Cows Of Different Breeds Research Articles

Amino Acid Composition, Antioxidant and Antihypertensive Activity in Extracts from Mexican Añejo Cheese.

Authentic Mexican cheeses have potential health benefits, although there are few studies on their bioactive components. In this study, we analysed soluble extracts from añejo cheese from Zacazonapan (Mexico), obtained from two dairies (A and B) that used milk from cows of different breeds and differed in processing. The soluble extracts of Zacazonapan añejo cheese during ripening (0, 30, 95 and 180 days) were used to determine proximate composition, amino acid composition, peptide profile, molecular mass profile, antioxidant and antihypertensive activities. The molecular mass of the released protein fragments ranged from 0.10 to 22.43 kDa. During ripening, amino acids such as Pro, His, Tyr, Trp, Met, Cys, Ala, Gly, Leu and Val were present, which are associated with antioxidant activity. The inhibition of β-carotene bleaching was below 50 % at all ripening times. A significant difference between the cheese samples was observed only after 180 days. Amino acids associated with angiotensin-I converting enzyme (ACE-I) inhibition were found in the extracts (Trp, Phe, Tyr, Pro, Lys and Arg). The highest activity was observed in cheese ripened for 180 days (IC50 of cheese A and B was 0.38 and 0.42 mg/mL, respectively). These results suggest that Zacazonapan añejo cheese is a potential source of antioxidant and antihypertensive peptides, which are influenced by the dairy factor (milk source and production technique) and ripening time. This is relevant as there are no reports of these bioactivities in this type of cheese.

Genotyping of Holstein Cows by SELL, MX1 and CXCR1 Gene Loci Associated With Mastitis Resistance.

Mastitis is a significant factor that decreases milk production in cows of different breeds in Kazakhstan. The objective of this study was to determine the genetic makeup of Holstein cows by analysing specific gene loci (SELL, MX1, CXCR1+291C>T and CXCR1+1093C>T) that are linked to resistance against mastitis. The goal was to identify cows with favourable genotypes that are less prone to udder diseases. At the SELL gene locus c.567T>C, all three genetic variants were identified in the control population with the respective frequencies: TT (0.20), CT (0.44), and CC (0.36). Genetic variation was also detected at the MX1 gene c.567T>C, CXCR1 c.+291C>T and CXCR1+1093C>T loci. Deviation from the expected Hardy-Weinberg equilibrium was observed for two gene loci, MX1 g.143182088 and CXCR1+1093C>T, with increased chi-square values of 10.6261 and 9.7137, respectively. The analysis of subclinical mastitis incidence indicates that cows carrying the heterozygous CT genotype at the L-selectin gene locus exhibit greater resistance to the disease. Animals carrying the CCCCCT genotype at the MX1 c.567T>C, CXCR1 c.+291C>T and CXCR1+1093C>T gene loci were discovered to have a significant likelihood of developing subclinical mastitis. This suggests that these genes could serve as potential indicators of susceptibility to the condition. The practical significance of this study lies in determining the frequency of genotypes linked to mammary gland morbidity in Holstein breeding farms in Kazakhstan.

The use of a recombinant equine chorionic gonadotropin (reCG) in fixed-time AI programs in beef cattle

The aim of the current study was to evaluate the effect of a novel recombinant eCG (reCG) on pregnancy rates to AI (P/AI) in suckled beef cows of different breeds that were synchronized with an estradiol/progesterone (P4)-based protocol for fixed-time AI (TAI). In experiment 1, 1244 Bos taurus suckled cows were used. On Day 0 all cows received an intravaginal P4 device (600 mg P4) and 2 mg of estradiol benzoate. On Day 7, devices were removed, and all cows received 0.150 mg of D-cloprostenol plus 1 mg of estradiol cypionate and were randomly divided to receive 140 IU or 105 IU of reCG or no reCG treatment (controls) at that time. Cows were tail painted for estrus detection and those in estrus by 48 h after P4 device removal were inseminated; whereas those not showing estrus were also inseminated and received GnRH at the same time. In experiment 2, 818 Bos taurus x Bos indicus crossbred suckled cows received the same FTAI protocol used in Experiment 1. Cows were randomly divided at the time of P4 device removal into 4 groups to receive 140 IU, 105 IU or 84 IU of reCG or no reCG treatment. In experiment 3, 345 Bos indicus suckled cows were submitted to the same FTAI protocol as those in previous experiments and were randomly divided into three groups to receive 140 IU or 105 IU of reCG, or 300 IU of serum derived eCG (PMSG). In Experiment 1, estrus rate and P/AI was greater (P < 0.05) in cows treated with reCG (79.9 and 53.5 %, 76.9 and 52.3 % for the 105 UI and 140 UI reCG groups, respectively) than those in the control group (69.9 and 44.4 %, respectively). In Experiment 2, cows treated with reCG tended (P < 0.1) to achieve a greater P/AI than control cows (38.6 %, 37.1 %, 36.2 % and 28.2 % for those receiving 84 IU, 105 IU,140 IU of reCG, and those in the control group); but when P/AI of all cows treated with reCG was contrasted to that of control cows, the difference was significant (P < 0.01). In Experiment 3, P/AI in cows treated with 84 IU of reCG (54 %) did not differ from that of cows treated with serum derived eCG (59 %) but both were greater (P < 0.05) than cows treated with 105 UI of reCG (41 %). In conclusion, treatment with reCG improved fertility in suckled Bos taurus and Bos taurus x Bos indicus beef cows. In suckled Bos indicus cows, although treatment with reCG and serum derived eCG were comparable, the higher dosage of reCG was detrimental to their P/AI.

Features of hematological status of cows of different breeds of Western Siberia

Features of hematological status of cows of different breeds of Western Siberia

Identification of some genetic markers as productive and reproductive traits in Ukrainian dairy cattle breeding

A Selection based on DNA markers is a breeding technique grounded in the genomic selection value of animals. The aim of the research is to study the genotypic profile of cows of different breeds in Ukrainian breeding in relation to the genes LEP, CSN3, TG5, BLG, and Pit-1 and to identify the probability of using them as markers for reproductive traits in cows. During the study, the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method was used to analyze the genes and determine their polymorphic characteristics. The obtained data indicated that the same gene variants have varying effects in the studied breeds due to their diverse influences on the genomic background. Specifically, the homozygous state of leptin genes (LEPCC) and pituitary-specific transcription factor (PIT-1BB) was observed to impact the reproductive characteristics of cows in the evaluated breeds. Meanwhile, for the genes casein (CSN3AB), thyroglobulin (TG5CT), and beta-lactoglobulin (BLGAВ), the heterozygous state of alleles was found to influence the key reproductive traits of dairy cattle of Holstein origin. The polymorphism of the genes CSN3, βLG, TG, PIT-1, and LEP indicated the presence of genetic potential for the reproductive function of cows and can be utilized as molecular markers in selective breeding, providing significant progress in improving not only the traits of dairy cattle productivity but also reproductive function. Therefore, in the implementation of selective breeding work, it is advisable to consider genotyping for the genes CSN3, βLG, TG, PIT-1, and LEP as an additional criterion for the selection of animals to enhance both their milk and reproductive characteristics.

Distribution, forms of clinical manifestation and features of postpartum metritis in high yielding cows of various breeds

Purpose: to study the forms of clinical manifestation and features of the course of postpartum metritis of inflammatory diseases of the uterus in highly productive cows of different breeds with free-stall and traditional technologies of their operation. The novelty of the work lies in the fact that for the first time the distribution and forms of clinical manifestations of postpartum metritis in cows of different breeds were studied under free-stall and traditional housing technologies.Materials and methods. The degree of distribution, forms of clinical manifestation and features of the course of postpartum metritis in highly productive cows of different breeds (n = 5345) were studied using traditional and free-stall technologies of their operation. To study the above indicators, anamnestic and veterinary data were used. Clinical and obstetric examination was carried out using generally accepted methods: transrectal palpation and ultrasound sonography, in accordance with the “Methodological manual for the prevention of infertility in highly productive dairy cattle”.Results. As a result of the studies, it was found that obstetric pathology is registered on average in 71.3% of new-born animals. The most frequently affected animals were the Holstein breed with an annual milk yield of 7500-8500 kg. They were diagnosed with postpartum metritis in 78.0-86.4 % of cases of the number of calvings. In cows of the Simmental breed of domestic selection with tether housing technology and an annual milk yield of 4000 to 5300 kg, obstetric pathology was recorded much less frequently, in the range of 59.3-65.1%. In highly productive Holstein cows, severe forms of the inflammatory process most often developed: purulent-fibrinous - in 12.4 %, purulent-necrotic - in 13.2 %, gangrenous - in 1.1 %, postpartum sepsis - in 0.8 % of cases , whereas it was not diagnosed in animals with traditional exploitation technology. The more frequent manifestation of severe forms of this disease in highly productive animals may be associated with a decrease in the general nonspecific resistance of their body. In 65.7%, postpartum metritis occurred in an acute form, regardless of the breed and conditions of detention.

THE CORRELATIVE VARIABILITY OF THE FINAL SCORE BY LINEAR CLASSIFICATION AND LIFETIME PRODUCTIVITY INDICATORS AMONG BLACK-AND-WHITE DAIRY COWS OF DIFFERENT BREEDS

A study on the correlative variability of the final score by linear classification and lifetime productivity indicators of Black-and-White Dairy cows of different breeds was conducted in the herd of the private enterprise "Burynske" in the Podlisniv branch of the Stepaniv territorial community. Foreign studies on the cows evaluation of different breeds by conformation type using the linear classification method were analyzed, which proved that the lifetime productivity indicators of animals depend on many genotypic and paratypic factors. In this direction, the existence of significant moderate and close positive correlations between the majority of linear traits and functional life of cows in the herd was established. It has also been proven that the final score level of cows by type is closely correlated with descriptive traits that significantly affect lifetime productivity indicators. According to the results of our own research, it was found that degree of the final score of first-born cows for the conformation type directly determines the variability level of indicators to the duration of use and lifetime productivity within both experimental breeds. Cows of the Holstein and Ukrainian Black-and-White dairy breeds with a rating of "very good" exceeded animals with ratings of "good plus" and "good" by indicators of duration productive use and milk productivity throughout life. Holstein cows rated "very good" were better than animals rated "good plus" and "good" in terms of lifetime milk yield and milk fat yield, respectively by 4589 and 21653 kg, and 191 and 918 kg. The final score, in the presence of a correlation with lifetime productivity indicators, can serve as a predictor of longevity, which will allow effective selection of first-born dairy cows based on the results of a linear evaluation in the first months of lactation.

Electrical conductivity and total dissolved solid of raw milk for the detection of bovine subclinical mastitis.

Bovine subclinical mastitis (SCM) is highly prevalent among dairy cattle. A cross-sectional study was conducted in Bangladesh to evaluate the performance of electric conductivity (EC) and total dissolved solids (TDS) tests for the detection of SCM. We randomly selected 108 milk samples from cows of different breeds in the primary milk-producing region of Pabna and Sirajgonj districts of Bangladesh. Samples were subjected to the California mastitis test (CMT), white side test (WST), electric conductivity (EC), TDS, and culture. A cow was considered positive for SCM if it tested positive in CMT, WST, and culture, whereas a cow was considered negative for SCM if it tested negative in all three methods. These gold standards have been used to evaluate the performance of the EC and TDS tests. The optimal EC and TDS cutoff values for the detection of SCM were determined using the "optimal cutoff" function in R version 4.3.1. The optimal EC cutoff value for SCM detection was found to be 6159 μS/cm or 6.16 mS/cm. A positive likelihood ratio (LR+) of 31.2 and an area under the curve (AUC) of 0.905 were obtained for this cutoff value. The optimal cutoff value for TDS was 3100 mg/L of milk, which resulted in a positive LR+ of 45.5 and an AUC of 0.924. To the best of our knowledge, this is the first study to evaluate the performance of EC and TDS tests in detecting SCM in Bangladesh. These results suggest that EC and TDS tests, which are inexpensive, rapid, and easy to conduct, can effectively detect SCM at the farm level.

GENETIC POTENTIAL FOR MILK AND CHARACTERISTICS OF LACTATION ACTIVITY OF COWS OBTAINED BY PUREBRED BREEDING AND CROSSING

GENETIC POTENTIAL FOR MILK AND CHARACTERISTICS OF LACTATION ACTIVITY OF COWS OBTAINED BY PUREBRED BREEDING AND CROSSING

Electrocardiographic Analysis of the Cardiac Activity of Large-Horned Cattle in the Ecological Conditions of the Republic of Karakalpakstan

In this article, the physiological basis of natural resistance in unfavorable environmental conditions of the Republic of Karakalpakstan, as well as indicators of bioelectric activity and effectiveness of the heart of cattle belonging to the black and Latvian brown breeds of different ages are determined. The study of the electrocardiogram of large-horned cattle was carried out under the influence of different intensity and duration of air temperature and solar radiation. To increase the fertility of large-horned cattle, the physiological mechanisms of adaptation of brought breeding animals to extreme conditions of the Republic of Karakalpakstan have been studied. Changes in the bioelectric activity of the heart have been detected in cows of different breeds (black, Latvian brown cattle, Zebu cattle) and calves that are now born and up to 6 months old. In this article, it is indicated that the functional state of the cardiovascular system of agriculture animals is one of the main physiological indicators through which it is possible to determine the nature of the impact of the environment on the body.

Milk productivity of cattle of different breed belonging under the conditions of Yakutia

The purpose of the work was to evaluate the milk productivity of imported purebred and locally selected cows of diff erent breed belonging under the economic conditions of the Republic of Sakha (Yakutia). The comparative characteristics of dairy productivity of cattle breeds imported to the republic and animals of local breeding have been considered. The research was carried out on the livestock of breeding cattle of Simmental breed in LLC “Ampaardaakh” in the Vilyuysky ulus, where heifers of Simmental breed were imported from the Novosibirsk region. In the daily ration of lactating cows of the farm, the content of energy feed units and digestible protein was 100,0 and 95,2 % of the standard feeding norm. In the fi rst lactation the milk yield of cows of the imported Simmental breed was 3198,8 kg of milk with a fat content of 3,94 %. A comparison of the productivity of cows of the original Simmental breed showed that they were more productive compared to their herdmates of Red steppe breed, which were imported to the republic from the Altai Territory. Thus, for all analyzed lactations 798, 1610, 1014, 1389 and 938 kg (P &gt; 0,999) more milk was received from cows of Simmental breed imported to the republic than from herdmates of Red steppe breed. Cows of Simmental breed imported to the republic were statistically signifi cantly superior to their herdmates of Simmental breed of local selection for all mature lactations (P &gt; 0,999). Comparison of the fat content of cows of diff erent breeds did not show significant differences. According to the yield of milk fat, imported cows of Simmental and Red steppe breeds had a higher indicator than Simmental cattle of local breeding (P &gt; 0,999).

Composition and cheese suitability of milk of cows of different breeds

The aim of this work was to compare the quality of milk and its suitability for processing into cheese in cows of the local Ukrainian black-and-white dairy (UBW) breed and their crossbreeds with the Swiss breed. The research was conducted on a commercial farm in Vinnytsia region. The first farm keeps purebred cows of the Ukrainian black-and-white dairy breed and crossbreeds of the first generation obtained as a result of crossing with the Brown Swiss breed. Two groups (purebred and local) analog cows were formed with 20 heads each. It was found that crossbreeding had a positive effect on the content of fat and protein in milk in crossbreeds UBW and Brown Swiss cows, these values were 0.21 and 0.13% higher than in purebred cows. At the same time, the crossbreeds lost some of their productivity - the average daily yield of UBW and Brown Swiss cows was 1.83 kg lower than that of purebred counterparts. The crossbreeds of UBW and Brown Swiss cows were dominated by purebred analogues in terms of energy value of 1 kg of milk and theoretically possible yield of rennet cheese by 0.141 MJ and 0.53 kg. The duration of the coagulation phase of milk obtained from crossbred cows was shorter than that of purebred analogues: in crossbreeds of UBW and Brown Swiss cows by 1.23 minutes. Samples of milk obtained from crossbreeds had the highest class on the characteristics of the rennet clot. Out of 20 studied samples of milk of UBW cows of breed 15 samples (75%) are referred to I and 5 (25%) - to II class; in the milk of UBW and Brown Swiss breeds of cows 17 (85%) - up to I and 3 (15%) - up to II class.

Changes of acute-phase proteins, glucose, and lipid metabolism during pregnancy in lactating dairy cows.

The study aimed to evaluate the effects of different stages of lactation (0 to 300 d) and pregnancy (0 to 180 d) on serum amyloid A (SAA), C-reactive protein (CRP), glucose, total cholesterol (TCho), and triglyceride (TG) concentrations in dairy cows of different breeds. Thus, 40 healthy multiparous cows (10 Holstein, 10 Simmental, 10 Brown, and 10 Modicana) were randomly selected, and blood samples were collected once every 60 d for 1 year. Overall, SAA and CRP serum concentrations progressively increased and became more variable along the lactation, peaking at 240-300 d, and then decreased in the last period ( 300 d). Along pregnancy, SAA and CRP initially increased, with the highest concentrations at 60-120 d, and then decreased until the last phase of pregnancy ( 180 d). However, lactation and gestation phases did not significantly affect SAA and CRP when all the cows were analyzed together. A significant and positive correlation was observed between SAA and CRP both along lactation ( ; ) and pregnancy ( ; ). Breeds only showed differences in CRP levels along gestation ( ), due to a peak registered at 0-60 d in Holstein cows. In pregnant cows, glucose was positively correlated with SAA ( ; ) and CRP ( ; ). Hence, these significant and positive relationships reflect the physiological adaptations of the dairy cows along both gestational and lactational dynamics, suggesting that these proteins may also be involved in non-pathological processes. In this perspective, this study established that the obtained response markedly varies among healthy individuals along lactation and gestation and thus that the physiological range of acute-phase proteins (APPs) is wide; this makes it difficult to use these proteins as a marker of different physiological reproductive and productive periods.

INFLUENCE OF BREEDING BULLS ON THE SIGNS OF THE EXTERIOR OF PRIMARY COWS OF UKRAINIAN BLACK-AND-WHITE DAIRY BREED IN SC RF "SHEVCHENKIVSKE"

A number of recommendations on the method of linear classification of dairy and dairy-meat cows by body structure type have been proposed in Ukraine and other countries. A certain experience of their implementation in practical selection was obtained. In recent years, the interest in the study of the exterior-constitutional features of dairy cattle has increased significantly, as it has become obvious that in countries where the improvement of livestock productivity was carried out simultaneously with the intensification of selection for exterior-constitutional qualities, positive results were achieved.Objective of the research: to study the influence of bogai breeders of different genealogical lines on the signs of the posteriority of the cows – the first Ukrainian Black-and-White dairy breed.&#x0D; The research was conducted according to the materials of the primary breeding stock in the breeding plant of the Ukrainian Black-and-White dairy breed DP "Shevchenkivske" of the Kyiv region. The materials of the electronic information database in the format of SUMS ORSEC were used. We evaluated the level of the first cows of the Ukrainian Black-and-White dairy breed at 2–5 months of lactation according to the method of linear classification.&#x0D; The differences in absolute values of certain dimensions of Ukrainian Black-and-White dairy cows of different breeds have been established.&#x0D; Relation of signs of the stud to the duration and efficiency of long-term use of cows has been investigated by many scientists. The results of our research testify to the presence of a significantly complementary and statistically significant correlation between both individual and group characteristics, the overall complex linear evaluation of dairy cows by the type of body structure and the duration of economic use and long-term productivity.&#x0D; Among the described features the sufficient correlation level was found for the breast width (r = 0.264 ... 0.11 with P &lt; 0.05), trunk width (r = 0.310 ... 0.10 with P &lt; 0.01) and compactness (r = 0.394 ... 0.10 with P &lt; 0.001). Also high level of correlation we have for the group signs of the mammary type (0.413 ... 0.11 for P &lt; 0.001), tulub (0.371 ... 0.12 for P &lt; 0.01) and nominal (0.370 ... 0.11 for P &lt; 0.001) for the general estimation of the type of corps (0.413 ... 0.11 for P &lt; 0.001).&#x0D; It is recommended to conduct selection of first-calf cows with the highest indicators by measurements and linear evaluation by type for maternity herds repair, which will provide more functional reliability and prolong the duration of economic exploitation of the cows.

Immunological and Nutritional Characterization of Bovine Colostrum: Effect of Some Variation Factors

Background: The importance of colostrum is twofold: it plays a role in the metabolism and nutrition of the newborn, in addition to its immediate supply of functional immunoglobulins. The current paper aims to study the main factors of variation in the nutritional and immunological bovine colostrum values at the Centre National de l’Insémination Artificielle et d’Amélioration Génétique (CNIAAG) of Baba Ali (Algiers, Algeria). Methods: The study was conducted on 23 colostrum samples from cows of different breeds (Prim-Holstein pie rouge, Prim-Holstein pie noire and Fleckvieh), from calving until the 11th day of milking. These females have calved during March 2020. Result: The results obtained indicate that the chemical composition of colostrum changes during milkings. The average rates of dry matter, protein and mineral matter, at the 1st milking, respectively 20; 9.70 and 0.95 g/100 g tend to decrease to reach milk standards. Unlike lactose rate which gradually increase from milking to another. The average concentration of colostrum in immunoglobulins, evaluated at 34.3 g/L at birth, decreases during the milkings that follow. The fall is considerable (89%) from the 2nd post-partum day.

КАЧЕСТВО ПРОСТОКВАШИ В ЗАВИСИМОСТИ ОТ ПОРОДЫ КРУПНОГО РОГАТОГО СКОТА

The aim of the work was to conduct a comparative assessment of the quality of yogurt made from milk of cows of different breeds. The milk of the black-and-white breed of cows was more acidic, less fatty and with a lower content of skimmed milk residue and was fermented longer than the milk of the Simmental breed cows. The curdled milk from the black-and–white breed was more liquid, and the Simmental milk was thicker. When the enzyme was added, the milk of the Sim-mental breed had the densest clot. In the curdled milk of a black-and-white breed with the addition of an enzyme, the clot was looser. Curdled milk from the Simmental breed of cows was the dens-est when using the enzyme. Curdled milk from the black-and-white breed contained more organic acids in terms of lactic acid. The content of organic acids without the use of the enzyme increased faster in the curdled milk of the black-and-white breed. The breed of cows has proved to be one of the main factors influencing the technological properties of milk and the quality of fermented milk products produced from it.

Effect of the fatty acid marker gene diacylglycerol o-acyl transferase 1 (DGAT1) on the fatty acid composition and organoleptic properties of samples of butter produced from the milk of domestic breeds of cows

In modern conditions, effective breeding work in animal husbandry is impossible without DNA technologies. The search for selective marker genes that determine the dairy productivity of animals allows us to more reliably assess the genetic potential of breeds, adjust breeding processes, and select animals of desirable genotypes. In the Republic of Belarus, almost no work was carried out to identify genetic markers that affect the fat content, fatty acid composition of milk fat, and as a result, the yield and quality of the finished product (butter). In this regard, a special interest is the diacylglycerol O-acyltransferase 1 (DGAT1) gene, which determines the fat content. The paper presents a comparative assessment of the fatty acid composition and organoleptic properties of butter samples produced from the milk of cows of natural selection according to the gene marker of fatty milk diacylglycerol o-acyl transferase 1 (DGAT1). The results of tests of the fatty acid composition of butter from cow’s milk obtained from cows of different breeds and pedigreed its balance, compliance with the established values for volatile and unsaturated fatty acids, absence of phytosterols and adulteration of the fatty phase of the oil were emphasised. The practical significance of the conducted research lies in the use of the results obtained to carry out targeted breeding of dairy cattle according to the gene marker of fat content of diacylglycerol o-acyl transferase 1 (DGAT1) in order to increase the mass fraction of fat in milk and the yield of the finished product, as well as to improve the technology of making butter from cow’s milk and the formation of an evidence base in case of disagreement when evaluating the fatty acid composition of the product.

STUDY OF BETA-CASEIN GENE POLYMORPHISM AND ITS RELATIONSHIP WITH MILK COMPOSITION IN SIMMENTAL COWS

STUDY OF BETA-CASEIN GENE POLYMORPHISM AND ITS RELATIONSHIP WITH MILK COMPOSITION IN SIMMENTAL COWS

The influence of different genotypes of kappa-casein and beta-lactoglobulin on the productivity of cows of Ayrshire, Holstein and Yaroslavl breeds

Under the conditions of intensification of dairy cattle breeding, genetic markers of protein-milk content, namely allelic variants of kappa-casein and beta-lactoglobulin, are increasingly used. They are established by the method of DNA testing on blood samples of breeding animals. This method is also being introduced in our country, which is especially important when selecting breeding sires for the artificial insemination network. The purpose of the research was to study the quality indicators of milk of cows bred in the region of breeds (Ayrshire, Holstein, Yaroslavl), and the protein-milk product produced from it as cottage cheese, depending on the influence of the genotype. The research has been carried out in CJSC “Agrofirma “Pakhma” in the Yaroslavl region. The object of research was cows of Ayrshire, Holstein and Yaroslavl breeds. The sample included 99 cows, including 36 animals of Ayrshire breed, 33 Holstein and 30 Yaroslavl breed. A comparative comprehensive evaluation of the dairy productivity of cows of Ayrshire, Holstein and Yaroslavl breeds under the conditions in one herd using DNA testing has been carried out, for the entire productive period of economic use, the realization of the genetic potential has been traced. For the first time in the Yaroslavl region DNA testing of Ayrshire cows was carried out and new data on the polymorphism of the CSN3 and LGB genes in Holstein and Yaroslavl cows were obtained. The association of CSN3, LGB genotypes and complex genotypes with milk productivity and technological properties of milk has been investigated. The yield and quality of cottage cheese from the milk of cows of different breeds in association with CSN3 genotypes have been studied. As a result of studying the quality indicators of milk of cows of different breeds and the protein-milk product produced from it as cottage cheese, depending on the influence of the genotype. It has been found that cows of different breeds and different genotypes had significant differences in the quality of milk and cottage cheese produced from it, which must be taken into account when conducting breeding work with these breeds.

Поліморфізм гена капа-казеїну у корів різних порід молочного напряму продуктивності

Genetic polymorphism of milk proteins, in particular kappa-casein, is of considerable research interest due to its possible associations with economically important traits of dairy cattle. The aim of the study was to determine the polymorphism of the kappa-casein gene and its association with signs of milk productivity in cows of different breeds. Polymorphism of the kappa-casein gene was studied in cows of Ukrainian red-spotted dairy (UCHERM), Ukrainian black-spotted dairy (UCHRM), Montbeliard (M) breeds and crossbred cows obtained by crossing cows of Ukrainian red-spotted dairy breed with Mongolians. DNA studies were performed in the Department of Animal Genetics and Biotechnology of the Institute of Animal Breeding and Genetics nd. a. M.V.Zubets NAAS using the PCR-RFLP method. As a result of research, three genotypes of the kappa-casein gene were identified: AA, AB, BB. Genotypes AA and AB were found in all studied groups of cows, genotype BB was found only in cows of Montbeliard breed with a frequency of 0.366. The highest hopes for 305 days of the first lactation among all studied cows were in crossbred cows with genotype AB (7029 kg), the lowest - in crossbred animals with genotype AA (6359 kg). According to the distribution of genotypes and alleles of the kappa-casein gene, domestic breeds of UCHRM and UCHERM are similar in genetic structure and have a low concentration of B-allelic variant, apparently due to the fact that these breeds were created by reproductive crossing with Holstein breed, in populations of which this allele quite low. The presence of such genotypes in the studied groups of first-borns is determined by the peculiarities of selection work in the herd of SE "DG" Niva "of the Institute of Animal Breeding and Genetics named after MV Tooth of NAAS ». Research results genotypes and alleles of the kappa-casein gene is an additional genetic characteristic of animals, which makes it possible to create herds with the desired characteristics of milk productivity