GENETIC TRENDS AND SELECTION IN A DAIRY CATTLE HERD

1968 ◽  
Vol 48 (3) ◽  
pp. 243-250 ◽  
Author(s):  
E. B. Burnside ◽  
J. C. Rennie ◽  
G. H. Bowman
Keyword(s):  
Weighted Average ◽  
Female Offspring ◽  
Breeding Value ◽  
Genetic Trend ◽  
Holstein Breed ◽  
Ayrshire Breed ◽  
Positive Rate ◽  
Class Average ◽  
Fat Yield ◽  
The University

Lactation records completed by 104 Holstein and 51 Ayrshire cows in the University of Guelph herd, in 1955 to 1965 inclusive, revealed a steady improvement in each breed for milk and fat yield. Maximum likelihood constants for environmental change indicated an annual increase of 3.9 and 4.0 breed age-class average (BCA) points for milk, and 2.2 and 2.3 BCA points for fat yield for the Holstein and Ayrshire breeds, respectively. In contrast, fat percent showed an equally strong negative environmental trend of −0.05 and −0.07% annually for the Holstein and Ayrshire breeds. The annual genetic trend in the Holstein breed was insignificant, in contrast to significant positive estimates of 1.3 BCA milk, 1.7 BCA fat, and 0.03% fat for the Ayrshire breed. The weighted average within-year difference in breeding value between dams that left female offspring and all cows making records in a given year was generally small, averaging +0.77 and +0.08 BCA points, respectively, for the Holstein and Ayrshire breeds. The weighted average superiority in breeding value for milk of sires of females in the Holstein and Ayrshire breeds was +0.04 and +1.56 BCA points, respectively. The significant positive rate of genetic improvement for milk yield in the Ayrshire herd was attributed to more extensive use of AI sires with high breeding values for milk production.

FACTORS OF EVALUATION OF BREEDING BULLS AND MANAGEMENT OF BREEDING POPULATIONS

2021 ◽  
pp. 26-30
Author(s):  
Н.А. ПОПОВ ◽  
В.Ю. СИДОРОВА
Keyword(s):  
Milk Yield ◽  
Production Capacity ◽  
The United States ◽  
Breeding Value ◽  
Genetic Trend ◽  
Offspring Quality ◽  
Accounting Data ◽  
Holstein Breed ◽  
Digital Format ◽  
Significant Difference

В статье рассмотрены цифровой формат оценки племенной ценности инбредных быков-производителей по качеству потомства и ее влияние на последующие поколения животных. Выявление инбредного гетерозиса у производителей помогает сделать оценку быков по качеству потомства более информативной за счет определения глубины изменения параметров генетической структуры популяции и степени увеличения частоты рецессивных генов в подконтрольных популяциях. Одной из причин значительной разницы в удое, МДЖ и МДБ российских и американских коров голштинской породы являлась их удаленность от родоначальника. Другой причиной считается стремление селекционеров к инбридингу на выдающихся предков, однако в случае инбредного гетерозиса высокие показатели родителей быстро затухают в последующих поколениях потомков. Исследования были проведены в хозяйствах Московской области малой и средней производственной мощности. Для сравнения проанализированы результаты оценки быков-производителей из США и других стран с высокоразвитым молочным скотоводством. Методами изучения были имитационный и регрессионный анализ данных первичного зоотехнического учета и собственных исследований. Эксперимент показал, что быки-производители с высокими степенями родства уменьшали изменчивость признаков молочности среди дочерей: по удою — на 77,9%; по МДЖ — на 33,4%; по МДБ — на 36,0%, по сравнению с отцами, имеющими низкие степени родства. При этом в их поголовье в первом поколении повышается генетический тренд по удою на 14,3—21,4%, а племенная ценность — на 10,8—26,8%. В настоящее время в зарубежных популяциях голштинской породы широко применяют геномный метод оценки племенной ценности, при котором не требуется информация о родословных животных и не учитывается степень их родства, что отрицательно влияет на получение высококачественного потомства. Повышение племенной ценности по признакам в популяции сыновей и внуков быков-лидеров породы угасает, если в генофонде родителей имел место инбредный гетерозис. The article considers of the inbred breeding bulls breeding value by offspring quality and its impact on subsequent generations of animals’ digital format assessing. Identification of inbred heterosis helps to make the bulls’ assessment by the offspring quality more informative, by determining the depth of changes in the genetic structure of the population parameters and the recessive genes at populations frequency degree increase controlling. One of the reasons for the significant difference in milk yield, MJ and MDB of Russian and American Holstein cows was their distance from the ancestor. Another reason is considered to be of the breeders to inbreeding for outstanding ancestors’ desire, but in the case of inbred heterosis, high rates of parents quickly fade in descendants in subsequent generations. The research was carried out in the farms of the Moscow region of small and medium production capacity. For comparison, the results of the evaluation of breeding bulls in the United States and other countries with highly developed dairy cattle breeding were analyzed. The research methods were simulation and regression analysis of primary zootechnical accounting data and authors’ own research. Experimental data showed that breeding bulls with high degrees of relation reduced the variability of milk production among daughters by milk yield in 77.9%: for MJ in 33.4%; for MDB in 36.0% in compared with fathers with relation’s low degrees. At the same time, in livestock’s first generation, the genetic trend in milk yield increases in 14.3—21.4%, and the breeding value in 10.8—26.8%. Currently, the genomic method of assessing the breeding value is widely used in foreign populations of the Holstein breed, which does not require information about the pedigrees of animals, and does not take into account the degree of their kinship, which negatively affects the production of high-quality offspring. The breeding qualities of the sons of the bull leaders of the breed are quickly disabled the surge of increased breeding value by signs in the population of sons and grandchildren of bulls-leaders of the breed is fading if inbred heterosis took place in the parents' gene pool.

Association of class I bovine lymphocyte antigens with production traits in the Ayrshire breed

1994 ◽  
Vol 74 (4) ◽  
pp. 703-705
Author(s):  
T. R. Batra ◽  
P. A. Macdonald ◽  
M. J. Stear
Keyword(s):  
Key Words ◽  
Milk Fat ◽  
Breeding Value ◽  
Additive Effects ◽  
Production Traits ◽  
Substitution Model ◽  
Ayrshire Breed ◽  
Bovine Lymphocyte ◽  
Lymphocyte Antigens ◽  
Fat Yield

Ninety progeny tested Canadian Ayrshire bulls were serologically typed for the BoLA-A locus to determine the association of these alleles with production traits. After exclusion of bulls carrying alleles that occurred at frequencies lower than 2% or whose production proofs were not available, records from 78 bulls remained for analysis. A gene substitution model, which included the effects of BoLA alleles and the breeding value of the sire of the bull as covariate, was used to evaluate the additive effects of BoLA alleles of bulls (ETAs) on the production traits of their daughters. Allele W17 was significantly associated with ETA for milk, fat and protein yields. Allele CA96 was associated with significant increases in ETA for fat yield. There was no significant association of BoLA alleles with either ETA for fat or protein percentage. Key words: BoLA, production traits, Ayrshire

scholarly journals PREDICTION OF PEDIGREE VALUE OF PROVEN BULLS DURING THE USE OF THEIR SEMEN IN SELECTION

2018 ◽  
Vol 56 ◽  
pp. 41-49
Author(s):  
А. P. Krugliak
Keyword(s):  
Initial Level ◽  
Correlation Coefficients ◽  
Breeding Value ◽  
Milk Productivity ◽  
Genetic Trend ◽  
Genetic Progress ◽  
Black And White ◽  
Holstein Breed ◽  
Forecasting Method ◽  
Method Of Evaluation

The results of research on the variability of breeding value of proven bulls of the Holstein breed during 8-year utilization of their semen in herds of German Holstein and Red-and-White breeds are presented. The correlation coefficients between the estimation of the breeding value, obtained as a result of the first assessment with a high rank of repeatability (75% and above) and revaluation of the second year of the use of bulls were +0.747 ± 0.133 and constantly decreased with subsequent revaluation up to +0.320 ± 0.271, obtained during the 8th year of using their semen. There is also a straightforward regression between the values of the breeding value of each subsequent estimate to the first breeding value (Rni / 1), which decreased from 0.880 ± 0,153 between the indicators of the second and the first up to 0.185 ± 0.189 – the eighth with the first estimate. On the basis of correlation coefficients and regression between the indicators of the first assessment with a rank of repeatability of 75% and above with its (annual) revaluations, the genetic trend of milk productivity in the populations of Ukrainian Black-and-White and Red-and-White dairy breeds during 2010–2017 years, and the results of previous research, a forecasting method has been developed duration of preservation of proven bulls breeding value, depending on its initial level. The duration of keeping the bulls breeding value according to the indicators of milk productivity of Ukrainian black-and-white and red-and-white dairy breeds depends on its initial level and the size of the genetic trend. The bulls with an initial breeding value up to 500 kg of milk keep it within the limits of the plus variant for 4 years, 501–1000 – 8; 1001–1500 – 11; 1501–2000 – 15 and 2001–2500 – 18 years. In the process of researching the variability of the pedigree values of bulls by the results of their daughters' productivity, obtained in different generations, we have established the following factors that influence the accuracy of its forecasting for the th year of the use of bulls: - method of assessing breeding value (should use the same method of evaluation for all bulls); - repeatability of the results of the first assessment of the breeding value (must be at least 75%, depending on the number of daughters and herds in which the assessment is carried out); - the peculiarities of the animal genotypes on which the first estimate is made (genetic progress of the milk productivity of different breeds is different); - level of milk production of herds; - the breeding value of other bulls used in herds.

ASSESSMENT BY ORIGIN OF BULLS OF DIFFERENT GENOTYPES ASSOCIATED WITH DISEASE RESISTANCE AND PRODUCT QUALITY

2020 ◽  
pp. 29-32
Author(s):  
Х.Х. ГИЛЬМАНОВ ◽  
С.В. ТЮЛЬКИН ◽  
Р.Р. ВАФИН ◽  
Н.С. ПРЯНИЧНИКОВА
Keyword(s):  
Milk Fat ◽  
Dairy Products ◽  
Research Work ◽  
Well Being ◽  
Breeding Value ◽  
Cattle Breeding ◽  
Holstein Breed ◽  
Milk Performance ◽  
Fat Yield ◽  
The Republic

Успешное развитие скотоводства с целью получения биологически безопасной молочной продукции высокого качества возможно лишь в условиях эпизоотического благополучия. Повышенная молочная продуктивность коров сопряжена со снижением резистентности к различным заболеваниям, включая лейкоз и мастит. Изучена оценка племенной ценности чистопородных и помесных с голштинской породой быков-производителей, принадлежащих племпредприятию Республики Татарстан, с комплексными генотипами iNOS и LTF по характеру проявления молочной продуктивности у ближайших женских предков. Установлено, что наибольшие показатели по удою и выходу молочного жира женских предков оказались у быков с комплексным генотипом BB/AA генов iNOS/LTF. Согласно результатам исследований рекомендуем в хозяйствах Республики Татарстан с часто встречаемыми случаями заболевания животных лейкозом и маститом целенаправленно использовать в селекционно-племенной работе быков-производителей, несущих в своем генотипе A и B аллели соответствующих генов iNOS и LTF. The successful development of cattle breeding in order to obtain biologically safe high-quality dairy products is possible only in conditions of epizootic well-being. The increased milk performance of cows is associated with the reduction of the resistance to various diseases, including leukemia and mastitis. In this research work we studied purebred breeding bulls and bulls crossbred with Holstein breed (both type of bulls have a complex iNOS and LTF genotypes) belonging to the plempredprime of the Republic of Tatarstan. We made an assessment of their breeding value based on the nature of milk production in the closest female ancestors. It was found that the highest indicators of milk yield and milk fat yield of female ancestors were found in bulls with a complex genotype BB / AA of the iNOS / LTF genes. According to the research results, in breeding work in farms of the Republic of Tatarstan with frequent cases of animal disease with leukemia and mastitis, we recommend purposefully using breeding bulls that carry in their genotype A and B alleles of the corresponding iNOS and LTF genes.

EFFICIENCY AND COMPARISON OF THE TEST-DAY MODEL AND BLUP METHOD MODIFICATIONS FOR ASSESSING BULLS BREEDING VALUE IN SIMMENTAL CATTLE BREED

2020 ◽  
Author(s):  
А.И. МАМОНТОВА ◽  
С.А. НИКИТИН ◽  
Е.Е. МЕЛЬНИКОВА ◽  
А.А. СЕРМЯГИН
Keyword(s):  
Animal Model ◽  
Milk Yield ◽  
Cattle Breed ◽  
Breeding Value ◽  
Am1 Method ◽  
Production Traits ◽  
Genetic Trend ◽  
Sire Model ◽  
The Russian Federation ◽  
Simmental Cattle

Целью проведенных исследований являлась отработка и адаптация применения методик BLUP AM (Animal Model — модель животного) и TDM (Test-Day Model — модель тестового дня) для прогнозирования племенной ценности быков-производителей и оценки селекционно-генетических параметров на популяции скота симментальской породы четырех регионов РФ. Проведен сравнительный анализ указанных методов с более ранним методом BLUP SM (Sire Model — модель отца). Рассчитана племенная ценность быков и коров симментальской породы по признакам молочной продуктивности: удой за 305 дней, выход молочного жира, выход молочного белка. Анализ полученных средних значений достоверности оценок быков-производителей, рассчитанных на основе сопоставляемых методов, свидетельствует, что достоверность для признака «удой за 305 дней» при переходе от метода SM1 к AM1 увеличивается на 2,4%, а при переходе от SM1 к TDM1 — на 7,8%. Даны варианты генетического тренда по удою с использованием различных уравнений моделей расчета племенной ценности. На основании полученных данных можно сделать вывод о том, что модель тестового дня позволяет не только повысить точность оценок быков, но и более рельефно выявить их ранги, а также несколько уменьшить срок получения достоверных оценок производителей по качеству потомства по продуктивным признакам. The purpose of this research was to develop and adapt the application of BLUP AM (Animal Model) and TDM (Test-Day Model) methods for predicting the sires breeding value and evaluating genetic parameters for Simmental cattle population in four regions of the Russian Federation. A comparative analysis of these methods with the earlier BLUP SM (Sire Model) method is performed. The breeding value for sires and cows of Simmental breed was calculated by milk production traits: milk yield for 305 days; milk fatyield; milk proteinyield. The sires reliability of average breeding value calculated by different methods reveal that milk yield for 305 days when switching from the SM1 to AM1 method increases by 2.4%, and when switching from SM1 to TDM1 — by 7.8%.The variants of the genetic trend for milk yield are given using various equations of BLUP and TDM. Based on the obtained data, it can be concluded that the Test-Day model allows increasing the accuracy of bull’s evaluation and also more clearly identifying their ranks, as well as slightly reducing the time for obtaining reliable estimates of bulls by offspring for production traits.

ВЛИЯНИЕ БИОКОНСЕРВАНТА «СИЛОСТАН» НА КАЧЕСТВО СЕНАЖА ИЗ КОЗЛЯТНИКА ВОСТОЧНОГО И СЫРОПРИГОДНОСТЬ МОЛОКА КОРОВ

2019 ◽  
pp. 51-56
Author(s):  
A.S. KARAMAEVA ◽  
N.V. SOBOLEVA ◽  
S.V. KARAMAEV
Keyword(s):  
Serum Proteins ◽  
Metabolizable Energy ◽  
Holstein Cows ◽  
Technological Properties ◽  
Holstein Breed ◽  
Feed Digestibility ◽  
Ayrshire Breed ◽  
Milk Coagulation ◽  
Dry Substance

От породы коров и ее особенностей зависят эффективность использования кормов, качество и технологические свойства молока. Материалом исследований служили коровы чернопестрой голштинской и айрширской пород. Для повышения качества сенажа из козлятника восточного использовали микробиологический препарат. В готовом корме с биоконсервантом содержание сухого вещества было выше на 3,66, обменной энергии на 8,04, сырого протеина на 10,86, переваримого протеина на 13,59. Улучшение качества корма оказало положительное влияние на метаболические процессы в рубце подопытных коров. Независимо от технологии приготовления сенажа коровы айрширской породы лучше переваривали, по сравнению с голштинами, сухое вещество на 2,062,91 (Р0,05), органическое на 1,212,04 (Р0,05), сырой протеин на 2,222,49 (Р0,05), БЭВ на 0,921,36, но при этом голштины лучше переваривали сырой жир на 2,732,78 (Р0,05) и сырую клетчатку на 1,551,86. В результате внесения в сенаж биоконсерванта Силостан и улучшения переваримости корма у коров опытных групп значительно улучшился химический состав и технологические свойства молока. Очень важно для сыроделия, что в молоке коров, получавших в рационе сенаж с биоконсервантом, повышается массовая доля казеина на 2,42,7, а доля сывороточных белков и фракции казеина, которые не свертываются под действием сычужного фермента, наоборот, снижается на 1,41,5 и на 0,30,9, соответственно. Уменьшается продолжительность свертывания молока сычужным ферментом, снижаются потери сухого вещества с сывороткой, и увеличивается выход казеинового сгустка. Плотность казеинового сгустка повышается в молоке голштинских коров на 14,3, айрширских на 5,7 и составляет, соответственно, 1,92 и 2,96 г/см2.The efficiency of feed use, the quality, as well as technological properties of milk depend on cow breed and its characteristics. Blackandwhite Holstein and Ayrshire breeds were used as the material for research. Microbiological preparation was used to increase the quality of halyage made of Eastern galega. The content of dry substance in the readymade feed was 3.66 higher, the metabolizable energy 8.04 higher, raw protein 10.86 higher, and digestible protein 13.59. Improvement of feed quality positively influenced the metabolic processes in the rumen of experimental cows. Without regard to the technology of halyage preparation, cows of Ayrshire breed showed betterdigestion of dry substance by 2.06 2.91 (P0.05) than Holstein cows, organic substance by 1.21 2.04 (P0.05), raw protein by 2.22 2.49 (P0.05), nitrogenfree extractive fraction by 0.92 1.36, but Holstein breed showed better digestion of raw fat by 2.73 2.78 (P0.05) and raw fiber by 1.55 1.86. Chemical composition and technological properties of milk improved significantly as a result of addition of Silostan biopreservative to the halyage and improvement of feed digestibility in cows from test groups. The fact that the mass percentage of casein is increased by 2.4 2.7, and the share of serum proteins and ycasein fractions which do not coagulate under the influence of enzyme rennet is inversely decreased by 1.4 1.5 and 0.3 0.9, accordingly, is very important for cheese making. The duration of milk coagulation with rennet is decreased, the loss of dry substance with serum is decreased, and the yield of casein coagulate is increased. Density of casein coagulate is increased in the milk of Holstein cows by 14.3, Ayrshire cows by 5.7, and equals to 1.92 and 2.96 g/cm2, accordingly.

scholarly journals THE ESTIMATION OF THE ECONOMIC USE AND LIFETIME PRODUCTIVITY OF COWS OF UKRAINIAN BLACK-AND-WHITE DAIRY BREED DEPENDING ON THE REASONS OF THEIR DISPOSAL

2018 ◽  
Vol 56 ◽  
pp. 84-93 ◽  
Author(s):  
A. L. Shulyar
Keyword(s):  
Dairy Cows ◽  
Total Duration ◽  
Correlation Coefficients ◽  
Breeding Value ◽  
Lactation Period ◽  
Black And White ◽  
Holstein Breed ◽  
Reproductive Capability ◽  
Economic Use ◽  
Dairy Breed

An important selection peculiarity of dairy cows is their productive longevity. Besides, the indicators of cow productivity along with genetic potential are the most important criteria of the economic efficiency of their use. Low or not sufficient level of lifetime productivity indicators and of the period of the economic use of cows determine the necessity of monitoring of the selection information according to these indicators in the breed herds as well as the of using corresponding selection methods for their improvement. The goal of our research was the estimation of an economic use of lifetime cow productivity of Ukrainian Black-and-White dairy breed depending on the reasons of their disposal from the herd and genotype. The research was conducted at a private agrarian firm (PAF) «Yerchyky» Zhytomyr oblast according to the data of breeding and productive use of 497 cows which were disposed from the herd on different reasons. The reasons for the cow disposal were determined according to the veterinary disposal acts. The indicators of cow economic use and lifetime productivity were determined on the ground of the term of rearing, life duration, term of economic use, amount of lactations, the total duration of lactation period, milk yields, milk yield per one lactation day, per life, and per economic use. Statistical processing was performed by means of Microsoft Excel software kit using the methods of variation statistics. As follows from the results of the research, in the process of holsteinization the dynamics of the parameters of the economic use of cows is characterized by curvilineal type: as follows from the heterotic effect they increased in animals with an conditional share of genetic heredity of Holstein breed from 50 and 62.5 to 75%, and then when the genetic heredity share of the improved breed increased by more than 75% they got worse due to the contradiction “genotype-environment”. At the same time within the determined genotypes (1st group-up to 50%, 5th group-87.6–100%) the indicators of lifetime productivity increase in case of 66% of reliable results. Besides, the interconnection level of the indices of lifetime use of the dairy cows of different genotypes has been studied. The criteria of the significance of the correlation coefficients according to Student has been used. The closer the linkage, the higher the correlation coefficients and the higher the criteria of their reliability. Generalized criteria of reliability on the grounds of all indicators of lifetime use was the lowest in cows of the 1st and 2nd groups, and the highest in cows of the 3rd group with further decrease in high half-bred cows and pure-breed cows of the 4th and 5th groups. It testifies to the fact that there is a close interconnection between given parameters and real milk yields in 3rd group cows (62.6–75.0% of the improved Holstein breed). At present, the reason of the shortening of the period of economic use is an early disposal of cows from the herd. A greater part of milking cows is disposed in the most productive period or even before it. At the given enterprise, a vast majority of holsteinized cows (77.5%) was disposed from the herd on four main reasons: unsatisfactory reproductive capability (32.2%), limbs diseases (22.3%), postpartal complications (13.9%) and low productivity (9.1%). The other reasons for cow disposal were within 1.6–7.0% (totaled up 22.5%) as to the total number of cow population that were disposed of the herd. It should be mentioned that the disposal caused by low productivity was only in the first calvers of the 1st and 2nd groups, in which the conditional share of genetic heredity of a Holstein breed did not exceed 62.5%. The parameters of the economic use and of lifetime productivity of Ukrainian Black-and-White dairy cows of different genotypes which were disposed of the herd because of their unsatisfactory reproductive capability, limbs diseases, postpartal complications and low milking productivity have been also analyzed. It has been determined that the indicated reasons for the disposal had different effects on the parameters of an economic use and on cow productivity. Because of any of four indicated reasons for cow disposal of the herd under condition of in-barn keeping and optimal feeding the preference on lifetime productivity belongs to the cows of the 4th and 5th groups (with a conditional share of Holstein heredity of more than 75%) with simultaneous worsening of the indicators of economic use. As a third part of cows at this enterprise was disposed of the herd ahead of time on the reason of unsatisfactory reproductive capability, that results in breeding value and in the results of the economic use of cows, the updating of the technology of artificial animal insemination and renewal will promote to solving the problem.

scholarly journals FEATURES OF BREEDING VALUE INHERITANCE SIRES OF HOLSTEIN BREED

2021 ◽  
Vol 61 ◽  
pp. 64-72
Author(s):  
А. P. Кrugliak ◽  
Т. О. Кrugliak
Keyword(s):  
Milk Yield ◽  
Population Level ◽  
Point Of View ◽  
Breeding Value ◽  
Phenotypic Correlation ◽  
Intermediate Form ◽  
Theoretical Point ◽  
Genetic Progress ◽  
Holstein Breed ◽  
Additive Form

In our studies, the phenotypic manifestation of the additive form of inheritance of breeding value by milk yield (intermediate and parental dominance) was in 334 (82.2%) bulls, and non-additive form (over-dominance and regression) – in 72 (17.8%) including: over-dominance in 55 (13.5%) and regression in 17 heads (4.2%). In the population assessment, for all forms of inheritance, there was a clear quantitative shift of the breeding value of sons of milk yield to positive (+) values, compared with the breeding value of their parents. This confirms that sons, selected after their evaluation, and recognized as milk yield improvers. The variability of the breeding value of sons by milking depending on the forms of its inheritance has been established. According to the group of bulls by intermediate type of inheritance, milk yield sign were found in 291 (71.7%) sons, whose pedigree value was 606.4 ± 11.6 kg and was higher than the half-sum of both parents (554 kg), which deviates from the action of intermediate inheritance at 52 kg (109%). After all, the recognition of the intermediate nature of inheritance involves obtaining in the offspring of animals with the same set of chromosomes as their parents, and hence with the same phenotype. Therefore, from a theoretical point of view, genetic progress in the population should be not expected from this group of animals. However, in this case, the increase in breeding value was 9%, which is statistically significant (P > 0.99). A rather high variability of the breeding value of sons from its level in their parents with an intermediate form of inheritance has been established. Thus, of the 159 bulls-breeders in which the breeding value was inherited by intermediate form, only 30 sons (7.3% of the total population) of the bull Duster 2147488 (BV +579 kg and mothers with an average BV +632 kg, half the amount of the BV of both parents was +605 kg), was +605.5 ± 30.8 kg and was equal to the half-sum of the BV of both parents, and 9 (2.2%) sons of the bull Manfred 2183007, whose breeding value was, on average, at the population level +856.3 ± 37.6 kg and was equal to the half-sum of the indicator of the parents' BV (+851 kg). The inheritance of breeding value of bulls on quantitative signs of milk productivity in highly consolidated breeds on these signs, at intra-breeding selection occurs by a combination of phenotypic display of action of additive and non-additive (super-dominance) forms of inheritance. The frequency of these forms of inheritance probably is determined by the number and quality of chromosome pairs in the karyotype of animals on the probable basis of their manifestation in the population [15]. The relative variability of breeding value by milk yield along the line "father – son" and "mother – son" depends on the form of its inheritance. The coefficient of phenotypic correlation between the breeding value of parents and sons in the intermediate form of inheritance is +0.524 – +0.560 and increases with parental dominance to +0.907 ± 0.040 and +0.985 ± 0.006, and over-dominance to +0.887 ± 0.044 and +0.905 ± 0.033, at high statistical significant. Inheritance by non-additive form (over-dominance of both parents) is more effectively associated with increasing of breeding value by milk yield their sons than by the additive form.

scholarly journals Evaluation of breeding bulls based on quality of offspring considering crossing options

2021 ◽  
Vol 59 (4) ◽  
pp. 452-463
Author(s):  
M. V. Abramova ◽  
S. V. Zyryanova
Keyword(s):  
High Reliability ◽  
Breeding Value ◽  
Milk Productivity ◽  
Cattle Breeding ◽  
Breeding Programs ◽  
Holstein Breed ◽  
Genetic Potential ◽  
Dairy Cattle Breeding ◽  
Holstein Bulls

Breeding takes the main place in the complex of measures for intensification of dairy cattle breeding. A characteristic feature of breeding work is identification of the most valuable genotypes and their further use in cattle population. The Holstein breed is considered one of the most highly productive breeds, in many countries of the world it is used for the genetic improvement of local breeds. In this regard, a comparative assessment of methods for determining the breeding value of bulls of different genotypes obtained by interbreeding is relevant. The results of assessment of genetic superiority of the used breeding bulls in terms of milk productivity of daughters for the first lactation through interannual deviations of the homogeneous peers are presented, the best producers in all the studied herds are identified, it is established which breeds the best and worst breeding bulls belong to. The research revealed that 18% of bulls had genetic superiority at controlled farms (9% - Holstein breed, 6% - Yaroslavl crossbreeding bulls, 3% - Mikhailovsky type’s bulls), a negative value - 24% including 9% - Yaroslavl crossbreeding bulls, 9% - Mikhailovsky type’s bulls and 6% - Holstein bulls. A comparative evaluation of the two methods showed a high reliable positive correlation between results of Mikhailovsky type bulls and Yaroslavl crossbreeding bulls equal to 0.82 and 0.56, respectively, which indicates a high reliability of the method of genetic superiority index, which can be used to evaluate bulls during crossbreeding. It is possible to increase the genetic potential of herds by excluding producers with a negative genetic index. The obtained results are recommended to be used when mating bulls and for development of breeding programs for individual herds or entire population

ARE TODAY’S DAIRY CATTLE BREEDING PROGRAMS SUITABLE FOR TOMORROW’S PRODUCTION REQUIREMENTS?

1980 ◽  
Vol 60 (2) ◽  
pp. 253-264 ◽  
Author(s):  
A. J. McALLISTER
Keyword(s):  
Dairy Cattle ◽  
Genetic Improvement ◽  
Herd Size ◽  
Breeding Program ◽  
Genetic Trend ◽  
Genetic Progress ◽  
Breeding Programs ◽  
Holstein Breed ◽  
Dairy Cattle Breeding ◽  
National Production

In the last decade the dairy cattle population has declined to a level of 1.9 million cows in 1978 with about 56% of these cows bred AI and nearly 20% of the population enrolled in a supervised milk recording program. The decline in cow numbers has been accompanied by an increase in herd size and production per cow. The current breeding program of the dairy industry is a composite of breeding decisions made by AI organizations, breeders who produce young bulls for sampling and all dairymen who choose the sires and dams of their replacement heifers. Estimates of genetic trend from 1958–1975 for milk production in the national milk recorded herd range from 21 to 55 kg per year for the four dairy breeds with Holsteins being 41 kg per year. Both differential use of superior proven sires and improved genetic merit of young bulls entering AI studs contribute to this genetic improvement. Various national production and marketing alternatives were examined. Selection is a major breeding tool in establishing a breeding program to meet national production requirements for milk and milk products once the selection goal is defined. AI and young sire sampling programs will continue to be the primary vehicle for genetic improvement through selection regardless of the selection goal. The current resources of milk-recorded cows bred AI is not being fully utilized to achieve maximum genetic progress possible from young sire sampling indicate that the number of young bulls sampled annually in the Holstein breed could be tripled with the existing milk-recorded and AI bred dairy cow population. Expanded milk recording and AI breeding levels could increase the potential for even further genetic improvement. The potential impact of selection for other traits, crossbreeding and the use of embryo transfer of future breeding programs is highlighted.

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