Milk Science International - Milchwissenschaft
About the Journal Milk Science International – Milchwissenschaft is a scientific, open access journal with a double-blinded review process. Since 2015, the print version of the traditional journal "Milchwissenschaft" (ISSN : 0026-3788) has been continuously published as the open acces online journal "Milk Science International - Milchwissenschaft" (ISSN: 2567-9538). Scientists of all disciplines associated with milk and dairy production are invited to submit papers to the peer-reviewed journal Milk Science International – Milchwissenschaft. Milk Science International - Milk Science conducts a rigorous peer review process based on double-blind reviews with two independent reviewers. A final acceptance/rejection decision is made by the Editor-in-Chief or another academic editor approved by the Editor-in-Chief. The main topics of the journal are following: Dairy processing and technology Milk and dairy products in human nutrition Milk marketing and economics Milk production Dairy chemistry and physics Dairy microbiology The principle aim of the journal is to present newest scientific knowledge in short and precise articles. The papers comprise original articles, short communications and letters to the editor. As editorial decisions do not depend on perceived significance or impact of a study authors should not hesitate to submit manuscripts reporting negative results. A fee of 300 € is payable by the author(s) after acceptance of the paper. The contact adress is: volker.kroemker@hs-hannover.de
University of Applied Sciences and Arts Hannover
Which criteria can be used to select antibiotic intramammary tubes for non-severe clinical mastitis therapy?
The treatment of mastitis is one of the most frequent indications for antibiotic use in dairy cattle. Among the different manifestations of mastitis, non-severe clinical mastitis (CM) represents the majority of cases and thus accounts for a large proportion of antimicrobial consumption on dairy farms. While bacteriological cure (BC) is the primary measure of treatment success, no randomized controlled trials currently demonstrate significant differences in BC rates between the antibiotic intramammary injectors available in Germany. Consequently, the selection of an appropriate injector must be guided by other criteria. This article provides a structured, evidence-based overview of the most relevant decision criteria for the selection of antibiotic udder injectors for the treatment of non-severe CM, and presents a comparative economic analysis of all injectors with market relevance in Germany. The criteria considered include the classification of active substances as critically important antimicrobials (according to EMA categorization), the resistance profile of mastitis pathogens, practical and operational factors (soft criteria), and economic calculations. For the economic analysis, direct costs were calculated for all 14 udder injectors listed in the Lila Liste, comprising medication costs, labor costs for application, and costs due to discarded milk during the withdrawal period. Based on the available evidence, injectors containing non-critical active ingredients with short milk withdrawal times represent the most favorable choice under current regulatory and economic conditions. Soft criteria, such as once-daily application, are increasingly relevant on farms with external labor or automatic milking systems.
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Farm-specific selective dry cow treatment protocols using a new rapid tube test for identifying mastitis pathogens in dry off milk samples
Blanket dry cow treatment has long been routine on dairy farms, but rising antimicrobial resistance has increased the need for targeted approaches. Selective dry cow treatment (SDCT) treats only cows with infections that warrant antibiotic use. Implementing SDCT, however, can be challenging. In this observational study, farm-specific protocols were developed and applied on ten commercial dairy farms in Germany. Regular milk recordings and on-farm visits were used to design suitable protocols that also reflected farmers’ concerns about reducing antibiotic usage. Each protocol included farm-specific somatic cell count (SCC) thresholds for preselection and a newly developed rapid tube test for final decision-making. The test contained a pink medium that turned white when bacterial growth occurred. Tests were performed by farmers or staff at cow or quarter level. Udder health was monitored through milk recordings (SCC, new infection risk, and cure risk during the dry period), with protocols adjusted as needed. A total of 930 rapid ube tests were conducted and compared with cyto-microbiological diagnostics. Of 3,093 dry-off samples, over 70% showed no treatment-worthy infections, with farm variation between 54% and 86%. Treatment-worthy Gram-positive cocci infections were detected with 62.34% sensitivity, 73.74% specificity, and 70.95% accuracy at quarter level. The overall udder health was not negatively affected by SDCT; several farms even showed improved cure risk (n=6) or reduced new infection risks (n=6). Antimicrobial use decreased by 13.33% overall, with greater reductions when treatment occurred at quarter level. Based on microbiological results, a potential reduction of over 70% would be possible. The findings indicate that the on-farm test can support more targeted dry cow treatment decisions, while additional measures to prevent new intramammary infections remain essential in any SDCT protocol.
Copyright (c) 2025 Milk Science International - Milchwissenschaft http://creativecommons.org/licenses/by/4.0
Adhesion of Staphylococcus aureus to the liner in relation to subsequent machine milkings in a lab test
Staphylococcus (S.) aureus is one of the main causes of bovine mastitis, and its transmission during milking is a significant challenge for herd management. This study investigates the persistence of S. aureus on teat liners after simulating the milking of a cow infected with S. au- reus, testing two common liner materials: nitrile butadiene rubber (NBR) and silicone (SIL). A bucket milking system and a rubber udder were used to simulate the milking process, with an initial milking using S. aureus-contaminated milk, followed by six subsequent simulated milkings with uncontaminated ultra-high-temperature (UHT) milk. The presence of S. aureus on the teat liners was quantified by using a modified wet-dry swab method. Results demonstrated that S. aureus was consistently detectable on both liner materials throughout all six subsequent milkings, with a significant decrease in bacterial counts of approximately 85% for NBR and 78% for SIL. Importantly, NBR liners showed a higher risk of pathogen adherence compared to SIL liners. The findings reaffirm the risk of transmission of S. aureus through teat liners and highlight the importance of intermediate cluster disinfection between each milking to decrease this risk.
In-vitro Antimicrobial Resistance of Pasteurella multocida and Mannheimia haemolytica from Bovine Mastitis on Bavarian Dairy Farms between 2015 and 2023
As the leading disease in dairy cows, mastitis and its major pathogens have been extensively researched. However, mastitis can also be caused by other, opportunistic pathogens, such as Pasteurella (P.) multocida and Mannheimia (M.) haemolytica, which are usually associated with bovine respiratory disease. To better understand the effects of these as mastitis pathogens, the objective of this study was to describe the in-vitro antimicrobial resistance of P. multocida and M. haemolytica in quarter milk samples from Bavarian dairy farms between 2015 and 2023. P. multocida was isolated almost as frequently from clinical (48.6%), as from subclinical cases (51.1%), while samples with M. haemolytica came predominantly from clinical mastitis (82%). And while P. multocida was isolated in roughly equal parts (49.6% vs. 50.4%) from samples of herd screenings as well as individual submissions, M. haemolytica was more frequently found in individually submitted samples (87.2%). P. multocida was in-vitro mostly resistant against erythromycin (81.4%) and pirlimycin (95%), and M. haemolytica against erythromycin (89.7%), pirlimycin (87.2%), and oxacillin (58.9%). Yet they showed only few resistances to the other tested antimicrobials. The high occurrence of resistances against those few antimicrobials were also reflected in a high percentage of multiple resistances (83.7%). As antimicrobial resistances of those pathogens vary throughout different regions, the numbers in this study were mostly consistent with those from other studies from Germany or Austria. In general, low resistances to penicillin were reported when P. multocida and M. haemolytica were isolated from cases of mastitis, as well as a high success rate in eliminating the pathogens from the udder. However, the possibility of self-cure remains unexplored for these pathogens. When treatment with antimicrobials was selected, penicillin seemed to be the antimicrobial of choice for mastitis caused by P. multocida and M. haemolytica.
Destruction of penicillin residues in waste milk
To destroy the antibiotic residuals in waste milk on dairy farms, the aim of this study was to develop an approach for the degradation of Penicillin G in waste milk on the farm, working efficiently and without posing a risk to the user or the environment. Bovine pasteurized and homogenized milk with 3.8 % of milk fat was spiked with Penicillin G sodium-salt to an initial concentration of Penicillin G in the milk of 4 µg/kg to 500 mg/kg. Degradation of Penicillin G was performed by physico-chemical treatments, namely 1) exposure to heat and 2) exposure to heat after prior acidification and by 3) enzymatic degradation by β-lactamases from Escherichia (E.) coli strains tested positive for extended spectrum β-lactamases (ESBL) production. Heating to 95 °C for 120 minutes led to a degradation of 4 µg/kg Penicillin G below the detection limit of 2 µg/kg. A higher Penicillin G concentration of 8 µg/kg could not be sufficiently degraded anymore. Heat treatment for 120 minutes at pH 5.0 resulted in a degradation of 500 µg/kg, whereas it was 64 µg/kg pH 5.5. In conclusion, it is technically possible to degrade Penicillin G in waste milk. A combination of acidification of the milk and heating lead to a degradation of very high antibiotic concentrations but assumes a high level of technical equipment, time, and energy supply. The enzymatic degradation process of the antibiotic by β-lactamases promises better results than heating and acidification and requires lower temperatures than the methods without enzymatic degradation. A possible transmission of plasmids from the enzyme solution must be considered and needs to be solved.
Heart Rate Variability Measurement and Emotional Profiling to Describe Milk Quality?
This preliminary study examined whether the measures of heart rate variability (HRV) and emotional profiling (EP) are suitable for differentiating milk samples. Three different milk samples with the same fat content were tested: one ultra-high temperature (UHT) milk (conventional), one extended shelf-life (ESL) milk (organic) and one pasteurized only milk (organic). Their standard chemical parameters were determined, and a sensory descriptive analysis was performed. Two panels (12 and 13 subjects) trained in self-observation underwent HRV measurements and responded to an EP questionnaire. The panels differed in food testing experience. The experienced panel distinguished the pasteurized milk from the ESL and the UHT milk samples through EP, while the panel with little experience found no differences. No statistically significant differences were found between the three milk samples with respect to HRV parameters. The sensory descriptive analysis revealed a difference only in a taste characteristic between the UHT and the pasteurized only milk. The fatty acid patterns of the UHT sample differed from the other two, probably due to different cow feeding regimes. The results indicate that the applied methods differentiate milk differently: conventional UHT milk is at least partially distinguished from the other samples by three methods, namely fatty acid analysis, sensory analysis, and EP. No significant differences between the samples were detected using HRV.
Heifer Mastitis Risk Post-Parturition: Management factors associated with a low rate of Subclinical Heifer Mastitis in a Herd-Level Study
This study focused on assessing risk factors for heifer mastitis post-parturition, with a particular emphasis on understanding the associated management factors at herd level. Through examination of on-farm practices, milking routine observation and heat-stress consideration of 77 German dairy herds, the study set out to unravel the complexities contributing to a high / low rate of subclinical mastitis in heifers. For this purpose, the annual heifer mastitis rate (HMR) was provided by the dairy herd improvement (DHI) test and farms were categorized into two groups based on their HMR: herds with a low HMR (LHMR) and herds with a high HMR (HHMR). In the final multivariable model, two variables differed significantly among the herd categories. Herds with a higher proportion of heifers with a BCS < 3 were more likely to fall into the LHMR category. Herds with a higher proportion of heifers with a lameness score of 3 were more likely to be HHMR herds. These findings offer practical implications for dairy farmers in optimizing udder health and productivity in heifers at herd level. These associations from our cross-sectional study should be verified in a prospective study.
Copyright (c) 2024 Milk Science International - Milchwissenschaft http://creativecommons.org/licenses/by/4.0
Different European Perspectives on the Treatment of Subclinical Mastitis in Dairy Cows
As part of the European Network for Optimization of Veterinary Antimicrobial Treatment (ENOVAT), a webinar on the topic "Different European Perspectives on the Treatment of Subclinical Mastitis in Lactation" was held on September 21, 2022, during which eight mastitis experts from different European countries (France, Hungary, Italy, the Netherlands, Portugal, Slovenia, Sweden, and the United Kingdom) presented their treatment approaches for subclinical mastitis during lactation. The information provided by the experts is based on experience, guidelines, surveys, and opinions of the university to which they belong. The aim of this study was to compare the therapeutic approaches to identify commonalities and differences. It was not the aim of the webinar to identify the best approach for the treatment of subclinical mastitis, but to better understand the different approaches in the different countries in order to find starting points for long-term harmonization. The definition of subclinical mastitis varies from country to country. However, in all countries the definition is based on the presence of increased somatic cell count (SCC) in the quarter milk but without clinical signs or visual changes in the milk and is usually caused by an intramammary infection (IMI). Particularly regarding the cell count limit, the definitions differ between countries. In all participating countries, treatment of subclinical mastitis is not standard practice. This varies from a general rejection of treatment during lactation to treatment in special situations, involving the risk of penalties if a certain threshold of cells in the bulk tank milk is exceeded. Diagnostically, in its simplest form, subclinical mastitis in cows is determined by an individual cow SCC being greater than a threshold.
Herd-related risk factors associated with the severity of clinical mastitis and the incidence of severe mastitis in German dairy herds
Severe mastitis can result in a range of serious general health complications for the infected dairy cow, including septicemia, which can ultimately lead to death. This cross-sectional study aimed firstly to identify the herd-level risk factors associated with severe clinical mastitis (CM) in the diseased dairy cow. The second aim was to investigate herd-related factors associated with the incidence of severe mastitis in the dairy herd. The study was conducted on dairy farms (n = 58) in Northwestern Germany. In addition to data from dairy herd improvement (DHI) tests, possible herd-related predictors were collected on dairy farms. The most frequently isolated pathogens among all CM cases in this study were coliform bacteria (32.6 %), followed by Streptococcus (Str.) uberis (17.2 %). Mastitis cases in clean dairy herds (in > 80.0 % of the examined udders ≤ 10.0 % of the udder surface was soiled), in dairy herds with > two milkings per cow and day, and in herds with a new infection risk (NIR) during the dry period ≤ 28.0 % in the last DHI test prior to CM were identified as herd-related factors associated with more severe CM in the diseased dairy cow. The group of causative pathogens in mastitis cases was another risk factor positively associated with severe CM in the diseased dairy cow. Mastitis caused by coliform pathogens was more likely to be severe than mastitis caused by other pathogens. The mean incidence for severe mastitis in this study was 4.1 severe cases per 100 cow years at risk. The herd milk protein content based on the average of all DHI tests was significantly associated with the incidence of severe mastitis, such that dairy herds with a lower herd milk protein content < 3.4 % were associated with a higher incidence of severe mastitis.
Copyright (c) 2023 Milk Science International - Milchwissenschaft http://creativecommons.org/licenses/by/4.0
Camel Milk; A Nutritious Superfood for Health Complications
The camel is an essential food resource for arid and semi-arid environments in food security conditions. Camel milk is a unique source of nutrients with therapeutic properties. The amount of vitamins C, B3, Mn, iron, Cu, and Zn in camel milk is higher than cow milk. It is a suitable substitute for human milk for kids allergic to cow milk due to the lack of β-lactoglobulin. Also, camel milk has a high amount of unsaturated fatty acids for heart health. Probiotic bacteria of camel milk may de-conjugate bile salts, prevent reabsorption and reduce cholesterol absorption from the intestine. Camel milk contains insulin like proteins, which does not form coagulum in the acidic condition of stomach, can be absorbed from the intestine and may be treat diabetes. The smaller size of immunoglobulins of camel milk enhances the immune system and anti-inflammatory responses. Camel milk lactoferrin is antiviral and antibacterial agent against infections and lactic acid bacteria are effective on gut health. Camel milk has beneficial effects in the stomach disorders, cancer, food allergy, autism and viral Hepatitis. Therefore, camel milk is not only food but also a fantastic superfood for many health complications.
Survey on dairy farmers' management practices for and satisfaction with the detection of clinical mastitis by automatic milking systems in Bavaria, Germany.
The objectives of this study were to identify (i) management practices for the detection of clinical mastitis (CM) in dairy farms with automatic milking systems (AMS), and (ii) the farmers’ personal assessment of their work with the AMS as well as the mastitis detection performance of the AMS through an online survey. Complete responses of 47 of the 108 contacted Bavarian dairy producers were available for analysis. Warning lists of AMS, highlighting cows with potential udder health problems, were checked twice a day by 68% and once per day or less frequently by 27% of the farmers. Checking warning lists reportedly took five minutes per day (median). Besides the presence of flakes on the milk filter (75%), data from the AMS (78%) was another important factor that farmers considered for their decision to assess an indicated cow in the barn. Electrical conductivity (EC; 50%), milk color/ blood presence (49%), and, if available, somatic cell count (66%) were selected most frequently as “extremely important” from provided options in the survey. Flagged cows were commonly checked within 12 hours of the alert (23%) in the barn. Most commonly, these cows were assessed by organoleptic examination of the udder and/or the first milk strains (50%). Most farmers (68%) agreed with the statement of being very satisfied with the detection performance of CM by the AMS. However, almost half of the farmers (44%) perceived the number of false-positively flagged cows by the AMS as too high. While farmers were overall positive towards the detection of CM in AMS, some management factors such as the frequency of monitoring the warning list and cows in the barn could be intensified.
Comparison of different swab techniques for the quantitative analysis of mastitis relevant pathogens on liner surfaces
During machine milking, udder-pathogenic microorganisms can be transmitted. Unclean teats or milking of cows infected with mastitis pathogens can lead to contamination of the liner. To understand pathogen transmission through the liner, it is necessary to identify how many microorganisms adhere to the liner. Therefore, the microorganism density on the inner surface must be determined quantitatively. In this study, a multifactorial laboratory test was used to identify which is the best sampling technique and subsequent diagnostic procedure for quantitative analysis. Liners were contaminated with several mastitis pathogens using a standardized procedure and four different sampling techniques were applied. Three of these techniques were wet-dry swabs (WDS); the first was performed with high contact pressure, the second with low contact pressure, and the third used high contact pressure with cosmetic swabs instead of swabs from laboratory supplies. These WDS techniques were compared with a dry swab (DS). Contamination was detectable in the used pathogens with all techniques. The use of a WDS is shown to have advantages over the DS, as the contact pressure applied to the swabs and the moisture of the swabs itself play an important role in recovery of pathogens. Thus, with the WDS with high contact pressure, a pathogen recovery of 2.503 log10cfu/cm² was achieved, while with the DS, only a value of 1.342 log10cfu/cm² was obtained. Our findings demonstrate that the different sampling techniques differ in their results and that there is a need for standardized sampling of the liner surface to compare the results of the microorganism density quantitively. The WDS technique in accordance with DIN 10113-1: 1997-07 for determining surface microbial counts in the food industry proves to be a more suitable method than the DS technique due to a higher recovery of microorganisms and uniform results of the determined microbial densities.
Mastitis pathogens in Bavaria, Southern Germany: apparent prevalence and herd-level risk factors
The aim of this cross-sectional study was to determine the prevalence of mastitis pathogens in Bavaria and to identify management practices as possible risk factors for the presence and within-herd prevalence of the four most common pathogens . For this purpose, aseptic quarter milk samples of 6,188 dairy cows on 152 Bavarian dairy farms were collected and a California mastitis test was performed. Udder and leg hygiene scores as well as teat end condition scores were recorded at cow-level. Teat end hygiene score after udder preparation was evaluated for about ten cows per herd. Herd information and information on management practices were obtained using a standardized checklist. To determine herd-level risk factors, Fisher’s exact test for categorical, and Student’s t-test or Mann-Whitney-U test for continuous data were performed. The most frequently detected pathogens at quarter-level were coagulase-negative staphylococci (4.4%), Staphylococcus aureus (2.9%), Streptococcus dysgalactiae (0.9%), and Streptococcus uberis (0.9%). Each of these four pathogens was detected in more than half of the herds (90%, 70%, 61%, and 54%, respectively). Free stall housing and larger herds were associated with detection of coagulase-negative staphylococci and Streptococcus uberis. The usage of post-milking teat disinfection was associated with a lower within-herd prevalence of Staphylococcus aureus. The use of internal teat sealants and blanket dry cow therapy reduced the odds for detection of Streptococcus dysgalactiae at the herd-level. However, the latter practices were implemented by only a minority of herds. The study shows for the first time the apparent prevalence of mastitis pathogens in Bavaria using an unbiased sample. Coagulase-negative staphylococci were found to be the most frequently isolated pathogens, further studies on the etiology and reduction of these pathogens should be considered.
Evaluation of quality and shelf-life of yak milk phrum during refrigerated storage
Phrum is an acid-coagulated yak milk product popular in the West Kameng district of Arunachal Pradesh, India. However, the available research data on this milk product is very limited. Therefore research was undertaken to study the characteristics of fresh yak milk phrum and its quality changes during refrigerated storage. Results have shown that yak milk phrum has a higher yield, protein, fat, and highly acceptable sensory scores compared to cow milk paneer. During refrigerated storage, yak milk phrum showed a significant increase in titratable acidity, thiobarbituric acid reactive substances value, standard plate count, psychrophilic, lactobacillus, and yeast and mold counts. Sensory scores of yak milk phrum for appearance, flavor, body, texture, and juiciness declined significantly during the refrigerated storage. The shelf-life of yak milk phrum was nine days under refrigerated storage (4±1°C) with well acceptable quality attributes.
Single step fractionation of raw milk with FraMiTrACR® prior to detection of the residual contaminants chlorate and perchlorate
Residues of chlorate and perchlorate in dairy products are causing challenges for stakeholders in the dairy food chain. Both residues enter the dairy food chain almost exclusively as a disinfection or cleaning by-product. As these substances can endanger food safety, a cost-effective, passive and rapid raw milk sample preparation workflow was developed. By means of centrifugal ultrafiltration, unprocessed raw milk was fractionated into its constituent phases (water and fat/protein), using a FraMiTrACR®° unit. When the water phase prepared by this method was analyzed by liquid chromatography with tandem mass spectrometry (LC-MS/MS), it was possible to achieve quantification and detection levels of 0.001 mg/kg and 0.0005 mg/kg, respectively, for perchlorate, and quantification and detection levels of 0.01 mg/kg and 0.005 mg/kg, respectively, for chlorate.
Associations between udder health, udder health management and antimicrobial consumption: Insights into the mechanisms influencing antibiotic usage in German dairy farms
There is growing interest in preventing the development and spread of antimicrobial resistance worldwide through the prudent use of antimicrobials and the reduction in antimicrobial use (AMU). Treatment of mastitis is the main cause for the application of antimicrobial substances in dairy cows. The aim of this study was to investigate associations between udder health, udder health management, and AMU. Factors AMU directly depends on should be found out to achieve the overall goal of optimizing antibiotic consumption without negative effects on animal health. The subclinical and clinical udder health situation of 44 German dairy farms were analyzed at farm-level for the year 2020 using data from the Dairy Herd Improvement (DHI) testing and from herd-specific documentation on clinical cases. A questionnaire was used to describe the udder health management. AMU was measured by the mean number of days under antibiotic therapy due to mastitis per 100 cow years. The results showed that a higher clinical mastitis incidence (CMI) led to a higher AMU. The farm-specific mastitis treatment concept had an influence on the AMU as well. In addition, the actual existence of written treatment protocols was indicated to be associated with higher antimicrobial consumption. In conclusion, our study confirms that CMI directly correlates with AMU on dairy farms. Therefore, reducing the number of clinical cases should remain in the focus of farms. Treatment protocols that consider the current state of science and the dynamics of mastitis pathogens on the farm can reduce AMU. They should always be developed with the supervising veterinarian and be regularly reviewed and adjusted. It is also advisable to follow the latest scientific findings and, as far as possible, adapt the treatment concept accordingly, as modern treatment methods can also save on antibiotics.
Copyright (c) 2022 Milk Science International - Milchwissenschaft http://creativecommons.org/licenses/by/4.0
Is the incidence of clinical mastitis associated with changes of weekly average dry matter intake in lactating dairy cows?
The aim of this cross-sectional study was to test whether there is an association between clinical mastitis incidence and variations in dry matter intake in lactating dairy cows. Data were collected and analyzed from two voluntarily participating dairy herds (1,000 -1,200 cows) between 2017 and 2018. Lactating cows were assigned to seven “effective” husbandry groups (HGeff), considering important performance parameters such as lactation number, lactation day, reproductive status, and health status. The average daily dry matter intake of a cow in a husbandry group was determined once a week. Dry matter was determined using dehydration equipment that dried the fresh masses of the total mixed ration (TMR) in a standardized way. The incidence of clinical mastitis was calculated for different aetiological groups (environment associated mastitis pathogens, cow-associated mastitis pathogens, NAS (non-aureus staphylococci) and no growth cases). Dry matter intake (DMI) per individual cow was calculated as the averaged value plus the associated standard deviation (DMI (sd)) from weekly examinations of each husbandry group (HGeff). The average dry matter intake per cow per day was 23.6 kg +/- 3.7 kg. Environment associated pathogens were found in about half of all clinical mastitis cases (49.4 %). Cow-associated pathogens were found in 4.8 % of clinical mastitis cases. In all models, the different clinical incidences of mastitis studied were significantly associated with HGeff. In most cases, the incident rates were significantly higher in the fresh milking and high milking groups compared to the other groups. The incidence of clinical non severe mastitis cases (only mild and moderate cases) caused by environment associated microorganisms was further associated with variation in dry matter intake, with higher variation related to higher clinical mastitis incidence. Further studies are needed to verify this association.
Increased somatic cell counts at first milk control are associated with decreased milk yield in the first lactation in dairy heifers
Intramammary infections have a negative impact on the development of the mammary gland, udder health, the risk of clinical mastitis in early lactation, the risk of premature culling and future milk production in dairy heifers. The aim of this study was to reveal whether and how the somatic cell count of the first dairy herd improvement (DHI) affects the 305 day milk yield (energy corrected milk) of first lactation in German dairy heifers. Also, to investigate whether the threshold of 100,000 cells/ml used in Germany for herd analysis is appropriate to estimate possible economic losses, as the threshold of 200,000 cells/ml is often used in other countries. In addition, it should be examined whether a milk loss, which is associated with an increased initial SCC, differs between different German dairy cattle breeds Heifers with a SCC in the first DHI test of > 100,000 cells/ml showed a significantly (p <0.001) lower milk yield (on average -98.3 kg; 95% confidence interval (CI): -116.4 - -80.2) during the first lactation compared to heifers with an SCC ≤ 100,000 cells/ml. Heifers with a SCC in the first DHI test of > 200,000 cells/ml also showed a significantly (p <0.001) lower milk yield (on average -96.3 kg; 95% CI: -118.4 - -74.2) in the first lactation compared to heifers with a SCC ≤ 200,000 cells/ml. The effect of milk loss due to an increased initial SCC did not differ significantly between the breeds. It appears to be possible possible to use both thresholds for assessing udder health in individual heifers and at herd level. However, the present study only shows the relationship between increased SCC and the loss of milk yield measured in different German breeds of dairy heifers. Future studies must validate further risk factors that influence the udder health of dairy heifers.
Copyright (c) 2021 Milk Science International - Milchwissenschaft http://creativecommons.org/licenses/by/4.0
Associations of husbandry management factors with the new infection risk of bovine intra- mammary infections in lactation of dairy herds in Northern Germany
The purpose of this investigation was to compare herd-level new infection risk of bovine intramammary infections regarding husbandry management factors. The new infection risk was derived from cow-level somatic cell counts that were provided by monthly dairy herd improvement tests and collected over a period of 3 years and 4 months from 60 commercial dairy farms located in Lower Saxony, Germany. Factors of the management of the farm, the livestock and milking were generated as potential predicting variables. Based on the results of linear mixed models, the herd-level new infection risk was significantly associated with the pre-milking routine and the housing of fresh-lactating cows. When forestripping of every cow was included in the pre-milking routine, this had a beneficial impact on the new infection risk, especially when a foremilking cup was used. Keeping fresh-lactating cows in pens separated from the herd had a negative impact on the udder health, especially when housed together with sick cows. The results of this study confirm that the management of the milking routine and the environment can contribute to the control of udder health and milk quality.
Total viable, psychrotrophic and thermoduric population of market samples of pasteurized milk
Pasteurization, the process of heating every particle of milk to at least 63oC for 30 min or 72oC for 15 sec or to any temperature-time combination which is equally efficient is one of the major thermal preservation processes adopted by the dairy industry. The microbial groups of high relevance in terms of quality and safety aspects of pasteurized milk are the pasteurization surviving thermodurics and the low temperature growing psychrotrophic bacteria. So a study was conducted to determine the standard plate, psychrotrophic and thermoduric bacterial counts of market samples of pasteurized milk available in the local market and to derive correlations in between them. A total of forty market samples of pasteurized milk belonging to five different brands were assessed for their standard plate (SPC), psychrotrophic (PC) and thermoduric (TC) counts. The mean (±standard error) SPC, TC and PC of the pasteurized milk samples were 4.64±1.04, 2.9±0.64 and 2.63±1.3 log CFU/ml respectively. All the samples contained thermoduric organisms whereas psychrotrophic organisms were present in 87.5 % of them only. Standard plate count was found to be significantly (p≤0.05) positively correlated with TC and PC. Statistically significant (p ≤0.05) positive correlation was observed between PC and TC also. Among the different correlation coefficients obtained the highest was observed between SPC and PC (r=0.824). Significant differences (p≤0.01) were observed in between the mean values of SPC, TC and PC of the different brands of pasteurized milk samples tested.
A Survey of Mastitis Detection Practices and Treatments on Dairy Farms in Bavaria, Southern Germany
The objective of this study was to quantify the approaches of Bavarian dairy farmers towards mastitis diagnostics and implemented treatment options. Between fall 2017 and spring 2018, a stratified random sample of Bavarian dairy farmers (shipping >200kg milk) was contacted to participate in this anonymous survey. In the end 156 dairy farmers participated. Mastitis severity scores (1-3) were used on 74 % of farms. However, regular laboratory mastitis diagnostics were done on only 44 % of farms. Therapeutic approaches depended on the severity of the mastitis cases. Farmers reported that mild cases were treated with non-antibiotic treatments, e.g. homeopathy, or intramammary antibiotics. They were more likely to call the veterinarian for more severe cases. Few farmers reported to have regular discussions with their herd veterinarian about the reduction of antibiotic usage on their farms. In conclusion, the herd veterinarians should use their role as primary advisor to farmers to push for more diagnostics to enable more specific prevention and treatment strategies on Bavarian dairy farms.
Copyright (c) 2020 Milk Science International - Milchwissenschaft http://creativecommons.org/licenses/by/4.0
Evaluation of an early warning system for elevated ß-hydroxy­butyrate and non-esterified fatty acid values based on Fourier transform infrared spectra from routine milk samples
The objective of our study was to evaluate an early warning system for the detection of elevated ß-hydroxybutyrate (BHB) and non-esterified fatty acid (NEFA) levels in Fourier transform infrared (FTIR) spectroscopy data from routine milk samples. Starting from the monthly milk performance test of the German Dairy Herd Improvement Associations (DHIAs), we evaluated the benefit of more frequent milk sampling in early lactation to detect cows at risk for hyperketonemia and exaggerated fat mobilization. For the validation of the early warning system, milk and blood samples as reference data were obtained from Holstein-Friesian (HF) and German Simmental (GS) dairy cows in a one-year field trial. To establish an early warning system that utilizes a prediction model for FTIR data, the preferable day in milk (DIM) and a suitable sampling interval were investigated. For elevated NEFA values, a DIM of 6 – 13 was identified as the period for preferable sampling. A weekly testing frequency was used for nearly all of the cows in early lactation, and the number of identified cows with elevated NEFA or BHB values was three times higher than the actual situation of milk testing. Prediction models based on the regression tree full model selection (rtFMS) method, as presented by previous work, were validated to detect elevated BHB and NEFA values in FTIR data from routine milk samples. Different model options were compared in the regression tree regarding their significant impact on the prediction performance, measured in balanced accuracy. The chosen prediction model for each metabolite was validated on the reference data set as the gold standard. The evaluated early warning system might be implemented as an additional flexible milk sampling in the routine processes of the milk performance test of the DHIAs.
Some Properties of Kirklareli Ripened White Cheese
Kirklareli ripened white cheese (KRWC) is a traditional cheese produced within the borders of Kirklareli province and produced with abomasum, without adding any kind of fermentation sterter. KRWC is produced from milks of sheep, goat and cow which are blended at 30%, 25% and 45%, respectively. The main objective of this study was to detect the properties of KRWC and to compare them with the properties of other ripened white cheese mentioned in literatures. For this purpose, volatile flavor compounds, fatty acid composition and some physico-chemical properties of 10 KRWC samples were investigated. A total of 10 cheeses were analysed and there was not observed a huge variation among the cheeses in terms of fat, salt, protein, dry matter, fat free dry matter, ash, calcium content, pH, titratable acidity. When the aroma compositions were analyzed, there were totally determined 36 compounds in KRWC. Acids (14), alcohols (9), ketones (8), esters (4) and sulfur (1) compounds were determined in KRWC samples.
Predicting metabolic health status using milk fatty acid concentrations in cows – a review
The extent of a metabolic disorder (e.g. ketosis) is not necessarily reflected by the concentration of ß-hydroxybutyrate (BHB) in the blood, which is currently held as the gold standard in diagnosis. Also, for both economic and work-efficiency reasons, analysing blood is currently not applicable as a routine monitoring method for cows in the critical phase. Aim of this review was to examine the possibility of using milk fatty acids (FAs) and fatty acid (FA) ratios to predict negative energy balance (NEB), ketosis or metabolic disorders. After searching in two pertinent databases, eleven studies matched the relevant criteria. FA profiles were examined for correlations with the concentration of non-esterified fatty acids (NEFA) in blood in three studies, concentration of BHB in blood in five studies and different indicators of energy balance in four studies. One study developed linear regression models using FAs and FA ratios. Most studies found that short and medium-chained FAs (C4 – C14 and C5 – C15) are decreased during NEB, increased BHB or NEFA concentrations, whereas long-chained FAs (> C16) increase, especially cis-9 C18:1. A few single FAs and FA ratios such as cis-9 C16:1, cis-9 C16:1 to C15:0, C17:0 to C15:0 and C18:1 to C15:0 are correlated with a more severe NEB, elevated blood BHB or NEFA concentrations. Some might be useful in routine herd health monitoring despite having only moderate correlation coefficients. More promising than using single FAs or FA ratios to detect cows suffering from excessive NEB or metabolic disorders might be the implementation of refined prediction models in order to use all available information to predict the health status of both individual cows as well as the whole herd as exactly as possible.
Comparison of two teat skin sampling methods to quantify teat contamination
The aim of this research was to compare two sampling methods quantifying microbial load on teat ends, especially mastitis pathogens originating from the cows’ surroundings. Methods were compared using a split udder design, including 132 teat pairs in the study. For the first method, the wet/dry swab technique, a moistened swab was rotated 360° around the teat end, followed by a dry swab in the same manner. For the second and new method, the dipping technique, teat ends were immersed in a cup filled with Ringer’s solution and were removed after five seconds. Microbial load per milliliter as well as per teat end was calculated by determining the number of total aerobic mesophilic bacteria as well as environmental pathogenic bacteria, including coliform bacteria and esculin-positive streptococci. The concordance correlation coefficient (CCC) was used to quantify the agreement between two series of measurements and revealed the following coefficients: 0.112 for total aerobic mesophilic bacteria; 0.008 for coliform bacteria and 0.001 for esculin positive streptococci. The results of this study point out that under field conditions, the new method does not provide similar results when compared with the wet/dry swab technique for determining teat end microbial load.
Copyright (c) 2020 Milk Science International - Milchwissenschaft
Pre-treatments of Milk and their Effect on the Food Safety of Cheese
In the manufacture of traditional cheese varieties, processing fresh milk that has been treated as little as possible is crucial. Preserving the microbiome and the activity of the original enzymes in the raw milk to the greatest extent possible allows these cheeses to retain their original character. This objective conflicts with the growing demands placed on products in terms of food safety. The present literature search addresses the influence of the pre-treatment of cheesemaking milk on the food safety and quality of ripened cheeses, with particular focus on heat treatment, bactofugation, and microfiltration.
Copyright (c) 2019 Milk Science International - Milchwissenschaft
Studies of the Microbiological and Physico-Chemical Composition of Goat´s Milk from North-Western Spain
Twenty-seven samples of raw goat’s milk were collected from four farms in the North-West of Spain with the aim of analysing counts of various mesophilic bacteria and of determining the physical and chemical composition during different seasons of the year. Overall mean values for mesophilic aerobic micro-organisms (Standard Plate Counts, SPCs) were above 5.6 log cfu/ml, very similar to the counts on M17 agar (presumptive Lactococcus, 5.6 log cfu/ml) and higher than the counts on MSE agar (presumptive Leuconostoc, 4.6 log cfu/ml) and on MRS agar (presumptive Lactobacillus, 4.4 log cfu/ml). Counts were generally higher in winter than in spring and summer, although no statistically significant differences were found. The microbiological quality of raw goat’s milk produced in the farms investigated in the North-West of Spain is only partially in accordance with European Union standards. Hence, hygiene practices should be improved so as to decrease the standard plate counts on some of the farms checked. The physical and chemical composition tests also showed higher values for fat, protein and dry extract during the winter season. The average fat content (5.5 g/100 ml) and dry extract (14.7 g/100 ml) were higher than the values noted in other studies, making this of interest for cheese making.
Copyright (c) 2019 Milchwissenschaft - Milk Science International
Comparison of a non-antibiotic treatment with an antibiotic treatment of chronic mastitis
A non-blinded, positively controlled trial was conducted to evaluate the efficacy of an alternative, non-antibiotic therapy with Pyrogenium® to reduce ineffective antibiotic usage in the treatment of non-severe clinical mastitis (CM) in cows with longer lasting udder diseases. The solely treatment with Pyrogenium® (6 times, at a 12 hourly interval and then 4 times in a 24-hour interval) were compared with the reference treatment of solely local antibiotic therapy. The matched field study was conducted on five free-stall dairy farms located in Northern Germany. Cases of mild-to-moderate CM in cows with longer lasting high somatic cell counts in preceding dairy herd improvement test days and with previous CM cases in current lactation (chronic mastitis) were randomly allocated to one of the two treatment groups. A foremilk sample of the affected quarter was taken before treatment and again approximately 7 days, 14 days and 21 days after the end of therapy for cyto-bacteriological examination. Primary outcome was clinical cure (CC). Bacteriological cure (BC), quarter somatic cell count cure (CYC) and CM recurrence within 60 days after the end of treatment were chosen as secondary outcomes although low probabilities of bacteriological cure and quarter somatic cell count cure for selected cows were expected. The study resulted in the following findings: the pathogens mostly cultured from pretreatment samples were Staphylococcus aureus, followed by Streptococcus uberis. There were no significant differences between the test treatment (EG) in comparison with the reference treatment (CG) regarding all outcome variables (e.g. CC: EG 60.0%, CG 54.7%). Having regard to the selection criteria of cows in this study, the findings indicated that sole treatment with Pyrogenium® in non-severe CM cases may constitute an alternative therapy to reduce antibiotics.
Physico-chemical, microbiological, textural and sensory properties of dahi prepared from Vechur cow milk
Vechur cow is a rare breed of Bos indicus cattle of Kerala, India listed under the category of Critical Breeds in ‘The World Watch List of Domestic Animal Diversity’ published by Food and Agriculture Organisation of the United Nations (FAO).The present study reports the quality parameters of a product prepared from Vechur cows’ milk. Physico- chemical, microbiological, textural and sensory properties of dahi prepared from Vechur cow milk was assessed and compared with that of standard dahi prepared from cross-bred cow milk. Dahi prepared from Vechur cow milk exhibited significantly (p<0.01) lower syneresis, a* , b* values, cohesiveness, adhesiveness and higher hardness than the cross- bred cow milk dahi. Vechur cow milk dahi scored significantly higher values for the sensory attributes body and texture and color and appearance. However no significant differences were observed in terms of overall acceptability, flavor scores and microbiological parameters. This is one of the first reports elaborating the quality characteristics of a fermented product prepared from Vechur cow milk. The data generated is expected to contribute significantly to the currently available database on this subject matter. This study also opens up the possibilities of exploring fermentation as a highly economical and suitable process for value addition of Vechur cow milk which could effectively support the efforts towards the conservation of this rare indigenous cattle breed.
New infection rate of bovine mammary quarters after application of a bismuth subnitrate-free internal teat sealant at dry-off
Internal teat sealants (ITS) are applied to prevent new intrammary infection during the dry period in dairy cattle. The common ITS products with confirmed efficacy contain the heavy metal salt bismuth subnitrate. The aim of this field study was to determine the efficacy of a novel bismuth subnitrate-free ITS prototype (BSFITS) in reducing new infections in comparison to untreated quarters (control). Therefore 50 cows from two organic German farms were treated with the BSFITS in a split-udder design. Cows included in the trial were free of clinical mastitis in the previous lactation and had a somatic cell count < 200,000 cells/mL in the last three dairy herd improvement tests. Quarter milk samples were collected at dry-off, within 5 to 12 d in milk (DIM) and 7 d later. The new infection rate (NIR) did not differ between treated and untreated quarters (12.6%). The predominant new infection causing agents were coryneforms and coagulase-negative staphylococci. The probability of developing NI during the dry period was higher in quarters infected with minor pathogens at dry-off. Within the first 100 DIM no case of clinical mastitis was reported in treated and untreated quarters. The present study could not determine a positive effect of the BSFITS in reducing the NIR in comparison to untreated quarters. Future studies with novel ITS should be performed on farms with a high incidence of IMI caused by environmental pathogens and further research about the relationship of causing agents and the sealing effect is recommended.
Copyright (c) 2015 Milchwissenschaft - Milk Science International