Amount Of Milk Fat Research Articles

Increasing the productivity of cows through the use of premixes based on forest and mineral resources in feeding

The influence of premixes based on forest (pine needles, pine nut shells, arabinogalactan) and mineral (bentonite clay, expanded vermiculite) raw materials on dairy productivity of cows has been studied. The experiment was conducted in the Krasnoyarsk region on three groups of Black-and-White breed cows (10 heads per group) at the age of the third calving, with a live weight of 530–550 kg. The control group was fed the basic diet, the 1st experimental group was fed a premix consisting of bentonite clay, pine coniferous flour, pine nut shells, vitamin and mineral complex and arabinogalactan in addition to the basic diet. Cows of the 2nd experimental group were fed a premix of a similar compo sition with the exception of bentonite clay, instead of which expanded vermiculite was included in the premix. The duration of the experiment was 60 days. The cows were kept tethered and walking, milking was automatic in the milk pipeline. The feeding ration corresponded to zootechnical standards. The studied premixes were fed in a mixture with concentrated feeds once a day. The research was carried out according to generally accepted methods using modern certified equipment. Feeding the cows of the studied premixes had a positive effect on milk productivity in both experimental groups, however, the greatest increase in productivity compared with the control was found in cows of the 2nd experimental group who received a premix with expanded vermiculite in the composition. Milk yield of natural fat content in this group increased by 7.60%, milk yield of basic fat content – by 14.02%, the mass fraction of fat in milk – by 0.23 percentage points, the amount of milk fat – by 14.02%, milk protein – by 9.65%. The organoleptic parameters of the milk of experimental cows under the influence of the studied premixes did not deteriorate and met the requirements of the GOST (Russian National Standard) for premium milk.

Dietary supplementation of phytoncide and soybean oil increases milk conjugated linoleic acid and depresses methane emissions in Holstein dairy cows

The objective of this study was to determine whether adding phytoncide oil (PO) and soybean oil (SBO) to the dairy cow diet could increase milk conjugated linoleic acid (CLA) and depress methane (CH4) emissions in Holstein dairy cows. Rumen fermentation was conducted at four levels of SBO (0, 1, 2, and 4%, on DM basis) and two levels of PO (0 and 0.1%, on DM basis) with in vitro experiment. To evaluate blood parameters, fecal microbe population, milk yield and fatty acid compositions, and CH4 production, in vivo experiment was conducted using 38 Holstein dairy cows divided into two groups of control (fed TMR) and treatment (fed TMR with 0.1% PO and 2% SBO as DM basis). In the in vitro study (Experiment 1), PO or SBO did not affect rumen pH. However, SBO tended to decrease ruminal ammonia-N (p = 0.099). Additionally, PO or SBO significantly decreased total gas production (p = 0.041 and p = 0.034, respectively). Both PO and SBO significantly decreased CH4 production (p < 0.05). In addition, PO significantly increased both CLA isomers (c9, t11 and t10, c12 CLA) (p < 0.001). Collectively, 0.1% PO and 2% SBO were selected resulting in most effectively improved CLA and decreased CH4 production. In the in vivo study (Experiment 2), 0.1% PO with 2% SBO (PSO) did not affect complete blood count. However, it decreased blood urea nitrogen and magnesium levels in blood (p = 0.021 and p = 0.01, respectively). PSO treatment decreased pathogenic microbes (p < 0.05). It increased milk yield (p = 0.017) but decreased percentage of milk fat (p = 0.013) and MUN level (p < 0.01). In addition, PSO treatment increased both the concentration of CLA and PUFA in milk fat (p < 0.01). Finally, it decreased CH4 emissions from dairy cows. These results provide compelling evidence that a diet supplemented with PSO can simultaneously increase CLA concentration and decrease CH4 production with no influence on the amount of milk fat (kg/day) in Holstein dairy cows.

ВЛИЯНИЕ ЖИВОЙ МАССЫ МОЛОДНЯКА НА ПОСЛЕДУЮЩУЮ МОЛОЧНУЮ ПРОДУКТИВНОСТЬ ПЕРВОТЕЛОК В РАЗНЫХ КЛИМАТИЧЕСКИХ ПОЯСАХ РОССИЙСКОЙ ФЕДЕРАЦИИ

The purpose of research is to study the effect of live weight of heifers at the age of 6 months on their subsequent milk production. Objectives: to study the growth rate of heifers with different live weights at 6 months; to assess the level of milk productivity (milk yield, mass fraction of fat and protein, amount of milk fat and protein) in first-calf heifers with different live weights at 6 months. The study included more than 25 thousand first-time Holstein heifers of the same genotypes (lines), bred in four climatic zones co-vering the territory of the Russian Federation. These zones include subtropical, temperate continental, extreme continental and arctic climates. The regions of the Far North with the most severe and cold climate, unsuitable for breeding Holstein dairy cattle, were not taken into account. Data from the Selex information system were used for the analysis. Statistical processing of the obtained data was carried out on the basis of generally accepted methods of variation statistics (using MS Excel). The reliability of the difference bet¬ween the compared values was determined using the significance criterion according to the Student's table. It was found that the live weight of calves at 6 months has a certain influence on the subsequent milk productivity of first-calf heifers. However, the optimal live weight varies depending on the climatic zone. Thus, in a subtropical climate, the optimal live weight is more than 175 kg; in a temperate continental climate – more than 185; in a sharp continental climate – less than 166; in a harsh arctic climate – over 200 kg. These results make it possible to optimize the breeding process and ensure maximum milk production in different climatic conditions.

Frequency of occurrence of k-casein genotypes and their effect on the milk productivity of Kholmogory cows

To increase the volume of domestic dairy products, it is necessary to use modern breeding methods and select animals with high genetic potential. To determine the genetic potential of animals, molecular genetic markers are used, which make it possible to study how a specific genetic variant or combination of genes affects the desired trait. The purpose of the study is to identify the frequency of occurrence of allelic variants of the kappa-casein gene (CSN3) in Kholmogory cows and their relationship with milk production. The object of the study is 195 cows. To determine the genotypes of kappa-casein, the method of polymerase chain reaction of restriction fragment length polymorphism was used. The research was carried out in 2023 on the basis of JSC Kholmogorsky Breeding Plant (Arkhangelsk region). Results: in the studied herd, allele A of the kappacasein gene dominates – 80 %, respectively, allele B was 20 %. The predominant genotype is AA – 63.08 % (n = 123), the less common genotype AB is 33.33 % (n = 65), the least common genotype is BB – 3.59 % (n = 7). To assess milk productivity and milk quality in cows with different CSN3 genotypes, productivity indicators for the last completed lactation were compared. The total number of cows with completed lactation in the study sample was 130 heads, of which: 37 cows were first-calf heifers, 6 cows in the second lactation and 87 cows in the third or more lactation. In total, according to the comparison results, cows with the BB genotype had the highest indicators: milk yield – 6916±275 kg, mass fraction of fat – 4.14±0.22 %, mass fraction of protein – 3.16±0.07 %, amount of milk fat – 286±19 kg, amount of milk protein – 219±12 kg. Thus, the desired genotype for the CSN3 gene is BB. At the moment, there are very few carriers of this gene, so it is necessary to carry out selection and breeding work aimed at increasing their numbers.

Sustainable fodder production and optimization of cow feeding rations in the ar-id climate of southern Ukraine

In the south of Ukraine, which traditionally belongs to the zone of risky land use due to frequent droughts and the last 10–15 years of steadily progressing global warming, the production of rye silage as a basic feed ingredient is gaining the status of an excellent insurance fund, which is essential in the region's feed production, as it will help to remedy the situation with the shortage of juicy fodder. Optimisation of dairy cow feeding rations during lactation in southern Ukraine involves the use of traditional dietary ingredients (corn silage, alfalfa haylage) and innovative ones (rye silage, wet beer pellets), which is mainly due to climate change in recent years. The research used commonly available methods: zootechnical (setting up experiments, developing feed rations, assessing dairy cattle productivity, milk quality, reproduction rates); biological (morphological and biochemical composition of blood); statistical (biometric processing of data) and economic analysis of the research. Thus, in terms of actual milk yield, amount of milk fat and milk protein for 305 days of lactation, cows of all experimental groups outperformed analogues of the control group (milk yield for 305 days of lactation was 7898.0 l; amount of milk fat and protein – 278.7 and 245.1 kg, respectively) by 1.2–3.3 %, by the amount of milk fat – by 5.1–16.9 % and by the amount of milk protein – by 3.4–10.9 % for 305 days of lactation. It was found that the diets of dairy cows of the experimental groups, which included rye silage in different amounts and wet beer pellets, had a positive effect on reducing the duration of the service period, and hence the duration of the intercalation period by 5.5–27.0 days in animals of the I–IV experimental groups compared to cows of the control group. There was a tendency to increase the content of carotene in the blood serum of animals of the II experimental group by 39.5 %, as well as a significant difference of 72.7 % (P &lt; 0.05) and 81,3% (P &lt; 0.01), respectively, in cows of the III and IV experimental groups compared to the same indicator of the control group, which was 209.6 μg/100 ml.

Evaluation of milk yield of Three-breed (1/4 Caucasian grey x 1/4 Jersey x 1/2 Holstein) genotype cows under conditions of manger-pasture keeping

The F6 generation cows, which were made from “itself” breeding of three-breed cows (1/4 Caucasian Gray x 1/4 Jersey x 1/2 Holstein) (1/4 CG x 1/4 J x 1/2 H), the 305 days of first lactation exceed the Holstein breed to the standard by 175 kg or 4.2 %, milk fat content by 0.65 %, protein by 1 %, milk fat by 33.5 kg or 22.2 %. During pasture period from each cow was obtained 2540 kg of milk conforming to sanitary and hygienic standards. In the third calving, 170 days of pasture period and 195 days of manger keeping, the amount of milk in 305 days of lactation was 5337 kg, the amount of milk fat + milk protein was 407.7 kg, the reproductive ability was 100%. During manger period 0.77 FU (feed unit) or 0.90 EFU (energetic feed unit) and 80 g of digestible protein were spent to produce 1 kg of milk. The realization of pasture promotes to the increase generation, high vitality, proportionated exterior, strong limbs and a dense composition.

Связь между массовой долей жира, удоем и показателями сервис‑периода у крупного рогатого скота в высокопродуктивных стадах

The work is devoted to studying the relationship between the duration of the service period, quantitative and qualitative indicators of milk content in groups of highly productive cows, divided in accordance with the 3σ rule according to MFA in the UK with different values of the service period. With the visible dynamics of an increase in productivity indicators, accompanied by an increase in the service period, only a slight connection was established between the duration of the service period with the level of milk productivity and the amount of milk fat, however, no statistically significant differences were identified, which indicates a significant influence on the above characteristics of feeding and housing technology animals. At the same time, in all groups divided by the size of the service period in accordance with the 3σ rule, in terms of milk yield and milk fat, a level of variability was noted approaching 20 %, which indicates the influence of the genetic component (combinative variability) on these characteristics and opens further opportunities to improve the breeding process.

МОЛОЧНАЯ ПРОДУКТИВНОСТЬ И КАЧЕСТВО МОЛОКА КОРОВ С РАЗНЫМИ ГЕНОТИПАМИ ЛЕПТИНА И ЛИНЕЙНОЙ ПРИНАДЛЕЖНОСТИ

A review of the scientific literature has shown that the genotype by loci of the Leptin (LEP) gene and linear affiliation to the leading Holstein breed of cows have an impact on milk productivity and the quality of their milk. The purpose of our research was to study the milk productivity and qualitative composition of the milk of Tatarstan-type cows with different genotypes according to the loci of the Leptin gene and linear belonging to the Holstein breed. The research was carried out in the conditions of the agricultural company "Agrofirma Rassvet" of the Kukmorsky district of the Republic of Tatarstan on the livestock of 79 cows of the Tatarstan type. The Tatarstan type is one of the leading dairy cattle breeds bred in the Republic of Tatarstan, and created by crossing the Kholmogorsky, Black and White, and Holstein breeds, while the bloodline was 1/8 Kholmogorsky + 1/16 Black and White + 13/16 Holstein. As a result of a molecular genetic study (PCR-RFLP), the animal population was sorted into groups, taking into account the genotype by the loci of the Leptin gene. The conducted studies have shown that in Tatarstan-type cows after the first lactation, the highest milk yield indicators, the amount of fat and protein in milk were noted in animals with the leptin gene genotypes LEP/CC and LEP/CT in comparison with peers of the LEP/TT genotype. However, in terms of the mass fraction of fat and protein in milk, the trend was reversed. Also, among the cows of the Tatarstan type, according to the first lactation, the highest values of milk productivity indicators (milk yield, amount of milk fat and protein) are in cows with the LEP/CC genotype of linear belonging to the Holstein breed, namely W. Ideal 933122 and R. Sovering 198998.

Analysis of the influence of the Norwegian Red bull-sires with different breeding value on milk productivity, health, exterior and reproductive traits of daughters

An analysis of the influence of breeding bulls of the Norwegian Red (NR) breeds with different breeding values (BV) on the milk productivity of daughters, their health, reproductive characteristics, udder characteristics, exterior, and indices of productive use. The study material was the data from the electronic catalog of breeding bulls of the NR breed as of April 4, 2023. The sample was formed from the data of only those breeders recommended for reproduction in 2023 by Geno SA. The animals were grouped according to the Total Merit Index (TMI). Breeding bulls with the highest TMI – 53-35 (n = 24) were assigned to the I group, to the II group – with an average TMI – 34-25 (n = 25), and to the III group – bulls with the lowest TMI – 24-10 (n = 22). As a result of the research, it was established that the most significant influence on the indices of productive use of daughters was observed in breeding bulls of the NR breed of the I group (High production index (HPI) – 118.13 % (Р &lt; 0.001), Grazing index (GI) – 110.88 % (Р &lt; 0.05)). According to the TMI index, bulls of the I and II groups prevailed over the sires of the III group, according to their improving effect, on such signs of milk productivity of daughters as milk yield (Р &lt; 0.01), amount of milk fat (Р &lt; 0.05; Р &lt; 0.01) and protein (Р &lt; 0.01; Р &lt; 0.001) and milk productivity index (Р &lt; 0.001 and Р &lt; 0.01) in daughter cows. The greatest improving effect on the udder health of the daughter cows was observed in breeding bulls of the NR breed with TMI 53-35. Bull-sires of groups I and II reduced the number of somatic cells count in the milk of daughter cows by 15.58 and 9.16 %, and bulls of III – only by 3.82 %. Breeder bulls of groups I and III increased milking speed in daughter cows by 4.25 and 1.68 %, and breeders of group II decreased it by 1.96 %. However, the difference was significant only between groups I and II (P &lt; 0.05). Studied breeding sires increased daughters' stature (height) in all groups. Group I sires had the most significant influence on daughters' stature – 114.88, and III group sires had the most minor influence – 102.00. However, the difference was significant between the I and II and I and III groups (Р &lt; 0.05; Р &lt; 0.001). Bull-sires of the I group of the NR breed increased the feet and legs index in daughter cows, as well as the foot angle by 7.58 and 7.38 %, II breeders by 3.48 and 2.48 %, and bulls III reduced these traits in daughters by 0.41 and 0.14 %. The difference between the I and III groups was significant (P &lt; 0.05). Breeder bulls of the NR breed with TMI 53–35 were leaders in improving the udder index of daughters, as well as in reducing its udder depth, strengthening the fore udder attachment, increasing the rear udder width and rear udder height. Therefore, the most significant impact on most of the studied traits was observed in breeding bulls of the NR breed with the highest BV – TMI 53-35. The influence of sires with TMI 53-35 and 34-25 on daughters' milk production was almost the same and improving. However, in terms of the effect on the reproductive characteristics of daughter cows, no significant difference was found between all experimental groups of breeding bulls.

THE INFLUENCE OF THE FATHER'S GENETYPE ON THE PRODUCTIVITY OF COWS AND THE PROBABILITY OF THEIR MASTITIS UNDER DIFFERENT HOUSING

Introduction. The purpose of the study was to determine the influence of genetic factors on the productivity of cows and the probability of their disease with mastitis under different housing technologies.&#x0D; Materials and methods of research. The work was carried out according to the data of two breeding plants for the breeding of the Ukrainian black and white dairy breed with free and stall housing. The data of more than 16,000 milk samples over the past six years were analyzed. Heritability of the average indicators of the quantity and quality of milk of cows according to the data of control milkings, yield for 305 days of lactation and the number of cases of diagnosis of mastitis using correlation analysis. Variability of milk quality of cows was monitored depending on the technology of housing. The research determined the influence of breeding bulls and their line on milk yield and milk quality indicators. To determine the influence of these factors, dispersion analysis was used. Processing of the obtained data was carried out according to basic statistical techniques using computer programs.&#x0D; Research results. According to the research results, it was established that the variability of daily milk yield during free housing was higher by 6.1%, fat content by 7% compared to stall housing, and protein content, the number of somatic cells and their evaluation was lower. The strength of the influence of housing on the parameters of daily milk yield was: on the daily yield – 1.8%, on the fat content – 22.8%, on the protein content – 0.8%, on the number of somatic cells – 1.6%, on their evaluation – 4.1%, on the reliability of cows for 305 days of lactation – 4.1%, on milk fat output – 13.6%, on milk protein output – 6.3%, on the frequency of mastitis diagnosis – 4.5%. The coefficients of heritability of daily milk yield under stall housing were 2.2 times higher, fat content – 3.5 times, protein content – 1.8 times, number of somatic cells – 2.7 times, estimates of the number of somatic cells – 2 times, milk yield for 305 days of lactation – 2.4 times, the amount of milk protein – 1.6 times, and the number of cases of mastitis diagnosis – 1.7 times. The influence of bulls on indicators of the quantity and quality of cow milk was significantly higher than on daily milk yield. The strength of the influence of this factor on indicators of daily milk yield during free housing was: the milk yield – 5.5%, the fat content – 2.5%, the protein content – 2.7%, the number of somatic cells – 2.5%, the estimation of the number of somatic cells – 2.8%, and for stall housing – 4.3%, 6.7%, 6.7%, 2.9%, 7.3%, respectively. The strength of the influence on productivity indicators per lactation was as follows: for free housing on milk yield – 13.4%, on the amount of milk fat – 20.1%, on the amount of milk protein – 13.5% and on the number of cases of mastitis diagnosis – 12.7%, and for stall housing 19.1%, 13.6%, 18.0% and 35.2%, respectively (Р &lt; 0.001). The influence of the factor "bull" was higher than the "bull line" factor on indicators of physical and chemical properties of milk and the frequency of cases diagnosis of mastitis in their daughters.&#x0D; Conclusions. The housing technology has a significant impact on the productive indicators of dairy cows, their variability and heredity. For free housing of cows, the genetic conditioning of indicators of productivity and milk quality of cows, the probability of their mastitis disease was lower in comparison with stall housing.

Slaughter indicators of purebred Hereford bulls depending on the genotypes of the gene GDP-l-fucosynthetase (TSTA3)

The paper presents the results of studying the associated effect of complex genotypes for the genes diacylglycerol O-acyl transferase 1 (DGAT1), somatotropin (GH), prolactin (PRL) and beta-lactoglobulin (BLG) on the milk productivity of Holstein dairy cattle of domestic selection. The object of research was cattle and biological material (ear pluck) from cows of Holstein dairy cattle of domestic selection, contained in the agricultural production cooperative named after I.P. Senko, Grodno region. DNA genotyping of animals for the genes of diacylglycerol O-acyl transferase 1 (DGAT1), somatotropin (GH), prolactin (PRL), and beta-lactoglobulin (BLG) was performed using the polymerase chain reaction (PCR) method and restriction fragment length polymorphism ( RFLP). The results of studies on the assessment of the associated effect of complex genotypes for the genes diacylglycerol O-acyl transferase 1 (DGAT1), somatotropin (GH), prolactin (PRL) and beta-lactoglobulin (BLG) on the milk productivity of Holstein cows of dairy cattle domestic selection showed that in terms of the mass fraction of fat and the amount of milk fat in milk, in most cases, the highest rates were in animals with the complex genotype.

Association of the complex of polymorphic variants of the DGAT1, GH, PRL and BLG, genes with dairy productivity indicators of holstein dairy cattle cows of domestic selection

The paper presents the results of studying the associated effect of complex genotypes for the genes diacylglycerol O-acyl transferase 1 (DGAT1), somatotropin (GH), prolactin (PRL) and beta-lactoglobulin (BLG) on the milk productivity of Holstein dairy cattle of domestic selection. The object of research was cattle and biological material (ear pluck) from cows of Holstein dairy cattle of domestic selection, contained in the agricultural production cooperative named after I.P. Senko, Grodno region. DNA genotyping of animals for the genes of diacylglycerol O-acyl transferase 1 (DGAT1), somatotropin (GH), prolactin (PRL), and beta-lactoglobulin (BLG) was performed using the polymerase chain reaction (PCR) method and restriction fragment length polymorphism ( RFLP). The results of studies on the assessment of the associated effect of complex genotypes for the genes diacylglycerol O-acyl transferase 1 (DGAT1), somatotropin (GH), prolactin (PRL) and beta-lactoglobulin (BLG) on the milk productivity of Holstein cows of dairy cattle domestic selection showed that in terms of the mass fraction of fat and the amount of milk fat in milk, in most cases, the highest rates were in animals with the complex genotype DGAT1ККGHLLPRLAABLGAB.

Productive traits of daughters of sires of Holstein breed depending on the country of origin and genotype according to gene CSN3

Numerous studies have proven the effect of the allele B of the kappa casein gene (CSN3) on protein milk content, because the protein controlled by this allele has a number of distinctive features: difference in micelle size, higher protein content, greater stability when heated and frozen, better properties for cheese making (shorter coagulation time, coagulate of a denser consistency and a higher cheese yield by 5–10 %). The purpose of the research was to study the frequency of occurrence of alleles and genotypes of the kappa casein gene (CSN3) in sires of Holstein breed, depending on the country of origin, and to trace the infl uence of the identifi ed genotypes on the productive traits of the daughters of sires (milk yield, fat and protein content in milk). It was revealed that the highest frequency of occurrence of the desired allele B kappa-casein was found in sires of Dutch and Canadian breeding 33,3 and 34,7 %, respectively. The highest frequency of occurrence of homozygous genotype CSN3 BB was found in Dutch–bred sires – 22,2 %. The frequency of occurrence of the heterozygous CSN3 AB genotype was higher than others in Canadian–bred sires – 36,1 %. The best milk yield was characterized by the daughters of Canadian and Dutch-bred sires with CSN3 AA genotype, among the daughters of Germanbred sires it was CSN3 AB. The highest amount of fat in milk of daughters of sires of Dutch origin was found in cows with the sire’s genotype AB, in daughters of sires of German and Canadian breeding itwas AA, but the indicators practically did not differ from those of daughters of sires with the genotype AB. The highest protein content in milk was found in the daughters of sires of diff erent origins with the allele B of the kappa-casein gene.

BREEDING WORK WITH THE UKRAINIAN BLACK-AND-WHITE DAIRY BREED IN THE SUMY REGION

Researches were carried out in breeding farms for the breeding of the Sumy inbred type of the Ukrainian black and white dairy breed. The total experimental herd is 1150 cows, 1120 heifers and 62 bulls. It has been established that the animals mainly come from breeders of four Holstein lines, such as Starbuck 352790 (28%), Bell 1667366 (27%), Chiff 1427381 (26%) and Elevation 1491007 (15%). In recent years, farms have mainly used breeders of three lines, unlike bulls of the Bell 1667366 line. The breeding value of breeders of different lines is slightly different. Bulls of two Holstein lines – Chiff 1427381 and Elevation 1491007 – have the advantage in terms of average breeding value in the amount of milk fat and protein. The country of origin has a significant influence on the breeding value of breeding bulls. Animals of German selection make up the majority of those used in breeding farms for the breeding of livestock of the Sumy inbred type. A somewhat smaller number of breeders come from the United States of America. The latter are superior to German bulls in terms of average breeding value, both in terms of the amount of milk and the amount of milk fat and protein. Progeny-descendants, which are more distant from the progenitor of the line, are characterized by a higher average breeding value in comparison with bulls, which are closer to the progenitor according to the pedigree. In order to create micropopulations with the desired genotypes for beta- and kappa-caseins, homozygous breeders with the A2A2 and BB genotypes are used at the State Enterprise of the Northeast Institute of Agriculture. The strength of influence of the researched factors on the breeding value is in the range of ή2=11.4-57.9%. The year of the bull’s birth and the distance from the progenitor of the line have the greatest influence on this indicator (Р&lt;0.05-0.001). In order to preserve the population of the Sumy inbred type of the Ukrainian black and white dairy breed, it is necessary to apply the proposed measures, which include the use of genetic material of breeders of the Ukrainian black and white dairy breed and a certain set of biotechnological measures.

Влияние скармливания микроводорослей лактирующим коровам на качество молока и молочную продуктивность

In the conditions of a dairy commercial enterprise, a scientific and economic experiment was carried out on two groups of cows – analogues. The duration of the experiment was 104 days. In a scientific and economic experiment, we studied the effect of feeding a suspension of chlorella in the first phase of lactation in the diets of freshly calved lactating cows and cows 2–3 lactations per amount of milk fat and protein in milk. The analysis of average values according to the dynamics of changes in the content of milk fat was carried out. Data were obtained on the positive effect of chlorella suspension on the quality indicators of fat and protein in the milk of cows of the experimental group.

МОЛОЧНАЯ ПРОДУКТИВНОСТЬ КОРОВ ДОЧЕРЕЙ БЫКОВ-ПРОИЗВОДИТЕЛЕЙ РАЗНЫХ ЛИНИЙ И ГЕНОТИПА КАППА-КАЗЕИНА

The aim of the study was to study the milk productivity of cows of daughters of sires with different linear affiliation and kappa-casein genotype. An analysis was made of the productivity of Black-and-White cows, originating from 60 sires of different lines, as well as those evaluated by the kappa-casein gene, which were used in Krasny Vostok Agro JSC. It has been established that cows of the R. Sovering line are characterized by the highest rates of economically useful traits, with an advantage in milk yield by 65-281 kg, in live weight by 6-24 kg, in terms of milk production index by 1-8 kg, in terms of milk yield by 0.01-0.12 kg/min. The worst indicators of productivity were found in animals of the Governer line. In general, interstrain differences are not high and productive indicators are within the normal range. When analyzing the milk productivity of the daughters of sires, carriers of various kappa-casein genotypes, it was revealed that cows of fathers with the AA genotype for kappa-casein have higher quantitative indicators of milk productivity and significantly (P&lt;0.05-0.001) exceed the CSN3 AB and CSN3 EE by milk yield per 254-715 kg, by the amount of milk fat by 8.5-23.9 kg, by the amount of milk protein by 9.2-27.2 kg. At the same time, daughters of bulls with the CSN3 AA genotype are characterized by the maximum proportion of milk protein in milk, with an advantage over other groups by 0.03-0.12% (P&lt;0.05-0.001). The CSN3 EE group is characterized by a high fat content in milk (4.11%) and exceeds other groups by 0.07-0.10% (P&lt;0.01-0.001). Thus, the daughters of bulls with the AA CSN3 genotype had a higher milk production.

The effect of dietary pioglitazone supplementation on milk yield, insulin sensitivity and GH-IGF-I axis in Holstein dairy cows during the transition period.

High-yielding dairy cows develop insulin resistance during late gestation associated with disruption of the growth hormone (GH)-insulin-like growth factor (IGF)-I axis and cause metabolic and reproductive disorders. This study aimed to determine the effects of dietary pioglitazone (PIO) supplementation as an insulin sensitizer agent on milk yield, plasma metabolite status and GH-IGF-I axis in transition Holstein dairy cows. Twenty multiparous cows were randomly assigned into two experimental groups (n = 10 animals per group) and either fed with a basal diet (control) or the basal diet supplemented with 6mg PIO/kg body weight (BW) from day 14 before parturition to day 21 postpartum. The BW and body condition score (BCS), non-esterified fatty acids, beta-hydroxybutyrate (BHBA), insulin, glucose, GH and IGF-I concentrations, milk production and composition were measured weekly. BW and BCS losses were lower in PIO than in control cows (p<0.05). The percentage and amount of milk fat were decreased, and the amount of protein increased only in the first post-calving week in the PIO-treated cows compared to the control (p<0.05). Dietary PIO supplementation increased glucose concentration at calving, but insulin concentration was increased at calving and in the first post-calving week (p<0.05). Plasma concentrations of IGF-I and the ratio of IGF to GH were increased in the PIO group (p<0.05). The mean revised quantitative insulin sensitivity check index with BHBA, as an insulin sensitivity index, was greater in PIO-supplemented cows (p < 0.05). Our results showed beneficial effects of PIO supplementation on improving insulin sensitivity and the GH-IGF-I axis that may cause lower negative energy balance and better metabolic and health status in transition dairy cows.

Productive and reproductive qualities of animals of the Ukrainian black and spotted dairy breed in breeding farms of the western region of Ukraine

Productive and reproductive qualities of animals of the Ukrainian black and spotted dairy breed in breeding farms of the western region of Ukraine

Productivity of cows depending on environmental conditions, genotype and linear affiliation

The results of research on the current state and productivity of Ukrainian black-and-white dairy cattle in the natural and climatic zones of the Forest-Steppe, Polissya and Steppe of Ukraine, belonging of cattle to the relevant genealogical formations and productivity of cows of the same lines, but in different influence of conditional blood of Holstein breed on manifestation of milk productivity of cows of different zones of their operation.&#x0D; Studies of the condition and productivity were conducted on breeding animals in 141 controlled herds of three natural and climatic zones, taking into account the geographical division of the territory of Ukraine. To study the milk productivity of cows, depending on their heredity by Holstein animal breed was divided into 6 genotypic groups for each natural and climatic zone. Significant differentiation of cattle of the Ukrainian black-and-white dairy breed by area, purebredness, economic and useful features depending on environmental conditions has been clarified. The main livestock of the breed is concentrated in the Forest-Steppe zone, the highest milk yield is characterized by cows in the Forest-Steppe and Steppe zone. Among the diversity of cattle of different linear affiliation and range common to all natural and climatic zones are the lines of Bell 1667366, Valiant 1650414, J. Besna 5694028588, Elevation 1491007, Marshall 2290977, Starbuck 352790 and Chief Chifane obtaining the same milk productivity in different conditions of their maintenance. There is no clear increase or decrease in milk productivity of cows depending on the value of conditional blood of Holstein breed in their genotype with certain differences in each natural and climatic zone of animal exploitation.&#x0D; The amount of milk for I-III lactation by 2.7; 2.4 and 2.2%, and the amount of milk fat by 1.6; 1.6 and 1.9%, respectively, depended on the heredity of the Holstein breed. The influence of the factor of natural and climatic zone of keeping cows on milking of the first – third lactation was 0.01 – 0.05 %, and the amount of milk fat 0.3 - 0.5%.

Variability of cows milk productivity traits depending on origin of father and country of selection

A number of specialized dairy breeds of intensive type have been created in Ukraine, among which the Ukrainian black-and-white dairy farm occupies a prominent place. Currently, the improvement of this breed is carried out by using various breeding techniques with a focus on achieving maximum milk productivity of cows, improving milk quality, body type, health, stress resistance and prolonging productive longevity.&#x0D; The aim of the research was to investigate the formation of signs of milk productivity of cows depending on the origin of the father and the country of his selection.&#x0D; The researches have been conducted on bred heifers and mature cows (third lactation) of Ukrainian Black-and-White dairy breed in the State Enterprise "Alexandrovske" in Vinnytsia region. The traits of milk productivity (yields, fat content in milk and quantity of milk fat ) were studied for the last 10 years by retrospective analysis of bred heifers and mature cows (3-rd lactation), theoretically substantiated and proven feasibility of the study variability of these traits and their intergroup differentiation depending on the father’s origin and the countries of its selection, the consideration and application of which in the selection process will support creating of highly productive competitive herds of dairy cattle. The research showed the great influence of the origin of the father and the country of its selection on the variability of milk yield, fat content in milk and cows’ milk fat yield.&#x0D; It was found that the cows of the controlled herd were characterized by quite high indicators of milk productivity: the yields of bred heifers – 6115, mature cows - 6899 kg. The descendants of the bull Jorin 114414759 were the most productive during the first lactation (milk yield - 6936 kg, milk fat - 248.9 kg), and for the third - the daughters of the breeder Detective 349159846 (8148 and 295.2 kg respectively). The descendants of breeding bulls of German selection gave the most milk and milk fat quantity for the studied lactations (6269- 7014 and 224.8-250.3 kg, respectively). At the same time, the daughters of Canadian breeders gave the most fat- milk yield for the first lactation (3.66%), and for the third lactation – the daughters of the Dutch bulls (3.59%).&#x0D; Breeding bulls had a more significant influence on the traits of milk productivity (depending on lactation 13.1-31.8%), the country of their selection – much smaller (0.9-11.9%). In this regard, these factors had the greatest impact on milk yields, and the least - on the fat content in milk.