Terms Of Milk Yield Research Articles

Reproductive ability and milk productivity of mares of different genealogical lines of Argaleisky type of Transbaikal breed

Productive herd horse breeding in Transbaikal region is one of the traditional branches of animal husbandry. The problem of preserving and improving local (aboriginal) horse breeds in our country is extremely important for their eff ective economic use and maintaining the diversity of the original gene pool of farm animals. Therefore, line breeding is an important aspect of horse breeding. The purpose of the research was to study the reproductive ability and milk productivity of mares of diff erent lines of Argaley type of Transbaikal breed. Research was carried out at the APC “Plemzavod imeni Kalinina” in the Aginsky district of the Trans-Baikal Territory. The objects of the study were mares of Transbaikal breed of Argaley type of diff erent genealogical lines origin, the age of the mares was 8–9 years after 4–5 foalings. The conformation and constitutional features and live weight of mares depending on their genealogical lines origin have been presented in the article. The average fertility performance rate for mares of different lines was 93,7 %, with foaling being 98,8 %. The greatest live weight was in mares belonging to the line Argali. It exceeded the indicators of herdmates from the lines Premier, Chetkiy and Kagor by 20,0; 15,0, 10,0 kg, respectively. During 5 months of lactation, mares of the line Argali produced 1854,0 kg of milk with an average daily milk yield of 12,36 kg. Mares of the line Argali over 5 months of lactation were superior to herdmates of other lines in terms of milk yield by 459,0; 336,0 and 223,5 kg and average daily milk yield by 3,06, 2,24 and 1,49 kg, respectively. It has been established that the physicochemical composition and environmental safety of milk from mares of the different lines of Argaley type of Transbaikal breed indicate its fairly high nutritional value.

Характеристика быков с разным генотипом гена OLR по продуктивности женских предков

The aim of the research was to assess the origin of Black-and-White breed bulls with different genotypes according to the low-density lipoprotein receptor (OLR1) gene. The object of the study was one sample represented by 58 bulls-producers of black and motley breed belonging to JSC "Head breeding enterprise "Elite" of the Vysokogorsky district of the Republic of Tatarstan. A preliminary assessment of the breeding value of Black-and-White bulls with different genotypes for one of the lipid metabolism marker genes (low-density lipoprotein receptor - OLR1), which are mainly used in insemination of dairy cows bred in the Republic of Tatarstan, is presented. As a result of a molecular genetic study (PCR-RFLP), the animal population was selected by groups, taking into account the genotype at the loci of the OLR1 gene. Evaluation and selection based on indicators of milk productivity of mothers, mothers and fathers of bull mothers showed that producers with AA and AC genotypes of the low-density lipoprotein receptor gene had the greatest breeding significance in terms of milk yield and mass fraction of fat in the milk of female ancestors. Thus, the parental index of bulls with AA and AC genotypes of the OLR1 gene was 9071 kg, 3.90% and 9510 kg, 3.95% in terms of milk content and fat mass, which is slightly higher than in bulls with CC genotype by 817 kg and 1256 kg (P<0.05) of milk, 0.03-0.08% fat, respectively.

Productivity and milk quality of Saanen and Anglo- Nubian breeds of goats under the conditions of the Lower Volga region

Prospects for the development of dairy goat farming and goat milk production in many countries of the world, including Russia, are directly related to the dietary and healing properties of the product. An urgent problem is the comparative assessment of the adaptive and productive traits of dairy goats of imported selection under various ecological and climatic conditions of Russia, including the conditions of the sharp continental climate of the Lower Volga region. The purpose of the work was to give a comparative assessment of the eff ectiveness of breeding lactating goats of Saanen and AngloNubian breeds of imported selection under the conditions of the sharp continental climate of the Lower Volga region. The object of research was imported dairy goats. Two groups of female goats of Saanen and Anglo-Nubian breeds of the fi rst lactation of 10 heads in each were formed, taking into account their live weight, age of insemination and origin. The duration of the scientific and farm experiment was 210 days.Consistently high milk yield was found in goats of Saanen breed compared with the milk yield of their herdmates of Anglo-Nubian breed. The signifi cant diff erence in milk yield in favor of Saanen goats by months ranged from 13,24 to 16,51 % (p < 0,05). In general, during lactation the superiority of Saanen goats over their Anglo-Nubian herdmates in terms of milk yield was 61,2 kg or 15,75 %. A comparative analysis of quality indicators revealed a significant superiority of milk from goats of Anglo-Nubian breed such as in the mass fraction of fat by 1,48 abs.% (p < 0,05), in the mass fraction of protein by 0,24 abs.% (p < 0,05), in terms of milk fat yield by 3,15 kg (p < 0,05). It was found as a result that in the production of milk from goats of Anglo-Nubian breed, the level of profitability of milk with basic fat content (3,5 %) was higher by 27,78 abs.% compared with herdmates of Saanen breed.

ECONOMIC USEFUL AND BIOLOGICAL SIGNS IN PUREBRED AND CROSS-BRED COWS OF THE UKRAINIAN BLACK-AND-WHITE DAIRY BREED UNDER THE EFFECTS OF HIGH TEMPERATURES AND TYPES OF FEEDING

The results of studies of economically useful and biological traits in purebred (Ukrainian Black-and-White dairy breed) and cross-breed (Ukrainian Black-and-White dairy breed x Swiss) cows are given, taking into account the effect of high temperatures and types of feeding. At the same time, it was established that purebred cows exceeded crossbred cows in terms of milk yield, but were inferior to the latter in terms of milk quality (fat content, protein content). In general, the advantage in milk fat and protein yield in favor of crossbred cows, in the section of three lactations, was from 3.0 to 9.5 kg and from 2.6 to 6.4 kg, respectively.
 Along with this, the dependence of heat resistance of cows on their genotype was established. Cross-breed cows were characterized by better adaptation properties to the effects of hot weather conditions, as they had more balanced indicators of heat resistance.
 Analysis of indicators of milk productivity of cows with different types of feeding showed that the use of the same type of feeding provides an increase in milk yield per 533 kg of milk, fat content by 0.14% and protein by 0.01% compared to traditional feeding technology.

INFLUENCE OF PHENOTYPIC TRAITS OF COWS ON THEIR MILK PRODUCTION

The research was conducted in LLC JV "Imeni Volovikova", Rivne region (Polissya zone, n=1840), SE DG "Oleksandrivske", Vinnytsia region (Forest-Steppe zone, n=714) and SE "Experimental farm "Askaniyske" (Steppe zone, n=926) on firstborn and full-grown cows (III lactation) of the Ukrainian Black-and-White dairy breed. In the controlled cows, by retrospective analysis of zootechnical accounting data for the last 10 years, the signs of milk production were studied depending on phenotypic traits (live weight of newborns, 6-, 12- and 18-month-old animals), age and live weight at first calving, duration of the first service period).
 It has been established that animals of the Ukrainian Black-and-White dairy breed in different farms are characterised by rather high live weight during the period of their rearing. The highest values of this trait in newborn and 18-month-old heifers were observed in the Forest-Steppe zone, and in 6- and 12-month-old heifers - in the Polissya zone. The best average daily growth from birth to 6 months of age was observed in heifers from the Polissya zone, and in all subsequent age periods and from birth to 18 months - in animals from the Forest-Steppe zone. The highest values of the relative speed and tension of live weight growth of heifers were noted in the period from birth to 6 months, and these indicators decreased with age. Intergroup differentiation in terms of reproductive capacity was observed in the first-born heifers of the controlled farms. Animals from the Steppe zone had the highest live weight at first calving and the shortest duration of the first service period, while animals from the Forest-Steppe zone were the fastest maturing. Cows from the Steppe zone were also the best in terms of milk yield.
 The formation of milk production of first-born cows was significantly influenced by their live weight during the growing period. In the Forest-Steppe zone, the most productive were the first-born cows with a live weight of 40-42 kg at birth, 181-190 kg at 6 months of age, 321-335 kg at 12 months of age and 421-435 kg at 18 months of age; in the Polissya zone - 43 kg and more, 181-190 kg, 321-335 kg and 421-435 kg, respectively; in the Steppe zone - 43 kg and more, 191-200 kg, 336 kg and more and 421-435 kg. Multidirectional relationships were observed between the live weight of first-born heifers at different ages during their rearing and signs of milk production. In animals from the Forest-Steppe zone, they were insignificant and in almost all cases unreliable, while in first-born cows from the Polissya and Steppe zones these relationships were somewhat more significant and in most cases reliable.

Application of the BLUP Animal Model method in assessing the breeding value of the breeding stock of Ayrshire cattle

The aim of the study is to assess the breeding value of the breeding stock of Ayrshire cattle from 13 breeding farms in various regions of the Russian Federation using the BLUP Animal Model method.Materials and methods. The analyzed sample included data on 14,450 cows with a first calving date of 1987 – 2021, which were analyzed for identification errors and discrepancies in the dates of birth of parents and offspring. The forecast of the breeding value of cows based on milk productivity traits for 1 lactation was made using the best linear unbiased forecast method BLUP Animal Model using the RStudio program.Results. The dynamics of milk yield EBV values during the studied time period with different numbers of first calving cows was studied. EBV estimates varied not only depending on the level of absolute milk yield of first-calving cows, but also under the influence of factors such as reproduction, the number of herds being assessed, as well as management, by which herds differed.Conclusion. The assessment of breeding value using the BLUP AM method made it possible to reliably evaluate the studied array of animals of the Ayrshire breed breeding stock on farms in the Russian Federation. The best and worst producers in terms of milk yield were identified, taking into account the effects of various factors.

309 Dairy Cow Response to Heat Stress Modeled with a System Dynamics Approach

Abstract Modeling the individual animal response to heat stress (HS) conditions is challenging because of the complex interactions that characterize the system behavior. In explaining the resulting animal behavior, the dynamicity, nonlinearity, and delays in the HS response are often unaccounted for or misinterpreted. The system dynamics (SD) methodology, a mathematical modeling approach based on feedback loop structures, allows for modeling and understanding the behavior of complex systems over time. By applying SD methodology, this study developed a preliminary conceptual model to capture the cow response and observed milk yield (MY) under HS. The data on the temperature-humidity index (THI) and MY used for model development were collected from a dairy cattle farm in August 2021. The parameters related to the HS response of 20 selected cows were used for calibration and parameterization of the model. To minimize the effect of the lactation stage on milk production and model results, 20 cows were selected for days in milk (DIM) to be between 70 and 220 d. After the parameter calibration using MY data, it was found that the historical data pattern of 13 out of 20 cows followed the expected behavioral pattern generated by the model. In contrast, the behavior of the remaining seven cows did not align with that generated by the model. Therefore, based on their patterns, the cows were identified as fitting or non-fitting the model’s structure. The structure of the model captured the effect of HS on fitting cows with high accuracy (mean absolute percentage error, MAPE < 5%; R2 > 0.6; concordance correlation coefficient, CCC > 0.6). At the same time, the behavior of the non-fitting cows could not be explained by the defined parameter space. We believe they either had heat-resistant behavior or experienced different biological delays than average. Based on the obtained results, the evaluation of parameter values should be done only for the fitting cows, as the work aimed to develop a model to understand the HS response. The behaviors generated by the model can help farmers and decision-makers distinguish heat-sensitive from heat-tolerant cows and quantify the animal response in terms of MY so that mitigation strategies can be implemented.

Allelic frequency of beta-lactoglobulin gene in different cattle breeds

The results of research on the frequency of genotypes AA, AB, BB and alleles A and B of milk protein beta-lactoglobulin in various cattle breeds over the past decades were presented and summarized. The livestock of the following foreign countries was considered: Italy, India and the Czech Republic. Also, on the territory of the Russian Federation, breeding stock and sires of the Republic of Bashkortostan, Tatarstan, Pskov, Samara and Arkhangelsk regions, as well as sires in the Altai Territory, were studied. Black-and-White breed is the most studied one. Moreover, there are data on the Simmental and Kholmogory breeds of cattle. The frequency of allele B among the breeding stock of Black-and-White breed in farms ranged from 0.21 to 0.64. The frequency of allele B among the breeding stock of Simmental breed in farms ranged from 0.42 to 0.65. The frequency of allele B among the breeding stock of Kholmogory breed in farms was from 0.60 to 0.70. The frequency of allele B among sires of Black-and-White breed ranged from 0.43 to 0.69. In most farms, BB genotype leads in terms of quality indicators of milk productivity, and AB genotype leads in quantitative indicators of milk productivity. However, in some farms, AA genotype prevails in terms of milk yield and protein, and this genotype is also associated with a high content of dry skimmed milk residue and resistance to mastitis. Thus, further in-depth study of the beta-lactoglobulin gene is necessary, since new data will expand the understanding of the effect of this gene on economically useful traits of animals and will eliminate contradictions in the available data.

The influence of the behavior of cows and the method of feeding a grain mix-ture on their milk productivity

At the “Pchany-Denkovych” farm of the Stryi district of the Lviv region, the influence of the behavior of Simmental cows and the method of feeding a grain mixture on their quantitative and qualitative composition of milk depending on the level of feeding was studied, as well as the possibility of using ethological assessment as one of the criteria when selecting animals for industrial use. It was established that there was a slight advantage in terms of expenditure on foraging behavior by classes in active and ultraactive individuals in both experimental groups of cows. Thus, animals from the first and second groups of the active class spent the most time on feed consumption, respectively – 21.4 and 22.0 min, which is 20.2 and 19.6 % more than the rate of infrapassive animals (17.8 and 18.4 min). A similar pattern was found in cows and in terms of time spent on water consumption. Thus, cows of the infrapassive classes spent the least amount of time on water consumption, respectively – In the first group – 9.6 minutes, and in the second group – 10.5 minutes. Cows of the active class with a high level of general activity of the first and second groups spent the most time on water consumption, respectively – by 16.3 and 16.6 minutes. The influence of the level of general activity of cows on their milk productivity was established - with an increase in the level of activity, an increase in milk productivity was observed. It was established that the cows belonging to the active class were characterized by the highest milk yield. At the same time, in order to increase the efficiency of the use and assimilation of feed, it is recommended to feed concentrated feed to dairy cows in portions – part of it as part of the feed mixture, and part of it during the milking of the cows. It was established that the cows of the first group with a low level of general activity, which received concentrated feed during milking, were characterized by the lowest milk productivity. Thus, the infrapassive animals of the first group had a 15.1 % (Р < 0.05) lower hope for lactation, compared to the peers of the active class, which were given the feed mixture in portions. In each class, there were also differences in milk productivity depending on feeding Thus, the cows of the second group exceeded their peers from the first group of different classes of ethological activity in terms of milk yield, respectively – by 2.4, 3.9, 2.1, and 2.9 %, given the grain mixture during milking. A little higher the milk productivity of the animals of the second group is associated with better eating of the feed mixture and the content of the percentage of concentrated feed in the recipe. Better consumption of feed mixture by animals contributed to greater consumption of nutrients in the diet, which was reflected in the milk productivity of cows. It was established that the density and acidity of milk of different classes of ethological activity were within normal limits. There are practically no differences in these indicators between groups, and small intergroup fluctuations are statistically improbable.

Effect of Yeast Cell Wall on Gut Health, Immunity and Milk Production of Dairy Cattle in Normal and Heat Stress Conditions. Review

This review focuses on the most recent literature to bring to light the major beneficial effects of the yeast cell wall (YCW) and its products on dairy cattle. These products include viable yeast, yeast culture, nutritional yeast, and fractionated yeast products. The yeast cell wall is one of these products and belongs to the fractionated yeast products used to promote production performance and health in dairy cows. The yeast and YCW were proven to have positive impacts on dairy cattle performance in terms of milk yield, milk components, and overall quality. As well, these products showed beneficial effects under heat stress conditions. The YCW is a natural fermentation derivative of yeast cells such as Saccharomyces cerevisiae species consists mainly of β-glucan (29% to 64%), mannan (31%), and some other compounds like protein (13%), lipids (9%), chitin (1–2%) with β-glucan and mannan being the main bioactive molecules. The mode of action through which YCW elicit their beneficial functions in dairy cow explain their effect on cows' metabolism and digestion, immunity, rumen and intestine health, and subsequent performance and well-being. These modes of action include improving gastrointestinal (GI) tract health, stimulating immune system components as it is considered an immunomodulator additive, mycotoxin binding ability, and improving antioxidant capacity. Therefore, yeast and YCW products are one of the promising areas of ruminant nutrition in dairy cows, not only because of their nutritional and health benefits to dairy cows but also due to their negligible residual effects on dairy cows’ bodies and products.

Improvement of the Red Steppe cattle by the Holstein breed gene pool

The results of the comparative assessment of productivity, reproductive ability and profitability of milk production when using cows of the Red Steppe breed and the crossbreeds of different blood relationship by the Holstein breed of the Red-and-White color type are presented. The studies of economically useful traits and profitability were conducted in 2019-2022. The objects of the research were representatives of the Red Steppe breed (control), mixtures with 50% (1st experimental group) and 75% of the blood of the Holstein Red-and-White color type (2nd experimental group). The superiority of the crossbred heifers over their herd mates of the Red Steppe breed in terms of milk yield was established: for the 1st lactation it was 605-673 kg (p > 0.999), for the 2nd lactation it was 714-788 kg (p > 0.999), for the 3rd lactation it was 817-868 kg (p > 0.999). The highest coefficient of the milk yield was observed in Holstein F1 and F2 crossbreeds (9.4-9.7 kg), whose average advantage during all lactations ranged from 0.9-1.2 kg (p > 0.95-0.99). In all analyzed service-periods, the highest fertilization rate after the first insemination was demonstrated by the Red Steppe breed animals; as a result, their semen consumption was on average 0.2-0.5 doses lower than that of the Holstein crossbreeds of different blood relationship. Cows of the Red Steppe breed had the highest reproductive ability coefficient 0.98-1.01 units vs. 0.85-0.95 units for crossbred cows. The analysis of the feed efficiency shows lower costs per unit production by cows of the first and second generations, in which they were 0.95-0.98 EFU, which is lower than in the Red Steppe breed peers, by 1.11-1.12 EFU. Milk production by half-blooded crossbreeds was more profitable 30.8-32.9% with no significant differences between the Red Steppe and high-blooded Holstein individuals.

Effects of dairy cows' personality traits on their adaptation to an automated milking system following parturition

The objectives of this study were to determine how dairy cow personality traits affect their adaptation to an automated milking system (AMS) upon parturition, as well as whether these personality traits are consistent across the transition from gestation to lactation. Sixty Holstein dairy cows (19 primiparous and 41 multiparous) were assessed for personality traits using a combined arena test conducted at 24 d before parturition and 24 d after first introduction to an AMS, which occurred ∼3 d after parturition. The combined arena test comprised 3 parts: a novel arena test, a novel object test, and a novel human test. Principal component analysis of the behaviors recorded during the personality assessment revealed 3 factors interpreted as personality traits (75% cumulative variance) in the pre-calving test, interpreted as explore, active, and bold. The post-calving test revealed 2 factors (78% cumulative variance), interpreted as active and explore. Data from d 1 to 7 after introduction to the AMS were summarized by cow and associated with the pre-calving factors, and data from d 21 to 27 after introduction to the AMS were summarized by cow and associated with the post-calving factors. The active trait had a moderate positive correlation between the pre- and post-calving tests, whereas exploration had a weak positive correlation between tests. Cows that scored high for activeness in the pre-calving test tended to have fewer fetching events and a higher coefficient of variation of milk yield in the first 7 d after introduction to the AMS, whereas bolder cows tended to have higher milk yield during that period. In the post-calving test, more active cows tended to have more frequent milkings and voluntary visits per day, as well as a lower cumulative milk yield from d 21 to 27 after introduction to the AMS. Overall, these results indicate that personality traits of dairy cows are associated with adaptation and performance in an AMS, and that personality traits are consistent across the transition period. Specifically, cows that scored high for boldness and activeness adapted better to the AMS immediately after calving, whereas cows that scored low for activeness and high for boldness performed better in terms of milk yield and milking activity in early lactation. This study demonstrates that personality traits affect milking activity and milk yield of dairy cows milked with an AMS and, therefore, may be useful for selection of cows who might best adapt to and use an AMS.

On-Farm Water Use Efficiency: Impact of Sprinkler Cycle and Flow Rate to Cool Holstein Cows during Semi-Arid Summer

Sprinkler cooling is a common heat abatement method in dairy cows and uses huge quantities of groundwater. Sprinkler flow rate and timing affect cow cooling and water use efficiency, but little is known about how these strategies may influence dairy cow performance under heat stress conditions in Pakistan. The objective of this study was to evaluate the cooling efficiency of different sprinkler cycles and flow rates in Holstein Friesian cows under semi-arid summer conditions in Pakistan. Thirty (30) lactating cows were subjected to 2 sprinkler flow rates and 3 sprinkler cycle strategies in a crossover design. Flow rates were 1.25 and 2 L/min, and the sprinkler cycles (water on|off) were: 3 min on|3 min off, 3 on|6 off, and 3 on|9 off. Results showed that the 1.25 L/min flow rate had a similar performance to the 2.0 L/min group in terms of milk yield and behavior, despite using 37.2% less water. The respiration rate was lowest in the 3|3 sprinkler cycle (SC) group, followed by the 3|6 and the 3|9 SC groups, respectively. Milk yield in the 3|3 group was 2 kg/d higher than the 3|9 group. In conclusion, these findings suggest that the 3|3 sprinkler cycle and 1.25 L/min flow rate may be a more efficient option in terms of water use while maintaining cow performance in semi-arid heat stress conditions.

ANALYSIS OF THE GENOTYPE PARAMETERS FOR SELECTION OF RABBIT DOE OF DIFFERENT STRUCTURAL ELEMENTS HYLA CROSS

Modern methods of breeding rabbits are based on the use of genotypic parameters, the assessment of which allows effective work on increasing the productivity of rabbits. The aim of the work was to study the indices of heritability of female rabbit productivity traits, to establish a relationship between them, and to determine the influence of males on the performance of doe productivity. The research was conducted using rabbits of the ancestral forms of the Hyla cross - male GPC (n=47) and female rabbits GPD (n=79), as well as doe of the maternal form - NG (n=223). The heritability of breeding traits of female rabbits was studied, the correlation and regression between them were evaluated, and the influence of males with different weight indices on the productivity of doe of the maternal form. The results of research indicate that doe of the maternal form prevailed over females of the ancestral form in terms of milk yield by 1814 g (р ≤ 0.01), but were inferior to them in terms of multifertility. Evaluating the correlation coefficients between the characteristics of the performance of female rabbits of the ancestral form, a probable (р ≤ 0.05) average inverse relationship (r = -0.561) was found between multiple fertility and high fertility. In female rabbits of maternal form, there was a strong direct relationship between high fecundity and live weight of rabbits at the age of 21 days (r=+0.794) (р ≤ 0.05). It was established that the main reproductive characteristics of female rabbits of the maternal form have low heritability (0,04-0,21). The probable influence of males with different weight indices on doe fertility was revealed (21% (р≤0.001)) and on the milk yield (18% (р≤0.001)) of the maternal form. The obtained research results will have significant practical value when planning breeding work with various structural elements of the Hyla cross.

INFLUENCE OF GENOTYPE AND PARATYPE FACTORS ON THE REALIZATION OF MILK PRODUCTIVITY OF COWS

The article examines the influence of genotypic and paratype factors on the milk productivity of cows of the ukrainian red-spotted dairy breed in the conditions of LLC "ATZT Myrne" of the Kitsman district of the Chernivtsi region. As a result of own research, it was established that cows of different genealogical formations differ in milk productivity, which indicates their hereditary influence. Cows of the Cavalier Rf line had the highest indicators of milk productivity during the first lactation: hope – 6402.1 kg, milk fat – 233.9-247.7 kg, milk protein – 201.3-212.8 kg (P<0.05). They exceeded their peers in milk yield by 101.8-734.9 kg, milk fat by 5.0-36.6 kg, milk protein by 5.3-29.2 kg. Cows of the Chief line had the highest hope for the third lactation – 6193.9 kg. They exceeded their peers in milk yield by 172.5-1436.9 kg, milk fat by 11.4-53.0 kg, milk protein by 7.9-46.9 kg (P<0.05; P<0.01; P<0.001). It was established that the highest milk yield in 305 days of the first lactation was in the daughters of the bull G. Arti Et Red Tv Tl Ti (6889.1 kg). They exceeded their peers in terms of milk yield, milk fat and milk protein by – 497.0-1974.7, 18.7-78.3, 16.9-68.1 kg, respectively (P<0.01; P<0.001). The results of our research prove that the milk productivity of cows depends on the line and origin of the father by 11.3-25.4%. The greatest influence on productive indicators of animals is the origin of the father, its power of influence on fertility is 25.4%, the content of fat and protein in milk is 16.5-24.3%.

Методы совершенствования продуктивных качеств скота палево-пестрых и черно-пестрых пород

The article presents the results of individual linear selection in the Sychevskaya and Blackand- White breeds based on the use of domestic breeding lines (in the Sychevskaya breed) and lines of the Holstein breed in the Sychevskaya and Black-and-White breeds, carried out under the conditions of the Smolensk region. The study used materials from the breeding records of farms in the Smolensk region. The object of the study were cows descendants of the line breeding of the Sychevskaya and Black-and-White breeds of different genealogical affiliation. Lines of bulls of domestic selection in the Sychevskaya breed: Albert 4191, Anis 4593, Vakhter 4333, Danzig 3641, Clover 68, Levant 5091 Ratmir 2003, Toreodora 3032; in Holstein fawn and black-and-white color Vis Beck Idial 1013415, MontvikChiftein 95679, ReflectionSovering 198998, SilingTraijun- Rokit 252803, Governor Of. Kornation 629472, PabstGoverner 882933. The selection efficiency is reflected by a significant excess of the level of milk productivity in terms of milk yield, milk fat and protein content. Cows obtained from Holstein lines in the Black-and-White breed, compared with cows obtained from domestic lines, in the Sychevskaya breed significantly exceed the indicators of milk productivity. The study also showed an excess of productive qualities in cows of the Sychev breed of imported lines.

ԳԵՐՄԱՆԻԱՅԻՑ ՆԵՐԿՐՎԱԾ ՀՈԼՇՏԻՆ ՑԵՂԻ ԿՈՎԵՐԻ ԿԱԹՆԱՅԻՆ ՄԹԵՐԱՏՎՈՒԹՅՈՒՆԸ ՀՀ ԱՐՄԱՎԻՐԻ ՄԱՐԶԻ «ՊԵՊԻԱԳՐՈ» ՏՆՏԵՍՈՒԹՅԱՆ «ԽԵԼԱՑԻ» ԱՆԱՍՆԱՇԵՆՔԻ ՊԱՅՄԱՆՆԵՐՈՒՄ

The study was conducted on Holstein cows, which were imported from Germany and kept in the “smart” barnyard of the “Pepi Agro” farm at the Armavir Marz of the Republic of Armenia. According to the results, during the first lactation, 5827 kg of milk was yielded, fat and protein contents in milk were 3.82 and 3.27 %, live weight was 535 kg, and milk yield was 10.9 with the average milk flow rate of 2.37 kg/min. According to the 1990 appraisal, these cows exceeded the standards of the Holstein breed in terms of milk yield, fat, and protein content, as well as live weight. However, their milk yield was lower than the mothers bred in Germany by 2933 kg or 50 %. We propose to continue the importation of Holstein cows and their further breeding in “smart” farming conditions in the Republic of Armenia.

МОЛОЧНАЯ ПРОДУКТИВНОСТЬ КОРОВ ДОЧЕРЕЙ БЫКОВ-ПРОИЗВОДИТЕЛЕЙ РАЗНЫХ ЛИНИЙ И ГЕНОТИПА КАППА-КАЗЕИНА

The aim of the study was to study the milk productivity of cows of daughters of sires with different linear affiliation and kappa-casein genotype. An analysis was made of the productivity of Black-and-White cows, originating from 60 sires of different lines, as well as those evaluated by the kappa-casein gene, which were used in Krasny Vostok Agro JSC. It has been established that cows of the R. Sovering line are characterized by the highest rates of economically useful traits, with an advantage in milk yield by 65-281 kg, in live weight by 6-24 kg, in terms of milk production index by 1-8 kg, in terms of milk yield by 0.01-0.12 kg/min. The worst indicators of productivity were found in animals of the Governer line. In general, interstrain differences are not high and productive indicators are within the normal range. When analyzing the milk productivity of the daughters of sires, carriers of various kappa-casein genotypes, it was revealed that cows of fathers with the AA genotype for kappa-casein have higher quantitative indicators of milk productivity and significantly (P<0.05-0.001) exceed the CSN3 AB and CSN3 EE by milk yield per 254-715 kg, by the amount of milk fat by 8.5-23.9 kg, by the amount of milk protein by 9.2-27.2 kg. At the same time, daughters of bulls with the CSN3 AA genotype are characterized by the maximum proportion of milk protein in milk, with an advantage over other groups by 0.03-0.12% (P<0.05-0.001). The CSN3 EE group is characterized by a high fat content in milk (4.11%) and exceeds other groups by 0.07-0.10% (P<0.01-0.001). Thus, the daughters of bulls with the AA CSN3 genotype had a higher milk production.

Molecular Marker-Assisted Selection of ABCG2, CD44, SPP1 Genes Contribute to Milk Production Traits of Chinese Holstein.

Based on our results of genome-wide association analysis, we performed gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis; three candidate genes (ABCG2, CD44, SPP1) were screened in this study for SNPs association analysis with production traits in 999 Holstein cattle. In this research, flight mass spectrometry genotyping was used to detect the polymorphism of SNP seats. It was shown that four, four, and two single nucleotide polymorphisms (SNP) loci were detected for the ABCG2, CD44, and SPP1 genes, respectively, and the different genotypes of these 10 SNPs significantly affected the milk production performance of Chinese Holstein cattle in terms of milk yield, milk fat percentage, milk protein percentage, somatic cell score, and urea nitrogen content. Among them, ABCG2-G.80952G > T locus, ABCG2-G.120017G > A locus and CD44-G.2294G > C locus had significant effects on somatic cell score (p < 0.01). Cows with GG genotypes at ABCG2-G.80952G > T locus, AA and GG genotypes at ABCG2-G.120017G > A locus, and GG genotypes at CD44-G.2294G > C locus had lower somatic cell scores. The present study elucidated that ABCG2, CD44, and SPP1 could be selected for marker-assisted selection and will benefit for future precise molecular breeding.

GROWTH, REPRODUCTIVE CAPACITY AND PRODUCTIVITY OF COWS OF DIFFERENT BREEDS, METHODS OF SELECTION AND PATERNAL ORIGIN

GROWTH, REPRODUCTIVE CAPACITY AND PRODUCTIVITY OF COWS OF DIFFERENT BREEDS, METHODS OF SELECTION AND PATERNAL ORIGIN