„dairy cows“ 37 výsledků

The aim of study was to evaluate the impact of genetic and non-genetic factors on somatic cells count in Slovak Simmental dairy cows in period 2009 to 2013. We observed subsequent results in dairy cows of 55 822 Slovak Simmental cattle. Data were analysed using the SAS and linear model with fixed effects of herd, years and months controls, sire, breeding type. The results of somatic cells count during the years 2009 and 2013 were as follows: the highest number of samples was analysed during 2010 (n = 288 215), where the average count was 560.48*103 ·ml-1. The lowest average value of somatic cells count was of amount of 535.93*103 ·ml-1 (n = 280 732) in 2009.The linear model represents coefficient determination R2 = 0.038296 % (P<0.001) for SCC with all fixed effects. According to the analyses by the effects on SCC the highest effect was the effect of herd R2 = 0.021625, then effect of sire R2 = 0.015075. These effects were highly statistically significant (P<0.001). Correlation coefficients among milk in kg, fat, protein in % with somatic cells count were r = -0.12918, r = 0.04166 and r = 0.11423. These coefficients were highly statistically significant (P<0.001).

Pregnancy assessment is a very important tool for the reproductive management in efficient and profitable dairy farms. Nowadays, mid-infrared (MIR) spectroscopy is the method of choice in the routine milk recording system for quality control and to determine standard milk components. Since it is well known that there are changes in milk yield and composition during pregnancy, the aim of this study was to develop a discriminant model to predict the pregnancy state from routinely recorded MIR spectral data. The data for this study was from the Austrian milk recording system. Test day records of Fleckvieh, Brown Swiss and Holstein Friesian cows between 3 and 305 days of lactation were included in the study. As predictor variables, the first derivative of 212 selected MIR spectral wavenumbers were used. The data set contained roughly 400,000 records from around 40,000 cows and was randomly split into calibration and validation set by farm. Prediction was done with Partial Least Square Discriminant Analysis. Indicators of model fit were sensitivity, specificity, balanced accuracy and Area Under Receiver Operating Characteristic Curve (AUC). In a first approach, one discriminant model for all cows across the whole lactation and gestation lengths was applied. The sensitivity and specificity of this model in validation were 0.856 and 0.836, respectively. Splitting up the results for different lactation stages showed that the model was not able to predict pregnant cases before the third month of lactation and vice versa not able to predict non-pregnancy after the third month of lactation. Consequently, in the second approach a prediction model for each different (expected) pregnancy stage and lactation stage was developed. Balanced accuracies ranged from 0.523 to 0.918. Whether prediction accuracies from this study are sufficient to provide farmers with an additional tool for fertility management, it needs to be explored in discussions with farmers and breeding organizations.

The increase of milk production at the farm level requires an accurate balancing of the diet and the nitrogen supply also to minimise the possible environmental pollution deriving from dairy farming. The aim of this study was to evaluate dietary protein utilization at different crude protein (CP) levels and to predict nitrogen content in faeces on the basis of nutritional parameters and milk urea nitrogen content (MUN, mg dL-1). The study was conducted on three groups (A, B, C) of lactating dairy cows (8 cows per group, including Latvian Brown and Holstein Black and White breeds) from 10 to 30 days in milk. Total mixed rations containing different levels of CP (approximately 18.0%, 17.5% and 17.0% for A, B and C, respectively) were fed. The amount of feed consumed by each cow was measured and feed samples collected during the trial. Milk yield (kg d-1-1) and faeces amount were recorded, and samples were collected at day 21 of the study for further analysis. Feed samples were analysed for CP, net energy for lactation (NEL, MJ kg-1) and other parameters. Milk samples were analysed for fat (%), total protein (%), casein (%) and urea content (mg dL-1). The statistical investigation was conducted using ANOVA, and correlation and regression analyses. The results showed that milk yield, fat, total protein, casein, urea, and MUN were not significantly different among groups being not affected by the dietary CP levels. The correlation between faecal nitrogen content and CP content in feed was moderately positive and statistically significant (r=0.44, P=0.03), while the correlation between faecal nitrogen content and MUN was moderately negative and showed tendency towards significance (r=-0.39, P=0.06). The regression analysis showed that feed CP explained approximately 20% of faeces nitrogen content.

The purpose of the study was to asses the effect of calving season and dams’ parity on milk yield and gestation length of dairy cows. We examined 93 animals of Slovak spotted breed from the farm located in western Slovakia (Lower Váh region), in years 2014-2017. The herds’ average 305-d milk yield was 8133±1380 kg. The calving season was divided into four categories: spring (March to May), summer (June to August), autumn (September to November) and winter (December to February). The factor of dams parity was divided into 4 groups: 1st parity cows, 2nd-3rd parity cows, 4th and higher parity cows. Calving season affected significantly milk yield of dairy cows (P < 0.01). The highest 305-d milk production was oberved in winter calvings (8942±218 kg) and the lowest in spring calvings (7377±287 kg). The gestation length was not signifficantly altered by calving season (P > 0.32). Dams’ parity was not significantly affected by 305-d milk yield (P > 0.22). Nevertheless, the animals on the 4th and higher lactation were numerically more productive (8481±259 kg) compared to the dairy cows on their 1st,2nd-3rd lactation (8123±264 kg; 7884±223 kg; resp.). The dams’ parity significantly affected gestation length (P < 0.02), with the shortest gestation length in 1st parity dams (278±2 days) and the longest gestation in 2nd-3rd parity dams (284±1 days).To sum up, our results suggest significant role of calving season in relation to milk yield and significant effect of dams’ parity on gestation length.

This research aimed to evaluate the effect of live yeast additive to cattle ration on milk yield of dairy cows. The research was conducted on a dairy farm, on a sample of 265 dairy cows during winter. The dairy cows were fed with a feed containing live yeast of Saccharomyces cerevisiae species (CNCM I-1077). The dosage was 2.1010 cfu.head-1.day-1. Milk yield and the components of milk were monitored for a three-month-long period – starting one month before the supplementation of yeast to feed and ending two months after. The addition of live yeast to cattle ration had a significant positive impact already in the first month on milk yield (+1.25 kg.day-1), and the amount of fat (+0.055 kg.day-1), protein (+0.057 kg.day-1), lactose (+0.056 kg.day-1) and milk solids (+0.170 kg.day-1) contained in milk (p<0.001). The general conclusion of the experiment is, that the Saccharomyces cerevisiae additive had an apparent positive impact on milk yield and milk components.

The aim of this study was to determine the effects of the claw diseases of dairy cows on the protein and urea content in milk. The study was conducted on 198 dairy cows, half of which was lame. Animals were divided into three groups according to their current phase of lactation. The cause of lameness was diagnosed in the claw crush. Milk samples were taken from all animals and the protein and urea content were determined. The content of protein and urea in milk of the lame cows in the first phase of lactation was reduced by 9.55 % and 29.9 %, respectively. Lame cows in the second phase of lactation had milk and urea content reduced by 6.94 % and 18.9 %, respectively. The cows in the third phase of lactation had content of milk protein and urea decreased by 10.3 % and 18 %, respectively. These results point to the fact that painful claw diseases affect the protein and urea content of milk.

The objective of this study was to analyse eight milk yield and longevity traits in dependence on feeding (grazing) system. Data of purebred Slovak Spotted dairy cows (35,812 heads) culled in the period between 2006 and 2019 were evaluated. Only herds those feeding (grazing) system was known were taken into account. Dairy cows were assigned to four groups: (1) heifers not grazed, cows not grazed (17,628 heads), (2) heifers grazed, cows not grazed (13,056 heads), (3) heifers not grazed, cows grazed (156 heads) and (4) heifers grazed, cows grazed (4,972 heads). The highest average 305-day milk yield (6,139.22 kg) and lifetime milk yield (18,606.78 kg) were found in animals of group (1). Contrariwise, longevity traits were found more favourable in animals of group (4). Their productive life was by 102.78 days longer and average parity was by 0.14 higher in comparison to group (1). The differences between groups were found significant.

The purpose of the work was aimed at determining changes in locomotion activity of dairy cows with healthy claws, as opposed to cows suffering from claw disorders. To achieve this goal, Heatime RuminAct technical equipment was used. Data gathering took place at the dairy farm of University of Agriculture in Nitra, where locomotion activity was measured via Heatime RuminAct hardware with DataFlowTMII software. This data came from 87 dairy cows, whose locomotion activity was monitored during a period of 21 days. This period consisted of 10 days of monitoring before the claw trimming, monitoring during the day of the trimming, and afterwards, another 10 days of monitoring after the trimming was complete. Units of locomotion activity in 24 hours (u.24h-1) were used to formulate the locomotion activity of the dairy cows. Health conditions of claws of the dairy cows were recorded and based on the presence of claw disorders, the cows were divided into two groups - cows with observed claw disorders formed a group of 33 cows, and cows exhibiting no claw disorder related symptoms formed a group of 54 cows. Conclusions based on results from the data gathered confirm a crucial difference in locomotion activity between healthy cows and cows afflicted by claw disorders.

The aim of this study was to evaluate lactose in relation to milk production and calving interval in dairy cows of Slovak Spotted cattle. A total of 92,730 lactations from 45,800 dairy cows evaluation from 2015 to 2019 were used for investigating lactose percentage (LP), milk yield (MY), lactose yield (LY), fat percentage (FP), proteins percentage (PP) and calving interval (CI). Data were analysed using the SAS version 9.4 and linear model with fixed effects: herd-years-season (HYS), sire (S), breeding type (BT), coding of milk (Cod-MY) and coding of calving interval (Cod-CI). In the dataset the average of LP was 4.77±0.20 %, while the one of MY, LY, FP, PP and CI were 6,778.53±2,014.18 kg, 325.27±100.45 kg, 3.96±0.47 %, 3.39±0.23 % and 406.66±91.09 days. The correlation of LP with MY, LY, FP, PP and CI was equal to r = 0.1712, r = 0.3157, r = 0.0546, r = 0.1852 and r = -0.0147. These correlation coefficients were statistically highly significant P <0.0001. Among all fixed effects in the analysis of variance of LP, the most relevant effect was observed for HYS (P<.0001).

The aim of this review is to consolidate the already much published knowledge concerning the gastrointestinal tract of the dairy cow in relation to nutrition. This review document deals with the essential living conditions of dairy cows, with an attention to nutrition, and highlights the importance of correct ration design. Dairy cows in different production cycles have special requirements for the composition, structure and nutrient composition of their rations. This review document provides more detailed information on the physical structure of feedstuffs as well as the need for individual nutrients for the right functioning of the dairy cow. These elements determine total health, feed intake, rumination, the development of metabolic diseases and last but not least, milk yield and composition. Rumination is an important and valuable tool that indicates the correctness of these aspects. Many published studies point to the relationship between rumination and health status where early intervention can be made to prevent a reduction in milk yield and consequent negative selection from the breeding stock. Many studies describe rumination as an indicator that forms the basis of the herd on which the very substantial and developing benefits of breeding as well as reproduction itself are built. The rumination-based relationships of heat stress and dairy cow health are also nowadays receiving a great deal of attention in studies. In nowadays also receiving a great deal of attention in studies about relationship not only between rumination - heat stress but also dairy cow health status. Heat stress is characteristically labelled as an unwanted factor that has an adverse effect on dairy cow milk yield.

The aim of this review, which has been compiled on the basis of the available existing literature, is to summarise the basic information regarding alimentary metabolic disorders in high-producing dairy cows. The disorders included in this review are among the most commonly occurring in herds. Specifically, ketosis, acidosis and milk fever. It is known worldwide that high producing dairy cows are more susceptible to ruminal dysfunction - alimentary metabolic disorders. Causes of alimentary metabolic disorders can be of different nature, such as unbalanced feed ration, stress, inadequate management and environmental factors, genetic factors and various infections or diseases of the animals. The most frequent cause of metabolic disorders is considered to be the feeding of an inadequate ration with an excess or deficiency of the required nutrients. Dairy cows must be fed a ration containing all nutrients in the correct proportions to maintain optimum metabolic function. The physical structure of the forage itself has a major influence on the health status of dairy cows and the development of dysfunctions, where not maintaining the correct technique (structure) has a negative impact on the overall rumen complex of the dairy cow.

Silages represents the principal component of the diet of high-producing dairy cows. The objective of this review is to provide a comprehensive summary of the existing literature on the impact of silage quality on the feed intake, performance, and health of dairy cows. The review described the impact of the nutritional quality of silages and fermentation products on dairy cow performance, including the implementation of preventive practices to avoid the undesirable fermentation process. The following section focused on the prevalence of pathogens that present a risk to animals and humans. A summary was provided of the most recent findings on the occurrence of Clostridium spp., Enterobacteriaceae, Bacillus spp. and Listeria monocytogenes in silage. The final section of the review addressed the most recent findings on the prevalence of undesirable metabolites, such as mycotoxins and biogenic amines, in silage. The mycotoxin section concentrated on the adverse health effects of elevated mycotoxin concentrations in dairy cow feed rations.

The aim of this study was to show the individual relationships between selected parameters within the groups of high-producing Holstein-Friesian dairy cows in the Early Lactation (EL), Peak Lactation Multiparous (PLM) and Peak Lactation Primiparous (PLP). Firstly, the relationship of individual fractions (Penn State Particle Separator (PSPS) method) retained on Pennsylvanian sieves on dairy cow activity - feed intake time/ eating time (ET); rumination time (RT); time no-active (TN) - was evaluated using BouMatic‘s RealTime Activity program. It was found that there was a statistically significant difference between the EL group, which intake less amount of fibre retained on the sieve with 8 mm hole size (46.90%) with the PLM (50.19%) and PLP (49.41%) groups (p <0.05). The decrease in fibre intake (8 mm) was related to the fraction intake retained per pad where there was a statistically significant difference between EL (28.02%) and PLP (25.69%); PLM (25.19%) group (p <0.05). The data obtained regarding ET and RT between the groups showed a statistically significant difference where low RT and ET was observed just at higher fraction intake per pad (28.02%) and lower fibre intake (46.90%) in the EL (4:16 h) group compared to PLM (4:41 h) and PLP (5:37 h) (p <0.05), where the percentage intake of fractions contained per pad was lower. The study also evaluated the effect and relationship between selected parameters (starch, lactic acid-LA, fermentation processes-FP, NH3 ,acid-detergent fibre-ADF, neutral-detergent fibre-NDF, pad, physically effective neutral-detergent fibre-peNDF) on ET and RT. The starch content of the total mix ration was in medium high negative correlation with RT (p <0.05) and on the other side the peNDF content was characterised by a strong positive correlation with RT (p <0.01). Based on these results, it was found that dairy cows in the EL group preferred a rather higher intake of fractions contained on the pad, which influences the reduced intake of particles retained on the 8 mm average sieve and thus their overall activity (ET, RT, TN) is influenced. Dairy cows in the PLM and PLP groups preferred a higher intake of fiber particles (8 mm) which influenced the increase in activity time (ET, RT).

Milk is considered not only a source of nutrient for the offspring but also a font of immunoregulatory compounds capable to predispose the naïve intestinal immune system of the new-born to react to the external environment. In the present study we evaluated the composition of milk microbiome from cows classified according to milk total and differential somatic cell counts. A total of 34, 13 and 13 milk samples of healthy, at risk and subclinical or chronic cows, respectively, were collected during the same milking from a local dairy herd. Through Next Generation Sequencing (NGS) of bacterial 16S rRNA gene, the differences of taxa in terms of relative abundances (RA) and alpha and beta biodiversity were analysed. The RA of several genera were statistically significant in the three groups, such as Arcanobacterium (p=0.001), Rhodococccus (p<0.05) and Rubrobacter (p<0.05), while at species level the presence of Propionibacterium granulosum, Pseudomonas alcaligenes and Prosthecobacter debontii were found. Shannon and Evenness indices computed at the genus level were not significant, while beta biodiversity showed a clear clusterization between groups. The results highlighted that milk microbiome is associated to a different cellular response at udder level, although more specific studies are needed to assess the source of bacteria species identified in milk microbial population of healthy animals.

β-carotene has many important functions in the body: as a precursor of vitamin A, it works as antioxidant and affects the fertility of cows. This paper presents the results of measurements of the content of β-carotene in the blood serum of cows from different farms in Slovenia. Blood samples of cows (n = 604) from 176 farms with impaired fertility were analysed for β-carotene content using Yudkin's photometric method. The descriptive statistics and the proportion of samples that deviated from the reference values were calculated. Influence of month of sampling and farm on β-carotene level was studied as well. The median value of β-carotene in the investigated samples was 5.02 mg/L (minimum 0.63 mg/L, maximum 16.10 mg/L) and was within the reference range. In 32.8% of cow samples, the content of β-carotene was below the reference value (4.0 mg/L). According to the results, we believe that this is not a negligible problem in Slovenian farms, and that it is advisable to control β-carotene status in cows, especially in herds where fertility is impaired and in farms where the composition of the diet indicates the possibility of β-carotene deficiency.

The administration of high quality colostrum reduces preweaning morbidity, mortality and, therefore, economic losses related to replacement animals. It also stimulates and improves calf growth, increasing milk production and longevity of the future dairy cows. The aim of the present study was to evaluate the influence of breed and parity of the dam on colostrum quality, and of breed and gender of the calf, and time from calf birth to the administration of the first colostrum meal on the transfer of passive immunity to the calf by the field test of the Failure of Passive Transfer (FPT) on calf serum. A further objective was to improve the diagnostic accuracy of the field FPT test through a second laboratory phase improving the turbidity evaluation. The amount of IgG fed to calves (IgG concentration multiplied by the volume of colostrum administered) was influenced by dam parity as significant differences (P < 0.05) were detected between first- and fourth-parity cows, and between second- and fourth-parity cows. The administration of good quality colostrum (IgG > 50 mg/ml) between 5 and 9 h of life was able to reduce the risk of FPT more effectively than the administration performed within the first 4 h of life. However, further studies on larger sample size is needed to confirm the present findings. The spectrophotometric measurements confirmed the results obtained by the field turbidity test at 14% sodium sulphite dilution. It would be interesting in future to expand the dataset and validate the spectrophometric method.

Many bacterial species are currently known as etiologic agents of dairy cattle metritis. Antimicrobials for endometritis treatment are infused into the uterus, and these therapies are aimed to achieve high concentrations of antibiotics in the site of infection. The aim of this work was to verify the possibility of using a non-antibiotic active substance to prevent the emergence of postpartum infections in cows. The study was realised in 12 herds of Holstein, Simental and Pinzgau cattle (4,563 animals), where the incidence of postpartum reproductive disorders was higher than 20%. After parturition, animals (4,563) were divided into four groups: (I) 1,967 primipara cows treated, (II) 2,596 pluripara cows treated, (III) 638 primipara cows untreated and (IV) 667 pluripara cows untreated. Animals were treated 24 hours after parturition with 100 ml Lactobacillus spp. (LBC), lyophilised preparation (1 ml contained 1.0 ×109 microorganisms). Lyophilisate was diluted just before the application with a sterile solvent with pH 4.4–4.7. The most prevalent pathogens were E. coli (74.7%) and Trueperella pyogenes (17.3%). E. coli caused up to 88.2% of genital inflammation – mostly endometritis. The positive effect of the preventive application of preparation based on LBC significantly eliminated the occurrence of bacterial microflora after the parturition on the 14th and 20th day of the puerperium, respectively. The preventive application was manifested to a demonstrable extent also in the subsequent reproductive parameters of cows. The preparation appeared to be more effective in primipara, especially concerning the incidence of inflammatory conditions of the genitals (P <0.01).

This research was conducted on 147 cows of purebred Montbéliarde dairy cattle during their first to seventh lactation. On average, each dairy cow provided 161 values on live weight during lactation via the automatic milking system (AMS). The average live weight of a dairy cow of said herd was 699.94 kg, the daily milk yield was 33.67 kg on average and the average day of lactation (DIM) was 111.75. This research discovered a statistically significant decrease of live weight in dairy cattle before the 60th day of lactation in every observed lactation. On the contrary, the changes in live weight in the last 60 days of standardized lactation proved to be inconclusive. Between days 60 and 240 of the lactation, an increase of live weight of varying intensities was observed, mainly in cows who had undergone less lactation cycles in the past. Similarly, the research has proven an impact of the number of lactation cycles the cow has undergone in the past on the live weight of the cow during the first, second and third lactation (645.21 kg, 700.35 kg and 752.10 kg respectively). On the contrary, there was no conclusive difference in live weight between the third and more lactation cycles. The results have also shown that the changes in live weight during lactation were significantly different in first-calf heifers, as opposed to cows after more lactation cycles, similarly to the differences in milk yield.

High-yielding dairy cows have several critical periods during lactation. These include the drying period, parturition, postpartum period and the first 100 days of lactation. The mineral profile displays the balanced feed ration appropriate for the category. Therefore, investigation of serum mineral profile of dry cows and cows in 12th week after calving was the aim of this study. In this work 12 high producing Holstein Friesian dairy cows from dairy farm were used. The analysed elements Ca2+, P, Na+, K+, Mg2+ and chlorides (Cl-) were determined at 4th week after drying and during 12th week after calving. The data obtained were compared with the standard for dairy cows. Compared to reference interval, before calving 8 and after calving 5 cows had hypocalcaemia. Hypophosphatemia was detected for 2 cows before calving and 3 after calving. For the other elements Na, K, Mg2+ and chlorides (Cl-) no deviations from the reference intervals were found. In blood serum mineral profile between dry cows and cows in 12th week of lactation significant differences were found for Mg Cl- (increase) and K (decrease). Results shown, that main problem of dry and lactating cows was the hypocalcaemia and partly the hypophosphatemia.

The aim of the study was to compare improved bedding composition with conventional straw bedding under farm conditions, regarding its effects on the indicator microorganisms influencing hygiene levels. Dairy cows were housed in newly-built stables divided into two parts each with four sections and bedded cubicles arranged in three rows. In the first part, the bedded cubicle floors were layered with straw up to a height of 20 cm. In the second part, the cubicles were layered to a height of 20 cm with improved bedding composition consisting of recycled manure solids (RMS; 10 kg), ground limestone (200 kg), straw (40 kg) and water (110 l). After layering the bedding was treated with a concrete selector to provide strength and sufficient resistance. Samples for microbiological examination were taken from four sections according to the time interval of production and bedding. From three sections were taken bedding samples according to a new recipe in intervals of 1-3 months after its use. A control sample of bedding, consisting of straw, was taken from the last, fourth section. Comparing classical straw bedding with the improved recipe bedding, the total viable count (TVC) and coliforms bacteria (CB) in a first and second month after laying were found to be reduced. In addition to TVC and CB, decreased numbers of faecal coliforms (FC) and faecal streptococci (FS) were observed in the first, second and third months after layering. In addition to reducing the number of microorganisms, the improved bedding showed a stabilizing effect by keeping the litter thickness up to the bedding threshold (200 mm), which has a beneficial effect for increased purity of the body and udder.