Pipeline Milking 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.

Genomic Insights into Methicillin-Resistant Staphylococci and Mammaliicocci from Bulk Tank Milk of Dairy Farms in Serbia.

The potential risk to human and animal health provides a rationale for research on methicillin-resistant staphylococci (MRS) and mammaliicocci (MRM) in dairy herds. Here, we aimed to estimate their occurrence in the bulk tank milk (BTM) samples collected in 2019-2021 from 283 bovine dairy farms in the Belgrade district. We used whole-genome sequencing to characterize the obtained isolates and assess their genetic relatedness. A total of 70 MRS/MRM were recovered, most frequently Staphylococcus haemolyticus and Mammaliicoccus sciuri. Five clusters of 2-4 genetically related isolates were identified and epidemiological data indicated transmission through, e.g., farm visits by personnel or milk collection trucks. Most MRSA isolates belonged to the typical livestock-associated lineage ST398-t034. One MRSA isolate (ST152-t355) harbored the PVL-encoding genes. Since MRS/MRM isolates obtained in this study frequently harbored genes conferring multidrug resistance (MDR), this argues for their role as reservoirs for the spread of antimicrobial resistance genes. The pipeline milking system and total bacterial count >100,000 CFU/mL were significantly associated with higher occurrences of MRS/MRM. Our study confirms that BTM can be a zoonotic source of MRS, including MDR strains. This highlights the urgent need for good agricultural practices and the continuous monitoring of MRS/MRM in dairy farms.

The Association between Socioeconomic Profiles, Attitudes, and Knowledge of Dairy Farmers Regarding Somatic Cell Count and Milk Quality.

The primary objective of this study was to investigate the association between the bulk tank somatic cell count (SCC) and dairy farmers' knowledge about milk quality, mastitis control, and their socioeconomic characteristics. Additionally, we estimated the association between the bulk tank SCC and bulk tank milk hygienic quality in dairy herds. Bulk tank milk samples from 120 dairy herds enrolled in the milk quality payment program were collected for the determination of the SCC, the total bacterial count (TBC), the preliminary incubation count (PIC), the laboratory pasteurization count (PC), and the coliform count (CC). Based on the bulk tank SCC results, 63 herds were selected and categorized into three groups: (a) low SCC: ≤250,000 cells/mL (n = 16); (b) medium SCC: >250,000 ≤ 400,000 cells/mL (n = 24); and (c) high SCC: >400,000 cells/mL (n = 23). Socioeconomic profiles, attitudes, and knowledge of somatic cell count and milk quality were assessed using previously tested questionnaires, which were used to interview the herd managers of the 63 selected dairy herds. Among the findings, 87.0% of the dairy herds had an SCC < 400 × 103 cells/mL, and presented milk production as the main economic activity of the farm, whereas only 47.0% of dairy herds with an SCC > 400 × 103 cells/mL had milk production as the main economic activity of the farm (p < 0.031). In a total of 95% of the selected herds (n = 60), milking machines were used, with pipeline milking machines being more predominant, accounting for 70.8% in herds with a medium somatic cell count (SCC) and 78.3% in herds with a high SCC, as opposed to herds with a low SCC at 50% (p < 0.031). The frequency of dairy producers' awareness of the maximum legal requirements for the bulk tank SCC and TBC was higher in herds with a higher SCC than in herds with a medium SCC. In conclusion, the results of this study indicate a significant association between the bulk tank somatic cell count (SCC) and dairy farmers' knowledge about milk quality, mastitis control, and socioeconomic characteristics. These findings emphasize the importance of knowledge and the socioeconomic profiles of dairy farms in maintaining and enhancing milk quality in dairy herds.

Comparative characteristics of disinfectants for dairy equipment and quality of dairy products under the influence of paratypical environmental factors

The parameters of the microclimate of the barn under the untethered method of keeping cows in the spring were studied. It was found that the temperature in the barn was on average 8.8±1.34 °C, the relative humidity and air velocity in the compared rooms were within the limits of hygienic standards. Microbiological indicators of bacterial air contamination correspond to the upper limits of hygienic standards and amounted to 116.64±6.32 CFU/sс3. The bacterial contamination of technological equipment averaged 119.33±14.71 thousand CFU/sc3. The content of harmful gases in the premises did not exceed the permissible sanitary and hygienic standards and was within the limits of the standards of VNTP-APC-01.05 Livestock enterprises (complexes, farms, small farms). The average number of MAFANM in the flushes from the study objects (teat rubber, collector, milk hose, milk pipeline) after washing with water was 368.4±9.8 thousand CFU/ sс3, and with 0.5% soda ash solution - 249.0±11.7 thousand CFU/sс3. The best level of microbiological cleanliness of the internal surfaces of dairy equipment was provided by sanitization using the disinfectant "Perfo Grif", with the number of MAFANM in the flushes averaging 139.7±7.0 thousand CFU/sс3. The best indicators of microbiological cleanliness of dairy equipment were obtained during sanitization with 0.5% Higienic-K solution. The average number of MAFANM was 126.2±1.5 thousand CFU/sс3. When using a solution of soda ash for sanitizing dairy equipment, the amount of MAFANM in freshly milked milk taken from the cooler was 198.3±12.16 thousand CFU/ sс3, which corresponds to the first grade according to DSTU 3362:2018 "Cow's milk". Technical conditions. At the same time, during the sanitization of equipment with acidic detergents and disinfectants "Perfo Grif" and "Higienic-K", the amount of MAFANM in milk was 114±8.14 and 102.0±16.3 thousand CFU/sс3, respectively, which corresponds to the highest grade. At the same time, the BCCP titer was more than 1.0, and the number of somatic cells (SCC) was within the permissible range (400 thousand/ml). Therefore, for effective sanitary and hygienic treatment of milking equipment, working solutions of disinfectants based on peracetic, nitric and phosphoric acids should contain 0.5% of the active ingredient, which will ensure the destruction of microorganisms during exposure for 5 – 15 minutes. Key words: dairy equipment, dairy products, disinfection, milk production hygiene, microbiological indicators of milk, milk production technology, milk quality.

Ergonomic and economic indicators of milk production using different cow milking technologies

The purpose of this work was to study the effect of changing the way of keeping and milking equipment on ergonomic and economic indicators. The research was carried out at «Ostriykivske» LLC, Bilotserkivskyi district, Kyiv region, where the milking herd was transferred from a capital-type room with tethered housing and milking into the milk pipeline to an easy-to-assemble room with loose housing and milking in the milking hall at the «Carousel» plant. The material for the research was lactating cows of the Ukrainian black-spotted dairy breed of II and III lactations. In order to accurately determine the duration of the technological operations of the milking process through the milk pipe and at the «Carousel» milking plant, it was filmed during the morning milking of cows. The change in the method of keeping (from tethered to loose housing) and the milking option (in the stall to the milk pipeline to the milking hall) had a significant impact on the time spent when performing the technological operations of one cow milking. The total time spent by machine milking operators in the slope decreased by 31.35 seconds. When moving the animals to the milking parlor, the duration of such operations as washing, wiping and massaging of the udder decreased by 4.8 s, milking of the first trickles of milk – by 0.6 s, and putting milking cups on the udders – by 1.3 s. The duration of preparatory and final milking operations decreased by 7.2 seconds, and other operations related to milking decreased by 58.2 seconds. At the same time, the complex indicator of the ergonomics of the milking installation when transferring cows to the milking parlor increased significantly (by 0.60) and met the requirements of the standard. The total labor costs when the conditions of keeping and milking were changed decreased by 52.96 man hours/year per cow. Labor costs for the following types of work decreased most significantly: milking and primary processing of milk; cleaning of stalls and manure passages; making litter and operating costs: 22.00; 19.40; 2.60 and 6.60 man hours/year per cow, respectively. Electricity consumption per cow per year increased by 22 kWh, and water for the milking process increased by 560 liters. Key words: dairy cows, ergonomics of milking, change of housing conditions, milking facilities, consumption of energy resources.

Longitudinal Study for the Detection and Quantification of Campylobacter spp. in Dairy Cows during Milking and in the Dairy Farm Environment.

Campylobacteriosis outbreaks have repeatedly been associated with the consumption of raw milk. This study aimed to explore the variation in the prevalence and concentration of Campylobacter spp. in cows' milk and feces, the farm environment and on the teat skin over an entire year at a small German dairy farm. Bi-weekly samples were collected from the environment (boot socks), teats, raw milk, milk filters, milking clusters and feces collected from the recta of dairy cows. Samples were analyzed for Campylobacter spp., E. coli, the total aerobic plate count and for Pseudomonas spp. The prevalence of Campylobacter spp. was found to be the highest in feces (77.1%), completely absent in milking equipment and low in raw milk (0.4%). The mean concentration of Campylobacter spp. was 2.43 log10 colony-forming units (CFU)/g in feces and 1.26 log10 CFU/teat swab. Only a single milk filter at the end of the milk pipeline and one individual cow's raw milk sample were positive on the same day, with a concentration of 2.74 log10 CFU/filter and 2.37 log10 CFU/mL for the raw milk. On the same day, nine teat swab samples tested positive for Campylobacter spp. This study highlights the persistence of Campylobacter spp. for at least one year in the intestine of individual cows and within the general farm environment and demonstrates that fecal cross-contamination of the teats can occur even when the contamination of raw milk is a rare event.

Historical and Analytical Assessment of Automation and Robotization for Milking Processes

The paper shows the main ways of machine technology development from manual milking to robotic and notes the ambiguity of expert assessments regarding the introduction of robotic milking. (Research purpose) To conduct historical, analytical and feasibility studies of various options for automating cow milking on dairy farms, to determine the overall capital intensity of various options for the transition from manual to automated and robotic cow milking technologies, as well as the capital intensity of individual transition stages such as mechanized bucket milking, pipeline milking, automated milking in milking parlors, robotic milking in individual boxes and milking parlors. (Materials and methods) The paper analyzes the revolutionary transitions associated with a drastic change in technology, a change in the way of keeping cows and a change in the organizational and economic forms of operations; the modernization transitions, those with a complete or partial replacement of equipment but without a fundamental change in technology; and the reverse transfer transitions - a forced return to the previous more economical technology. (Results and discussion) We considered 7 main ways of developing machine milking over 100-110 years from the manual milking method to the automated and robotic ones. It is determined that their total estimated capital intensity for a hypothetical reference farm per 1000 heads accounts for 78.0-474.5 million rubles in modern figures. The concept of a standardized unit is introduced, that is equal to the price of the DAS-2V milking unit, that is, approximately 0.2 million rubles at the moment. (Conclusions) The research reveals the most costly transition ways, the optimal least capital-intensive way of transition from traditional milking to automated quarter-by-quarter milking in parlors, whose functionality is up to the robotic milking.The modernization transition to robotic milking in parlors is proved to be possible by gradual replacement of the automated milking manipulators controlled by an operator with the robotic unmanned manipulators and without any changes in technology.

DEVELOPMENT AND RESEARCH OF MULTIFUNCTIONAL MILKING MACHINES BASED ON THE MILK FLOW INTENSITY BY UDDER SHARE'S CONTROL SENSOR

The material on the milking machines' technical justification and research of udder each quarter's milk flow intensity controlling capable, mastitis diagnosing and in depending on milk flow intensity for the number of beats in the cycle changing is presented. The description of its electronic interaction with milking machine units, providing current milking control during milk excretion intensity from udder's each quarter and their physiological state is given. Experimentally confirmed the technical feasibility, technological and economic efficiency list of milking machines' functions performed by equipment's expanding with devices for milk flow intensity's monitoring. It is shown that the hybrid milking machine device operates in a more milk extraction's gentle mode in compared to the Duovac-300 one. According to investment projects' evaluation methodology, the calculations of modernized milking machines functioning in a cowshed with tie-free cows' keeping during milking in a milk pipeline's economic efficiency were carried out. The developed technical means introduction in a cowshed for 200 cows with tie-free cows' keeping pays off the initial costs and makes a profit during the first year of using. The expected DSO of the developed technical means ranges from 0,10-0,12 g. The confirmed economic effect of the tie-free cows' keeping in a cowshed with 200 heads of livestock's milking machines equipped with devices for milk flow intensity control using to 3319 thousand of rubles' prices in 2017 is amounted.

ХАРАКТЕР ЛАКТАЦИОННЫХ КРИВЫХ КОРОВ-ПЕРВОТЕЛОК ГОЛШТИНСКОЙ ПОРОДЫ В ЗАВИСИМОСТИ ОТ МОЛОЧНОЙ ПРОДУКТИВНОСТИ

The article assesses the lactation activity of first-calf heifers of the Holstein breed of a highly productive herd with different methods of keeping and milking technologies. It has been established that the highest milk productivity (8434 kg) is possessed by first-calf heifers with tethered content, with milking technology in the milk pipeline. The highest content of milk fat (4.09 %) and milk protein (3.18 %) was noted in milk obtained from free-standing cows with automated milking. It was noted that the highest rate of milk flow (2.45 kg/min) is typical for animals with loose housing with robotic milking technology, with the highest daily milk yield of 32.7 kg. It was determined that the peak of the highest productivity in the studied cows falls on the 3rd month of lactation, from the 4th month a systematic decrease begins. It has been proven that cows with a tethered content, with the highest milk yield (8434 kg) have an indicator of lactation constancy – 84.5 %, with a decrease in milk productivity (8353 kg and 7138 kg), it decreases (83.8 and 82.8 %), in loose housing groups with robotic and automatic milking technology, respectively. It has been established that in free-stall cows with robotic milking technology, the correlation between the rate of milk flow, the index of constancy and the coefficient of lactation stability is positive. In all the studied groups, the degree of influence of the highest daily milk yield on the coefficients of lactation constancy and sustainability is negative. It was determined that the lactation curves in the studied groups have a different character: high stable is typical for the control group; the 1st experimental group is characterized by high, but unstable lactation activity, the 2nd experimental group is unstable, sharply decreasing. It has been proven that in the group of free-range cows with robotic milking, a significant decline in milk yield was noted in the last months of lactation (by 7.4 %).

Analyses of Operational and Economic Conditions in Selected Dairy Farms

Dairy farms are an essential component of livestock production in Türkiye. This article aims to show the current situation on these dairy farms and incredibly show the technical and operational conditions in milking technology. We researched 32 dairy farms with 6 to 681 lactating dairy cows. The milking technology on these farms corresponds to the usual structure of milking equipment on Turkish dairy farms. It includes bucket milking, pipe-line milking systems, tandem milking parlour, herringbone milking parlours and side-by-side milking parlours. To analyse the current situation, we used a calculation on the model, with evaluation criteria: the total time required for milking and the final direct specific costs. Evaluation of existing milking systems showed the possibilities of reducing human labour costs by optimizing the work activities. Larger farms characterize by more progressive milking technology, higher milk yields, and lower specific costs.

Стрессоустойчивость и молочная продуктивность крупного рогатого скота Урала в зависимости от технологии доения

Abstract. In modern conditions of intensification of the agro-industrial complex of our country, the level of influence of stress factors on the indicators of dairy productivity of cattle is an urgent topic for research. According to scientists, the stress resistance of the animal body is characterized by a number of hormones, such as prolactin, adrenocorticotropic hormone and cortisol. The scientific novelty lies in the study of the level of stress resistance of cattle with the use of intensive technologies. The purpose of our research work was to analyze the indicators of stress resistance and dairy productivity of cattle in the Urals, depending on the milking technology. Research methods. Scientific work was carried out in breeding herds of black-and-white cattle in the period 2016–2019 on the basis of agricultural enterprises of the Tyumen and Sverdlovsk regions. Distributing the evaluated heifers by types of stress resistance, the level of hormones in their blood was determined during the first lactation in the laboratory using STEROIDIF tests. Results. As a result of the analysis, it was found that in the groups where milking was used in the milk pipeline, animals with a high type of stress resistance had 22.6 % more heads compared to the groups of robotic milking. At the same time, it was noted that the first heifers with an average type of stress resistance during milking by a robot milker are a quarter more than in groups of cows when milking in a milk pipeline. Consequently, the first heifers adapt better to robotic milking. Milk yield is higher for first-time heifers milked with the help of a robot milker compared to linear milking. The difference in this case was more than 700.0 kg (17.3 %) in the studied herds. We recommend that when selecting first-calf cows for intensive milking in breeding herds of the Urals, along with generally accepted assessment indicators, the level of stress resistance of animals should be evaluated.

ON THE SANITARY CONDITION OF THE MILK TRANSFER SYSTEM OF MILKING MACHINES

The article contains a review material on the level of microbial contamination of the milk-carrying sections of the transport system of the 2ADS-N (milk pipeline), Merry-go-round, Herringbone and Parallel milking plants.&#x0D; The differences in the level of bacterial contamination of the surfaces of components and parts in contact with milk, depending on the volume and structural features and types of materials used for their production, have been noted.&#x0D; The critical contamination limits have been identified that allow taking timely corrective actions to mitigate potentially&#x0D; dangerous biological risks in accordance with the HACCP principles.&#x0D; It is indicated on the necessity of investigation of microbial contamination of milk hoses for pumping milk from the milking parlor to the cooling tank and milk hoses for pumping milk from the cooling tank to the milk delivery truck, as well as the correction of sanitary treatment regimes for these types of products.

Establishing an interconnection between the technical and technological parameters of milking equipment based on the movement of a milk-air mixture in a milking machine

Machine milking is one of the main technological processes in the dairy industry whose efficiency level largely affects cattle breeding in general. The key role, in this case, belongs to milking equipment. The design and use of technical means of milking are associated with certain difficulties related to the imperfection of milk discharge. Therefore, the current study is due to the need to investigate the process of moving the milk mixture in a milking machine. A physical-mathematical model of the process of moving the two-phase milk-air mixture along the milk-conducting line of a milking machine has been built. The mathematical model relates the value of the fluctuating of vacuummetric pressure ΔP, the rate of milk discharge QM, the pulse rate ζ, and the value of working vacuummetric pressure P. It was found that in the milk-conducting system with the upper milk pipeline there is a large fluctuation of vacuummetric pressure ΔP=1.02–4.69 kPa, which exceeds the regulated value (2.5 kPa). In a milk-conducting system with a lower milk pipeline, the vacuummetric pressure fluctuation is ΔP=0.59–1.84 kPa. The patterns of change in the value of working pressure P and the frequency of pulsations ζ in the milking machines of simultaneous and pair action depending on the rate of milk discharge from the udder have been determined. It is established that the maximum deviation of the value of fluctuation of vacuummetric pressure ΔP between the experimental and theoretical data within a predefined range of factors is 0.81 kPa. The correlation coefficient is 0.92, which indicates the adequacy of the constructed models. Owing to this, the task of the rational choice of milking equipment is resolved

Влияние роботизированного доения коров на эффективность производства молока

Abstract. Purpose is to study the effect of milk production technology in the SPK “Glinskiy” with the use of robotic milking machines Lely Astronaut, DeLaval and linear milking machine ADM-8A, on the efficiency of milk production. Methods. An analysis of the efficiency of milk production with various technologies of keeping and milking cows was carried out on the basis of materials for accounting for milk productivity obtained for 2016–2019, and also the marketability of milk, the cost per unit of milk and the profitability of milk production during robotic milking and milking in a milk pipeline were determined. Scientific novelty. The analysis of the economic efficiency of milk production in the conditions of one farm is carried out, the differences in the level of milk productivity and milk quality are determined. Calculated: the cost price of 1 kg of milk obtained using the milking machine ADM-8 and automated milking machines Lely and DeLaval, profitability. Results. A large number of factors, both genetic and paratypical, affect the milk production of cows. The main paratypical factor is milk production technology, which includes keeping, feeding and milking livestock. Nowadays, the widespread technology is tethering cows with milking in a long milk pipe in stalls, this technology is considered traditional. She is being replaced by a more productive one – keeping a milking herd without a tether in groups with milking on automatic milking machines (robotic milking). Feeding with these two technologies is organized according to different principles. Our study revealed the influence of milking technology on the efficiency of milk production. As a result of the study, differences in the level of milk productivity and milk quality were determined. Our study revealed a positive effect of milking technology with the help of robotic installations on the efficiency of milk production: milk yield for each lactation increases by 7–28 %, which is confirmed by the lactation constancy index, the content of somatic cells in milk decreases to 2.4 × 105 cells per 1 cm3 providing an increase in the marketability of milk to 97.4%, in terms of physical and chemical indicators, milk of cows, with different methods of keeping, was within the normal range and average values for the herd.

Ways of restoration of dairy livestock of ukraine on a new technological basis

The article highlights the results of the evaluation of new spatial planning and technological solutions of dairy farms and the impact of easily collapsible structures of cowsheds on the conditions of keeping highly productive animals and their behavior. The process of milking cows in a specialized milking parlor and directly in the stalls was studied and the indicators of milk quality and its technological properties were determined. It is established that spatial planning and technological solutions of prefabricated structures of cowsheds by increasing the parameters and volumes per head from 45.6 m3 to 96.3 m3 and their new design have a positive effect on the conditions of high-yielding cows, including gassiness premises and animal behavior. Studies of the process of milking cows in a specialized milking parlor and at the stall have shown that the milk reflex reflex in cows when using a milking machine type "Parallel" is more fully manifested than in the installation type "Milk pipeline". It is established that when organizing milking of cows in a specialized milking parlor on the installation type "Parallel" the need for milking machine operators is reduced by 5 times, which reduces labor costs for the production of 1 quintal of milk to the European level. This technology provides high quality milk and its technological properties, which has a positive effect on the economic efficiency of production.

КОРРЕЛЯЦИОННЫЙ АНАЛИЗ ФАКТОРОВ, ВЛИЯЮЩИХ НА УРОВЕНЬ БАКТЕРИАЛЬНОЙ ОБСЕМЕНЕННОСТИ МОЛОКА

When analyzing raw milk properties, we should take into account the complexity and ambiguity of the “bacterial contamination” criterion. The authors evaluated the influence of physico-chemical and microbiological parameters of milk on its contamination over a year period. Milk testing protocols for 2020 were used as a source of information. The values of acidity, the number of mesophilic aerobic and facultative anaerobic microorganisms (CMAFAnM), the number of somatic cells, the proportion of protein and fat, and the density of milk were studied. To assess the influence of environmental parameters, the authors took ionto account the values of air temperature and humidity at the moment of sampling. Sampling was carried out according to GOST 26809.1-2014 “Milk and dairy products. Acceptance rules, sampling methods, and sample preparation for analysis”. The research was carried out on three dairy farms of the Knyaginino district of the Nizhny Novgorod region. They included a dairy farm with tie-up housing for 200 heads with milking in a linear type milk pipeline; a dairy farm with loose housing for 400 heads with milking in a herringbone type milk pipeline; a dairy farm with combined (tie-up and loose) housing for 450 heads with milking in a linear-type milk pipeline. The lowest indicator of QMAFAnM (total viable content) was noticed in March, and the highest – in November. The correlation analysis showed that the greatest influence of the studied factors on the level of bacterial contamination is exerted by the number of somatic cells (Pearson correlation coefficient R = 0.71 with a confidence probability P = 0.0619). The authors suppose that this situation may result from improper hygienic condition of the udder, equipment, and premises. There was a weak influence on the level of bacterial contamination of milk density (R = –0.18 at P = 0.096) and ambient air temperature (R = –0.18 at P = 0.095), which may be result from insufficient cooling of milk before transportation.

What are the potential sources of on-farm contamination of raw milk butter with Escherichia coli?

Description of the subject. According to Regulation (EC) No 2073/2005, Escherichia coli must be enumerated in raw milk butter before sales. Hygiene of batches is acceptable when a maximum of two samples out of five have levels of E. coli between 10 and 100 cfu·g-1. E. coli is still a threat to the safety of raw milk butter. Objectives. This study aimed to identify sources of E. coli in six farms facing recurrent contaminations in butter. Method. Farms were visited three times between March and May 2021. Surface samples and dairy products samples were collected throughout the process for E. coli enumeration and assessment of potential correlations between equipment contamination and hygienic quality of food products. Results. Two major sources of contamination were identified: the lack of efficacy of cleaning and disinfection practices on milk pipelines, junctions and cream separators, and absence of milk cooling in case of time-lapse of more than 2 h between milking and skimming. The use of lactic acid starters could be a helpful way to control E. coli during cream maturation, in association to adequate good manufacturing practices. Conclusions. Levels of E. coli in the considered raw milk butter batches were really high. A new decision tree is proposed that could help manufacturers and food controllers to improve hygienic quality of raw milk butter.

Laser Fluorescence and Extinction Methods for Measuring the Flow and Composition of Milk in a Milking Machine

Automation of milking systems is linked to accurate measurement of fluctuations in milk flow during milking. To assess the fluctuations of the milk flow, the formation and movement of milk portions in the milking machine-milk pipeline system was studied. By considering the movement of a milk plug along the milk pipeline, a hydraulic model of the formation of a critical volume of milk in the milking machine manifold was compiled. In practice, the most expedient way of determining milk flow parameters may be to measure the laser fluorescent and extinction responses of moving air-milk mixture. We have implemented a new laser sensing method for measuring the flow rate and composition of milk on the basis of counting the optical response pulses received from moving dispersed components by a CCD array or a randomized fiber optic bundle. Using the developed laser sensors, the theoretical model of milk flow was tested.

Metabolic Profiling of Rumen Fluid and Milk in Lactating Dairy Cattle Influenced by Subclinical Ketosis Using Proton Nuclear Magnetic Resonance Spectroscopy.

Simple SummaryKetosis metabolic research is extremely rare in Korea. This study aimed to compare the rumen fluid and milk metabolites between healthy and subclinical ketosis-diagnosed lactating dairy cattle. Six Holstein cows were allocated into two groups based on whether they fit the criteria for subclinical ketosis, and their rumen fluid and milk samples were collected from the stomach tube and pipeline milking system. Rumen fluid and milk samples metabolites were analyzed using proton nuclear magnetic resonance spectroscopy. They were identified and quantified using the Chenomx NMR Suite 8.4 software and statistical analysis was performed using Metaboanalyst 5.0. In rumen fluid, ruminant energy source metabolites (acetate, glucose, and propionate) were significantly higher in the healthy group, whereas in milk, ketone body metabolites (3-hydroxybutyrate and acetoacetate) were significantly higher in the subclinical ketosis-diagnosed group. This report will serve as a reference guide for future studies on ketosis metabolomics in Korea.Ketosis metabolic research on lactating dairy cattle has been conducted worldwide; however, there have been very few Korean studies. Biofluids from lactating dairy cattle are necessary to study ketosis metabolic diseases. Six Holstein cows were divided into two groups (healthy (CON) and subclinical ketosis diagnosed (SCK)). Rumen fluid and milk samples were collected using a stomach tube and a pipeline milking system, respectively. Metabolites were determined using proton nuclear magnetic resonance (NMR) spectroscopy and they were identified and quantified using the Chenomx NMR Suite 8.4 software and Metaboanalyst 5.0. In the rumen fluid of the SCK group, butyrate, sucrose, 3-hydroxybutyrate, maltose, and valerate levels were significantly higher than in the CON group, which showed higher levels of N,N-dimethylformamide, acetate, glucose, and propionate were significantly higher. Milk from the SCK group showed higher levels of maleate, 3-hydroxybutyrate, acetoacetate, galactonate, and 3-hydroxykynurenine than that from the CON group, which showed higher levels of galactitol, 1,3-dihydroxyacetone, γ-glutamylphenylalanine, 5-aminolevulinate, acetate, and methylamine. Some metabolites are associated with ketosis diseases and the quality of rumen fluid and milk. This report will serve as a future reference guide for ketosis metabolomics studies in Korea.

Research of the fluid flow regime during the milk pipeline washing

The aim of the research was to determine the change in the volume of fluid slug moving in the milk pipeline for calculating the initial length of the fluid slug and thus the air slug length. This allows to control the fluid and air inlet valve during circulatory washing of milking equipment with milk line and provides a stable plug flow during washing. The article deals with the problems of formation of a wave flow and plug flow regime in a milk line in dependance to the degree of filling and shear stress on the surface of the phases. As the result, the dependence curves have been obtained. They show that when the degree of filling the milk line with liquid is from 0.4d to 0.6d, the probability of slug formation decreases. To determine the loss of a fluid slug volume moving in a milk line, mathematical calculations with the use of the boundary layer theory have been carried out. As the result, the curves of the time of fluid and air intake into the system depending on the length and diameter of the milk pipeline have been obtained. These engineering calculation methods allow to set the operating parameters of the valves for fluid and air inlet into the system during washing. To calculate the parameters of pipelines with an internal diameter of 48, 63, 70 and 98 mm often used in milking equipment, a Delphi-based program was written. The article provides an example of calculating the time of opening and closing the valve for the inlet of fluid and air during washing for a milk line with 48 mm pipe diameter, 120 m length and pressure in the system of 48 kPa. Experimental studies have confirmed the reliability of the calculations, the loss of the liquid plug length for the milk pipeline Ø50. 8 mm is on average 5 cm per 1 meter of the fluid path.