physiology but the physiology principles are universal, even if a particular organism is being studied.
Animal physiology is the study of animal functions that is the study of "how animals work". The rapid development of animal physiology as a distinct discipline began in the 19th century and was stimulated by the requirements of animal husbandry and veterinary science. Animal physiology is subdivided into the four main parts, such as general physiology, special physiology, comparative physiology and age physiology. General physiology deals with the analysis of such universal and important processes as blood circulation, metabolism, respirations etc. Special physiology applies general physiological principles in order to investigate characteristics of a particular animal species. Comparative physiology concentrates on similarities and differences of physiological functions of various living organisms. The problems of how physiological functions change with animal age are of special interest to age physiology.
The main approach in animal physiology is to study the evolutionary origins of the physiological mechanisms in order to understand the significance of these mechanisms for modern-day animals. Modern physiology which is based on chemical, physical and anatomical methods investigates biological organisation of the animal body at different levels, that is, cells, tissues, organs.
One of the parts of special physiology is devoted to farm animal physiology. The aim of this science is not only to study physiological functions of the farm animal body, but to control them in order to increase the production of eggs, offspring, milk, meat and wool. The problem of how to maintain good health of farm animals throughout a long lifetime of high production is of great importance to farm specialists as well.
Farm animal physiology is closely related to veterinary science as it is necessary to know physiological standards and the physiological reactions which take place in the body of a healthy animal in order to cure sick animals and prevent different animal diseases. The problems of sterility and nutritional disorders are studied by physiologists as well as by veterinary surgeons.
Animal requirements in nutrients and energy depend on their physiological features, so feeding rations are calculated on the basis of physiological data. The feeding systems for rearing young animals are being developed on physiological parameters as well. Physiological characteristics such as age and weight are considered by the scientists when animals are fed with vitamins, antibiotics, microelements or hormones.
Farmers should take into account some important physiological features of animals in different situations, for instance, when a farmer is going to use artificial insemination9 or train sport horses or dogs. Physiological parameters of farm animals are of special value to engineers who design different farm mechanisms, such as milking or feeding machines.
Other major branches of scientific study that have grown out of physiology research include biochemistry, biophysics, biomechanics, pharmacology, cytology as well as genetics which are known as the biological bases for rational animal husbandry.
Notes:
Living organism – живой организм
Comparative physiology – сравнительная физиология
Age physiology – возрастная физиология
Blood circulation – кровообращение
Respiration – дыхание
Modern-day animals – современные животные
To cure sick animals – лечить больных животных
Nutritional disorder – проблема, вызванная недостаточным питанием
Artificial insemination – искусственное осеменение
ANIMAL BREEDING
The aim of farm animals breeding is to improve qualities which are considered desirable by humans. Long before the scientific principles to the selection of superior animals were developed and the planning of mating combinations was introduced in practice, all species of farm animals were subjected to selective breeding to some extent. At present, in order to modify livestock and poultry and control propagation of domestic animals, breeding procedures involve the application of several basic sciences, mainly reproductive physiology, genetics and statistics.
Animals are bred for utility, sport, pleasure, and research. The purposes of animal breeding vary with regard to species, local conditions, and time. For instance, early in history horses were bred mainly for riding and as draft animals; and nowadays, to a large extent, horses are being bred for sport (racing and hunting). As to poultry, in the past chickens bred for the combined production of eggs and meat, but nowadays most European countries farmers mainly specialise in such breeds and crosses which produce either eggs or meat.
At present, farmers are using special breeding programmes in order to maintain herds and flocks of higher genetic merit. These programmes include such steps as: 1) the estimation of the breeding value of animals; 2) thorough selection of animals for breeding; 3) the application of one of the mating systems.
The problem how to estimate the breeding value of animals has been researched thoroughly by scientists for different kinds of animals. On the one hand, it is necessary to select animals for breeding on the basis of objective measurements of traits that are decisive for the production. On the other hand, it is often impossible to judge animals' productivity only on the basis of their appearance, so farmers started systematic recordings of such individual animal characteristics as milk yields, growth rate and muscle development for bulls etc. Progeny testing and performance testing have been introduced to judge young males (bulls, rams, and boars) that will be used for breeding. Actual measurement of an individual animal's performance is a rather recent innovation in animal breeding and it has established the foundation of breeding programmes.
Nowadays it is known that the breeding value of an animal depends on the genes which it passes on to its offspring, so genetics has become the basis of animal selection and breeding. It has been found that some traits (coat colour, blood type etc) are inherited in accordance with the laws of heredity, while other traits (wool yield, egg production etc) are subjected to variations and are greatly influenced by the environmental factors.
Selection is based on the breeding value of animals and can be carried out in different ways such as mass selection, pedigree selection, family selection, and progeny selection. There are certain advantages and disadvantages of these systems, thus selection is usually made in a number of steps. With regard to dairy, bulls selection on the basis of pedigree is made soon after birth; a second selection is made later and based on growth rate during the first year of life and fertility in the first series of inseminations; and, finally, a third selection depends on the results of progeny tests, when offspring are old enough and may be judged.
Animal breeders apply different mating systems such as inbreeding, outbreeding, linebreeding, crossbreeding as well. The purpose of any method of breeding is to exclude undesirable traits and combine the most essential characteristics in a new animal breed. Along with various breeding methods, the introduction of such techniques as artificial insemination, transplantation of embryo from donor females of high merit has become of great use in breeding all species of farm animals.
To sum up, scientists apply the same basic principles of breeding to any animal species, though the practical approach to the problem may differ to a certain extent and it depends on the rate of animal reproduction, selection method, mating system, as well as on some genetic and environmental factors.
Notes:
- reproductive physiology — репродуктивная физиология
- mass selection — массовый отбор
- pedigree selection — отбор по родословной
- family selection — семейственный отбор
- inbreeding — межродственное скрещивание
- outbreeding — аутбридинг (неродственное спаривание)
- linebreeding —разведение в пределах одной линии
- crossbreeding — кроссбридинг, метизация (скрещивание особей разных пород или разновидностей)
ВАРИАНТ №3
ANIMAL NUTRITION
Since animal nutrition research began to develop rapidly during the 1930s, many discoveries about animal metabolism and nutrient requirements have been made. Nutrition is interpreted as the study of organic process by which an organism assimilates and uses food and liquids for normal functioning. Adequate nutrition for any living organism is necessary for the following reasons: 1) in order to provide adequate energy levels; 2) to maintain proper body structures and processes, for instance, muscle function, immune protection, bone density and strength; 3) to ensure the repair and development of all organism's systems, thus to maintain balance between health and disease. In the case of farm animals, proper nutrition is affected by various factors, such as animal species and breed, animal age, body shape and size and other physiological characteristics. The lack of or deficiency in any nutrient may cause animal weakness and even illness.
A nutrient is any element or compound which is necessary for an organism's metabolism, growth, development or other functions. It is essential to provide farm animals with adequate amounts of nutrients which they get from various feeds. In general, animals require the same nutrients as humans. There are six basic nutrients which are important animals' health and they are classified into the two main groups: substances that provide energy; 2) substances that support metabolism, former group includes carbohydrates, proteins and fats, the latter comprises minerals (for instance, phosphorus, calcium), vitamins and water.
It has been found that any particular substance can play more than role in the body. For example, most animals get energy from carbohydrates and fats, which are oxidised in the body. However, protein supplies energy if other sources are inadequate or if it is supplied in great excess above the requirements of the body. Moreover, proteins provide the building blocks (amino acids) for enzymes and other proteins within the body. Thus, for most living organisms nutrients provide not only the energy necessary for certain vital processes but also the various materials from which all structural and functional components can be made up.
On the one hand, there are so-called non-essential nutrients which are synthesised by the cell if they are unavailable to the living organism with the food or feed. On the other hand, there are essential nutrients which cannot be manufactured within the cell in the body. Consequently, it is important to supply farm animals with feeds which contain certain essential amino acids as well as essential fatty acids.
The problem of proper feed supply is of great importance to animal husbandry. Thus, various animal feeds are grown or developed for livestock and poultry, selected and prepared in order to provide highly nutritional diets that both maintain the health of the animals and increase the quality of such farm products as meat, milk, or eggs.
Scientists have studied the usefulness of different feeds as sources of essential amino acids, vitamins, and minerals, as well as lipids and carbohydrates. They also have suggested the proper balance of available nutrients in the animal diet and as a result different nutrient supplements and feed-processing technologies have been developed. Since the 1950s, antibiotics and other growth stimulants have been added to feeding rations in order to increase the rate of growth and reduce death loss of farm animals. Antibiotics help to overcome the growth-depressing effects of an inadequate and poor-quality diet or of imperfect management practices, but their effectiveness differs among animal species.
The achievements of animal physiology and special studies of life processes in farm animals have ensured the development of the optimal diet for each animal. Many of the feeds have appeared as the result of research, experimentation, and chemical analyses which were conducted by animal scientists. However, the problem of adequate animal nutrition is still the subject of current studies for farm scientists. Human nutrition has been improved as a result of animal nutrition investigations.
Notes:
1. to assimilate – зд. поглощать, усваивать
2. liquid – жидкость
3. bone density – плотность кости
4. feed-processing technologies – технологии по переработке корма
5. to overcome – преодолеть
6. management practices – способы содержания животных
ВАРИАНТ №4
ANIMAL ECOLOGY
The word ecology originates from the Greek language and means "the study of the place to live". In general, ecology as a branch of biology deals with the relationships between living organisms and their environment. Animal ecology began to develop rapidly as an applied area of ecology only in the middle of the 20th century. Animal ecology concerns the study of population dynamics, distribution, behaviour, and the interrelations of animals and their environment. In the beginning, animal ecology developed separately from plant physiology. However, animals depend upon plants for food and shelter, so it is impossible to understand animal ecology without plant ecology. This is particularly true in such applied areas of ecology as farm animal ecology as well as ecology of wildlife. Modern ecology considers interrelationship of both plant and animal communities as a whole biotic unit.
Ecology is mainly based on the ecosystem concept which is applied to units of various sizes such as a pond, a field, a pasture, a forest or a large ecoregion. When an ecologist is going to analyse any ecosystem, he will study the living organisms which inhabit this specific area, the physical environment, and all interrelations in this particular unit of space. The term "environment" includes both physical surroundings and biotic communities. The former means a large variety of local abiotic (nonliving) factors like temperature, sunlight, minerals, soil, and water. Different plants and other organisms that share the organism habitat are known as biotic communities. In farm animal ecology, the emphasis is put on farm animal relationships to human society and the whole economy within a particular ecosystem. For example, before a large commercial hog breeding farm is built, ecologists will study such problems as the pollution of the soil and water resources by the animal wastes, the influence of grazing on the ecology of the nearest pastures etc. Thus, a farm will not be built until the problems of water recycling and utilisation of animal wastes are considered and solved.
Within the ecosystem, species are connected and they depend upon one another in the food chain, and exchange energy and matter between themselves and with their environment. The concepts of the food chain and ecological niche were described in the theses by Charles Sutherland Elton (1900-1991), a British biologist and naturalist. The following food chain "the grass (or other plants) → the herbivore (cattle, sheep) → the man" is of great interest to farm animal ecology.
Human interference in the development of ecosystems is widely spread. Farming is the deliberate maintenance of such an ecosystem which is highly productive but relatively unstable. Consequently, the proper management of ecosystems for optimal food production as well as thorough study and analysis of various natural cycles (such as a water cycle or a nitrogen cycle) are of great importance to ecologists.
Farmers have widely adopted intensive systems of crop and animal production which provide bases for reliable food production. However, there are some advantages and disadvantages of intensive farming. On the one hand, if farmers apply modern cultivation practices and fertilisation in order to increase the soil fertility, yields of forage crops will be higher and farm animals will be provided with enough amounts of feed. Farmers widely use intensive methods for producing animal products which include confinement of poultry in small cages, swine in small pens, and sheep and cattle in small lots. Thus, the study of the relationships between farm animals and their surroundings such as temperature, air and light conditions is of special importance to ecologists. It has been found that proper lighting management may increase both poultry and livestock production, so lightening is controlled on any type of farm now. Furthermore, it has been shown that confinement leads to savings in labour, feed, and other production costs. Besides, when animals are kept in individual pens, it will be easier to ensure proper disease control. So, the introduction of new methods of intensive farming has enabled farmers to satisfy the needs of population in animal food product.
On the other hand, in the long run, such intensive systems of farming may cause serious ecological problems and even ecological crises. It has been shown that cultivation and fertilisation result in a disbalance of nutrients, an increase in pollutants, in pesticides accumulation in the soil, or an increase in susceptibility to plant diseases. Moreover, confinement of farm animals has come under attack as cruel to the animals, and protective legislation of animal right has been advocated.
Nevertheless, livestock and poultry farmers claim that if the animals are under any stressful conditions, they will show sharp decreases in productivity, but milk yields and egg production are maintained at high levels on commercial farms. Since the 1970s, the behavioural adaptation of animals to their surroundings and the effects of environmental stress on the immune status of livestock and poultry have been studied thoroughly by ecologists.
At present, ecology is a multi-disciplinary science which involves plant and animal biology, physiology, genetics, behaviour, meteorology, geology, sociology etc. It is often difficult to draw a sharp line between ecology and any of these sciences. The knowledge of ecology provides the necessary basis for proper management and conservation of natural resources as well as for maintenance of essential ecological processes and ecosystems.
Ecology is widely studied as one of the most important aspects of biology as it has become clear that such problems as the increase in population, food scarcity, environmental pollution, and some sociological and political problems are to a great degree ecological.
Notes: