Zootechny(redirected from zootechnician)
Also found in: Dictionary, Medical.
the science of breeding, feeding, housing and properly using agricultural animals in order to obtain from them the highest possible quantity of high-quality products with the least expenditure of labor and money. Zootechny generalizes the knowledge of animal breeding and develops the theory and practical methods of conducting this activity.
The term “zootechny” appeared in 1848, proposed by the French scientist J. Baudement, who defined zootechny as “the science of the technology of living machines.” Modern zootechny, which develops the most economical animal breeding technology through mechanizing and automating production processes, makes wide use of the exact sciences and computer technology. It is based on the sciences that study the biological characteristics of agricultural animals, such as general biology, anatomy, histology, embryology, physiology, biochemistry, and genetics, as well as allied sciences—veterinary medicine, agronomy, the organization of agricultural production, and the like. Like other sciences, zootechny uses historical, comparative, experimental, and statistical methods of research.
Zootechny is divided into general zootechny and specialized zootechny. The former elaborates the fundamentals of breeding, feeding, housing, and using all principal species and breeds of agricultural animals. The latter elaborates the technology of managing branches of animal breeding. General zootechny, in turn, has subdivisions: breeding, feeding, and housing of animals. The subdivision on breeding agricultural animals deals principally with the qualitative improvement and the quantitative population growth of domestic animals and with research and study on new ways in which man can affect domestic animals. The improvement of the qualities and productivity of existing breeds (in terms of meat, milk, eggs, wool) and the development of new breeds is accomplished by selection of animals, inbreeding, crossbreeding, hybridization, and so on. Theory and practice in this area is elaborated by the science of breeding agricultural animals. The subdivision of zootechny on feeding agricultural animals deals with methods of setting up feeding norms through research on the animals’ requirements for nutrients (proteins, fats, carbohydrates, vitamins) and study of the chemical composition and nutritive value of feeds. The subdivision of zootechny on housing agricultural animals develops methods of keeping the animals (stabling, loose housing system, housing in groups), studies the effectiveness of these methods, and studies the possibility of mechanizing and automating labor-consuming processes on animal-breeding farms.
Historical survey. Zootechny developed as the practice of animal breeding grew. In the epoch of primitive animal husbandry, ancient peoples developed the simplest ways of raising and using animals. Scientists and writers of the ancient world made zootechnical generalizations concerning the principles of growth and development of animals as well as the selection and evaluation of animals for breeding purposes based on their external form, ancestry, and even the quality of their offspring (the Roman writer Varro, first century B.C.); the theory concerning animal constitutions arose (the Greek physician Hippocrates and the Greek historian Xenophon, fifth to fourth centuries B.C.); guides appeared on problems of feeding and caring for animals, raising the young, obtaining mules, and so on; and the concept of breed was formed. In the Middle Ages, owing to widespread use of the horse in armies, special studies on horses appeared (for example, the treatise of the Arab scientist Abu-Bakr on the external form of the horse, 14th century). Beginning in the 17th century, with the transition from the barter feudal economy to commercial capitalism, when animal husbandry began to specialize in the production of certain products, attempts were made to work out feeding norms for agricultural animals (for example, by the German scientists A. Thaer and J. von Liebig) and to improve methods of breeding cattle (for example, by the English breeders R. Bakewell, C. Colling and R. Colling).
In the late 18th and early 19th centuries, the art of livestock raising attained a high level. By the end of the 18th century domesticated (stud-farm) breeds of sheep, beef cattle, swine, and horses were created in Great Britain—the country with the most highly developed animal husbandry—and by the beginning of the 19th century in other countries as well; these breeds are still important in the second half of the 20th century. The development of zootechnical knowledge of that period was promoted by the works of the French scientists G. L. Buffon, who developed a theory of crossbreeding that is close to the present one; C. Bourgelat, one of the first to formulate the theory of the external form of animals; and H. Weckerlin, one of the creators of the theory of the “constancy” (stability) of breeds. The evolutionary theory of C. Darwin, set forth mainly in his work The Origin of Species (1859), exerted enormous influence on the development of zootechny. The foundation of Darwin’s theory—the theory of selection—became the theoretical premise of animal breeders in developing domesticated animal breeds. In the second half of the 19th century there appeared works on zootechny that used Darwin’s theory extensively— Lectures on Livestock Breeding and Identification of Breeds by the German scientist H. Nathusius (1872)and Livestock Breeding by the German scientist H. Settegast (1881). Selection and crossbreeding became the principal means of improving animals and creating new breeds, but zootechnical work remained unorganized, since the causes of the variability of organisms were unknown. In the 20th century the achievements of genetics have become part of the theory and practice of animal breeding. Genetics has made possible a deeper understanding of the phenomena of heredity and an accumulation of information on the principles of the inheritance of certain characters in agricultural animals; as a result the art of livestock breeding has acquired a scientific base.
Important contributions to the development of zootechny in the first half of the 20th century were made by the German scientist C. Kronacher, who wrote numerous works on general animal husbandry; the Swiss scientist U. Durst, who wrote a basic manual on raising cattle; the English scientist J. Hammond, who wrote original works on the growth and development of agricultural animals and the biology of reproduction and lactation; and such American scientists as E. Davenport, S. Wright, J. Lush, and V. Rice, all authors of valuable studies on breeding agricultural animals based on the achievements of population genetics. Significant contributions to developing the theory of feeding agricultural animals were made by the German scientist, O. Kellner, who gave a scientific evaluation of the nutritional value of feeds in terms of their productive effect and who proposed a unit of the nutritive value of feeds—the starch equivalent; the American scientist H. Armsby, who introduced an energy unit for evaluating the nutritive value of feeds—the therm; and the Danish scientist N. Fjord and the Swedish scientist N. Hansson, who worked out the Scandinavian feed unit, which became the common Scandinavian unit in 1915 and is the unit used to this day in Sweden, Denmark, Norway, Iceland, and Finland.
Zootechnical progress in Russia is associated with the development of animal breeding. In the 18th and the early 19th centuries, specialized dairy cattle breeds (for example, the Kholmogory), meat-and-wool breeds of sheep, fast-maturing breeds of swine, fast-gaited breeds of horses (for example, Orlov Trotters), and egg-laying and meat breeds of chickens were created, and many previously developed animal breeds were improved. In the reign of Peter I new horse-breeding farms and pedigreed sheep farms for finewooled sheep were organized, and purchases of pedigreed cattle in England and Holland were begun. From the middle of the 19th century problems of animal breeding were taught in domestic science courses in institutions of higher learning such as Moscow University and the St. Petersburg Medical and Surgical Academy. In 1848 the first agricultural institution of higher learning in Russia was opened—the Gory-Goretsk Agricultural Institute (now the Byelorussian Agricultural Academy). The year 1865 saw the opening of the Petrovskoe Agricultural and Forestry Academy (now the K. A. Timiriazev Moscow Agricultural Academy), where animal husbandry was taught in the agronomy course and later separately.
In the second half of the 19th and early 20th centuries, there appeared important works on zootechny by such Russian scientists as N. P. Chirvinskii, P. N. Kuleshov, M. I. Pridorogin, E. A. Bogdanov, M. F. Ivanov, and A. A. Maligonov, who laid the foundations of modern Soviet zootechny. These works contained extensive materials on the origins, distribution, economic characteristics, and methods of improving domestic breeds of agricultural animals. They also dealt with problems of the growth and development, external characteristics and constitution, productivity, and methods of breeding animals, as well as with ways to determine feeding norms. An important contribution to zootechny was the development by I. I. Ivanov (and later by V. K. Milovanov, among others) of a method of artificial insemination of animals, which found broad application in domestic and foreign agricultural practice. The socialist reconstruction of agriculture in the USSR created the industrial base for incorporating the achievements of the socialist reconstruction of agriculture into agricultural production. The development of zootechny was promoted by the organization in 1929 of the V. I. Lenin All-Union Academy of Agricultural Sciences (VASKhNIL) and within its system of the All-Union Scientific Research Institute of Animal Husbandry (VIZh). It was also promoted by a broad network of scientific research branch institutes, experiment stations, and laboratories and the publication of special journals.
Many questions of zootechny were worked out by such Soviet scientists as E. F. Liskun (breeding and feeding cattle), M. M. Zavadovskii (the hormone method of increasing the fertility of sheep and cows), D. A. Kislovskii (theory of breeding animals), M. I. D’iakov and I. S. Popov (study of the nutritive values of feeds and elaboration of the theory of feeding agricultural animals), and V. O. Vitt (original research on horsebreeding). P. N. Kuleshov and M. F. Ivanov worked out scientific methods of developing new breeds of animals, by which they actively contributed to the radical transformation of breeds in the country’s animal husbandry. In the USSR (by 1970) more than 60 new, highly productive, stud-farm breeds of animals had been developed, and the majority of local breeds and groups of animals had been significantly improved. Work is also being conducted on the development of specialized meat breeds. The numbers of pedigreed livestock (cattle, swine, and sheep, among others) have almost doubled since 1916. The output of producing herds has been increased, and the principal products of animal husbandry have grown significantly. Methods of breeding animals on stud farms continue to be improved through a deepening knowledge of the biological basis of pedigreed breeding as the principal method of breeding, and a more perfect methodology of working with a breed has been created—line breeding. The existence of breeds of agricultural animals that are highly productive and valuable in terms of breeding has opened broad possibilities for the use of various forms of crossbreeding. For successful management of breeding, there has been developed in the USSR a single state system for evaluation of all species of agricultural animals based on a complex of characteristics to determine their value for breeding and use. (Abroad this system has its own special features.)
Owing to the efforts of Soviet and foreign scientists, many theoretical questions of animal breeding have undergone development. Among these questions are the theory of animal breeds and the practical use of various forms of selection; the relation of basic biological principles to inbreeding (mating close relatives) and heterosis (the phenomenon of hybrid vigor in cross-breeding and hybridization); the external form and constitution of animals and their connection with the productivity and viability of animals (definite connections have been established between external form and the development and functions of internal organs and with productivity); and the growth and development of animals (ontogeny). Experiments conducted to study genetic processes irr populations of agricultural animals by such Soviet investigators as S. S. Chetverikov, I. I. Shmal’gauzen, A. S. Serebrovskii, and N. P. Dubinin have made possible the discovery of the principles of inheritance of economically useful characters in agricultural animals. Without a knowledge of these principles it is impossible to plan the breeding process and work out a methodology for evaluating the genetic qualities of sires.
In the field of feeding agricultural animals the works of E. A. Bogdanov, M. I. D’iakov, and I. S. Popov have become fundamental in the USSR. Under Bogdanov’s direction the Soviet feed unit has been developed for evaluating the total nutritive value of feeds. On the basis of the study of local feed resources, the chemical composition of feeds and their digestibility, caloric content, and biological completeness, as well as research on physiological and biochemical processes in the bodies of animals, the nutritional requirements of all species of agricultural animals have been established. M. I. D’iakov and I. S. Popov have developed national feeding norms for all species of agricultural animals and created tables of the nutritive values of feeds, on the basis of which feed rations are determined. The energy aspect of metabolism has been studied, and the caloric content of feeds has been established; this permits the rationing of feeds according to their energy values (caloric content). The fundamentals of amino-acid, vitamin, and mineral nutrition of animals have been investigated, and methods of controlling metabolism in animals have been found. Study of the amino-acid composition of proteins has made possible the balancing of rations based on the amino-acid composition of feeds. Formulas for protein substitutes (urea, ammonium bicarbonate, and many others) are being developed, mixtures of concentrates and pelletized feeds are being created, and various formulas for complete mixtures of concentrates are being introduced for various species of animals. Methods for increasing the nutritive value of coarse feeds (hay, straw, silage) are being widely used; they include ensiling, fermentation, malting, chemical preserving, and accelerated drying, which preserves vitamins. Growth and fattening stimulators—antibiotics, estrogens, tissue preparations, growth substances, and the like—are widely used. Extensive research is being conducted on feeding the young, adult animals, and sires and on animals being fattened by feeds or by pasturing. There is also research on the feeding of highly productive cows for the purpose of increasing milk yield.
Various systems and methods have been worked out for the housing of agricultural animals both in the USSR and abroad (stabling and the loose housing system for cattle, keeping swine in large groups, keeping poultry in cages or in pastures, and so on). Optimal zoohygienic conditions are being determined for keeping animals in buildings of various types in various climatic zones. Systems are being perfected for organizing work and mechanizing and automating production processes on livestock-breeding farms.
The search for solutions to the main problems of zootechnical science has led to the substantial growth of animal husbandry on a high level and has promoted the use of industrial technology in leading branches of agriculture.
Modern problems in zootechny. Modern problems in zootechny are closely connected with the achievements of associated biological disciplines (physiology, biology, immunology) and population genetics. For this reason, in the USSR as well as abroad, there has been intensive research on the proteins in blood, milk, hens’ eggs, and so on for the purpose of ascertaining the proteins’ variability, genetic nature, and connections with the viability and productivity of animals. Research has established that such characteristics as the fat and protein content of the milk of cattle, the weight of hens’ eggs, the quality of a swine carcass, and the fineness of sheep’s wool have a high degree of heritability and that simple methods of mass selection of animals for these characters are sufficient for their rapid improvement. But such characteristics as viability, fertility, milk yield of dairy cattle, and intensity of egg-laying by hens have low heritability, and more complex methods of breeding (including a consideration of the ancestry of animals, the quality of their offspring, and the discovery of the best mating combinations) are necessary to improve them. Even under more extensive study are the immunogenetic characteristics of the blood groups of animals, which can be used to determine the ancestry of animals in controversial cases. Through the principles of population genetics, such important concepts as selection differential and selection index have been formulated for applied animal breeding. Basic research on problems connected with population genetics has been conducted in the USA (J. Lush, S. Wright), Great Britain (A. Robertson), and Sweden (I. Johansson). Much attention is being given by scientists of the USSR, USA, Great Britain, Canada, New Zealand, and Japan to the interaction of the genotype and the environment and to studying the concept of the compatibility of blood types. In the USSR, USA, Sweden, New Zealand, and the German Democratic Republic methods for breeding animals based on the quality of their products and the return on feed are being studied. In some countries (the Netherlands, for example) prices of milk are established according to fat and protein content; this was made possible by wide-spread use of colorimetric methods of analyzing milk for its protein content. In many countries effective methods have been worked out (by means of ultrasonic instruments) for evaluating the quality of swine carcasses in live pigs; they permit not only measurement of the thickness of the fat but also the area of the muscle. In swine husbandry and broiler poultry-husbandry, breeding for improvement in the return on feed has proved effective.
In some countries research is being conducted on increasing the hereditary resistance of animals to diseases, especially infectious ones. Breeding experiments conducted on chickens in the USA have made it possible to produce lines that are resistant to coccidiosis, white diarrhea of chicks, and leucosis. Many zootechnical institutions in the USSR, USA, and Europe are working on what role amino acids, vitamins, enzymes, antibiotics, and microelements in the ration play in forming the productivity of animals. The influence of biostimulators on the growth and development of animals is also being intensively studied.
Extensive research is being conducted in the USSR and abroad on feeding and housing animals. Owing to the creation of large animal-husbandry complexes for raising and fattening animals (‘‘meat and milk factories”) and the construction of poultry farms for tens of thousands of layers, work is being done to develop the best methods of housing animals, effective systems of illuminating and ventilating animal-husbandry buildings, and new methods of mechanizing and automating labor-consuming processes (such as feeding the animals, especially in fattening sections, and cleaning buildings).
In the scientific elaboration of zootechnical problems, contemporary methods of research (including chromatography, X-ray photometry, use of radiant energy, and tagged atoms) are being used more extensively and computer technology is being introduced. Many zootechnical problems are simultaneously being worked on in the USSR and abroad.
Zootechnical education, scientific establishments, and publications. By the early 1970’s zootechny was being taught in the USSR in departments of zootechny in 66 agricultural institutes that prepare zootechnicians with advanced training and in 256 agricultural technicums that graduate zootechnicians with intermediate training. Scientific research work in zootechny is conducted in departments of zootechny in institutions of higher learning, in the All-Union Scientific Research Institute of Animal Husbandry and branch scientific research institutes, at experiment stations, and in special laboratories. Work in zootechny is coordinated by the V. I. Lenin All-Union Academy of Agricultural Sciences.
The most important scientific institutions on animal husbandry abroad are the Institute of Animal Breeding (Rostock, German Democratic Republic), Kellner Institute of Animal Feeding (Rostock, German Democratic Republic), higher agricultural school of Cambridge University (Cambridge, Great Britain), Institute of Animal Genetics in Scotland (Edinburgh), scientific agricultural center of the USA Department of Agriculture (Beltsville), Institute of Dairy Husbandry in the Netherlands (Wageningen), Institute of Animal Genetics in Sweden (Wiad), and National Institute of Animal Husbandry of Japan (city of Chiba).
Scientific-industrial journals published in the USSR include Zhivotnovodstvo (Animal Husbandry, since 1939), Sel’skoe khoziaistvo za rubezhom: Zhivotnovodstvo (Agriculture Abroad: Animal Husbandry, since 1955) and specialized branch journals. The All-Union Scientific Institute of Information and Technical-Economic Research in Agriculture periodically publishes collections of information on zootechnical problems in foreign countries. Abroad problems of the development of zootechny are discussed in Great Britain in Journal of Agricultural Science (Cambridge, since 1905)and Journal of Reproduction and Fertility (Oxford, since I960), in the USA in Journal of Dairy Science (Baltimore, since 1917) and Journal of Animal Science (Menasha, since 1942), in France in Compte rendu, hebdomadaire des séances de l’Académie d’agriculture de France (Transactions of the Weekly Sessions of the Academy of Agricultural Sciences of France, Paris, since 1915), in Sweden in Acta agriculturae scandinavica (Stockholm, since 1950), in Japan in Japanese Journal of Zootechnical Science (Tokyo, since 1923), in Bulgaria in Zhivotnovudni nauki (Animal-Husbandry Sciences, Sofia, since 1964), in the German Democratic Republic in Archiv für Tierzucht (Archive for Animal Breeding, Berlin, since 1958), and in the Federal Republic of Germany in Tienuchter (Animal Breeders, Hanover, since 1949).
REFERENCESKuleshov, P. N. Teoreticheskie raboty po plemennomu zhivotnovodstvu. Moscow, 1947.
Chirvinskii, N. P. Obshchee Zhivotnovodstvo, 5th ed., part 2. Moscow, 1926.
Pridorogin, M. I. Ekster’er: Otsenka sel’skokhoziaistvennykh zhivotnykh po namzhnomu osmotru, 7th ed. Moscow, 1949.
Bogdanov, E. A. Izbr. soch. Moscow, 1949.
Liskun; E. F. Kmpnyi rogatyi skot. Moscow, 1951.
Popov, I. S. Kormlenie sel’skokhoziaistvennykh zhivotnykh, 9th ed. Moscow, 1957.
Kislovskii, D. A. Izbr. soch. Moscow, 1965.
Ivanov, M. F. Poln. sobr. soch., vols. 1–7. Moscow, 1963–65.
Dmitrochenko, A. P., and P. D. Pshenichnyi. Kormlenie sel’skokhoziaistvennykh zhivotnykh. Leningrad, 1964.
Borisenko, E. la. Razvedenie sel’skokhoziaistvennykh zhivotnykh, 4th ed. Moscow, 1967.
E. IA. BORISENKO