Cytogenetic analysis of breeding animals makes it possible to identify animals carrying cytogenetic abnormalities, the rate of spontaneous and induced somatic mutagenesis and the level of general genomic instability of animals. Scientists emphasize that in breeding work it is desirable to use animals whose offspring inherit high productivity and do not carry a genetic burden. The main factors that contribute to chromosomal instability are environmental factors, enzyme failure, changes in the system of repair or replication of chromosomes, suppression of immunity. It is important that the methods of breeding farm animals also have an impact on the stability of their karyotype. The appearance of deconsolidation of heredity and destruction of gene adaptive complexes during animal crossing has been established. This also applies to the use of related breeds, but obtained in different environmental conditions. As a result, aneuploidy, polyploidy may occur. It is proved that with the help of cytogenetic methods it is possible to establish new sources of genetic variability and prevent the spread of harmful chromosomal aberrations in animal populations. Such work was carried out on the Ukrainian brown dairy breed, created by crossing the local swan breed and related Swiss breed of American and European selections. That is, a related breed was used in its creation, but it had a difference in the selection system and ecological conditions of detention, which in turn may affect the stability of the karyotype of the new breed. The aim of our work was to study the variability of the karyotype of cows of the Ukrainian brown dairy breed. Materials and methods. Cytogenetic analysis, which was aimed at establishing the karyotype variability of Ukrainian brown dairy cows, was performed on biological material obtained from animals kept in the breeding plant of the State Enterprise "Research Farm of the Institute of Agriculture of the Northeast NAAS NAAS Sumy region. 15 cows were studied. Cytogenetic drugs were obtained from peripheral blood lymphocytes taken from the jugular vein using standard techniques. RPMI-1640 medium, bovine serum (preferably embryonic), antibiotic gentamicin, mitogen, a substance that stimulates mitotic division of lymphocytes in culture (phytohemagglutinin type P), were used to cultivate blood cells. The mixture was cultured in a thermostat at +37°C for 48 hours. Two hours before fixation, a solution of colchicine heated to 37°C at a final concentration of 0.3–0.5 μg/ml of culture medium was introduced into the culture. Freshly prepared 0.55% potassium chloride solution was used for hypotension. After hypotension, the culture was centrifuged, the supernatant was drained, and cooled to +4°C fixing fluid was added to the precipitate by mixing one part glacial acetic acid with three parts methyl (or ethyl) alcohol. The obtained preparations, after staining with the finished Giemsa dye, were analyzed for chromosomal variability under immersion magnification of the microscope by 1000 times and photographed. 100 metaphase plates were analyzed in each animal. The number of dinuclear lymphocytes (DJ), mononuclear lymphocytes with micronuclei (MJ), and mitotic index (MI) were counted on the same drugs. The frequency of DIA, IU, MI was calculated in ppm (number per 1000 cells). Analysis of karyotype variability of the studied animals showed the presence of quantitative and structural disorders of chromosomes. Quantitative disorders were detected in the form of aneuploidy, the average of which was 5.7%. Multiple chromosome enlargement (polyploidy) in the studied animals was not detected. The average value of asynchronous divergence of the centromeric regions of chromosomes was 0.5%. The limit of variability of ARCR in the studied cows was 0–5.0%, and structural chromosome abnormalities manifested themselves in the form of chromosomal breaks and amounted to 2.1%. According to the results of the micronucleus test, the proportion of lymphocytes with a micronucleus was 1.9‰, binuclear lymphocytes – 3.9‰, and the value of the mitotic index – 3.5‰. A positive relationship has been established between aneuploidy and ARCR, which are considered a prerequisite for chromosome loss; aneuploidy and mitotic index (P < 0.05), binuclear lymphocyte and mitotic index. A negative correlation was found between chromosome breakage and micronucleus lymphocyte. In animals of different blood levels according to the Swiss breed, chromosome set disorders in the form of aneuploidy were detected, the average values of which were 6.0 and 5.0%, respectively, which corresponds to the limit of spontaneous chromosomal variability. in the studied cows of brown dairy breed higher positive values were found between lymphocytes with a micronucleus and the duration of the service period and the interbody period. It was found that 43% of cows had stillborn calves during the life of the uterus with quantitative chromosome abnormalities (aneuploidy). In animals with undetected aneuploidy, only 25% of cows had stillborn calves during their lifetime. According to the results of cytogenetic testing of cows of the Ukrainian brown dairy breed of different linear affiliation, increased variability of the karyotype of animals of the Stretch line has been established. The results of the micronucleus test of brown dairy cows of different linear affiliation indicate the absence of mutagenic factors. Conclusions. Quantitative and structural chromosome disorders are characteristic of Ukrainian brown dairy cows. In animals of conditional blood status of 95% and more of the Swiss breed, the highest percentage of cells with aneuploidy (6.0%), the presence of asynchronous divergence of the centromere regions of chromosomes (0.63%) and chromosomal breaks (2.87%). According to the results of the micronucleus test, the cytogenetic parameters of cells (lymphocytes with a micronucleus, dinuclear lymphocytes and mitotic index) are 95% higher in animals of conditional blood status and more in the Swiss breed compared to animals of lower conditional blood status. karyotype (aneuploidy) on the percentage of stillbirth of calves and the proportion of lymphocytes with a micronucleus for the duration of the service and interstitial period. Differentiation of quantitative and structural chromosome disorders in brown dairy cows of different linear affiliation has been established. The fact of detection of chromosomal abnormalities indicates the need to significantly expand the scope of the survey of breeding stock, and especially in the leading breeding farms for the cultivation of Ukrainian brown dairy breed.

Los componentes biológicamente importantes de la leche son la grasa, la proteína, la lactosa y los minerales. Gracias a ellos, es una parte significativa y esencial de la dieta humana. En los últimos años, entre los componentes de la proteína, la beta-caseína ha ganado gran importancia y popularidad entre las personas que se preocupan por su salud. Por lo tanto, la composición beta-caseína de proteínas lácteas y productos lácteos se ha convertido en una característica de cría importante de los animales lácteos. Este estudio tiene como objetivo evaluar las perspectivas para el uso del polimorfismo del locus de beta-caseína en la selección de ganado marrón para determinar la posibilidad de crear rebaños de piscina genética con características únicas de la leche – exclusivamente con beta-caseína A2. La estructura genética identificada de las vacas y toros de la raza Lebedyn por beta-caseína, la participación de los toros de la raza original de la raza suiza marrón (BS) según el modelo recíproco propuesto, permite formar poblaciones homocigotas de genotipos A2A2 en generaciones posteriores. Un enfoque individual para las cuestiones de coincidencia y selección, control, con la ayuda de métodos de diagnóstico de ADN, por los procesos de transmisión de genes de padres a descendientes, permitirá reponer rebaños con portadores del gen A2. El modelo de cría propuesto en combinación con el uso de espermatozoides sexados y el genotipado de novillas, tiene la mayor aceleración de selección de la creación de una población homocigota para beta-caseína A2A2.

Marker-dependent breeding is one of the most relevant areas for improving the dairy productivity of cattle. It allows the selection of parent forms at the gene level. The growing demands of the market for milk quality make it necessary to select dairy herds using genetic markers associated with qualitative characteristics of milk productivity. A topical issue in dairy cattle breeding today is the study of the relationship between hereditary factors that determine the types of proteins in milk. Casein is the main component of milk proteins and is represented by three fractions – alpha (CSN1S1), beta (CSN2) and kappa (CSN3). The content of individual casein fractions depends on the breed of cows. Genetic variants of beta-casein significantly affect human health, while kappa-casein is associated with the quality of milk and the greater suitability of milk for processing and cheese production. The aim of this work is to evaluate the genotype of sires approved for use in Ukrainian farms in 2020 based on beta- and kappa-casein genes. Materials and methods. The research was conducted by analyzing the catalog of bulls of dairy and dairy-meat breeds for breeding stock reproduction in 2020. Bulls were analyzed according to the genotype of beta – and kappa-casein of Holstein (n = 872), Simmental (n = 17), Montbellard (n = 3), (wro.synel.net; motbeliarde.org) Jersey (n = 59), Red Danish (n = 8), Red Norwegian (n = 7), Schwyz (n = 17), Aishir (n = 8) breeds, evaluated by offspring quality and genomic assessment. The website DairyBulls.com is used to analyze the results of the evaluation of bulls-producers on a set of characteristics. The research results were processed by mathematical statistics methods using the "Statistica-6.1" package in a Windows PC environment. It was found that the majority of bulls-producers approved for use were evaluated based on these genotypes. Depending on the breed, the number of bulls estimated by the studied characteristics ranged from 43 to 85%. Depending on the breed, from 2 to 16 different combinations of beta- and kappa-casein genotypes were identified. The frequency of occurrence of the desired complex genotype A2A2/BB, depending on the breed, was in the range of 0.0 to 75.0%. Holstein bulls of the desired A2A2/BB genotype were estimated to be superior to bulls of some other complex genotypes in terms of daughter milk yield, the amount of milk fat, milk protein, lifetime profit indices, cheese profit, and milk profit. Therefore, the use of sperm production of bulls with the A2A2/BB genotype will improve the economically useful characteristics of offspring, and will further increase the number of livestock with the desired complex genotype. Summary. 1. Taking into account the data of many domestic and foreign scientists who claim that the genotype of animals by the beta – and kappa-casein polymorphism affects the qualitative composition of milk, it is necessary to have in herds the necessary number of animals carrying the A2 allele of beta-casein and the B allele of the kappa-casein gene. The desired breeding parameters of the herd can be achieved by using bulls with BB genotypes for kappa-casein and A2A2 for beta-casein. Correction of the bulls-producers selection system can only be carried out if the breeding stock of the herd is genotyped according to the polymorphism of the beta-and kappa – casein genotypes. Holding this event will increase the protein content and will improve cheese suitability of milk of cattle of future generations. The use of bulls-producers without taking into account their genotypes for the casein fractions described above and the lack of polymorphism control of these genes among cows can lead to a decrease in the frequency of desired genotypes in the herd and a decrease in the technological qualities of milk as raw materials. 2. The created database of bulls-producers approved for use in Ukraine, evaluated by the beta-and kappa – casein genotypes, allows us to establish a positive perspective on the possibility of forming staffed herds of animals with the desired complex A2A2/BB genotype in Ukraine. 3. It was found that bulls of dairy breeds have different frequencies of beta – and kappa casein alleles. The part of bulls-producers of the desired complex genotype A2A2/BB of Holstein breed is 8.49%, Holstein Red-pockmarked – 2.94%, Schwyz – 75%, Jersey – 13.79%, Red Danish – 12.5%, Red Norwegian – 20.0%, Montbellard – 25%. Among animals of Simmental and Aishir breeds – bulls with the desired complex genotype A2A2/BB were not detected. 4. Bulls of the desired complex genotype A2A2/BB according to the indicators of milk yield of daughters, the amount of milk fat, milk protein, indices of lifetime profit, profit for cheese, profit for milk were dominated bulls with separate complex genotypes CSN2-CSN3

Sklyarenko, Y.I. (2018). Features of milk productivity of cows of Ukrainian brown dairy breed and the influence of genotypical and paratypical factors on its formation. Scientific MessengerThe indicators of milk productivity of cows of Ukrainian brown dairy breed were studied. The research was carried out on the basis of breeding farms of animal breeding of this breed by assessing the data of primary zootechnical accounting. It is established that the level of milk productivity of cows meets the breed standard and is within 4.5 thousand kg of milk. A significant correlation between the indicators of milk productivity and reproductive capacity was found. Milk productivity is negatively correlated with the main indicators of reproductive ability. The influence of genetic and paratypic factors on the formation of milk productivity was studied. It is established that a conditional bloodedness, linear membership and origin in the father significantly affects the level of milk productivity of cows. The impact of genetic factors increases from conditional crow nest of Swiss breed to descent on the father. Animals with the highest proportion of Swiss breed were significantly dominated by other animals by the milk yield per the first lactation. The highest milk yield in the first lactation were obtained from the animal of Vigate 083352 line and the smallest of Payvan 136140 line. By the greater amount of milk fat and protein, the animals of the Vigate 083352 line also prevailed. Animals from different bulls for the first lactation had milk yield in the range of 2780-4464 kg of milk, the amount of milk fat and protein, respectively, 103-176 kg and 89-134 kg. A big impact on the economy of milk production having a term of economic use of animals. Therefore, in our view longevity as a symptom of dairy cows is an important selection basis. The significant influence of genotypic factors on the indicators of the duration of use and lifetime productivity of cows was established. The greatest impact of the paratypical factors had the farm, which contains animals. The conditions of keeping and feeding in the farm had a significant impact on the duration of use and lifetime productivity of cows. The presence of significant influence of genotypic and paratypical factors on the milk productivity of animals makes it possible to improve its breeding and technological activities.

Thanks to the breeding work carried out to create the Sumy intra-breed type of the Ukrainian Black-and-White dairy breed, it was possible to increase the level of milk productivity of animals, which today amounts to more than 6.0 thousand kg of milk. The level of milk yield is the main in the system of dairy cattle breeding. The quality indicators of dairy raw materials are also of great importance for the economy of milk production. This issue has become particularly important recently, which is associated with the negative consequences of using the Holstein breed, namely, a decrease in the level of fat and protein in milk compared to local breeds. Researchers attach great importance to the study of individual fractions of milk protein and their impact on technological qualities during its processing. Therefore, new achievements in genetics and biotechnology have been widely applied in practice. Genetic markers are even more widely used in global dairy cattle breeding. The latter allow us to identify individual genotypes at many loci and provide information about population parameters, such as alleles and genetic frequencies. Dairy cattle breeding programs in many countries around the world take into account genetic research. This is due to the possibility of rapid improvement of the quality and technological properties of milk. The effect of capa-casein genotypes on milk quality has been studied by many scientists. The capa-casein gene polymorphism has been known since 1964. By 1988, the capa-casein gene of cattle was isolated and its structure was characterized. To date, thirteen genetic variants of cattle capa-casein have been described: А, В, C, D, E, F, Н, J, I, Х, Az, A1. Genetic variants A and B are the most common, while other alleles are quite rare. The interest in this casein fraction is due to the fact that cheese from the milk of cows with the BB genotype thickens 25% faster and has a clot twice as dense as milk from cows with the AA genotype, and accordingly the yield of cheese from the milk of cows of the BB genotype is 10% higher than from the milk of cows of the AA genotype. The aim of our work was to study the features of the formation of the genealogical structure of the Ukrainian Black-and-White dairy breed in the Sumy region and its influence on the frequency of capa-casein genotypes. Materials and methods. The research was conducted at the State Enterprise "Experimental Farm of Institute of Agriculture of Northern East of National Academy of Agrarian Sciences of Ukraine" of Sumy region on the number of cows of the Ukrainian Black-and-White dairy breed (n = 23) (first group) and Sumy intra-breed type of the Ukrainian Black-and-White dairy breed (n = 40) (second group). Retrospective studies were conducted by studying the ORSEC SUMS database for the period from 1976 to 2020. The capa-casein gene polymorphism was determined in the genetic laboratory of the Institute of Physiology n. a. Bogomolets of NAS using real-time molecular biological analysis of allele recognition by polymerase chain reaction (PCR). The results obtained were processed by the method of variational statistics using the statistical 6.0 software package. The formation of an array of Sumy intra-breed type of Ukrainian Black-and-White dairy breed on the farm was started in the mid-80s of the last century. So on the breeding stock of the Lebedinian breed began to use the sperm of bulls-producers of the Holstein breed. Bulls-producers of the Holstein lines Aidial 1013415, S. T. Rokita 252803, Sowering 198998, M. Chiftein 95679, Eleweishna 1491007 and Astronaut 1458744 were involved in this process. Further formation of the genealogical structure of the herd of the Ukrainian Black-and-White dairy breed and Sumy intra-breed type had their own characteristics. Thus, in the period from 1991 to 2000, the breeding stock of animals of the Ukrainian Black-and-White dairy breed came from bulls-producers of 8 lines, while Sumy intra-breed type belonged to 13 lines. The most common lines in the first animals were – Aidial 1013415, Sowering 1989986, M. Chiftein 95679 in the second – Eleveishn 1491007, M. Chiftein 95679, Chief 1727381. The period since 2001 has been characterized by the fact that the formation of the genealogical structure of black and white herds in Sumy region was accompanied by the use of purebred bulls of the Holstein breed. The share of bulls of Ukrainian Black-and-White dairy breed was less than 10%. This contributed to the fact that the breeding stock of breeding herds belonged mainly to three Holstein lines: Chief 1427381, Eleweishna 1491007 and Starbuck 352790. We have found that the frequency of capa-casein is somewhat different in animals of different origins. Thus, animals of Sumy type were characterized with a higher frequency of both the desired homozygous BB genotype (20%) and the homozygous AA genotype (60%). A higher frequency of the heterozygous AB genotype (36%) was characteristic of animals of Ukrainian Black-and-White dairy breed. At the same time, the frequency of alleles was almost the same. There is a difference in the frequency of genotypes and alleles by capa-casein between first-born animals of different parental affiliation. Altodegri 64633889 bull daughters were characterized by a higher frequency of homozygous desired BB genotype. High frequencies of heterozygous AB genotypes were found at daughters of bull Morian 1402173979. All daughters of the bulls Detective 349159846, Maygold 534651702 were homozygous AA. The highest frequency of the BB allele was characteristic of the daughters of the bull Altadegri 64633889. Conclusions. According to the results of the study, the peculiarities of the formation of the genealogical structure of the herd of the Ukrainian Black-and-White dairy breed, which was formed according to various programs, were established. The genealogical structure at the beginning of herd formation had its own characteristics and depended on breeding directions. The period of the last twenty years in the region is characterized by the total use of Holstein Bulls on the breeding stock of the Ukrainian Black-and-White dairy breed, which explains the linear belonging of the majority of livestock to the lines of Chief 1427381, Eleveishna 1491007 and Starbuck 352790. The consequence of this is a high conditional bloodline in the Holstein breed of the firstborn. According to the results of genetic research, it was established that in the herd of Ukrainian Black-and-White dairy breed the genotype of cattle by capa-casein significantly depended on the origin. Thus, Sumy type animals are characterized by a higher frequency of homozygous genotypes – 80%, while the frequency of alleles in animals of different origins is almost the same. Parental origin also had a significant effect on the genotype of animals on this basis.