scholarly journals Reppoductive ability of ukrainian black and white dairy cows

Author(s):  
M. I. Kuziv ◽  
E. I. Fedorovych

The major components of economically useful traits in cattle dairy productivity, which conducted the selection is milk productivity and reproductive ability of cows. Studies conducted on animals Ukrainian black and white dairy cattle in the «Milk River» farm in the Sokal and Brody offices breeding reproducers «Breeder» Lviv region and plant breeding «Yamnytsya» Ivano–Frankivsk region. Ukrainian black and white dairy breed in the western region of Ukraine is characterized by good reproductive ability. Depending on the husbandry and lactation duration, service period lasted within 87.4 – 121.5 day, intercalving period – within 364 – 402.6 day, dry period within – 47.3 – 72.9 day, the fertility index was 46.3 – 48.0, coefficient of reproductive ability – within 0.92–0.99,  output of calves per 100 cows – within 91.8 – 98.8. The duration of pregnancy in cows of different  farms and lactations were in range 277 – 283.5 day and meet the requirements of the physiological norm. It has been shown that the milk yield of cows depends on the parameters of reproductive capacity. The correlation between duration of service–period and intercalving period, and milk yield, milk fat in most cases was positive. Correlation dry period duration and parameters of milk yield changed from negative to positive. Depending on the husbandry, lactation and index the impact share of service–period duration on milk yield was 7.0 – 29.7, for intercalving period – 8.8 – 31.8, for dry period – 9.2 – 23.8% respectively.

2021 ◽  
Vol 22 (4) ◽  
pp. 589-596
Author(s):  
Svetlana V. Titova

The article presents the results of the analysis of the reproductive ability of cows depending on the level of their milk productivity. The studies were conducted in the Republic of Mari El on cows of the Holstein black-and-white breed (n = 3828). There have been studied the influence of different levels of milk yield on the duration of the service period and period between calvings, the output of calves per 100 cows, the coefficient of reproductive ability. The studies used the comparison method, correlation, regression and one-factor analysis of variance. It has been established that the milk yield increases with the age of cows, but at the same time the duration of the service period and calving interval increases. In first-calf cows, the service period was 128.8 days (Cv = 75.1 %), the calving interval was 403.6 days (Cv = 23.5 %). By the third lactation, with an increase in milk yield by 1030 kg (15.4 %), the duration of the service period increased by 7.2 days (5.6 %), the calving interval  -by 12.3 days (3.0 %). The share of the impact (ƞ2x) of milk yield on the duration of the service period was 5.4 %, the calving interval -4.7 %. The correlation coefficients between milk yield for 305 days of the first lactation and the duration of the service period and calving interval were 0.24 and 0.22 (p<0.05), with milk yield for the entire lactation 0.81 (p<0.05). The optimal indicators of the service period (89.4 days), the calving interval (369.4 days), the reproductive capacity (0.94) and the output of calves (1.0) were possessed by the first heifers with low milk productivity-milk yield less than 5000 kg of milk. In animals with the milk yield of 6000-9000 kg of milk or more, the duration of the service period was 12.4-249.6 % higher, the calving interval -by 1.9-32.5 % (p<0.05). According to the regression coefficients, on average, each increase in milk yield per 1000 kg increased the duration of the service period by 25.9 days, the calving interval -by 23.1 days, which worsened the output of calves by 0.24 %, and the coefficient of reproductive ability decreased by 16.0 %.


2018 ◽  
Vol 51 ◽  
pp. 112-118
Author(s):  
V. V. Machulnyi

Milk yield of cows in breeding herds, Cherkassy region, for last completed lactation averaged 6442 kg of milk with 3.62 % fat content. Currently the question of interconnection of cows’ milk production and reproductive capacity is especially important, because the significant increase in milk yields makes minimize calves. The successful conduct of breeding had set the goal to detect the best options for combining milk production and reproductive ability of animals.To characterize the level of milk production including reproductive ability of cows we used indicator of daily average milk yield per one day of periods between calving (PBC). The best service period can be considered period of 51-90 days, that allows you to get one calf per cow per year (average PBC is 351 days) and maintain high milk production (6431 ± 39.6 kg during 305 days of lactation). With this service period all indicators of milk production and reproductive ability are at high level. Reduced service period below recommended levels will reduce the duration of lactation and milk production, and increasing service period will increase the duration of lactation with a simultaneous reduction in milk production for 305 days. Herewith deterioration of reproductive ability is marked and manifested in the increase of the insemination index, decline in the reproductive capacity, increase of periods between calving and as a result, reduce of calves and culling barren cows.Analysis of genealogical structure of the studied herds points to low diversity (Ukrainian Black-and-White dairy cows belong to 6 lines and Ukrainian Red-and-White dairy cows – to 8 ones) with high affinity (by Chief 1427381.62 to R. Sovereign 198998 bloodline, by Starbuck 352790.79 to Elevation 1491007 and Ideal1013415 bloodlines).Genealogical structure of the herds is saturated a lot of bulls genealogical groups of Holstein cattle: Chief 1427381 – 11 bulls in the array of Ukrainian Black-and-White dairy breed and 5 ones in Ukrainian Red-and-White dairy breed, Starbuck 352790.79 – 10 sires in the array of Ukrainian Black-and-White dairy cattle and 3 ones in Ukrainian Red-and-White dairy breed, Elevation 1491007.65 – 4 sires in the array of Ukrainian Black-and-White dairy cattle and 3ones in Ukrainian Red-and-White dairy breed.Currently the sires of Chief 1427381.62 (7712-3,76-289,9-3,14-242,1), Starbuck 352790 (7857-3,87-295,4-3,07-241,2), Jocko Besne 694028588.94(6687-3,88-259,5-3,03-202,6), and Bell 1667366 bloodlines (61341-3,95-242,3-3,02-185,2) among sires of Ukrainian Black-and-White dairy cattle and the sires of Cavalier 1620273.72 (7285-3,98-289,9-3,08-224,4), Chief 1427381.62 (7522-3,76-282,8-3,00-225,7),Starbuck 392405 (7667-3,87-296,7-3,00-230,0), and Elevation 1491007.65 bloodlines (7544-3,80-286,7-3,5-230,0) among sires of Ukrainian Red-and-White dairy breed are classified to a highly productive and promising for breeding and wider use by productive qualities.After the first insemination the lowest proportion of fertilized cows is among offspring belonging to Chief 1427381 bloodline which is only 38 % among both breeds. However, the milk yield of breeding stock belonging to this bloodline is 7712 kg with 3.76 % fat content for Ukrainian Black-and-White dairy cows and 7522 kg of milk with 3.76 % fat content for Ukrainian Red-and-White dairy cows. Daughters belonging to Elevation1491007, Valiant 1650414, and Hanover 1629391 bloodlines with yields of 4566-5478 kg of milk per lactation had a part of fertilized cows, after the first insemination, at the level of 41-49 %. Fertilization after the first insemination above 50% was in daughters belonging to Cavalier 1620273.72 (52%), Starbuck 392405(50-55 %), Bell 1667366(56%) and Jocko Besne 694028588.94 bloodlines (64 %). The level of performance of these animals for milk yield ranged from 6134 kg to 7857 kg.Heritability coefficients of milk yield and duration of service period were low (0.118-0.289). A positive correlation can be explained by the fact that extension of service period (to a certain level) leads to growing number of milking days (duration of lactation) and defers a decrease in productivity of cows by physiological reasons, namely as a result of pregnancy. Low rates of heritability indicate little genetic diversity of traits and the significant influence of physiological and environmental factors in their formation.As Ukrainian Black-and-White and Ukrainian Red-and-White dairy breeds have a high proportion of heredity of Holstein breed which has genetically large fetus, there is need to study the characteristics of nature passing calving in cows of these breeds. Itis found the number of first-calf heifers which needed help was 52.4%. Animals calve alone in 47.6 % of all cases. Calving was without complications if the live weight of calves not exceeding 6-7% of mother’s weight. The cows calved without help of staff exceeded by 11.7% of the width of the pelvis in the buttocks, 7.5 % of the width of the ilium, and 7.1 % of its oblique length compared with animals of same age.


2017 ◽  
Vol 19 (74) ◽  
pp. 52-56
Author(s):  
V. V. Fedorovych

It is well known with an increase of milk productivity of cows their reproductive capacity in general became worse. Therefore, it is important to establish optimal parameters of the first age insemination and first calving, duration of service- and inter-calving periods. In view of the above, the purpose of our researches was to study the influence of reproductive capacity parameters of Simmental cows on the formation of milk productivity. The study were conducted on 331 cows in agricultural LLC «Litynskyy» Drohobych raion, Lviv oblast. Evaluation of milk productivity and reproductive capacity of the animals (in 20 years) were performed according to the data of zootechnical accounting for the first, second, third and the best lactations. The differences in rates of milk productivity depending on the parameters of their reproductive capacity were established. Animals with age of first fruitful insemination 18.1–20.0, with first calving age – 27.1–29.0, duration of service period – 101–120 and duration of the inter-calving period – 381–400 days had the best yields and the highest quantity of milk fat. According to the above mentioned indicators of milk productivity they are likely dominated by animals with bigger or smaller indicators of reproductive capacity, but in most cases, this advantage was unreliable. It was found positive highly significant links between indicators of reproductive capacity of cows and milk yield. The highest correlation coefficients were observed between age of first calving and their milk yields, depending on lactation, they were 0.380–0.498, lower – between age of first insemination and milk yield – 0.316–0.456 and the lowest – between service- and inter-calving periods and yield – 0.124–0.335; 0.127–0.331 respectively. The impact of the abovementioned indicators on yield was within 23.13–39.88; 28.63–45.02; 30.98–35.17%, respectively. 


2021 ◽  
Vol 250 ◽  
pp. 178-184
Author(s):  
M.A. Grinchuk ◽  
◽  
Yu.A. Nesterova ◽  

The applicability of the work is to identify the possibility of productivity increase of cows of the Simmental breed due to reproductive qualities. The aim of the work is to assess the influence of the first insemination age, service period and dry period on milk productivity of Simmental cows. The research is aimed at studying milk productivity of Simmental cows with different levels of reproductive qualities. The obtained data were statistically processed in Excel. Descriptive statistics methods were used. The object of the research were Simmental cows of “ Tasaliev D.M. “ farm of Kaliningrad region. As a result of the study, a relation was established between the age of the first successful insemination, the service period duration, the dry period duration and parameters of milk productivity. The age of the first successful insemination at 18-24 months has the most beneficial effect on subsequent milk productivity. A service period of 90-120 days has a positive effect on milk yield increase for 305 days of lactation, a longer service period negatively affects the mass fraction of milk fat. Prolonged service period results in a calf loss of 100 calves per year. With an increase of dry period duration, the mass fraction of milk fat increases, but milk yield decreases. The influence of reproductive qualities on mass fraction of milk protein is insignificant. According to the results of the studies, it can be considered that reproductive qualities, in combination with other factors, influence milk productivity of Simmental cows.


2020 ◽  
Vol 60 ◽  
pp. 61-70
Author(s):  
N. Pelekhaty ◽  
D. Kucher ◽  
O. Kochuk-Yashchenko ◽  
A. Lypianets

The results of the studies carried out highlight the assessment of the adaptive ability of Jersey cows. The conditions of keeping Jersey cows in the Dan Milk subsidiary contribute to the realization of high milk productivity, which is due to heredity, but cause a deterioration in their reproductive capacity. At the same time, a high manifestation of milk productivity and satisfactory reproductive ability have observed only in the daughters of DJ Jante 302761 – whose adaptation index was closer to zero and amounted to -2.7. The force of influence (ηx2) of paternal origin on the signs of milk production in first-calf calfs was 21.1% versus 5.9% of the generalized mean value for cows belonging to the line. It has been founded that according to the adaptation index, the state of animals those characterized by the absence of harmonious interaction with the environment – cows show high productivity with a significant deterioration in reproductive capacity, which indicates the presence of a feedback between these characteristics. It was found not high enough, but statistically significant influence (P < 0.01 – P < 0.001) on the adaptation level of first-calf cows by milk yield for 305 days of lactation (8.0%), milk fat and protein (7.0%). A statistically significant effect (ηx2 = 82%) of the signs of reproductive ability of cows (service period and period between calving) was found depending on their level of adaptation (P < 0.001). With an increase in the level of milk production of cows, was established a clear connection between the deterioration of the adaptive qualities of livestock. So with an increase in milk yield for the entire lactation from 6000 to 10000 kg of milk, the adaptation index decreases from -0.5 to -9.5, which is confirmed by a statistically significant difference between the extreme groups of animals with different levels of productivity (P < 0.001). According to the adaptation index, the condition of animals were characterize by the lack of harmonious interaction with the environment - cows show high milk productivity with a significant deterioration in reproductive capacity, which indicates the inverse relationship between these traits. The influence of the father and belonging to the lines on such indicators of milk productivity as: yield for 305 days of lactation, milk fat and protein (P < 0.05 – P < 0.001) was statistically significant. Significant effect of increasing the level of milk yield of cows was observed on such signs of reproductive capacity as: service period, period between calves and reproductive ability coefficient (P < 0,001). There was no statistically significant effect of belonging to the lines and offspring of specific breeders on the signs of reproduction of cows in general (P > 0.05). We found that the reproductive quality of cows is more influenced by the level of milk yield of cows during lactation (23.1%, at P < 0.001), which is confirmed by our previous studies. The conditions of keeping Jersey cows in the Dan Milk State Enterprise contribute to the realization of high milk productivity, which is due to heredity, but causes a deterioration in their reproductive capacity.


Author(s):  
Y. I. Sklyarenko

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


2020 ◽  
Vol 50 (5) ◽  
pp. 47-55
Author(s):  
S. L. Belozertseva ◽  
L. L. Petrukhina

The paper presents the results of studying the effect of sire lineage on reproductive qualities and milk yield of cows. The study was carried out inIrkutskregion on a herd of Holsteinized black-andwhite cattle of Pribaikalsky type. The analysis of the main characteristics of reproductive capacity of herd cows on a farm was performed during 2013–2018. The material of the research work was based on the informational database of animals from the program of breeding register Selex. Cows were divided according to sire lineage and milk productivity into five groups by the level of milk yield: from 5000 to6500 kg, 6501-8000, 8001-9500, 9501-11000 and more than11001 kg. Successful insemination of heifers took place at the age of 15.7-16.6 months with the live weight of more than400 kg, which corresponds to zootechnical standards. The earliest (15.7 months) insemination was in heifers of Reflection Sovereign sire line, the age of first calving was 753 days with the live weight of561 kg. The latest (498 days) successful insemination was observed in heifers of Montvik Chieftain bull line with the live weight of498 kg. Cows of Sealing Trygen Rocket (8766 kg) and Reflection Sovereign (8704 kg) sire lines had the highest milk productivity with a significant difference (p ≥ 0.90). The cows of these lines had the longest service period (164 and 179 days), as well as the length of the calving interval (445 and 458 days), respectively. The coefficient of reproductive capacity of cows of different sire lines ranged from 0.80 to 0.88, which is a low indicator.


Author(s):  
О.В. Филинская ◽  
М.Ю. Лапина ◽  
С.В. Зырянова

Исследования проводились на одном из промышленных комплексов Ярославской области. Целью исследований являлась оценка по основным признакам продуктивности импортного скота голштинской породы селекции Нидерландов и их дочерей. Было установлено, что как матери, так и дочери имели удлинённую лактацию. Коровы импортной селекции имели высокую молочную продуктивность с первой лактации, которая составила 5597 кг с МДЖ и МДБ 4,23 и 3,38% соответственно, к третьей лактации удои увеличились до 6611,8 кг, МДЖ составила 4,35%, МДБ – 3,37%. Дочери достоверно превосходили своих матерей по продуктивным признакам, за исключением содержания белка по первой лактации, жира и белка – по третьей лактации. На комплексе и матери, и дочери имели удовлетворительную воспроизводительную способность. Выше принятых норм были продолжительность сервис-периода, сухостойного периода, возраст первого осеменения. При этом у дочерей сервис-период был меньше на 60,3 дня. Увеличение удоя является положительным показателем адаптации, с другой стороны, удовлетворительные показатели воспроизводства указывают на трудности адаптации импортного скота. Реализация продуктивных признаков имеет важное значение при ведении селекционной работы со стадом. При определении корреляции дочерей с матерями и генетического влияния наследуемости признаков от матерей была установлена корреляция по первой и третьей лактациям, соответственно: по удою – слабая отрицательная и слабая положительная, по содержанию жира в молоке – невысокая положительная, слабая отрицательная, по содержанию белка – положительная и отрицательная; наследуемость удоя, МДЖ и МДБ составила 45,1–48,3%, по третьей лактации наследуемость содержания жира от матерей – всего 12,4%. Основными причинами выбытия как матерей, так и дочерей послужили проблемы с воспроизводством, болезни конечностей и вымени. Меньше всего коровы выбывали из-за низкой продуктивности. Средний возраст использования матерей составил 1,6 лактации, у дочерей – 1,8. The researches were carried out at one of the industrial complexes of the Yaroslavl region. The aim of the research was to evaluate of imported Holstein cattle of the selection of the Netherlands and their daughters by the main characteristics of the productivity. It was found that both mothers and daughters had elongated lactation. Cows of imported selection had high milk productivity from the first lactation which was 5597 kg with WCF and WCP 4.23 and 3.38% respectively, by the third lactation milk yield increased to 6611.8 kg, WCF was 4.35%, WCP – 3.37%. The daughters were significantly superior to their mothers in productive features, with the exception of protein for the first lactation, fat and protein for the third lactation. In the complex both mothers and daughters had satisfactory reproductive ability. The duration of the service period, the dry period and the age of the first insemination were higher than the accepted norms. At the same time the service period for the daughters was 60.3 days less. The increase in milk yield is a positive indicator of adaptation on the other hand satisfactory reproduction rates indicate difficulties in adapting imported livestock. The realization of productive characteristics is important when conducting breeding work with a herd. When determining the correlation of daughters with mothers and the genetic influence of the heritability of signs from mothers, a correlation was established for the first and third lactations, respectively: by the milk yield – meanly negative and meanly positive, by fat content in milk – low positive, meanly negative, for protein content – positive and negative; the heritability of milk yield, WCF and WCP were 45.1–48.3%, according to the third lactation the heritability of fat content from mothers was only 12.4%. The main reasons for cow disposal of both mothers and daughters were problems with reproduction, diseases of the limbs and udders. Least of all cows were culled due to low productivity. The average age of use of mothers was 1.6 lactation, for daughters – 1.8.


Author(s):  
A. L. Rozhentsov

Blood inflow of Holstein breed in Mari El cattle breeding, which began in 80s of the last century, had a positive impact on the dairy productivity of Black-and-White cattle. The research explores the impact of Holstein breed bloodline and lineage on the main indicators of cows’ dairy productivity in OAO Ovoshchevod. The productive age increasing, the live weight of cows in the main herd increased as well while the animals were relatively small. The cows of the eighth and ninth calves had the maximum live weight. On average, the cows with the third complete lactation (6791.5 kg) had the highest milk yield. The mass fraction of fat was on average higher than the basic fraction and was equal to 3.71%. The increase of milk fat concentration was observed in cows of the fifth and sixth lactations, with the offsprings of Black-and-White bull lines being the most fatty. There is a direct correlation between milk yield and the degree of blood flow in the Holstein breed. The fattiest milk cows were those with a blood content of 19%, while the cattle with a blood content of 75% had the lowest fat concentration in milk. According to the hospitalization data, most of the cows in the herd (including the first heifer cows) belong to the R. Sawring line. The female offsprings of Adam, Rikus and M. Chiftein bulls differed in the most productive longevity. The most abundant were cows belonging to M. Chiftein line. Female offsprings of Black-and-White bulls were inferior to the Holstein ones in average by 324 kg of milk. This feature was traced from first to fifth lactation. In the lactation section, the most fatty-milk cows of the Rikus and M. Chiftein lines were the fattest. As the share of blood in the Holstein breed increased, the milk yield per cow in the main herd increased as well. Thus, for cows with blood content of 18.75%, the average milk yield for all lactations was 6313 kg of milk. Further blood inflow of Holstein bulls led to this parameter increasing by 4% on average for cows with blood content of 25 and 37.5% for Holstein breed.


Author(s):  
Т. В. Підпала ◽  
Є. М. Зайцев ◽  
А. О. Правда

Мета статті – оцінити прояв господарсько корисних ознак у корів-дочок різних бугаїв-плідників голштинської породи. Методика дослідження. У процесі дослідження використані загальноприйняті зоотехнічні методи (індивідуальний облік молочної продуктивності, відтворювальної здатності), лабораторні (визначення якісного складу молока), ретроспективний аналіз (показники за весь період використання тварин), варіаційно-статистичний метод (визначення параметрів ознак). Результати дослідження. У результаті вивчення використання бугаїв-плідників голштинської породи при створенні високопродуктивного стада молочної худоби з’ясовано, що на рівень розвитку продуктивних, відтворювальних і адаптивних властивостей корів-дочок впливає походження за батьком. Встановлено взаємозв’язок між господарсько корисними ознаками корів первісток голштинської породи німецької та української селекції, які походять від різних бугаїв. Незалежно від походження піддослідних тварин зберігається позитивна високого ступеня кореляція між надоєм і кількістю молочного жиру та білка. Загальною закономірністю для потомства бугаїв голштинської породи є наявність позитивної кореляції низького, середнього і високого ступенів між надоєм і тривалістю сервіс-періоду. Визначено відмінності за напрямом і ступенем кореляційної залежності між продуктивними і відтворювальними ознаками у корів-первісток, які й характеризують різноманітність впливу бугаїв на їхніх дочок. Елементи наукової новизни. Набули подальшого розвитку теоретичні та практичні положення щодо підвищення продуктивності тварин та створення високопродуктивних стад молочної худоби за використання генофонду голштинської породи. Практична значущість. Одержані результати потрібно враховувати у процесі поліпшуючої селекції під час формування високопродуктивного стада молочної худоби голштинської породи. The purpose of the article is to evaluate the manifestation of economically useful signs of cow-daughters of Holstein breed different servicing bulls. Methods of the research. In the course of the study, commonly used zoo-technical methods (individual accounting of milk productivity, reproductive capacity), laboratory (determining the qualitative milk composition), retrospective analysis (indicators for the entire period of using animals), variation-statistical method (determining sign parameters) were used. The research results. As a result of using bulls for service of Holstein breed in creating a highly productive herd of dairy cattle it has been established that the level of developing productive, reproductive and adaptive properties of cow-daughters is influenced by the origin of the father-parent.  The correlation has been established between economically useful signs of cows-firstlings of the Holstein breed of German and Ukrainian selection from various bulls. Regardless of the experimental animals’ origin, there is a high-level positive correlation between the milk yield and the amount of milk fat and protein. The common peculiarity for the offspring of the Holstein breed is the presence of a positive correlation of the low, middle and high levels between the milk yield and the duration of the service period. The differences as to the direction and the degree of correlation dependence between productive and reproductive features of cows-firstlings have been determined, which characterize the diversity of bulls’ influence on their daughters. The elements of scientific novelty. The theoretical and practical propositions for raising the productivity of animals and creating highly productive herds of dairy cattle by using the gene pool of Holstein breed have been further developed. Practical significance. The obtained results should be taken into account in the process of improving the selection during the formation of a highly productive herd of the Holstein breed dairy cattle.


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