EFFICIENCY OF IMPORTED COWS LIFETIME USE

2016 ◽  
Vol 52 ◽  
pp. 49-58 ◽  
Author(s):  
V. P. Oleshko

The study was conducted in high productive herd of Holstein breed in JV "Agrosvit" Myronivka district, Kyiv region by retrospective analysis of the primary materials of zootechnical and pedigree records. The research involved analysis of data about 78 cows imported from Hungary to the farm in 2000 and 2003 and the first calving was during 2002-2004 and 117 cows imported from Denmark in 2005, the first calving was during 2005-2006. In comparison to the imported cows, contemporaries of local reproduction were selected based on respective years of the first calving (n = 409). The selection of animals and computing performance were conducted by the method of Polupan Yu. (2010). The aim of the research was a comparative study of economic use duration and lifetime performance of the imported Holstein cows. Analysis of milk production during lactation showed high milk yield during the first lactation (7315-7688 kg) in the imported animals at this farm. A slight decrease in yields by 3.4-5.1% (to 6939-7426 kg) was observed to the third lactation This downward trend in milk yield of cows with age does not match the physiological capabilities of animals. No significant difference (P ˃ 0.05) in fat content of milk also was found with its tendency to increase by 0.08-0.22% with age. For the third lactation fat content in milk was 0.13% (P ˃ 0.05) higher for the cows imported from Denmark. Predominance in protein content of milk (P ˃ 0.05) was in the imported cows from Hungary on average values within 3.34-3.42%. This figure declined with age from 3.3% to 3.1% in the cows from Denmark. Significant differences were not revealed in comparing milk productivity of cows imported from Denmark with performance of their contemporaries of native origin. Difference in milk yield did not exceed 6.6%, fat yield – 5.8% and protein yield – 6.8% (P ˃ 0.05). The fat and protein content in the milk of cows in the compared groups was at the same level within 3.1-3.3%. Similar comparison of Holstein cows imported from Hungary and their contemporaries of native origin had slightly different results. The predominance in milk yield during the first lactation was noted for the local cows by 4%, fat content in milk – by 0.04% and protein content – by 0.1%, fat yield – by 5.4% and protein yield – by 7.1 %. Milk yield during the third lactation was significantly higher for imported livestock by 13.5% (1000 kg), fat content – by 0.04% and protein content – by 0.08%, fat yield – by 15%, protein yield – by10% at P ˃ 0,05. The research of duration and efficiency of economic use found slightly higher levels of lifetime measures of the imported cows from Denmark (R ˃ 0.05). In the calculation of milk yield per a day of life, economic use and lactation slight advantage (P ˃ 0.05) also was noted for the imported cows (by 0.6, 2.2 and 1.9 kg). The numbers of lactations and calves obtained from the cows were within 2.4-2.7 and 3.4-3.5 respectively. A similar slight predominance (P ˃ 0,05) of the animals imported from Denmark was for coefficients of economic use (by 6.5%), lactation (by 1.8%) and productive use (3.5%). A slightly different situation was observed in comparing the lifetime measures of the cows imported from Hungary with their contemporaries. In these groups of animals, small and insignificant predominance was in all the studied traits (P ˃ 0.05) recorded for local contemporaries. Lifetime milk yield was 2.641 kg lower, so fat yield was 73 kg less and protein yield – 64 kg less. Lifetime fat and protein content in milk was within 3.69-3.70% and 3.35-3.36% on average, respectively. Milk yield per a day of life, economic use and lactation in the both groups was almost at the same level (9.1-9.7, 16.2-16.7 and 20.2-20.6 kg respectively). On average in the both groups during lifetime of cows 3.5-3.8 calves were received and number of lactations was within 2.9-3.2. Coefficients of economic use, lactation and productive use were 0.5, 2.4 and 6.0% lower respectively in the cattle imported from Hungary as compared to the local contemporaries. Coefficient of variability of lifetime measures averages for the imported cows was to 66.6%. Coefficient of variability of average fat and protein content in milk during lifetime (1.9-2.9%) indicated high consolidation of the traits. High variability of lifetime measures confirms significant opportunities for selection of cows on these traits. Consequently, Holstein cattle imported from Hungary and Denmark showed satisfactory adaptive ability under condition of "Agrosvit" breeding farm that provided high milk yield (7315-7688 kg) during the first lactation with small (by 3.4-5.1%) reduction in yields during the third (to 6939-7426 kg). Fat content in milk was 3.64-3.86% and increased by 0.08-0.22% with age. The protein content in milk fluctuated within 3.30-3.42%. There was no difference in comparing milk productivity of imported Holstein cows and their local contemporaries. The difference in all cases is insignificant. The revealed tendency of higher productive performance is in favour of livestock imported from Denmark. The same traits in cattle from Hungary were slightly lower. Average lifetime measures at the imported animals from Denmark were slightly higher and insignificant (P ˃ 0.05) compared to local contemporaries. And the same averages at the cattle imported from Hungary were slightly lower and insignificant. High coefficients of variability of the studied traits were found that would allow intensive selection of cows and to create herds with high productivity and long-term economic use.

2016 ◽  
Vol 52 ◽  
pp. 6-12 ◽  
Author(s):  
M. V. Gladiy ◽  
G. S. Kovalenko ◽  
S. V. Priyma ◽  
G. A. Holyosa ◽  
A. V. Tuchyk ◽  
...  

The main goal of dairy breeds selection should be improving breeding and productive qualities of animals under modern conditions. The majority of farms, using native breeds to produce milk, has created optimal conditions for keeping and feeding, selection and matching, growing of replacements etc. Further improvement of created native dairy breeds for economically useful traits occurs at total use of purebred Holstein bulls (semen) of foreign selection. In order to realistically assess milk productivity (milk yield, fat content in milk and fat yield) of Ukrainian Black-and-White and Red-and-White Dairy cows should be conducted a comparative analysis of Holstein cows under the same conditions of feeding and keeping. It was established that Ukrainian Red-and-White Dairy cows were characterized by the highest milk yields for 305 days of all lactations, taken into account, the among three investigated breeds. Their milk yield during the first lactation was 5933 kg of milk, during the second – 6393 kg, the third – 6391 kg and during higher lactation – 6650 kg. Ukrainian Black-and-White Dairy cows were second by milk yield (except for the second lactation), during the first lactation – 5932 kg of milk, the third – 6462 kg and higher – 6541 kg, and Holstein cows were third, during the first lactation – 5794 kg of milk, the second – 6381 kg, the third – 6335 kg and higher – 6469 kg. The fat content was almost the same and varied within 3.49-3.58% in milk of Ukrainian Red-and-White Dairy cattle, 3.50-3.60% in milk of Ukrainian Black-and-White Dairy cattle and 3.50-3.56% in Holsteins’ milk. The difference between the breeds was within 0.01-0.04%. All the investigated breeds had predominance in fat yield for three lactations over standards of these breeds: Ukrainian Red-and-White Dairy cows from 75.1 to 93.4 kg, Ukrainian Black-and-White Dairy cows – 75.1-89.0 kg respectively and Holstein cows – 41.9-60.2 kg. It was found different level of positive correlation between milk yield and fat yield in all the cases and high correlation (r = 0.604-0.921, P < 0.001) in five cases (41.7%) Negative correlation coefficients indicate that selection of animals to higher milk yield in the herd will decrease the second trait – fat content in milk. Positive and highly significant correlation between milk yield and fat yield indicates that selection of cows in the herd to higher milk yields will increase fat yield. It was revealed that bulls were among the factors impacted the milk productivity (milk yield, fat content, fat yield) of three investigated breeds. So, the force (η²x) of father’s impact on milk yield was15.4-47.9%, fat content – 22.0-43.4% and fat yield – 14.9-47.7% taking into account a lactation and a breed. The force of lines impact (η²x) was second; it was on milk yield 6.1-24.5%, fat content – 4.1-17.1 and fat yield – 5.8-23.5%. The force of breeds impact (η²x) was last; it was on milk yield 0.3-2.9%, fat content – 0.2-0.3% and fat yield – 0.6-2.7%. So, the comparative studies of milk productivity of Ukrainian Red-and-White and Black-and-White Dairy cattle with Holsteins indicate that under similar conditions of feeding and keeping, these native breeds can compete with Holstein cattle. The milk yield for 305 days of higher lactation was 6650 kg of milk in Ukrainian Red-and-White Dairy cows, 6541 kg in Ukrainian Black-and-White Dairy cows and 6469 kg in Holsteins. It was found the inverse correlation r = -0.025-0.316 between milk yield and fat content in milk in most cases. Selection and matching of animals in the herd should be carried out simultaneously on these traits. It was found positive repeatability of milk yields between the first and second, the third and higher lactations (rs = 0.036-0.741), indicating the reliability of forecasting increase in milk productivity during the next lactations in all herd. Bulls have the greatest impact (η²x) on milk productivity among the factors taken into account: milk yield – 15.4-47.9%, fat content in milk – 22.0-43.4% and fat yield – 14.9-47.7%.


Author(s):  
Ertugrul Kul ◽  
Özden Çobanoglu ◽  
Eser Kemal Gurcan ◽  
Soner Çankaya ◽  
Samet Hasan Abaci ◽  
...  

This study aims to determine the correlations between the test-day milk yield (TDMY) and the fat and protein content as well as the fat and protein yields in Holstein dairy cows and to investigate the effects of lactation period and sampling season on these parameters. The study material consists of 1.380 records of a total of 151 head of Holstein dairy cows raised on a private farm in Samsun province. In the study, the mean TDMY, fat content, protein content, fat yield and protein yield were recorded as 20.6±5.10 kg, 3.97±0.734%, 3.23±0.276%, 0.81±0.210 kg and 0.66±0.160 kg, respectively. The effects of lactation period and sampling season on the TDMY, fat content, protein content, fat yield and protein yield were found statistically significant (Pis less than 0.01). Statistically significant negative correlations were determined between the TDMY and the fat and protein content, but positive and statistically significant (Pis less than 0.01) correlations between the TDMY and the fat and protein yields. In conclusion, it might be stated that the effects of lactation period and sampling season should also be taken into account to improve milk yield and milk components.


Genetika ◽  
2018 ◽  
Vol 50 (1) ◽  
pp. 243-251
Author(s):  
Marina Lazarevic ◽  
Dragan Stanojevic ◽  
Vladan Bogdanovic ◽  
Vlada Pantelic ◽  
Nevena Maksimovic ◽  
...  

The research was performed on Holstein-Friesian and Black and White bull dams reared on five farms of Agricultural Corporation of Belgrade - PKB. The study included 575 lactations of cows selected as bull dams and their progeny calved in the period from 2007 - 2014 and represent progeny of 24 bulls. The following dairy traits were analysed in a standard lactation (305 days): milk yield (kg) - MY, milk fat content (%) - % MF, milk fat yield (kg) - MFY, protein content (%) - % PC and protein yield (kg) - PY. Holstein-Friesian bull dams and their progeny, in standard lactation, produced on average 9239.84 ? 1607.64 kg of milk, with a milk fat content of 3.44 ? 0.20 and protein content of 3.21 ? 0.12. The impact of bull - sire, year of birth, lactation order, farm, year and calving season was present at different levels of statistical significance on yield traits, while the genetic group had no influence on any of the milk traits. Bull - sire, year of birth, lactation order and calving season did not influence the variability of milk fat and protein content. Heritability of observed milk traits was medium to low. The content of milk fat and protein had the lowest values of heritability, 0.014, and 0.024, respectively. The heritability of milk yield, milk fat yield and protein yield was 0.293, 0.319 and 0.273, respectively.


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):  
L. Istasse ◽  
E.R. Ørskov

Abomasal infusion of casein has been shown to increase the milk yield, fat yield, protein content and protein yield while no clear-cut effects were observed with infusion of glucose (Ørskov, Grubb and Kay, 1977 and confirmed by Oldham, Bines and MacRae, 1983). Little information is available about the changes in blood parameters with abomasal infusion of glucose or casein. The objective of the present experiments was to relate changes in milk production to blood parameters in dairy cows given casein or glucose as an infusion into the abomasum during early or late lactation.


2019 ◽  
pp. 26-28
Author(s):  
Z.S. SANOVA

Приведены результаты оценки быковпроизводителей голштинской породы по молочной продуктивности и воспроизводительным качествам их дочерей. Обработаны данные 563 первотелок и 45 быковотцов. В среднем удой дочерей за 1ю лактацию от разных отцов колебался от 6784 до 7789 кг, по содержанию жира и белка в молоке различий не выявлено. Большинство производителей обладали желательной степенью реализации генетического потенциала. Основной вклад в генетическое совершенствование стада вносят быки Altahessel Sex138929389, Altajupiter Sex 66011448 и ClearEc Altar2 62916235, достоверно увеличивая удой дочерей за 305 дней 1й лактации от 350 кг до 490 кг по сравнению со средними показателями по стаду. Уровень раздоя коров по 1й лактации достоверно обусловливает их дальнейшую продуктивность. У дочерей ClearEc Altar2 отмечена положительная корреляция (0,44) между удоем и белком, а у дочерей Бодо 354239752 (r0,68) между жиром и белком. Отмечены дочери с отрицательной коррелятивной связью между удоем и жиром, это свидетельствует о том, что в этих группах с высокой молочной продуктивностью отбор коров по жирномолочности не обеспечивает повышение белковомолочности. Самый короткий сервиспериод (98 дней) характерен для дочерей Магикон 536522893, наиболее длинный у дочерей Dinom Altatyson 66133528 и Short Cut 3504510619. Используемые быкипроизводители в хозяйстве реализуют свой потенциал в более сжатые сроки, что необходимо учитывать при дальнейшем их закреплении.The results of estimation of Holstein sires based on milk productivity and reproductive qualities of their daughters are presented .The findings of 563 heifers and 45 bullsfathers were processed.on average, the milk yield of daughters for 1 lactation from different fathers ranged from 6784 to 7789 kg, theee were not found any differences in the content of fat and protein in milk.most producers had a desirable degree of realization of genetic potential. Bulls Altahessel Sex138929389, Altajupiter Sex 66011448 and ClearEc Altar2 62916235mainly contribut to the genetic improvement of the herd, significantly increasing yield of daughters in 305 days of the first lactation from 350 kg to 490 kg compared to the average for the herd. The level of milking cows on the 1st lactation reliably determines their further productivity. Daughters of ClearEc Altar2 had a positive correlation (0.44) between milk yield and protein, and daughters of Bodo bull 354239752 (r0.68) between fat and protein. Daughters with a negative correlation between milk yield and fat were noted, this indicates that the selection of cows by fat content does not provide an increase in protein content in these groups with high milk productivity. The shortest service period (98 days) are typical for daughters of Magikon 536522893, the longest the daughters Dinom Altatyson 66133528 and Short Cut 3504510619.sires, used in farming, realize their potential in a shorter time, which should be taken into account in their further consolidation.


Author(s):  
S.V. NIKOLAEV ◽  
N.A. SHEMURANOVA

Представлены данные о продуктивности коров холмогорской породы и их помесей с различной степенью голштинизации. В период с 2000 по 2019 год установлено, что в условиях Республики Коми коровы с долей кровности более 75 по голштинской породе превосходят чистопородный холмогорский скот по показателям молочной продуктивности и жира в молоке за 1-ю лактацию на 40,3 и 0,63 абс., а в 3-ю на 52,8 и 0,64 абс., соответственно. Однако повышение молочности за лактацию не приводит к увеличению пожизненного производства молока, что обусловлено снижением продолжительности хозяйственного использования. У коров с долей кровности по голштинам более 75 средний возраст выбытия составляет 2,400,11 отела, что в 1,5 раза меньше по сравнению с чистопородными животными.Наибольший пожизненный удой имеют животные с кровностью 50, полученные при скрещивании чистопородного голштинского и холмогорского скота (19850618 кг), а наименьший с кровностью 2550 при разведении помесей в себе (123281134 кг). Продукция молочного жира за все лактации у коров с кровностью 50 составляет 799,625,3 кг, что в 1,9 раз больше аналогичного показателя животных с долей кровности до 25. При учете молочной продуктивности на 1 день жизни животного установлено, что наибольший показатель наблюдается у коров с кровностью 50 7,4 кг молока натуральной жирности, а при пересчете на базисную жирность (3,4) у высококровных (более 75) по голштинской породе помесей (9,00,3 кг), где также наблюдается наибольший показатель производства молочного жира на 1 день жизни 307,310,1 г.The article presents data on the productivity of cows of the Kholmogorskaya breed and their crosses with varying degrees of holsteinische. In the course of studies conducted in the period from 2000 to 2019, it was found that in the Komi Republic, cows with a blood content of more than 75 of the Holstein breed outperform pure-bred Kholmogorsky cattle in terms of milk productivity and fat in milk for the first lactation by 40.3 and 0.63, and in the third by 52.8 and 0.64 respectively. However, an increase in milk yield per lactation does not lead to an increase in lifetime milk production, which is due to a decrease in the duration of economic use: in cows with a Holstein blood ratio of more than 75, the average leaving age is 2.400.11 calving, which is 1.5 times less than in purebred animals. The highest lifetime yield is given to animals with a blood content of 50 obtained by crossing Chi-pedigree Holstein and Kholmogorsky cattle (19850618 kg), and the lowest with a blood content of 2550 when breeding crossbreeds in themselves (123281134 kg). The production of milk fat during all lactation in cows with a blood content of 50 is 799.625.3 kg, which is 1.9 times more than in animals with a blood content of up to 25. When accounting for milk production on a day in the life of an animal is established that the highest milk yield observed in cows with percentage of the blood 50 and 7.4 kg of milk, natural fat content, and at recalculation on basic fat content (3.4) from 75 of the Holstein breed hybrids (9.00.3 kg), which also has the highest production of milk fat on day 1 of life 307.310.1 grams


2011 ◽  
Vol 27 (4) ◽  
pp. 1469-1475 ◽  
Author(s):  
M. Krajinovic ◽  
I. Pihler ◽  
V. Simin ◽  
A. Jocic ◽  
S. Nicin ◽  
...  

Goat breeding is one of the least developed agricultural sectors in Serbia. This is reflected in the fact that the total number of goats in Serbia is less than 200,000, as well as the fact that no goat milk production has been recorded by the statistics. Over the last decade, there has been great interest of breeders for intensive breeding of highly productive goats, which resulted in imports of breeding goats. In the same period, several herds of the Alpine breed and German fawn goats were formed, while their production results in the growing conditions in our country have not been fully studied yet. During the first three lactations in the period 2003-2009, the following parameters of milk yield were studied: length of lactation, milk yield in one lactation, percentage and the milk fat yield, and percentage and the total protein yield. The average lactation period was 247 days for the first, 260.6 days for the second and 266.8 days for the third lactation. The average of milk yielded was constantly increasing from the first (594.51 kg) towards the third lactation (761.96 kg), showing statistically highly significant differences (P<0,001). What was also observed is that the order of lactation has not significantly affected the percentage of proteins in milk, whereas the total protein yield in lactations was influenced by the order of lactation due to the differences in average milk yield in lactations.


Author(s):  
V. V. Liubych

The biochemical component (protein content and fat content) of soybean seed, yield and fat and protein yield significantly depends on weather conditions and variety. It was found that the protein content in soybean seed, on average over two years of research on new varieties can vary from 36.1 to 44.4 %. Khana, Lenka and Alaska varieties have the highest protein content in soybean seed – 43.4–44.4 %. Protein content significantly depends on the weather conditions of the study year. Thus, soybean varieties of Kofu, Siberia, Volta, Asuka, Arisa, Khana, Lenka and Alaska, grown in 2020, have this figure 10–19 % higher than in 2019. In the seeds of Nordica, Carra, Kyoto, Ezra, Amadeus and Taurus soybean varieties, the protein content is 4–10 % lower. On average, over two years of research, the fat content in soybean seeds varies from 18.9 to 21.7 % depending on the variety. Only three out of 14 soybean varieties have the fat content ≤ 20.0 % – Khana, Alaska, Arisa. In seeds of other varieties, this figure is ≥ 20 %. Weather conditions reduce the fat content in the seeds by 7–20 % depending on the variety. Studies have shown that soybean seed yields vary significantly depending on the soybean variety. Thus, on average over two years of research, this figure varies from 1.30 t/ha in Amadeus variety to 1.88 t/ha in Siberia one. The highest yields (≥ 1.70 t/ha) were formed by Arisa, Volta and Siberia varieties. However, this figure varies greatly depending on the weather conditions of the study year. Thus, in a more favourable 2019, the yield is from 1.65 to 2.41 t/ ha, depending on the soybean variety. Moisture deficiency and small reserves of moisture in the deeper layers of the soil reduce seed yield from 0.95 to 1.35 t/ha or by 1.7–3.7 times, depending on the soybean variety. Two soybean varieties (Arisa, Siberia) have the highest protein yield at the level of 706–721 kg/ha. The highest fat yield was obtained by Siberia growing – 415 kg/ha. Under the conditions of the Right Bank forest-steppe, for stable formation of high protein yield in different weather conditions, it is necessary to grow Arisa soybean variety which has high protein content and high seed yield, and Alaska variety which has high protein content in seeds. In addition, in the best hydration years it is able to form a high fat yield. Volta, Asuka, Khana and Lenka varieties should be grown in years with sufficient moisture, as they provide the highest protein yield. These varieties should also be grown to obtain a high fat yield under the best moisture conditions. Siberia soybean should be used to produce fat in different weather conditions


Author(s):  
T. V. Pidpala ◽  
Yu. S. Matashnyuk

Under the conditions of intensive technologies used in production of livestock products, the main selection feature that characterizes the economic feasibility of dairy farming and breeding value of animals is milk productivity. One of the factors that affects, not only the economy of production, but also the improvement of herds and breeds of cattle, is the use of highly productive cows. Therefore, the aim of our research was to assess the level of development of productive traits in Holstein cows under the conditions of intensive milk production technology, according to selection and genetic parameters. To conduct the study, a group of 1089 first-born cows was formed with the help of the Dairy Comp program and Microsoft Excel. The material for the research was the milk productivity of Holstein cows during the first three lactations. The level of development of selection traits in animals was determined by selection and genetic parameters. It was found that from the sample n = 1089 to the group of highly productive animals (“>10560”) were included 266 cows, and low-productive animals (“<8706”) – 249 first-borns. They had an average milk yield for the first lactation, 11439 kg of milk with a fat content of 3.96 % and 7737 kg of milk and 3.95 %, respectively. There is a difference in milk yield, milk fat and protein between the groups of cows “>10614” and “<8706”, but there is a general tendency towards changes in productivity with age. Based on the data of milk recurrence and the amount of milk fat of high-yielding cows (group “>10614”), it was found that higher values of the coefficient are characteristic of lactations I–III (rw= 0.105; rw= 0.135). As a result of comparative analysis it was found that low-yielding animals (group “<8706”) were characterized by higher recurrence rates for I–II and I–III lactation (rw = 0.345;rw = 0.316;rw = 0.320 and rw = 0.664;rw = 0.646;rw = 0.651, respectively). Higher rates of recurrence of traits of milk productivity are the characteristic of low-yielding cows (group “<8706”), i.e. they had more consistency of traits during different lactations and animals with a high level of productivity did not differ in age constancy. At a high level of milk yield in cows of group “>10614” appeared a negative correlation of low and medium level (r = -0.423). It was also found a negative correlation of low and medium level between milk yield and protein content in milk (r = -0.007… -0.332). At lower milk yields, there is no negative correlation between milk yield and fat content in milk. Thus, the existence of a negative correlation between milk yield and fat content in milk at a high level of animal productivity, and between milk yield and protein content in milk at both high and low levels of cow productivity was proved.


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