First-calf Cows Research Articles

Impact of diferent types of selection on the milk productivity of Kostroma breed cows

The article studies the influence of homogeneous and heterogeneous selection on the milk productivity of first-calf cows (milk yield, fat and protein content in milk). The object of research is cattle of the Kostroma breed. The research methods were zootechnical, population-genetic and analytical using computer programs IAS “SELEX” Multifarm and BON-MilkRegion. The modern cattle breeding base in the Kostroma region is represented by three breeding plants and two breeding reproducers. In 2022, the Karavaevo Breeding Farm JSC received 9,297 kg of milk per cow, the Minskoe LLC pedigree reproducer received 7,371 kg of milk, and the Rodina collective farm, Gridino and Agrofirma Planet LLC received more 6000 kg of milk. Record milk yields reach 15,000 kg of milk or more in 305 days of lactation. The following lines have been identified as promising in the Kostroma breed: lines Ladka 2537 and Kursa 3722, related groups Master 106902, Meridian 90927 and Concentrate 106157. To improve the productive qualities of dairy cattle, it is necessary to use both intraline selection and cross-lines, taking into account their compatibility. In breeding farms, using homogeneous selection, high productivity indicators were obtained: in terms of milk yield - from first-calf heifers of the related groups Laird, Concentrate and Meridian, in terms of fat and protein content in milk - Laird and Ladka. With heterogeneous selection, the best combinations were identified across farms.

ОЦЕНКА КОРОВ-ПЕРВОТЁЛОК ЧЁРНО-ПЁСТРОЙ ПОРОДЫ ПО ДНК-МАРКЕРАМ, АССОЦИИРОВАННЫХ С ХОЗЯЙСТВЕННО-ПОЛЕЗНЫМИ ПРИЗНАКАМИ

At present time are widely used genetic markers as means in the selection of highly productive animals. Since the genes: CSN3 (kappa-casein), PIT-1 (pituitary-specific transcription factor), PRL (prolactin), GH (somatotropin) are polymorphic and encode various proteins, the study of their influence on the productive traits of cattle is relevant. In this regard, the goal of the work is to determine the influence of complex genotypes of the studied genes on the milk productivity of first-calf cows of the Black-and-White breed bred in the collective farm-breeding plant «Kazminsky» in the Kochubeevsky district of the Stavropol Territory. The place of research is the Department of Genetics and Biotechnology, VNIIOK, a branch of the North Caucasian Federal National Research Center. This article presents the results of DNA genotyping of allelic polymorphism for the CSN3, PIT-1, PRL, GH genes using PCR-RFLP methods in first-calf cows of the Black-and-White breed. It was established that these genes in the studied sample are polymorphic. The frequency of occurrence of the desired CSN3B allele in the studied sample was 0.23. The presence of alleles PIT-1A and PIT-1B of the pituitary-specific transcription factor gene was noted with a frequency of occurrence of 0.52 and 0.48. A feature of the PRL gene polymorphism was the fairly high frequency of occurrence of the PRLA allele (0.60). In this study sample of dairy cattle, the frequency of occurrence of the desired GHL allele of the somatotropin gene was 0.62. All variants of complex genotypes were also identified and their relationship with milk productivity in black-and-white cows was noted. The study sample was dominated by animals carrying complex desirable genotypes, consisting of four and three marker alleles of three and two genes (CSN3AB/PIT-1BB/GHLV; CSN3AB/PIT1AB/GHLL or PIT-1AB/PRLAB/GHLV; PIT-1AA/GHLL ) - 46.7 %. Milk yield per lactation between groups of black-and-white first-calf cows with different complex genotypes ranged from 5839.14 to 8611.33 kg. The mass fraction of fat in milk ranged from 3.93 to 4.04 %, and protein from 2.99 to 3.14 %.

Description of the linear features of the exterior of the first –calfs of different origin

In our country, a linear assessment of the exterior of animals is becoming increasingly widespread, which allows us to objectively assess the influence of the producer bull on the change in the most important exterior features that ensure the se-verity of the dairy type while maintaining high productivity and intensity of use in the herd. This ensures the ranking of animals by body type and helps to accelerate the genetic progress of productivity. In this regard, the introduction of a linear assessment of the daughters of breeding bulls in the herd of a breeding plant is relevant. We conducted research aimed at studying and analyzing the signs of a linear description of the exterior of the first-calf cows of the daughters of Holstein bulls and identifying the most common exterior flaws in one of the breeding plants of the Kirov region. The analysis of the data showed that the evaluated first-calf cows of different origins are characterized by exterior features: average height, body of medium depth, strong physique, pronounced dairy type. The most common disadvantages of the exterior of the examined heifer cows are: interception of the shoulder blades (25.6%), asymmetry of the udder lobes (23.0%), weak headstock (15.4%).

Продуктивность коров при разной комбинации линий

The purpose of the study was to study the milk productivity of cows with different combinations of lines. The object of the study were first-calf cows of the black-and-white breed of the line Vis Back Aidiala 101341, Reflection Soveringa 198998, Montvik Chiefteina 95679. Cows obtained by intraline selection of the Aidial line have a high level of milk productivity, with milk yield of 5571 kg of milk, milk fat yield of 226 kg and protein yield of 171 kg, while significantly (P<0.05-0.01) superior to first-calf heifers, belonging to the Sovering line for 102 kg, 4 kg of fat and 4 kg of protein, and to the Chieftain line - for 259 kg of milk, 16 kg of fat and 11 kg of protein, respectively. When crossing the Ideal-Sovering lines, the highest milk yield is observed (5667 kg), with good milk fat content (4.01 %), high yield of milk fat (227 kg) and milk protein (172 kg). With the reverse cross Sovering-Idial, slightly lower milk productivity rates were obtained. When using bulls of the Aidial line on cows of the Governer line, high milk fat content (4.07 %) and milk fat yield (228 kg) were obtained, with average values of milk yield (5596 kg), protein mass fraction (3.01 %) and its yield (168 kg). Unsuccessful combinations of lines in both forward and reverse directions are crosses of the Idial and Chieftain lines. The descendants of such combinations have the lowest milk productivity. Thus, the use of line manufacturers R. Sovering and V.B. Idiala, both with intraline selection and interline combination, gives the best milk productivity indicators. Consequently, it is necessary to evaluate bulls according to the compatibility of lines; this has a great influence on the productivity of the offspring, since sires of the same line, when inseminating cows of the same lines, produce offspring of different productivity.

THE INFLUENCE OF FEMALE ANCESTORS ON MILK PERFORMANCE IN FIRST- CALF COWS OF THE HOLSTEIN BREED DAIRY CATTLE OF DOMESTIC SELECTION

The results of studies on the influence of female ancestors on the milk performance in first-calf cows of the Holstein breed of dairy cattle of domestic selection are presented. The highest values of milk yield, the amount of milk fat and protein, as well as the mass fraction of protein in milk were observed in daughters whose mothers’ milk yield was over 10,000 kg and amounted to 9295 (p≤0.01), 341.3, 313.3 (p≤0.01) kg, 3.37% (p≤0.05), respectively. First-calf cows with a milk yield of MM 9001-9500–9227 kg (p≤0.001) have a high degree of abundant milk production. They also had the highest amount of milk fat and protein, which amounted to 344.8 (p≤0.01) and 309.4 (p≤0.001) kg, respectively. The highest milk yield, milk fat and protein content were in first-calf cows with a milk yield of MF over 14.000 kg. The realization of the genetic potential for milk yield over 305 days of lactation was 102.1%.

Ovarian dysfunction in cows and its distribution in black soil farms

A tendency was noted for an increase in the prevalence of ovarian hypofunction in cows with an increase in their milk productivity. On average, it is diagnosed in 28.9-43.9% of examined cows. It was noted that the prevalence of hypofunction decreased with the number of calvings in animals. In first-calf cows, ovarian hypofunction was registered in 37.6-52.8% of cases, which is 1.3-2.0 times higher compared to cows of the second lactation and 1.3-2.8 times higher compared to cows of the third or more lactations . The number of diagnosed cystic formations also increased with increasing milk production. In highly productive animals, ovarian cystic formations are diagnosed 1.3-1.8 times more often, including follicular - 1.4-1.9 times and luteal - 1.2-1.7 times.

Dairy productivity of Holstein cattle with different genotypes of the osteopontin gene (<i>OPN</i>)

The study was conducted in order to study the polymorphism of the osteopontin gene (OPN) and to evaluate the indicators of milk productivity of Holstein first-calf cows with different genotypes. The work was carried out in the agricultural complex "Plemzavod im. Lenin" of the Atninsky district of the Republic of Tatarstan and the laboratory of the Department of Physiology, Biochemistry, Genetics and Animal Nutrition of the TatNIISKh FIT KAZNTS RAS. Genotyping was carried out by PCR-PDRF at the locus of the OPN-Bse1 I gene. The analysis of the genetic structure showed that the studied population is polymorphic by the OPN gene. The distribution of alleles and genotypes was as follows: C-0.432 and T0.568; CC – 14.3% (37 goals), CT - 57.8% (149 goals) and TT - 27.9% (72 goals). The highest milk yield for 305 days of lactation and a high yield of milk protein was observed in individuals with the CC genotype. During DNA testing of 258 Holstein firstcalf cows by PCR-PDRF of osteopontin gene polymorphism (OPN), it was revealed that the studied cattle population is polymorphic and is represented by all alleles and genotypes. According to the content of the mass fraction of fat and the yield of milk fat, a statistically significant superiority is observed in animals with a heterozygous CT genotype. It has been established that the C allele has a positive effect on the signs of milk productivity and the qualitative composition of milk.

Comparative assessment of morphofunctional properties of the udder of the first-calf cows the caucasian brown breed of various genotypes

Relevance. The caucasian brown breed of cattle is the most common in Armenia. It has been bred in the republic for more than a century and, due to its low milk productivity and the form of the udder undesirable for machine milking, needs further improvement. Consequently, the study of the morphofunctional features of the udder of caucasian brown cows of various genotypes in the conditions of Armenia is necessary and relevant for science and practice.Methods. The object of the study is the first-calf cows of the Caucasian brown breed of various genotypes. For the experiment, 4 groups of first-calf cows of various genotypes were formed, 20 heads each: the control group — purebred caucasian brown cows first-heifers; 1st experimental — half-blood crossbreeds (1/2 caucasian brown x 1/2 holstein); 2nd experimental — two-breed crossbreeds (3/4 caucasian brown x 1/4 holstein); 3rd experimental — three-breed crossbreeds (5/8 caucasian brown x 1/8 jersey x 1/4 holstein). In the second and third months of lactation, the udders of experimental groups of animals were examined and studied by visual assessment, taking measurements and calculation methods.Results. A comparative study of the morphological features and functional properties of the udder of firstcalf cows of various genotypes has shown that the crossing of Caucasian brown cattle with producing bulls of Holstein and Jersey breeds has a positive effect on the level of milk productivity, the shape of the udder of cows and the rate of milk production, which is of great importance in industrial milk production technology.

Влияние новых кормовых добавок на продуктивность коров красной степной породы

Abstract. In dairy cattle breeding, feeding rations directly affect the general condition of animals, indicators of productive and reproductive capacity, as well as the level of nutritional and biological value of the raw materials obtained. The most important task of modern domestic cattle breeding is the development of balanced diets enriched with various feed additives, in particular, prebiotic orientation. The introduction of various prebiotics into the diet of first-calf heifers of the Red Steppe breed has an important practical significance. The aim of the work is to study the effect of new prebiotic feed additives “LaktuVet” and “LaktuSuper” on the productive ability of first-calf heifers, as well as on the qualitative and quantitative composition of the milk obtained. Methods. An experimental study was carried out at the dairy complex “Breeding farm – collective farm named after Lenin” of Surovikinsky district of the Volgograd region. During the experiment, it was planned to distinguish three groups of cows – the control and two experimental ones. The control group was fed with a standard diet approved at the complex. The experimental group I was fed with a standard diet with the introduction of the feed additive “LaktuVet” at a dose of 0.5 % by weight of the feed. For feeding the II experimental group, a standard diet was used with the introduction of the feed additive “LaktuSuper” 0.5 % of the mass of the consumed compound feed. The scientific novelty lies in obtaining new knowledge about the effect of new prebiotic feed additives on the productivity of cows, as well as changes in the physicochemical composition of the resulting milk. Results. It was found that the use of new prebiotic feed additives in the diets of first-calf cows contributed to an increase in the amount of milk received in animals of the I experimental group by 5.59 %, in analogues of the II group – by 8.07 % compared with the control group. The introduction of feed additives into the diet of the studied cows had a positive effect on the quality of the milk produced and its amino acid composition.

Polymorphic variants of the CD62L and ACSL1 genes in connection with the resistance of cows to mastitis

Relevance. In conditions of intensive dairy cattle breeding, the incidence of cows with mastitis continues to be an urgent problem. The number of somatic cells (CCCs) in milk is a breeding indicator for improving the health of the mammary gland of cows. The study of animal resistance to the disease, which is based, among other things, on the genetic component, will make it possible to increase the efficiency of breeding in the future. The purpose of this work is a comparative analysis of the relationship of polymorphic variants of the ACS L1 (rs208522533) and CD62L (rs41803917 and rs41803917) genes with indicators of milk productivity and the level of somatic cells in the milk of Ayrshire cows.Methods. A sample of first-calf cows of Ayrshire breed (n = 191) belonging to one of the breeding farms of the Leningrad region was formed. Animal genotypes were determined by PCR-PDRF. Analysis of the genotype frequency by rs208522533 of the ACS LI gene showed that 99% of the animals were carriers of the GG genotype.Results. The results of studies of the CD62L gene showed that rs41803917 determined a high frequency of the G allele (80.4%) and on average more than 60% of animals had the GG genotype. rs109966956 of the CD62L gene revealed a high frequency of the C allele (80.1%) and 64.9% of the animals had the CC genotype. High values of BOX PC were established in small groups of animals with the AA genotype according to rs41803917 (p £ 0.05) and the TT genotype according to rs109966956 (p £ 0.001). Individuals with the AG genotype according to rs41803917 of the CD62L gene had high protein percentages (p £ 0.05) and low BSC (p £ 0.05). The results obtained indicate that SNPs rs41803917 and rs41803917 of the CD62L gene can be considered as potential markers of resistance to mastitis in Ayrshire cows.

Productive Traits and Reproductive Capacity of First-Calf Cows at Different Selection Options

The research work is aimed at determining and establishing the degree of influence of various selection options on the productive and reproductive qualities of the first-calf cows of the black-and-white breed. The research results showed that according to the Parental Index of Cows (PIC), animals of the 5th experimental group surpass their mates in the 2 and 3 groups in milk yield by 746 kg, with p≤0.05 and 1746 kg, with p≤0.001 and the difference in fat content is 0.07 and 0.01%, respectively. The same advantage in milk yield over the 3 experimental groups is possessed by the 1st control and the 4th experimental groups 1827 and 1885 kg, with p≤0.001. In terms of protein, group 3 cows are inferior to first-calf heifers of groups 1, 2, and 5 by 0.03, 0.08, and 0.09%, with a significant difference p≥0.99. Groups 1, 2, and 5 have superiority over animals of the 4th -0.03%, with p≤0.05, as well as 0.05 and 0.06%, with p≤0.01. The Realization of the Genetic Potential (RGP) in milk yield for 305 days of lactation was higher in the 5th experimental group and amounted to 88.3%, which is 7.1% more than in the control, with p≤0.05. For milk fat, animals of groups 1 and 3 have a high potential of 99.5 and 99.9%. In terms of the mass fraction of protein, first-calf heifers of the 1st control and the 4th experimental groups surpass their mates from group 3 by 2.1 and 1.8%, with p≤0.05. The control group has the most optimal indicator of the calving period (406.5), while the tested ones exceed it by more than 40 days. The service period in all groups has been increased by almost 2 times. The highest calf crop (92.3%) and reproduction rate (0.92%) are observed in the control group.

Features of making soft cheeses from the milk of cows-daughters of different bulls-producers

Relevance . Milk, along with being a food product itself, is also a raw material for the production of a variety of dairy products, including cheeses. In the production of cheeses, additional requirements are imposed on milk. For the preparation of cheeses, milk of the second type is better suited, which forms a clot for 15–40 minutes. The study of the possibility of using the milk of cows-daughters of different bulls-producers for the production of cheese is relevant and has practical significance. Methods . The research was carried out in one of the typical breeding reproducers for the breeding of Holstein black-and-white cattle of the Sverdlovsk region in the period 2018–2022. The evaluation included first-calf cows that completed the first lactation, obtained and grown on the farm. All cows are daughters, descended from breeding bulls: Das, Sayan, De-Su, Gavano, Touareg, Marrs, Cassio, Bentley, having 15 or more daughters. The object of the study was the qualitative composition of the milk of the daughters of bulls-producers, as well as the control product obtained from milk — cheeses of the brand "Table fresh" and "Amateur fresh". The qualitative composition of milk was determined in the dairy laboratory of the Ural State Agrarian University. Results . As a result of the conducted studies, it was found that there are differences both in the content of individual components of milk, and in integral criterion — DSMR (dry skimmed milk residue). By the protein and casein content the milk of cows-daughters of Holstein bulls-producers met the requirements, the ratio of MFF and MFP in milk, which should be 1.1 : 1.25, in our case was 1.17; 1.17; 1.29; 1.17; 1.16; 1.20; 1.17; 1.16 respectively by groups of daughters. In terms of casein content, milk from the daughters of bulls-producers Das, De-Su, Gavano, Touareg, Mars, Bentley had lower casein values than specified in the requirements (at least 2.70%) by 0.01–0.06%. Regular changes in the quality of the clot, the efficiency of the use of milk and its components in the preparation of soft cheeses, depending on the origin—belonging to the bulls-producer — have been established. The research is exploratory and was carried out within the framework of scientific research of the Ural State Agrarian University, state registration number: AAAA19-1191014000069.

Variability of hematological parameters in cows depending on their physiological status

The object of the study was Holstein cows of the second-fourth milk secretion and first-calf cows of different production groups formed depending on the physiological status of the animals. The most pronounced hematological changes were observed in sexually mature cows during the first three months of milk secretion. After fawning, the number of erythrocytes, lymphocytes, and hemoglobin decreased. The concentration of bloodforming elements in the groups with a first-calf cow was significantly higher than in sexually mature cows. The level of erythrocytes and hemoglobin in first-calf cows reaches its maximum value at the beginning of milk secretion. Sexually mature cows after the first month of milk secretion were statistically significantly superior to first-calf cows at the beginning of milk secretion in terms of granulocyte content. Cows, in the first days of milk secretion, had the most fantastic range of variability in the scope of erythrocytes, leukocytes, and hemoglobin, which reflects the individual response of the body to significant changes in physiological status. At the same time, the first-calf cows at the beginning of milk secretion had the most stable level of these hematological indices. Dry cows, as a rule, occupied an intermediate position regarding the variability of the content of blood form elements. Thus, assessing the hematological profile of cows of different production groups helps specialists make targeted adjustments to rations and housing conditions, effectively manage genetic resources and obtain high profits.

Analysis of post-slaughter indicators of cattle bred on a collective farm (APK) named after Michurin, Vavozhsky district

The scientific and economic experiment was conducted in the conditions of the Michurin collective farm in the Vavozhsky district. The purpose of the research was to conduct a scientific and economic experiment to study the meat productivity of black-and-white cattle of different sex and age groups bred in the conditions of the Michurin collective farm (SHPC), followed by an assessment of the compliance of the beef obtained with the requirements of GOST 34120- 2017. The following experimental groups were formed in the experiment: 1 experimental group (AC) – adult cattle (cows of two or more calves); 2 experimental group (MCP) – young cattle, first-calf cows – young female cattle that calved once; 3 experimental group (MT) - young cattle, heifers aged from 8 months to two years. 4 experimental group (MB) - young animals, bulls aged from 8 months to two years. In the course of scientific and economic experience, it was found that among all sex and age groups of cattle entering for slaughter and primary processing at LLC Uvinsky Meat Processing Plant, only fattening bulls (a group of young animals) fully comply with the requirements of the modern standard GOST 34120-2017 in terms of carcass weight, morphological composition of carcasses.

The effective use of adaptogens of various origins on the cattle productivity.

In conditions of industrial animal husbandry, it is necessary to pay attention to the immune system, which regulates metabolic processes in the body of animals. To do this, additives with adaptive properties attract attention. The aim is to define a way to increase productivity using adaptogens of plant and animal origin in feeding cattle. In the farms of the Orenburg region and the Republic of Bashkortostan, which differ in climatic conditions, scientific and economic experiments were done on Kazakh white-headed bulls and first-calf cows of black-and-white breed, whose diet was introduced in the form of tinctures (at the rate of 0.01 ml of tincture per 1 kg of body weight), adaptogen may change (for animals of the II experimental group), drone homogenate (experimental group III), and pantocrine (experimental group IV), while the animals of group I were assigned to the control group and did not receive additives. The results of the evaluation of the live weight of bulls by age periods indicate that young animals consuming plant adaptogen exceeded control peers by 18 months of age by 18.60 kg (3.72%); animal origin-by 28.50 kg (5.71%; p < 0.05) and 21.00 kg (4.21%). A similar pattern was observed in cows, in which, against the background of the use of may chang, the milk yield for 305 days of lactation increased by 312 kg (5.61%; p < 0.05), drone homogenate-by 726.1 kg (13.04%; p < 0.001), pantocrine-by 494.4 kg (8.88%; p < 0.001). In all animals participating in the experiment, blood values were within the limits of physiological norms but with a slight increase toward the upper regulatory limits in the experimental samples. There is an improvement in the qualitative composition of the final livestock products. Thus, the indicator of the biological usefulness of beef was higher in samples taken from experimental animals by 0.18-0.36 units (p ≤ 0.05). The most significant nutritional, biological, and energy value was characterized by milk obtained from cows, in whose diet drone homogenate was introduced. Thus, the results of complex studies indicate the effectiveness of introducing adaptogens of both plant and animal nature into the diet. Still, the best effect is obtained from drone homogenate.

Parâmetros clínicos e peso de bezerros Nelore cujas matrizes foram suplementadas ou não com fósforo, durante a gestação e a lactação - estudo de caso

ABSTRACT The aim of this case study was to evaluate the clinical and productive data of Nellore cows during pregnancy and lactation, supplemented or not with P. Ninety-five pregnant heifers were divided into two groups (G40 and G0). Until the date of calving animals from G40 received a mineral mixture composed of 224g of Na and 40g of P/kg, and G0 received only NaCl. After calving heifers were divided into four treatments: from G40, 28 first-calf cows continued to receive the mineral mixture containing 224g of Na and 40g of P/kg (group 40/40) and 12 started to receive only NaCl (group 40/0); from G0, 26 continued to receive only NaCl (group 0/0) and 15 started to receive a mixture containing 224g of Na and 40g of P/kg (group 0/40). In the second experimental phase, 205 multiparous cows were divided into two groups: G1 (40/40) consisting of 40 cows, receiving a mineral mixture containing 244g of Na and 40g/P per kg, during pregnancy and lactation, and group 2 (0/0) formed by 165 cows, which were supplemented only with NaCl. In both experiments, whether in pregnant or lactating breeders, there was not any sign of P deficiency or differences in calves LW at 120 and 210 days.

The quality of milk of cows-daughters of different bulls-producers and assessment of its suitability for processing

Relevance. The increase in the productive qualities of dairy cattle continues through the further use of purebred bulls-producers of the Holstein breed both of domestic and offoreign breeding, which invariably leads to an increase in the blood of the Holstein breed. Milk is not only a valuable food product, but also raw material for the dairy industry, and its use for the production of certain products is determined by its technological properties , so the study of them in a new genetic formation of dairy cattle in the Middle Urals zone has both scientific and practical interest.Methods. The research was carried out in one of the typical breeding reproducers for the breeding of Holstein black-and-white cattle of the Sverdlovsk region in the period 2018–2022. The evaluation included first-calf cows that completed the first lactation, obtained and grown on the farm. All cows are descended from breeding bulls Das, Sayan, De-Su, Gavano, Touareg, Marrs, Cassio, Bentley, who all 15 or more daughters. Qualitative indicators of milk— chemical composition, physico-chemical, technological properties and sanitary and hygienic indicators — were evaluated four times in three-fold repetition according to generally accepted methods and techniques in the dairy laboratory of the Ural State Agrarian University.Results. As a result of the conducted research, it was found that the milk of cows-daughters of different bulls-producers differs in chemical composition. In the milk of cows-daughters of bulls-producers Sayan and Cassio, the content of dry matter (DM), nonfat milk solids, protein, and milk sugar is higher. There was a significant superiority of these cows over their peers from other bulls in MJ in milk (Р ≤ 0.001). Milk obtained from cows-daughters of all bulls-producers corresponds to the highest grade. Differences in the technological properties of milk, namely in cheese suitability, were revealed, despite the fact that it was all attributed to the second type, the most suitable for the manufacture of cheeses.

DEPENDENCE OF THE MILK YIELD OF DAIRY COWS ON LINEAR ESTIMATION BY TYPE

Sires breeding value determination was based on classification daughters at the age of first lactation, studies related to the breeding and genetic aspects of line scoring were limited to animals array scoring at the same age. Considering indisputable importance of linear estimation, existing correlative variability between individual descriptive and complex traits growth with dairy productivity and age-related variability in body parts of conformation development, a study was carried out of evaluation influence level of traits linear classification at the age of first lactation on cow milk productivity of subsequent second and third lactations.&#x0D; While maintaining a positive correlation in further use of cows, reliability of linear estimation by type was confirmed. Studies conducted on the livestock of Ukrainian Black-and- Red-and-White dairy breeds showed positive correlations between evaluation conformation traits and cow milk yield with variability in their direction, degree and reliability, depending on the recorded lactations. First of all, at the age of first lactation, positive correlation coefficients were determined between conformation traits and milk yield amount of cows, which were a significant confirmation of this breeding event use as one of components in the comprehensive determination of dairy cattle breeding value in the world. Next important element in the aspect of correlative variability conformation traits of linear estimation with productivity was the establishment of sufficiently high correlation coefficients between evaluation four complexes of linear traits by 100-score system with milk yield for first lactation within experimental dairy breeds.&#x0D; Positive relationship was, within group traits framework, by estimation of first lactation and milk yield of Ukrainian Black-and- Red-and-White dairy breeds for: dairy type (r=0.502 and 0.447), body (r=0.385 and 0.309), limbs (r=0.129 and 0.154), udder (r=0.404 and 0.383), respectively. Examining the question of whether existing relationship between assessment of group traits of conformation and milk yield amount of cows obtained at the age of first lactation, and between these traits and milk yield for subsequent lactations is preserved, it was found that within compared animals groups of both breeds, separate correlation coefficients received at the age of first lactation, repeated in the second with less force, but at sufficient reliability level. Correlation between indicators of linear estimation group traits of first-calf cows and milk yield for third lactation didn’t repeat level of similar relationships obtained at the age of first and second calving, although a certain pattern of their direction was followed with confirmation reliability of different level. Significant part of descriptive traits of the conformation was associated with milk yield amount for first lactation, as evidenced by reliable correlation coefficients.&#x0D; But they decrease with age, and by data of third lactation such relationship was almost absent. Descriptive traits of conformation, correlated with milk yield at the age of first lactation and repeating these relationships with yield at the second and third, belonged to the traits of dairy-type animals were reliable indicators of cow milking. They included: height, chest width, body depth, angularity, rear width, pelvic limb posture, fore udder attachment, rear udder attachment height and central ligament. Thus, reliable level of positive correlation established between estimation of group traits of linear classification at the age of first lactation and milk yield for the next second and third lactation testified about effectiveness of dairy cattle selection, evaluated by conformation type. Level of correlative variability a part of descriptive traits of the conformation with milk yield of first-calf cows will not be repeated in combination indicators of the same estimation with yield at the age of second and third lactations, which was explained by natural unevenness of age-related variability in body type parts development under genotypic and paratypic factors influence.

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.

Стрессоустойчивость и молочная продуктивность крупного рогатого скота Урала в зависимости от технологии доения

Abstract. In modern conditions of intensification of the agro-industrial complex of our country, the level of influence of stress factors on the indicators of dairy productivity of cattle is an urgent topic for research. According to scientists, the stress resistance of the animal body is characterized by a number of hormones, such as prolactin, adrenocorticotropic hormone and cortisol. The scientific novelty lies in the study of the level of stress resistance of cattle with the use of intensive technologies. The purpose of our research work was to analyze the indicators of stress resistance and dairy productivity of cattle in the Urals, depending on the milking technology. Research methods. Scientific work was carried out in breeding herds of black-and-white cattle in the period 2016–2019 on the basis of agricultural enterprises of the Tyumen and Sverdlovsk regions. Distributing the evaluated heifers by types of stress resistance, the level of hormones in their blood was determined during the first lactation in the laboratory using STEROIDIF tests. Results. As a result of the analysis, it was found that in the groups where milking was used in the milk pipeline, animals with a high type of stress resistance had 22.6 % more heads compared to the groups of robotic milking. At the same time, it was noted that the first heifers with an average type of stress resistance during milking by a robot milker are a quarter more than in groups of cows when milking in a milk pipeline. Consequently, the first heifers adapt better to robotic milking. Milk yield is higher for first-time heifers milked with the help of a robot milker compared to linear milking. The difference in this case was more than 700.0 kg (17.3 %) in the studied herds. We recommend that when selecting first-calf cows for intensive milking in breeding herds of the Urals, along with generally accepted assessment indicators, the level of stress resistance of animals should be evaluated.