Results of studying the efficiency of iodine containing preparation Jodon which was applied to highly productive cows with hypovarianism and to servicing bulls in order to increase their reproductive function realized in the Republic of Belarus were presented. On the basis of realized studies there was proved the considerable efficiency of Jodon preparation.

Analysis of morphological characteristic and parameters of a thyroid gland of a thyroid gland of growing cattle stock made it possible to specificate the age-specific and species-specific parameters of adaptation of cattle in concrete conditions of environment was realized in the conditions of cattle breeding complexes of the Republic of Belarus. As a result of studies there were obtained new data on form-building processes, macromorphology, topography and referential parameters of thyroid gland of cattle breeds.

Increase of diets nutrition energy in our experiment showed no significant effect on usage of nitrogen in feeds. Diets with different energy levels have no negative effect on hematological indices of animals

The use of subcutaneous progesterone-releasing devices in superovulatory treatment allow to get high results of embryo production per donor, viability and pregnancy rates after embryo transfer in cattle. Application progesterone hypodermic inserts has allowed to lower the cost price of one received embryo on 28461 rubles

Definition of quality parameters and chemical composition of feeds, evaluation their nutritional value and composing on this basis optimal rations for high productive animals are the most significant conditions for their health and production. More often metabolism disorders registers in the conditions of intensive animal production, at high dairy efficiency and intensive fattening. At animals at disorder of key parameters of technology (unbalanced feeding, hypodynamia, lack of insolation) is broken metabolism, decreases natural resistance, goes down quality of production that conducts to disease, premature culling and to the compelled slaughter of animals. On frequency these diseases occupy on the average 10% from all noncontagious diseases, and on dairy complexes with industrial technology and in specialized feeding economy at intensive cultivation on their share it is necessary over 30% of a noncontagious pathology. Today the control of rations on such indicators, as dry matter level, quantity of exchange energy, the maintenance of a crude and digested protein, amino acids, sugars, starch, cellulose, fat, macro-and microelements, vitamins, and also sugar-energy-protein and calcium-phosphoric parities, acid-base balance has got special value. The lack of those or other nutrients causes infringement of a clinical condition of animals and reduces their efficiency. Among the most widespread diseases of the animals registered in animal industry: cattle ketosis, osteodystrophy, endemic struma, hypomagnesiemia tetany, pasturable tetany, microelementosis, hypovitaminoses A and Е.

Improvement of the standards of energy and protein diets of young stock cattle of 1-6 month old and determination of its influence on animal productivity was realized in the conditions of the Republic of Belarus. The studied made it possible to determine that at the age of 1 month the calf diet should contain 1,02 kg of dry matter and 21,2 MJ of metabolic energy; at the age of 2 months - 1,26 kg and 23,5 MJ; at the age of 3 months - 2,2 kg and 25,6 MJ; at the age of 4 months - 2,9 kg and 31 MJ; at the age of 5 months - 3,28 kg and 34,2 MJ; at the age of 6 months - 3,76 kg and 37,6 MJ, respectively. Metabolic energy concentration per 1 kg of dry matter should not be lower than 20,7 MJ at the first month, 19 MJ - at the second month, after the third month it should lower up to 10 MJ. In course of 6 months the presented diet scheme made it possible get 832 g of average weight gain in the conditions of forage expenses of 3,52 forage units per 1 kg

The purpose of the research was establishment of hepatic diseases spread in cattle fattening. Trials were conducted with total number of hybrids IV-V generation of black-motley heifer with pedigree Hereford bulls. It has been established the wide spread (22,4%) of hepatic pathology. The leading place among all hepatic pathologies belongs to fatty hepatosis (13,4%) with weakly expressed symptoms, decrease of serum protein level, albumin, glucose and increase of bilirubin, globulins, hepatic enzymes and strong pathology-anatomical and histological manifestations. In the tabular form results of histologic research of liver, some biochemical indicators of blood of healthy and sick animals (M +/- m), the clinical symptoms revealed during the various periods are resulted | Целью исследований являлось изучение структуры и установление широты распространения болезней печени у крупного рогатого скота на откорме. Опыты проведены на широком поголовье помесей IV-V поколения тёлок чёрно-пёстрой породы с племенными быками герефордской породы. Установлено широкое (22,4%) распространение гепатопатий. Ведущее место среди различных форм поражения печени принадлежит жировому гепатозу - 13,4%, морфофункцинальный профиль которого определяется слабо выраженными клиническими симптомами, уменьшением уровня общего белка, альбуминов, глюкозы, повышением концентрации билирубина, активности гепатоспецифических ферментов, а также всех фракций глобулинов, яркой и характерной патологоанатомической и гистологической картиной. В табличной форме приведены результаты гистологического исследования печени, некоторые биохимические показатели крови здоровых и больных животных (M +/- m), клинические симптомы, выявленные в различные периоды

In the conditions of the Republic of Belarus there was studied the pathology and biology of cattle capillariasis. Capillariosis invasion rendered a substantial invasion on blood morphological composition which was revealed in lowering of erythrocytes and hematoglobulin, as well as in increasing of leukocytes quantity. There was noted the lowering of the natural resistance and immune reactivity. There were stated substantial deviations in protein metabolism which was expressed in lowering of total protein, quantity of albumins, changing of albumin and globulin coefficient, increasing of globulins. In the conditions of blood biochemical analysis of infesrated animals there was stated a disorder of vitamin and mineral metabolism; increasing of alanine aminotransferase and aspartate aminotransferase enzymes activity. Development of Capillaria bovis was realized in a direct line. In the natural habitat development of Capillaria bovis eggs varied from two up to three months.

In the conditions of the Republic of Belarus there were analyzed high productive traits of meaty calves and cross breeds bred in accordance with a system cow-calf, as well as the possibilities of using veal meat obtained in ecologically safe areas for infant food production. At the age of 6,5-7 months the weight of fresh carcass of bull-calves of sharolez breed in comparison with aberdin-angus х black-motley herdmates was on 41,6 kg (Р less than 0,001) higher, carcass yield and slaughter yield – on 13,8% (Р less than 0,001) and 13,6% (Р less than 0,001), respectively. The fat content in sharolez meat was 4,9% against 8,9%; protein - 21,9% against 18,8%. The black-motley suckling bull-calves surpassed their herdmates which were grown up by technology of dairy cattle breeding at the age of 6-6,5 months according to indexes of weight of fresh carcass - on 16,3 kg or 21,7% (Р less than 0,01); according to indexes in a slaughter yield - on 16,6% (Р less than 0,001); and according to indexes meat flesh in a carcass - on 1,5%. According to quality indexes, amino acid structure, acceptable concentration of toxic elements content, pesticides, antibiotics, radionuclides and other harmful substances the veal meat of calves which were bred on a system a cow-calve in ecologically pure zones proved to be important meat raw materials to produce infant food products.

In the conditions of Vitebsk region of the Republic of Belarus there was realized a programme on creation of breed type of Hereford cattle. In course of the study there were realized experiments on increasing the number of livestock of beef cattle breeding by means of accumulation cross breeding of black-and-white cattle with Hereford producer bulls as well as by means of pedigree breeding of Hereford cows and calves imported from Russia and Hungary for the production of marbled beef. Breeding background of obtained purebred calves was determined by DNA-testing method in accordance with the international standard of certification. Into the breeding group of created meat type of Hereford cattle in the analyzed cattle breeding enterprise there were selected 1183 heads, including 24,2% of purebred animals and 17,2% hybrids of the third and fourth generations. The breeding estimation thoroughbred Hereford cattle showed that all producer bulls belonged to the class elite-record. The percentage of cows and heifers of the elite-record class was 89,3% in the conditions of growing number of a thoroughbred livestock on 98 heads. Purebred young stock in number of 45 heads and their mother passed the estimation of their origin by DNA method-testing.