First-born Cows Research Articles

DETERMINATION OF FERTILITY OF FIRST CALVING COWS UNDER DIFFERENT HOUSING

The best fertilization rate of firstborns was established at the farm “Kutuzivka” under free housing, it was 11% times higher than at the farm “Agroprogres”, and 7% higher than the farm “Dekabrystiv”. The influence of the "farm" factor – 1.0% was probable (p < 0.001). In our opinion, the higher percentage of fertile inseminations of firstborns is explained by the use of an automatic system for determining sexual desire at the farm "Kutuzivka".The season of the year was the most influential factor in the fertilization of the first-born cows among the factors of the external environment. The largest number of inseminations of first-borns at farm “Agroprogres” was in the summer (28%), and the lowest in the winter (23%). On the farm of the farm “Dekabrystiv”, a greater number of inseminations were also carried out in the summer (30%) months, and the smallest share of inseminations – in the winter (21%). The nature of this impact is explained not by the state of the environment, but by the housing technology and feeding animals. During the first insemination after calving, a slightly lower percentage of fertilization of first-borns was observed in all studied farms. During the second insemination, it increased by 4% in the animals of the farm “Agroprogres”, by 7% in the farm “Decembrists”, by 3% in the farm "Kutuzivka". In the subsequent growth of the number of insemination of firstborns in the first two farms did not lead to probable changes in fertility. At the same time, the animals of the the farm "Kutuzivka", starting from the 5th insemination, were fertilized by 11–23% less than from the second insemination. The influence of this factor on the effectiveness of insemination of cows was improbable in the farm “Agroprogres” and amounted to 0.7%, in the farm “Dekabristov” and the farm "Kutuzivka" 0.8%. It was established that in all experimental farms, the number of artificial insemination after the first calving of cows is not the main factor that determines its fertility. The main factor related to the efficiency of insemination is the stage of lactation. Correlation coefficients of the lactation day with the number of artificial insemination in experimental farms ranged from +0.545 to +0.723 and with the daily productivity of first-borns equaled from +0.156 to +0.383. Low fertility in the first 90 days of lactation is primarily due to a high milk dominance, possibly a negative energy balance during this period of lactation.

Mолочна продуктивність корів західного внутрішньопородного типу української чорно-рябої молочної породи в залежності від їх генетичної структури

The analysis of milk productivity indicators of cows of the western inbred type of the Ukrainian black-spotted dairy breed was carried out, depending on the milk productivity level of their mothers. Certain features of the influence of maternal and paternal heredity on milk yield, milk fat content, reproductive capacity and duration of economic use of cows have been established. First-born cows, which come from mothers of the modal class (milk yield for 305 days of lactation in the range of 3411–5129 kg) and mothers from the group of plus variants (milk yield more than 5129 kg) prevailed in terms of the weight of peers from mothers from the group of minus variants (milk yield less than 3411 kg) by 20 % and 25 %, respectively. In the following age periods (second to fifth), due to the culling of low-yielding animals, the differences in milk yield between the cows of the experimental groups are evened out. The rate of elimination from the main herd of cows from plus-variant mothers is significantly higher than that of cows of other groups. By the fifth lactation, 91.2 % of the initial herd dropped out for various reasons, in other groups this figure was 63–67 %. Cows from the minus-variants group had the most fatty milk, the fat content in the milk during the first three lactations was 0.05–0.09 percent higher than that of other groups. The significant influence of the genotype of the parents on the level of milk yield for 305 days, the fat content in milk and the duration of the service period after the first calving in the whole herd, as well as on milk yield and the duration of the service period in the modal class and on the duration of the service period in the minus group were established

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.

Descriptive Statistics and Genome-Wide Copy Number Analysis of Milk Production Traits of Jiangsu Chinese Holstein Cows.

Milk production traits are the most important quantitative economic traits in dairy cow production; improving the yield and quality of milk is an important way to ensure the production efficiency of the dairy industry. This study carried out a series of in-depth statistical genetics studies and molecular analyses on the Chinese Holstein cows in the Jiangsu Province, such as descriptive statistics and copy number variation analysis. A genetic correlation, phenotypic correlation, and descriptive statistical analysis of five milk production traits (milk yield, milk fat percentage, milk fat yield, milk protein percentage, and milk protein yield) of the dairy cows were analyzed using the SPSS and DMU software. Through quality control, 4173 cows and their genomes were used for genomic study. Then, SNPs were detected using DNA chips, and a copy number variation (CNV) analysis was carried out to locate the quantitative trait loci (QTL) of the milk production traits by Perl program software Penn CNV and hidden Markov model (HMM). The phenotypic means of the milk yield, milk fat percentage, milk fat mass, milk protein percentage, and milk protein mass at the first trimester were lower than those at the other trimesters by 8.821%, 1.031%, 0.930%, 0.003%, and 0.826%, respectively. The five milk production traits showed a significant phenotypic positive correlation (p < 0.01) and a high genetic positive correlation among the three parities. Based on the GGPBovine 100 K SNP data, QTL-detecting research on the fist-parity milk performance of dairy cows was carried out via the CNV. We identified 1731 CNVs and 236 CNVRs in the 29 autosomes of 984 Holstein dairy cows, and 19 CNVRs were significantly associated with the milk production traits (p < 0.05). These CNVRs were analyzed via a bioinformatics analysis; a total of 13 gene ontology (GO) terms and 20 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were significantly enriched (p < 0.05), and these terms and pathways are mainly related to lipid metabolism, amino acid metabolism, and cellular catabolic processes. This study provided a theoretical basis for the molecular-marker-assisted selection of dairy cows by developing descriptive statistics on the milk production traits of dairy cows and by locating the QTL and functional genes that affect the milk production traits of first-born dairy cows. The results describe the basic status of the milk production traits of the Chinese Holstein cows in Jiangsu and locate the QTL and functional genes that affect the milk production traits of the first-born cows, providing a theoretical basis for the molecular-marker-assisted selection of dairy cows.

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).&#x0D; 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.&#x0D; 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.

Factors and their influence on the indicators of milk productivity of first-born of Ukrainian dairy breeds

The article examines the influence of genotypic factors on the formation of milk productivity indicators in first-born cows of various breeds. Genotyping of 744 cows of Ukrainian Brown Dairy, Ukrainian RedAnd White, Ukrainian Black-and-White Dairy breeds and Sumy inbred type of Ukrainian Black-and-White dairy breed, which are kept in breeding farms of State Enterprise "Experimental Farm of Institute of Agriculture of Northern East of NAAS" of Sumy district of Sumy Region and PRAE Ichnyanske and PRAE Khliborob of Chernihiv region. In order to determine the polymorphism of the beta-casein gene, genetic studies were carried out in the laboratory of Institute of Physiology named after Bogomolets of NAS with the help of molecular biological analysis of allele recognition by polymerase chain reaction (PCR) in real time. The study of milk productivity indicators was carried out with the help of generally accepted methods, using the electronic database of SUMS "Orsek". The influence of genotypic factors was determined based on the results of one-factor variance analysis. Between animals of different breeds, there is a significant difference in the influence of genotypic factors on indicators of milk productivity. Linear belonging had a statistically significant effect on milk yield and the content of fat and protein in milk in animals of the Ukrainian black-and-white and redand-white dairy breeds. Whereas in cows of Ukrainian brown dairy breed - only on the amount of milk yield. In first-borns of Sumy intrabreed type, linear belonging did not have a statistically significant effect on the studied indicators. Father's origin has a much greater influence (ή2,=22-62 %). The genotype of the animal according to beta-casein actually does not have a reliable effect on the indicators of milk productivity. However, in animals of Ukrainian red-and-white dairy breed and Sumy inbred type of Ukrainian black-and-white dairy breed, it reliably influenced the formation of milk yield and fat content in milk. Therefore, with the aim of forming the desired value of milk productivity traits in first-born cows, the primary task is to carry out the selection of breeders assessed for the quality of the offspring of the corresponding lineal affiliation. Key words: genotype, beta-casein, influence, milk productivity, breed

Heritability and correlative variability of the conformation linear traits of first-born cows of black-and-white cattle with milk yield

An in-depth analysis the publications of domestic and foreign authors was carried out in the aspect of research on the heritability of linear traits of the conformation type and their correlative variability with milk productivity.The research authors established that the level of existing variability in the heredity of linear traits depends on many genotypic and paratypic factors. However, they argue that despite the variability of traits heritability of dairy cows conformation, their level is generally sufficient for effective selection by linear type traits. Studies on the correlation between linear traits of type and milk productivity of cows of various breeds around the world have shown a high level of this relationship. This testifies about the effectiveness of indirect selection of dairy cattle by type, which will allow obtaining not only constitutionally strong and healthy animals, but also with high milk productivity.The population-genetic aspect of determining the heritability and correlative variability of linear traits with milking of first-born Holstein cows of domestic selection and Ukrainian Black-and-White dairy in the private enterprise "Burynske" of the Podlisniv branch of the Stepaniv territorial community in Sumy district was described. The magnitudes and reliability of the heritability coefficients of group linear traits indicate that they are controlled by the genotype of animals by 24.5-42.2 % in first-born cows of the Holstein breed, and by 26.6-40.1 % in female cows of Ukrainian Black-and-White dairy breed. The final score by type of 48.2 and 45.4 %, respectively, ensures the efficiency selection of cows by genotype. Variability of descriptive traits of Holstein cows ranges from insignificant and unreliable (h2=0.084; location of front teats) to high and reliable (h2=0.484; angularity). In females of the same age of Ukrainian Black-and-White dairy breed, the variability varies from 0.077 (location of rear teats) to 0.422 (angularity).In Holstein and Ukrainian Black-and-White dairy cows, the most reliable relationship was found between the characteristics of the dairy type (0.428 and 0.387), body (0.446 and 0.439), udder (0.486 and 0.478) and, especially, the final type score (0.492 and 0.488), which gives reason to assert about the effectiveness of selection based on these traits.The highest level of reliable positive correlation with the amount of milk yield for the first lactation was found according to the scores of descriptive traits of Holstein and Ukrainian Black-and-White dairy breeds, respectively: height (r=0.363 and 0.322), body depth (r=0.468 and 0.484), angularity (r=0.477 and 0.466), back width (r=0.366 and 0.322), posture of pelvic limbs (r=0.369 and 374), attachment of front (r=0.482 and 0.426) and rear (r=0.371 and 0.351) udder parts, central ligament (r=0.364 and 0.375) and locomotion (r=0.363 and 0.322) at Р&lt;0.001. Key words: Holstein, UkrainianBlack-and-Whitedairy, lineartypeevaluation, conformation, milkyield, first-borncows.

Manifestation of signs of milk productivity of firstborn cows depending on the productivity of their female ancestors

One of the most important breeding methods in cattle breeding is the determination of genetic similarity in productive traits of female ancestors and their descendants. In view of the above, the aim of the study was to determine the variability of cow milk production traits depending on the productivity of their mothers and fathers' mothers. The studies were conducted on farms located in different climatic zones of Ukraine, namely: SE DG “Oleksandrivske”, Vinnytsia region (Forest-Steppe zone, n = 714), LLC SHP “Imeni Volovikova”, Rivne region (Polissia zone, n = 1840) 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. The sample included cows that had completed at least the third lactation at the time of the study. It was found that the most productive cows in the controlled herds were those whose mothers' milk yields for the highest lactation reached more than 8000 kg, and the mothers' milk yields of the fathers, depending on the breeding zone, ranged from 9000 to 15000 kg. A certain influence of mothers on the value of indicators of cows' milk production traits is evidenced by correlation analysis. Thus, a rather significant straightforward and reliable relationship was established between the milk yield of mothers and their daughters in the controlled farms, and between the milk yield of mothers and the fat content of daughters, this relationship was inverse, but reliable. The correlation between maternal fat and milk yield and fat and milk yield of daughters was multidirectional and insignificant. The coefficient of heritability, which was determined by doubling the mother-daughter correlation, ranged from 0.47 to 0.59 for milk yield, from 0.30 to 0.55 for milk fat yield, and from incorrect (negative) in animals from the Steppe zone (-0.27) to positive (0.18) in animals from the Polissya zone. The analysis of variance confirmed a certain predetermination of phenotypic variability of quantitative traits of milk production depending on the productivity of mothers and mothers of fathers established by the comparison of group means. Thus, their mothers had a somewhat greater, although not significant, influence on milk yield (depending on the farm and lactation – 3.8–6.9 %) and fat content in cows' milk (4.2–6.6 %), and their fathers' mothers had a somewhat lesser influence (2.1–4.2 and 2.0–4.5 %, respectively).

Легеневий газообмін у телиць і молочна продуктивність первісток симентальської породи Прикарпаття різних типів конституції

Легеневий газообмін у телиць і молочна продуктивність первісток симентальської породи Прикарпаття різних типів конституції

LINEAR EVALUATION OF HOLSTEIN BULLS BY THE EXTERIOR TYPE OF THEIR DAUGHTERS IN "OSTRIYKOVSKE" LLC

Introduction. In the context of intensive milk production technologies, the dairy farming industry faces high demands on animal health, constitutional strength and manufacturability due to mechanization and full automation of production processes. Modern methods of breeding involve the creation of highly productive animals that are well adapted to the least costly production technologies, taking into account an objective assessment of their breeding qualities and the application of population genetics.&#x0D; Materials and methods of research. The study was conducted based on the materials of primary breeding records in the farm "Ostriykivske" LLC, Kyiv region. Evaluation of the milk production of cows was carried out for 305 days of the last completed lactation on the basis of the database of the dairy farming management system (Intersel-Orsek). An eyeball assessment of the exterior of the firstborn heifers was carried out according to the instructions for boning in the modification of Y. P. Polupan and the method of linear classification by type. The exterior of the animals was studied by taking the main 17 measurements at 2–5 months of lactation.&#x0D; The cow type was evaluated using two systems: a linear description of individual exterior traits; evaluation of complex traits on a 100-point scale. The total score was calculated based on complex traits, which in turn were based on linear descriptive traits. In the process of evaluating the animals, the results were recorded in the evaluation sheet for dairy and dairy-meat cows by body type, pre-recording the animal's identification number, nickname, date of birth, date of calving, and lactation number. A total of 114 first-born Holstein cows were evaluated at Ostriykivske LLC.&#x0D; Research results In the herd of Ostriykivske LLC, the best score for the complex of traits was obtained by the daughters of the bull sire Lobby 101916210 of the Eleweishna 1491007 line (83.2 points), which corresponds to "good with a plus". The daughters of the bull sire Kingly 101409948 of the H. H. Starbuck 352790 line received the lowest score – 78.0. The lowest score for the complex of limb traits was observed in the daughters of the bull Sleman 7817774 of the Valiant 1650414 line (70.5 points), and the highest in the descendants of Lobby 101916210 – 79.3 points. The variability of scores for udder traits ranged from 76.2 points in the daughters of Tandem 9434213 to 80.8 points in the daughters of Lobby 101916210 with a difference of 4.6 points between these extreme variants.&#x0D; In addition, the evaluated cows have undesirable development of certain appearance traits, such as additional teats, close proximity of the hind teats, rudiments behind the teats, underdeveloped udder lobes, and diseased limbs. Thus, the use of the linear classification methodology allows you to obtain information about the features of the body structure, identify the advantages and disadvantages of cattle.&#x0D; Such quantitative traits as milk yield, milk fat and protein yield are economically important for dairy producers. The obtained results of the research show that the best score for the complex of traits (83.2 points) and the highest milk yield (milk yield – 10560 kg; fat – 3.92%; protein – 3.15%) are observed in daughters of the bull of the sire Lobby 101916210 of the line Eleveishna 1491007.65. It was found that the firstborn cows with the best type indices are characterized by high milk production. Selection of the best performers by linear evaluation by type for the repair of the dairy herd of firstborn cows will provide more functional reliability and high milk production.&#x0D; Conclusions. Thus, the use of the linear classification methodology in dairy cattle breeding allows to objectively determine the characteristics of cows by type of appearance, and the existence of a relationship between milk production and group linear traits is the key to the effectiveness of animal selection by type of appearance.

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

Features of conformation type of black-andwhite cows of different origin estimated by linear classification method

The research was carried out in the aspect of studying features of conformation type cows of Ukrainian Black-and-White dairy and Holstein breeds estimated by linear classification method. Basis for research was the herd of company "Ukrlandfarming" private enterprise "Burynske", Pidlisniv branch in Sumy region. The aim was to conduct a comparative analysis of experimental breeds according to the assessment of linear classification and determine the impact of final score for type on milk productivity first-born cows. In general, first-born cows of both breeds were characterized by good linear estimation, especially on a 100-score scale. However, animals of Holstein breed in comparison with Ukrainian Black-and-White dairy were better in terms of body parts, which characterize the dairy type by 1.3 score, body - by 0.8 score, udder - by 1.2 score and the final assessment - by 0.8 score (P &lt;0.001). On the trait of chest width, Holstein animals were inferior to their Ukrainian Black-and-White dairy breeds with reliable difference of 1.3 score, but exceeded in angularity - by 1.2 score, strength of fore udder parts attachment - on 0.8 score, central ligament - by 1.1 score (P &lt;0.001). The final estimation level of first-born cows for conformation type directly proportionally determined their milk productivity in 305 days of the first lactation. Cows of Holstein and Ukrainian Black-andWhite dairy breed with score - "very good" exceeded their peers with score - "good with plus" for milking by 785 and 589 kg (P˂0.01) respectively, and with score of "good" - by 1705 and 1502 kg (P˂0.001). The use in the selection process of dairy cattle, in determining cows breeding value, linear classification method will be a very effective means of objective definition breed features of conformation type. The presence of correlative relationship between the final score and milk productivity level will contribute to the effectiveness of selection in the indirect sampling of animals on these traits. Key words: Holstein, Ukrainian Black-andWhite dairy, linear type assessment, conformation, milk yield.

Linear type traits that characterize body development as the predictors of lifetime of Ukrainian Black-and-White dairy and Holstein cows

The researches were conducted in the aspect of studying the problem of dairy cows lifetime depending on the linear traits assessment of the conformation type. By the linear classification method were estimated firstborn cows of the Ukrainian Black-and-White dairy (UBWD) and Holstein (H) breeds. Descriptive traits of the conformation that characterize the overall body structure were studied: chest width, body depth, angularity, body condition, rear width and position. According to the research results, the relative variability of the descriptive type traits assessment with cow's lifetime was determined. The relative variability of chest width and cow's lifetime was curvilinear. Cows for chest width assessment of 4–7 score had a higher lifespan with a variability of 2704–2844 (UBWD) and 2688–2789 (H) days. The highest lifetime was in animals with an assessment for body depth development of 6-9 score with an unreliable predominance of Ukrainian Black-and-White dairy breed cows, with the highest grades of both breeds 2824 (UBWD) and 2802 (H) days with an assessment of 9 score. Animals with an optimal angularity estimation of 5 score differed, lived the longest – 2842 (UBWD) and 2828 (H) days, while with increasing and decreasing score for this trait, the number of lifetime days of cows declined. According to the rump width assessment, lifespan was highest in cows with a 9 score – 2766 days (UBWD) and 2832 days (H). Cows of UBWD with the highest assessment for this body part development of 9 score were used on 592 (P &lt;0.001), and Holstein on 708 (P &lt;0.001) days longer compared to animals with 1 score. The maximum lifetime of animals with an average assessment for body condition of 5 score was 2842 (UBWD) and 2774 (H) days. Cows with body condition score below average lived and were used in the herd much longer than with a higher one. The degree of relationship variability between the assessment of these traits and the lifetime of animals depended on the specific body part. Key words: Ukrainian Black-and-White dairy breed, Holstein, linear type traits, lifetime.

Correlation between descriptive and group type traits in the system of cow’s linear classification of Ukrainian Brown dairy breed

Abstract The aim of this study was to evaluate the phenotypic relationships between descriptive and group linear-type traits and the final score of first-born cows of the Ukrainian Brown dairy breed. The data from the linear estimation were collected on the population of 707 cows in six herds in the Sumy region of Ukraine from 2000 to 2018. It was found that the level of correlations between descriptive and group traits of the conformation, which characterize the dairy strength, frame, feet/legs, and udder, differed in significant variability by direction, strength, and reliability. The level of positive phenotypic correlations of descriptive traits with all group traits of the conformation type and the final score was height (0.19–0.34 and 0.34), chest width (0.06–0.29 and 0.17), body depth (0.28–0.53 and 0.48), angularity (0.35–0.77 and 0.62), rump width (0.29–0.36 and 0.46), rear legs posture (0.33–0.37 and 0.48), front udder attachment (0.23–0.39 and 0.41), height of rear udder attachment (0.17–0.27 and 0.29), and central ligament (r = 0.16–0.39 and 0.36). The body condition score was related to group traits but in a negative value, with correlation coefficients ranging from −0.07 (legs) to −0.47 (dairy strength). The level of correlation between descriptive traits and the final score indicated that the selection based on the results of good development of these traits will contribute to the overall progress of cows in the direction of the desired dairy type.

DYNAMICS OF MILK PRODUCTIVITY AND BODY WEIGHT OF COWS BY AGE AND PERIODS OF LACTATION

The research was conducted on the farms of the Stepne State Enterprise and the Agroprogres Private Enterprise (stall housing) and on the dairy complex of the Kutuzivka State Enterprise (free housing). It was established that the shape of the lactation curve of first-borns significantly differed from the classical one during untethered confinement. The average daily milk yield reached a maximum at 3-4 months and almost did not decrease until the 7th month of lactation. In older cows, fertility increased and reached a maximum at 2-3 months of lactation, and then gradually decreased. The relative increase in milk yield in comparison with the first month of lactation was 31% in first-born cows, 17% in second-calving cows, 7% in third-calving cows, and 18% in older animals, and in stall housing – 33%, 17%, 10 % and 2 %, respectively. The power of influence (η2) of the month of lactation on the fat content in milk during untethered confinement was 8.5% in first-born cows, 14.5% in the second lactation, 13.1% in the third lactation, 12.2% in older cows, and for tethered confinement 14.8%, 36.9%, 33.6%, and 11.6%, respectively (р&lt;0.001). Similar to the fat content in milk, the protein content of cows also changed during lactation. At the same time, the influence of the month of lactation on this indicator was much smaller than on the fat content, and in some cases it was improbable for stall housing. The influence strength of the month of lactation on the daily yield of cows that were culled from the herd was 23.8% for free housing, 1.9% for body weight, and 8.0% for stall housing and 11.6 % (p&lt;0.001). Correlation coefficients are 0.181, +0.411, and –0.223, +0.335, respectively (p&lt;0.01). Age-related changes in the body weight of animals depended on the technology of their husbandry. In free housing, it was higher both in the sample as a whole (6%) and in animals of different lactations (3-14%). The increase in body weight of cows with age in free housing was: 31 kg in the second lactation, 71 kg in the third lactation, and 100 kg in adult cows, while in stall housing these differences were only 6, 11, 35 kg, respectively. Keywords: husbandry technology, dairy cattle, age, month of lactation, daily yield, fat content, protein content, body weight

INFLUENCE OF PATERNAL ORIGIN ON THE MANIFESTATION OF ECONOMIC USEFUL TRAITS IN THEIR DAUGHTERS IN ORGANIC AND CONVENTIONAL MILK PRODUCTION

INFLUENCE OF PATERNAL ORIGIN ON THE MANIFESTATION OF ECONOMIC USEFUL TRAITS IN THEIR DAUGHTERS IN ORGANIC AND CONVENTIONAL MILK PRODUCTION

Хромосомна нестабільність чистопородних і кросбредних корів молочного напряму продуктивності

The article presents the results of research on the karyotype characteristics variability in purebred and crossbred dairy cows. The material for the research was peripheral blood samples of purebred firstborn cows of the Ukrainian red-spotted dairy and Ukrainian black-spotted dairy breeds, as well as crossbred cows obtained from crossing Ukrainian red-spotted with Montbeliard bulls (DG “Nyva” SE of the Institute of Animal Breeding and Genetics named after M. V. Zubets NAAS. Preparation of cytogenetic preparations, analysis of morphology, identification and classification of chromosome aberrations were carried out according to generally accepted methods. We performed cell analysis with the Axiostar plus microscope (Carl Zeiss, Germany) under immersion magnification of 1000 times and took microphotographs. In all studies, the frequency of aberrant metaphases and the spectrum of chromosomal aberrations were determined as parameters of chromosomal instability. The following signs were taken into account: the frequency of aneuploid and polyploid cells, cells with premature separation of the centromeric regions of chromosomes (CRC), cells with structural aberrations of chromosomes (breaks, fragments and associations of non-homologous chromosomes). As a result of the analysis of karyotypes of firstborn cows of purebred and crossbred origin, it was established that the proportion of diploid cells in the norm is on average 85%. The remaining almost 15% are somatic cells with numerical and structural abnormalities. Crossbred cows have significantly higher frequencies (P&lt;0.001) of aneuploid (one and a half times), polyploid (by 27%), structural aberrations of chromosomes (by 20%) than in purebred cows of the Ukrainian red-spotted and black-spotted dairy breeds. 15–20% more cells containing chromosomes with breaks and fragments were also found in crossbred firstborns. The results of the cytogenetic study indicate greater chromosomal instability in crossbred cows compared to purebred cows. One of the reasons for this phenomenon may be the influence of breeding methods, in particular crossbreeding.

Exterior of Сows of the Ukrainian Black-Spotted Dairy Breed, Obtained under Various Selection Options

Analysis of the effectiveness of evaluating inline and inter-line variants of combinations by type and finding their best variants in practical selective breeding is a relevant task that allows obtaining offspring of the desired quality. The purpose of this study is to figure out the specific features of the body structure of the firstborn cows of the Ukrainian blackspotted dairy breed of the western inbred type, depending on their origin, as well as to establish the type of inheritance of these indicators in line crosses based on the results of the evaluation by type. The study found the types of selection through genealogical analysis of pedigrees, linear evaluation of cows by type according to two evaluation systems – linear description of individual articles of the exterior on a 9-point scale and evaluation of complexes of exterior features of the animal type on a 100-point scale, obtained results were evaluated according to Student’s t-test. Using the scheme, it was found that the firstborn cows obtained as a result of the inline selection are characterized by optimal scores by type. However, animals from the Valianta 1650414 line received the highest ratings for linear traits of height at the withers, width of chest and rear, body depth. The study analysed the evaluation of firstborn cows by type, obtained in the interline selection, and it was found that the indicators of linear evaluation by type of cross lines correspond to and prevail over the average values for the breed. Cross cows ♂Valianta 1650414 x ♀Eleveishna 1491007 received the highest score for milk type on a 100-point scale. It was proved that most of the evaluated traits in line crosses were inherited according to the intermediate type. However, in the cross ♂Chifa 1427381 x ♀Eleveishna 1491007, the evaluation of individual traits (height, chest width, angle of withers, rear attachment, and depth of udder) statistically probably exceeded the values of the corresponding evaluations of the firstborns of the paternal and maternal lines, and the dominance of the maternal line was observed in the cross-breed cows ♂Chifa 1427381 x ♀Valianta 1650414 according to the value of the assessment of individual udder traits. The obtained results will allow performing optimal selection of parent pairs from animals evaluated by type for selection and breeding work with cattle herds to consolidate them by type

DAIRY PRODUCTIVITY OF COWS OF UKRAINIAN RED-AND-WHITE DAIRY BREED OF DIFFERENT GENOTYPES IN NATURAL AND CLIMATE ZONES OF UKRAINE

DAIRY PRODUCTIVITY OF COWS OF UKRAINIAN RED-AND-WHITE DAIRY BREED OF DIFFERENT GENOTYPES IN NATURAL AND CLIMATE ZONES OF UKRAINE

Physiological Justification of Udder Emptying in Highly Productive Cows

This study encompasses to measure frequency of physiologically motivated emptying the udder by Holstein cows during lactation. With the recording of the hours of the day, the experiment shows that the first-born cows emptied the udder, on average, almost three times a day, the cows having second lactation emptied 2.5 times a day, and cows having 3rd and 4th lactations emptied udder three or more times a day. Analysis of the daily attending a robotic milking machine during lactation by first-born cows showed that the visitation frequency was relatively even, except for the maximum peaks from 11.00 to 12.00 o’clock and from 21.00 to 23.00 o’clock. Similarly, among the cows of the 2nd lactation there were two maximum peaks of milking or udder emptying – at night from 22.00 to 1.00 o'clock and in the day from 12.00 to 17.00 o'clock. For cows having 3rd lactation, there were two maximum peaks of udder emptying - one from 21.00 to 1.00 o'clock at night, and the second from 12.00 to 17.00 o'clock in the afternoon. Cows under 4th lactation had three relatively high maxima: the first from 1.00 to 4.00 o'clock at night, the second from 10.00 to 12.00 o'clock in the afternoon, and the third from 18.00 to 22.00 o'clock at night. This study concludes that high milk productivity of cows needs emptying (milking) of the udder at least three times a day. Since almost a third of udder emptying occurs at night, at that time it is necessary to provide animals with adequate water and feed on the feed table.