High-yielding Cows Research Articles

Comparative time series analysis of Anatolian water buffalo stock in Türkiye

Water buffalo holds an important place in the livestock heritage in Türkiye. In the current study, buffalo numbers between 2023 and 2032 were estimated by using buffalo number data from 1991 to 2022. In the study, FAOSTAT data between 1961 and 2021 and TÜİK data for 2022 were used to obtain the time series. ARIMA modeling method was used in the study conducted in R programming language. ARIMA is a time series model that can make predictions from time series based on explaining univariate data. According to the results of the analysis made in the study, it is seen that the number of buffaloes in Türkiye will continue to decrease. According to the results obtained, it is estimated that the number of buffaloes will be 157,755 heads in 2023, 96,851 heads in 2027 and 19,136 heads in 2032. The disease resistance of buffaloes, their high adaptability, the high demand for water buffalo products, the preference for high-yielding cows for milk production despite government support payments, increasing mechanization, the reduction of buffalo habitats and the increase in input costs have led to a decline in Anatolian water buffalo populations. To prevent the Anatolian water buffalo from being threatened with extinction, the population decline must be halted and improved. To ensure this, the decline of the pastures that form the buffalo’s habitat must be halted, pasture areas must be increased, and existing pastures rehabilitated, government subsidies for buffalo and calf rearing must be increased and market opportunities for buffalo products must be expanded.

Factors influencing pregnancy loss between days 30 and 70 in a single cattle herd: A comprehensive analysis of sire, cow, and other contributing factors

This retrospective study utilized a mixed-effects logistic model analysis to investigate variables associated with the probability of pregnancy loss (PL) between days 30 and 70 in a dataset comprising 9507 pregnancies from a single cattle herd over 10 years. The model incorporated fixed-effect variables including cow breed (Holstein, Crossbred, and Brown Swiss), parity (1st, 2nd, 3rd, and 4th or more), insemination seasons, insemination number (≤3 vs >3), estrus nature (spontaneous vs synchronized), postpartum problems, sire breed (Holstein, Fleckvieh, Brown Swiss, and Montbéliarde), zygote genotypic (pure vs crossbred), days in milk (DIM) at insemination, actual 305-day milk yield, and sire conception rate. Additionally, random effects included sire (n = 129), cow (n = 3463), and production years (n = 10). The results revealed that cows inseminated with Brown Swiss sires or sires with lower initial conception rates had higher PL rates. Biparous cows, cows with lower 305-day milk yield, cows inseminated later in DIM, cows receiving the 4th or subsequent insemination, and cows inseminated during winter or autumn had lower PL rates. The estrus type and zygote genotype did not significantly impact PL. The random effects of cow, sire, and production years were estimated at 0.230, 0.054, and 0.112, respectively. In conclusion, the study findings suggested that improving management practices for high-yielding cows, cows in early lactation stages, and cows exposed to thermal stress conditions, along with utilizing Brown Swiss cows and sires with high initial conception rates per insemination, could potentially decrease overall PL rates on the farm. Nonetheless, the results did not support the use of Crossbred cows, sires from different breeds, or specific sires to mitigate PL rates on the farm.

Intensive technology of harvesting silage from corn of high-yielding cows

Intensive technology of harvesting silage from corn of high-yielding cows

Heat stress affects mammary metabolism by influencing the plasma flow to the glands

BackgroundEnvironmental heat stress (HS) can have detrimental effects on milk production by compromising the mammary function. Mammary plasma flow (MPF) plays a crucial role in nutrient supply and uptake in the mammary gland. In this experiment, we investigated the physiological and metabolic changes in high-yielding cows exposed to different degrees of HS: no HS with thermal-humidity index (THI) below 68 (No-HS), mild HS (Mild-HS, 68 ≤ THI ≤ 79), and moderate HS (Mod-HS, 79 < THI ≤ 88) in their natural environment. Our study focused on the changes in blood oxygen supply and mammary glucose uptake and utilization.ResultsCompared with No-HS, the MPF of dairy cows was greater (P < 0.01) under Mild-HS, but was lower (P < 0.01) in cows under Mod-HS. Oxygen supply and consumption exhibited similar changes to the MPF under different HS, with no difference in ratio of oxygen consumption to supply (P = 0.46). The mammary arterio-vein differences in glucose concentration were lower (P < 0.05) under Mild- and Mod-HS than under no HS. Glucose supply and flow were significantly increased (P < 0.01) under Mild-HS but significantly decreased (P < 0.01) under Mod-HS compared to No-HS. Glucose uptake (P < 0.01) and clearance rates (P < 0.01) were significantly reduced under Mod-HS compared to those under No-HS and Mild-HS. Under Mild-HS, there was a significant decrease (P < 0.01) in the ratio of lactose yield to mammary glucose supply compared to that under No-HS and Mod-HS, with no difference (P = 0.53) in the ratio of lactose yield to uptaken glucose among different HS situations.ConclusionsDegrees of HS exert different influences on mammary metabolism, mainly by altering MPF in dairy cows. The output from this study may help us to develop strategies to mitigate the impact of different degrees of HS on milk production.

Evaluation of Rumen Microbes For Milk Fat Yield in Cattle Based on 16S rRNA Amplicon Metagenomic Sequencing

Background: Ruminal microbes support growth, lactation and maintenance of animals by providing energy and protein yielding nutrients. Metagenomics is the study of microbial communities directly in their natural environments such as soil, water, gut samples etc. The 16S rRNA gene sequencing is one of the basic genetic markers for the characterisation of prokaryote microorganism community. Current study exploited complex gut microbial communities present in cattle rumen based on variation in milk fat yield. Methods: The study was conducted in cattle reared at University Livestock Farm, Kerala Veterinary and Animal Sciences University. Twelve healthy cattle in the initial stages of lactation (less than three months) were selected and divided into two groups of six each based on high and low milk fat composition. Rumen samples were collected and DNA was isolated. Amplicons of 16S rRNA has been generated from metagenomic DNA targeting V3 and V4 hyper variable regions. Qiime2 was used for analysis for 16S rRNA amplicon sequencing. Result: Results revealed that a total of 38,28,241 sequences were obtained after demultiplexing. Majority of sequence length ranged around 295 to 301 nucleotides for forward reads and 216 to 300 nucleotides for reverse reads. After denoising, a total of 6,62,498 sequences were obtained. Clustering (de-replication) produced 711 unique sequence features. In kingdom level of taxonomy, for bacterial kingdom, there was no significant difference in abundance of organisms for high milk fat yield and low milk fat yield cows. For archaea, significant difference observed between abundance of high milk fat and low milk fat groups at five per cent level in the current study.

Unveiling the regulatory role of SIRT1 in the oxidative stress response of bovine mammary cells

High-yield dairy cows typically undergo intense cellular metabolism, leading to oxidative stress in their mammary tissues. Our study found that compared with ordinary cows, these high-yield cows had significantly elevated levels of H2O2, lipoperoxidase, and total antioxidant capacity in their blood. This increased oxidative stress is associated with heightened expression of genes such as GCLC, GCLM, and SIRT1 and proteins such as SIRT1 in the mammary tissue of high-yield cows. We stimulated MAC-T cells with H2O2 at a concentration equal to the average H2O2 level in the serum of ethically high-yielding cows, as detected by an assay kit. Our observations revealed that short-term exposure (12 h) to H2O2 upregulated the expression of the SIRT1 gene and SIRT1 protein. It also increased gene expression for SOD2, CAT, GCLC, GCLM, PGC-1α, and NQO1, elevated the phosphorylation of AMPK, and enhanced protein expression of PGC-1α, NQO1, Nrf2, and HO-1, as well as reduced the phosphorylation of NF-κB. Additionally, short-term H2O2 stimulation resulted in increased total antioxidant capacity and levels of superoxide dismutase, glutathione, and catalase in the mammary epithelial cells of dairy cows. In contrast, prolonged exposure to H2O2 (24 h) yielded opposite results, indicating reduced antioxidant capacity. Further investigation showed that the SIRT1 inhibitor EX 527 could reverse the enhanced cellular antioxidant capacity triggered by short-term oxidative stress. However, it is crucial to note that although 12 h of H2O2 stimulation improved antioxidant capacity, reactive oxygen species (ROS) and malondialdehyde (MDA) levels inside the cell gradually increased over time, suggesting greater damage under long-term stimulation. Conversely, the SIRT1 activator SRT 2104 could reverse the reduced cellular antioxidant capacity caused by long-term oxidative stress and significantly inhibit the accumulation of ROS and MDA. Notably, SRT 2104 demonstrated similar effects in MAC-T cells during lactation. In summary, SIRT1 plays a crucial role in regulating the antioxidant capacity of mammary epithelial cells in dairy cows. This discovery provides valuable insights into the antioxidant mechanisms of mammary cells, which can serve as a theoretical foundation for future mammary health strategies.

Differential diagnosis of chronic infertility in high-yield cows

The infertility of cows and heifers has been the most pressing problem in the livestock sector. The genitals and mammary gland have an increased functional load associated with pregnancy, childbirth, and lactation. The purpose of this study was to determine the prevalence of symptoms of chronic irreversible infertility in Ayrshire cows culled as a result of multiple artificial inseminations. The study employed analytical, structural-comparative, and statistical methods, as well as a modified differential palpation diagnosis of the clinical state of the reproductive organs in the ovary+oviduct area with lateral localisation was consistently applied in two stages. The findings of the study showed that cows with in vivo diagnosed symptoms of chronic adherent salpingitis and ovosalpingitis (52.17%), i.e., irreversible form of infertility, had significantly higher (+28.05%; P &lt; 0.01) milk production and better lactation compared to those without these pathologies. Furthermore, in the group of cows culled due to numerous ineffective inseminations, related gonadopathies were detected: from 4.35% to 10.87% of ovarian hypotrophy, 4.35% of gonadal sclerosis symptoms and 17.39% of cystic follicular degeneration cases. In 73.91% of females, the presence of sexual cyclicity with unchanged ovarian function in the follicular phase and in 84.78% – in the luteal phase of the cycle was established. The use of differential palpation diagnostics in production conditions allows in vivo predicting the tendency to loss of genetic resources (the ability of cow ovaries to maintain generative and secretory functions) in highly productive cows due to chronic inflammatory gynecological pathologies, which will contribute to the improvement of drug and biotechnological schemes of therapeutic measures for the prevention of infertility in the dairy herd

DETERMINATION OF PRODUCTIVITY OF COWS IN KETOSIS USING PROBIOTICS

High-yielding cows are prone to negative energy balance due to high lactation and insufficient dry matter intake after calving. This leads to the mobilization of fat and protein in the body to meet the nutrient needs of the lactating cow. High levels of nonesterified fatty acids are maintained by fat and protein mobilization, leading to ketosis due to incomplete oxidation of ketone bodies. The purpose of the research was to investigate the effect of probiotics on the productivity of cows and the quality of milk in ketosis. Research was conducted in the period from October to November 2021 on Holstein cows in the limited liability company "Lan" Agricultural Company of the North-Eastern region of Ukraine. It was found that in cows in the post-calving group, seven days after calving, the level of ketone bodies in the blood of the cows ranged from 1.0 to 2.1 mmol/l, which is higher than in the control by 71.42–185.71%. Two weeks after probiotic administration, ketone levels were between 0.5 and 1.2 mmol/L, 16.65–100% higher than controls. On the 28th day of the study, the content of ketone bodies in cows was within the physiological norm. In cows suffering from ketosis, productivity was reduced on the seventh day of research by 22.42–336.4%, on the 14th day by 11.6–29.35%. During the study of productivity, its restoration to the indicators of healthy animals on the 28th day after calving was established at the level of 28-29 kg/day. At the same time, the content of microorganisms and somatic cells had a direct correlation with productivity, and on the 28th day, the milk of all experimental cows was suitable for consumption and corresponded to the "extra" variety. In the first week after calving, the ratio of milk fat and protein in the milk of cows with ketosis was slightly imbalanced, which is a sign of ketosis. On the seventh day of the study, the milk fat level exceeded the protein content in cow 6905 by 32%, in cow 6852 by 39.25%, in cow 6916 by 30.34%, in cow 7642 by 41.17%, in cow 6187 – by 33.62%, in cow 2563 – by 36.40%, in cow 3891 – by 41.63%. At the end of the study on the 28th day, the fat/protein ratio approached the reference level of 1:1 in all experimental animals.

Influence of thermal heat load accumulation on daily rumination time of lactating Holstein cows in a zone with temperate climate

In the future, conflicts between animal welfare and climate change will gradually intensify. In the present study, we investigated the daily rumination time (RT) of lactating Holstein-Friesian cows in a zone with temperate climate and the effects of heat load duration and heat load intensity. Responses of individual cows to heat load were assessed, adjusting for milk yield, lactation number, days in milk as well as reproductive status and season. A total of 27,149 data points from 183 cows in a naturally ventilated barn in Brandenburg, Germany, were collected from June 2015 to May 2017. Ambient temperature and relative humidity were recorded at eight positions inside the barn every 5 min, and the temperature-humidity index (THI) was calculated. Based on THI, the degree of heat load was determined, using critical thresholds of THI = 68, 72, and 80. Daily RT was measured with a microphone-based sensor system (collar) on the cow's neck. The analysis models included autocorrelations in time series as well as individual cow-related effects. With each 5 min exposure to contemporaneous heat load, a decrease of approximately 1.17 min d−1 in RT per cow from non-heat stress to heat stress conditions by exceeding THI ≥68 (p < 0.01). This effect was intensified by exceeding the critical THI thresholds of 68 and 72.As heat load duration and intensity increased, daily RT decreased in comparison to daily RT under non-stress conditions. High-yielding (>38.4 kg milk/day) cows were more influenced in rumination time than low-yielding (≤28.8 kg milk/day) cows. With moderate contemporaneous heat load, RT decreased by 0.14 min d−1 per 5 min in high-yielding cows compared to low-yielding cows under moderate heat load. A decrease of 0.1 min d−1 was found in daily RT of mid-yielding cows. However, the delayed effects of heat load (one to three days after the heat stress event) were associated with days in milk and reproduction status. When the heat load duration lasted for several days, the responses were less pronounced than the impacts of contemporaneous heat load (when the heat stress event lasted for one day). Delayed mild heat load resulted in an increase in RT by 0.13 min d−1 in lactating cows ≤60 DIM. This was also found with delayed moderate heat load. Lactating cows ≤60 DIM showed a rise of 0.09 min d−1 in RT. RT also showed interactions with reproduction status of cows under delayed moderate heat stress. Lactating cows with ≤180 days of pregnancy showed an increase of 0.61 min d−1 in RT. Similarly, cows with >180 days of pregnancy had 0.64 min d−1 more RT compared to non-pregnant cows. Further analysis with higher temporal resolution of RT than data accumulation in 24-h blocks as well as the assessment of the correlation between feed composition, intake and rumination will elucidate the influence of heat load on daily RT.

Feed costs and indicators of reproductive capacity of high-yielding cows at different levels of Bypass soybeans in rations

The article presents the results of a scientific and economic experiment to study the influence of different levels of Bypass soybeans in the diets of high-yielding cows on feed costs per kilogram of milk and reproductive functions of cows. Provision of the rations of the experimental cows with an unequal amount of the difficult-to-dissolve fraction of crude protein, at the expense of Bypass soybeans, affected their consumption of bulk feed. The experimental cows consumed 4.1–4.8 kg from the specified 5 kg of alfalfa hay, 20.8–24.6 kg from 25 kg of corn silage, and 8.4–9.7 kg from 10 kg of alfalfa hay. The consumed feed provided cows with crude protein at the level of 16.0–16.5 % of the dry matter, its poorly soluble fraction at the level of 27.3 % of the crude protein in the 1st control group, 31.1 % in the 2nd experimental group, 35.2 % – in the 3rd experimental group and 40.0 % – in the 4th experimental group. The sugar-starch-protein ratio was normal and ranged from 2.20 to 2.28 : 1 with a norm of 2.1 : 1. The micronutrient rations were balanced due to micronutrients of organic origin. On the basis of the obtained data, it was proved that the lowest feed consumption per 1 kg of milk was observed in cows of the 4th experimental group, which were fed rations with 2 kg of Bypass soybeans, where the level of insoluble protein was 40 % of crude protein and these consumptions were 6.5 MJ against 7.4 MJ in the 1st control group. Cows of the 4th experimental group also had the best insemination and service period indicators. The duration of the service period in the experimental groups was less in percentage compared to the animals of the 1st control group by: 15.0 in the 2nd; 25.6 in the 3rd and 32.9 in the 4th. Partial and complete replacement in the diets of cows of the 2nd, 3rd and 4th experimental groups of soybean meal with Vypass soybeans at the level of 1.0; 1.7 and 2 kg of compound feed concentrate in the first 100 days of lactation has a positive effect on the physiological state, stimulates appetite and provides normal conditions for fertilization and embryo development.

Pathogen-specific patterns of milking traits in automatic milking systems

Early detection of intramammary infection (IMI) can improve animal health and welfare in dairy herds. The implementation of sensors and automatic milking systems (AMS) in dairy production inherently increases the amount of available data and hence also the potential for new approaches to mastitis management. To utilize the full potential of data from AMS and auxiliary sensors, a better understanding of physiological and pathological changes in milking traits associated with different udder pathogens may be imperative. This observational study aimed to investigate pathogen-specific patterns in milking traits recorded in AMS. The milking traits included; online somatic cell count (OCC), electrical conductivity (EC), milk yield (MY), and average milk flow rate (AMF). Data were collected for a study period of 2 years and included 101 492 milkings from 237 lactations in 169 cows from one farm. Measurements of OCC were recorded at cow-level and data on EC, MY, and AMF were obtained at quarter-level. In addition to the data obtained from the AMS, altogether 5756 quarter milk samples (QMS) were collected. Milk samples were obtained monthly for bacteriological culturing. We included findings of 13 known mastitis pathogens to study pathogen-specific patterns in milking traits. These patterns were compared with those in a baseline group consisting of cows that did not have any positive milk culture results throughout the lactation period. Patterns of the milking traits are described for all positive samples both across 305 d in milk (DIM), and in the 15-d period before a positive bacteriological sample. The association between a positive sample and the milking traits (ln(OCC), EC-IQR; the ratio between the quarter with the highest and the quarter with the lowest level of EC, and MY) for the 15 d before the detection of a pathogen was assessed using mixed effects linear regression models. All pathogens were associated with alterations in the level and variability of ln(OCC) relative to lactations with no positive bacteriological samples. A positive sample for Staph. aureus was associated with increased values for MY during the 15 d before a positive diagnosis. It is biologically plausible to interpret changes in OCC and EC-IQR as consequences of an intramammary infection (IMI), while higher MY in bacteriologically-positive cows is most likely linked to the increased risk of infection in high-yielding cows. In this study, the most notable changes in the traits (OCC and EC-IQR) were observed for Staph. aureus and Strep. dysgalactiae, followed by Strep. simulans, Strep. uberis, and Lactococcus lactis. Even if we did not detect significant associations between positive bacteriology and EC-IQR, visual assessment and descriptive statistics indicated that there might be differences suggesting that it could be an informative trait for detecting infection when combined with OCC and possibly other relevant traits using machine learning algorithms.

Detailing the chemical composition of roasted soybeans and the effect for its use in the diet of dairy cows

Roasted soybeans are a complete source of indigestible protein in the rumen, have high sanitary and hygienic indicators, are devoid of non-nutritional substances of ordinary raw soybeans. The SoyPass and RaPass technology provides all the advantages of roasting soybeans and creates prerequisites for prolonged storage of beans for up to two years without prior drying. The introduction of full-fat flattened soybeans roasted by the Roast-A-Matic roaster into the diet of dairy cows leads to an increase in their milk productivity. Certified results of chemical research show that after frying, the percentage of crude protein significantly increased (by 2.92 points, P &lt; 0.05) and the content of total digestible nutrients (by 8.1 %, P &lt; 0.05), urease activity decreased to 0.06 ± 0.007 units of pH. The biological value of soy protein after frying corresponds to the indicators of the reference protein. Two groups of cows were involved in the study: № 1 – high-yielding cows with a daily milk yield of 30.69–35.96 L (n = 307) and № 2 – medium- and low-yielding cows with a yield of 19.05–28.88 L (n = 377). Group № 1 was given 300 g of roasted soybeans (111 g of protein) daily in their diet instead of 250 g of a high-protein supplement (200 g of protein); group No. 2 – gradually replaced 230 g of the supplement (184 g of protein) and 1500 g of 51 % meal (765 g of protein) with 1700 g of roasted soybeans (629 g of protein). In both groups, the 65-day observation period should be divided into 2 periods: 1) a 30-day period of intensive growth with a rapid increase in milk yield (up to +24.2–25.0 %); 2) the period of stabilization (from the 31st to the 65th day), characterized by some fluctuations in the % increase in milk, but in general by reliable maximum values (up to +25.0–36.7 %). The maximum daily volume in group № 1 reached 41.83 ± 1.04 and 41.83 ± 0.3 L (Р &lt; 0.01) on the 32nd and 38th days, respectively. At the same time, the range of the indicators of the individual yield in the group ranged from 10.7 to 11.7 L. Similar indicators for group № 2 were: 32.56 ± 2.74 L (Р &lt; 0.025) on the 58th day and 10.4–23.8 L. So, in the first 30 days of feeding full-fat fried soybeans, there is a rapid but unstable (with fluctuating peaks) increase in milk productivity of cows. During the 2nd month of soy consumption, the maximum milk yield is reached, when the increase in added milk is not rapid, but stable. Thus, it is advisable to introduce 1.5–2.0 kg/day of roasted soybeans (equivalent to 0.3–0.4 kg of fat/day) into the diet of dairy cows.

Prevention of ketosis in cows: the role and effectiveness of Кеххtone

Ketosis is a common metabolic disease in dairy cattle that is often diagnosed in the late stages of pregnancy or early stages of lactation, especially in high-yield cows. To counteract this disease, we used the drug Kexxtone, which protects for 95 days, starting from 3–4 weeks before the planned calving. The study showed that the administration of this drug led to a significant decrease in the level of ketone bodies in the blood of cows on the third and ninth day after calving. Notably, on the third day after calving, the content of ketone bodies in the blood of animals treated with the drug during the second lactation was significantly lower than in the control group of cows by 1.38 times (Р &lt; 0.05), on the ninth day of research, this indicator in cows of this group significantly decreased by 2.48 times and amounted to 0.81 ± 0.05 mmol/L (Р &lt; 0.01), and in the control group – 2.01 ± 0.31 mmol/L. It was also found that the insemination index was almost the same in cows during the second lactation. Still, a significant decrease in this indicator was noted in the third and fourth lactation of cows when using the drug Kexxtone. Thus, during the third lactation in experimental cows, this index was 1.6 ± 0.18 (Р &lt; 0.01), and in the control group – 2.13 ± 0.35. In cows of the experimental groups, a higher average daily milk yield was observed compared to animals that were not given the drug. In some cows during the fourth lactation, which was not treated with Kexxtone, high levels of ketone bodies were detected in the blood, which may indicate the need for health monitoring and additional measures to prevent ketosis. In addition, a high average daily milk yield was found in cows from the experimental groups, possibly due to the drug Kexxtone's positive effect on the animal body's physiological processes and increased productivity of dairy cattle. These results indicate the potential benefits of using Kexxtone to ensure the health and productivity of cows at different stages of their life. These results allow us to recommend the use of the drug to prevent the occurrence of ketosis and increase cow yield. Additional research may be helpful for a deeper understanding of the mechanisms of the drug's action and its effect on the body and productivity of cows.

The use of soybeans in the structure of the ration of high-yielding cows

In the conditions of intensive milk production in order to ensure high productivity and at the same time preserve the general functional state of animal health it is impossible to do without the use of protein-rich grain components in the structure of compound feed. These include soybeans, which in the western region of Ukraine began to be widely used in the production of compound feed for cattle. The percentage of introduction of soybeans into the structure of compound feed is different and for high-yielding cows requires additional study, which explains the relevance of conducting research on its influence on milk productivity, quality indicators of milk against the background of assimilation of the main nutrients of feed. The study was conducted on four groups of Simmental cows, seven heads in each. The rations of experimental cows provided for three levels of provision of protein needs at the expense of soybeans and were balanced in terms of basic nutrients in compliance with the requirements of detailed requirements. The analysis of the feeding conditions of experimental cows showed that the use of heat-treated soybeans in the structure of the ration contributed to a significant increase in milk productivity, as well as quality indicators, the content of dry matter, fat, protein, calcium and phosphorus. A similar pattern was observed in terms of indicators of the intensity of metabolic processes of cicatricial digestion. Thus, a positive effect on the percentage of certain volatile fatty acids, in particular acetic as a precursor of milk fat was noted. An increase was noted in the digestibility indicators of the main nutrients (protein, fat, fiber digestibility coefficients). The positive effect of soybeans on the milk productivity of the experimental cows was also noted by the results of the balance experiment. The nitrogen balance was positive and its use for milk production in cows of the fourth group compared to the control group was 27.4 % higher. A similar trend was observed in the balance of calcium and phosphorus. So, the conducted studies on the study of the productive effect of different amounts of soybeans instead of cereal components in the structure of compound feed on milk productivity give reason to recommend that farms use prepared soybeans in the proportion of 10–15 % in compound feed for high-yielding cows.

Associations of lameness with milk composition, fatty acid profile, and milk coagulation properties in mid-lactation high-yielding Holstein cows

Lameness, an animal welfare and profitability related problem in dairy industry, was evaluated on 126 multiparous Estonian Holstein cows on a 5-point scale; score three or above indicated lameness. Milk samples of the cows were analysed for basic composition, content of mineral elements, fatty acid (FA) profile and coagulation properties (MCP). Lame cows had lower milk yield and a lower milk protein and milk fat yield compared to non-lame cows. MCP and content of mineral elements were not affected by lameness. The concentrations of most individual milk FA, their groups formed by chain length, degree of saturation or by origin were not affected by the lameness. Lameness was associated with a higher concentration of odd- and branched-chain fatty acids and C18:0. Milk from lame cows is suitable for consumers as lameness did not impair nutritional value nor MCP of the milk.

Longitudinal characterization of the metabolome of dairy cows transitioning from one lactation to the next: Investigations in the liver

This study aimed to investigate the metabolic changes in the livers of dairy cows from 1 wk before dry-off to 1 wk after calving. Twelve high-yielding Holstein cows were included in a longitudinal study and housed in a tie-stall barn. The cows were dried off at 6 wk before the expected calving date (dry period length = 42 d). During the entire lactation, the cows were milked twice daily at 0600 and 1700 h. Liver biopsies were taken from each cow at 4 different times: wk -7 (before drying off), -5 (after drying off), -1 and +1 relative to calving. A targeted metabolomics approach was performed by liquid chromatography and flow injection with electrospray ionization triple quadrupole mass spectrometry using the MxP® Quant 500 kit. A total of 185 metabolites in the liver were used for the final data analysis. Principal component analysis (PCA) revealed a clear separation by days of sampling, indicating a notable shift in metabolic phenotype from late lactation to dry period and further changes after calving. Changes were observed in several classes of compounds, including amino acids and biogenic amines. In particular, the changes in acylcarnitines (AcylCN), phosphatidylcholines (PC), sphingomyelins (SM) and bile acids (BA) indicated extensive remodeling of the hepatic lipidome. The changes in AcylCN concentrations in early lactation suggest incomplete fatty acid oxidation in the liver, possibly indicating mitochondrial dysfunction or enzymatic imbalance. In addition, the changes in PC and SM species in early lactation indicate altered cell membrane composition, which may affect cell signaling and functionality. In addition, changes in BA concentrations and profiles indicate dynamic adaptations in BA synthesis, lipid digestion and absorption during the observation period. In particular, PCA analysis showed an overlapping distribution of liver metabolites in primiparous and multiparous cows, indicating no significant difference between these groups. In addition, Volcano plots showed similar liver metabolism between primiparous and multiparous cows, with no significant fold changes (>1.5) in any metabolite at significant P-values (false discovery rate <0.05). These results provide valuable insight into the physiological ranges of liver metabolites during dry period and calving in healthy dairy cows and should contribute to the design and interpretation of future metabolite-based studies of the transition dairy cow.

Mastitis impact on high-yielding dairy farm's reproduction and net present value.

Poor udder health can have a negative impact on milk production and reproductive performance, which reduces the net present value (NPV) of dairy farms. The aim of this study is therefore to investigate the relationship between clinical mastitis and NPV and the financial impact of impaired reproductive function. For this purpose, 473 dairy cows were included in our study, 146 cows with clinical mastitis (CM group) and 327 clinically healthy cows (CH group) from a high-yielding dairy farm in Romania, milking approximately 780 dairy cows with an average milk production of 46 kg milk/day. We found that, in contrast to CH cows, CM cows had a significantly lower conception rate at first service (58.2% vs. 41.7%, p < 0.05), third service (45.3% vs. 30.2%, p < 0.05), and total services (49.2% vs. 36.4%, p < 0.05). However, this positive effect was not observed for the average days open, which were significantly lower in CM cows than in CH cows (112 ± 4.3 days vs. 142 ± 3.1 days, p < 0.05). The fact that the non-pregnant CH cows had higher somatic cell counts (>400,000 SCC/mL) in their milk around artificial insemination (AI) and 1 month earlier than the pregnant cows (<250,000 SCC/ml) supports the idea that poor uterine health affects the reproductive activity of high-yielding cows. However, by using the UW-DairyRepro$ decision support tool, we found that despite the impairment of reproductive function in dairy cows, the largest negative impacts on NPV are still the cost of milk loss (US$14,439.4/farm/year) and treatment costs (US$4,380/farm/year). We considered the costs associated with poor reproductive function in the CM group (US$3,577/farm/year) as an additional cost of mastitis. Finally, it appears that the impact of mastitis on reproduction is associated with a lower chance of conception than it is with a daily risk of services.

Structural equation models to infer relationships between energy-related blood metabolites and milk daily energy output in Holstein cows.

During lactation, high-yielding cows experience metabolic disturbances due to milk production. Metabolic monitoring offers valuable insights into how cows manage these challenges throughout the lactation period, making it a topic of considerable interest to breeders. In this study, we used Bayesian networks to uncover potential dependencies among various energy-related blood metabolites, i.e., glucose, urea, beta-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), cholesterol (CHOL), and daily milk energy output (dMEO) in 1,254 Holstein cows. The inferred causal structure was then incorporated into structural equation models (SEM) to estimate heritabilities and additive genetic correlations among these phenotypes using both pedigree and genotypes from a 100k chip. Dependencies among traits were determined using the Hill-Climbing algorithm, implemented with the posterior distribution of the residuals obtained from the standard multiple-trait model. These identified relationships were then used to construct the SEM, considering both direct and indirect relationships. The relevant dependencies and path coefficients obtained, expressed in units of measurement variation of 1σ, were as follows: dMEO → CHOL (0.181), dMEO → BHB (-0.149), dMEO → urea (0.038), glucose → BHB (-0.55), glucose → urea (-0.194), CHOL → urea (0.175), BHB → urea (-0.049), and NEFA → urea (-0.097). Heritabilities for traits of concern obtained with SEM ranged from 0.09 to 0.2. Genetic correlations with a minimum 95% probability (P) of the posterior mean being >0 for positive means or <0 for negative means include those between dMEO and glucose (-0.583, P = 100), dMEO and BHB (0.349, P = 99), glucose and CHOL (0.325, P = 100), glucose and NEFA (-0.388, P = 100), and NEFA and BHB (0.759, P = 100). The results of this analysis revealed the existence of recursive relationships among the energy-related blood metabolites and dMEO. Understanding these connections is paramount for establishing effective genetic selection strategies, enhancing production and animal welfare.

JUSTIFICATION OF THE BASIC PARAMETERS OF A DAIRY FARM FOR 500 COWS WITH ROBOTIC MILKING SYSTEMS

The article highlights the results of research on the assessment of the conditions for keeping high-yielding cows in a new type of room with a width of 36 m and a height of 10.5 m according to indicators of the microclimate and daily behavior of cows. It has been established that the volume-planning and technological solutions of this room with robotic milking systems provide comfortable conditions for keeping highly productive cows. So, the air temperature and relative humidity of the room meet the existing standards. The presence of side curtains and a light-aeration comb ensure a high speed of air movement at the level of 0.65 m/s, which has a positive effect on its gassiness. The ammonia content is at the level of 2.9 mg/m3 against 20 mg/m3 according to regulations, and the level of hydrogen sulfide is 0.2 mg/m3 against 10.0 mg/m3, and the level of carbon dioxide is two times lower. Studying the behavior of cows under the conditions of a new type of room, it has been established that animals show the greatest activity during the change in daylight hours, and the least one - in the middle of the day or night. The behavior of cows under the conditions of the new technology changes depends on the productivity of the cows. Thus, as productivity increases, the duration of feed and water consumption and stay in the robotic box increases. Animals with the productivity of 20 kg stand for 13 hours and lie down for 11 hours, while cows with the productivity of 40 kg stand for only 10 hours and lie for 14 hours, which corresponds to their physiological needs. Based on the obtained research results, we have justified the main parameters of a new type of premises with robotic milking systems for 500 cows.

Joint application of gonadotrop rilizing-hormone, prostoglandine F2α and progesterone against non-pregnancy in high-yielding cows

Joint application of gonadotrop rilizing-hormone, prostoglandine F2α and progesterone against non-pregnancy in high-yielding cows