Bulk Milk Research Articles

Evaluation of factors associated with bulk milk somatic cell count and total plate count in Indonesian smallholder dairy farms

Increasing milk quality in smallholder dairy farms will result in a greater quantity of milk being delivered to milk collection centers, an increased milk price for farmers and consequently an improved farmers’ livelihood. However, little research on milk quality has been performed on smallholder farms in Southeast Asia. The objective of this study was to identify risk factors associated with somatic cell count (SCC) and total plate count (TPC) in Indonesian smallholder dairy farms. One dairy cooperative in West Java, Indonesia was selected based on its willingness to participate. All 119 member farmers in the cooperative, clustered in six groups, were interviewed and a bulk milk sample from all farms was collected in April 2022. Risk factors associated with dairy farms’ SCC and TPC were investigated using multivariable population-averaged generalized estimating equations (GEE) models. The mean geometric SCC and TPC from these farms were 529,665 cells/mL of milk and 474,492 cfu/mL of milk, respectively. Five risk factors including manure removal frequency, receiving mastitis treatment training, washing the udder using soap, number of workers, and ownership of the pasture area were associated with SCC. Two risk factors, manure removal frequency and dairy income contribution, were associated with TPC. These findings can therefore be used as a starting point to improve udder health and milk quality in Indonesia and other countries where smallholder farmers play a significant role in milk production.

Seasonal dynamics of bulk milk somatic cell count in grazing Norwegian dairy goats

Somatic cell count (SCC) is a widely used indicator of milk quality in the dairy industry. It is a relatively good indicator of udder health in dairy cows, but strongly confounded by non-infection factors, including season, in dairy goats. This study's objectives were to estimate the variation in SCC explained by season and stage of lactation. We also investigated associations between SCC and other milk quality parameters routinely measured, including total bacterial count, fat, protein, and lactose content, in different seasons and stages of lactation. In this observational study, we included results from the routine analyses of bulk milk samples (n = 5,180) collected every third day in 88 Norwegian goat herds through one year. Herd information was collected via a questionnaire and from the dairy herd recording system. The herds had a notable increase in bulk SCC associated with the pasture season. The median bulk SCC was 470,000 cells/mL in deliveries from the indoor spring period and 1,100,000 cells/mL in the pasture season. During the indoor fall season, when most goat herds are in late lactation, the median SCC was 940,000 cells/mL. The combined effect of the season and herd stage of lactation explained 53.5% of the variation in bulk milk SCC. Fat and protein contents varied significantly with season and stage of lactation, and the association with SCC was non-significant for fat content and explained less than 3% of the variation in protein content. Lactose content was associated with SCC, stage of lactation, and season. Total bacterial count was associated with SCC and the indoor seasons. Determination of normal seasonal variation of goat bulk milk SCC is necessary to establish thresholds for defining milk as abnormal and unacceptable for further processing and improving the usefulness of SCC as a tool for milk quality improvement in dairy goats. The results suggest that SCC thresholds for taking action to improve the milk quality should be adjusted for season and stage of lactation.

Exploring the heights: Impact of altitude on dairy milk composition

The aim of the present study was to assess the impact of altitude on the quality of milk from dairy cows housed in small-scale farms in alpine areas. Therefore, a dataset comprising 5,680 bulk milk samples from 32 farms located at different geographical altitudes was considered. Milk traits such as fat, protein, lactose, free fatty acids, casein, milk urea nitrogen content, pH value, and somatic cell score were examined in the laboratories of the South Tyrolean Dairy Association using mid-infrared spectroscopy. The data were analyzed using a statistical model that considered altitude category, grazing practice, housing system, and season of milk analysis as fixed effects. The findings revealed a positive association between altitude and milk fat, free fatty acids, and somatic cell count. Conversely, lactose content, milk urea nitrogen, and pH value in milk from cows kept on farms at higher altitude (>1,200 m above sea level) showed a negative relationship with altitude. Farms located at altitudes above 1,200 m exhibited higher fat, protein, urea, and somatic cell content than farms located at lower levels. The results provide new insights into a production effect that has so far received little attention and should be considered in farm management (e.g., feeding management, breed decision) to ensure animal health and the associated animal welfare as well as the productivity of dairy cows reared in traditional small-scale mountain dairy farms.

The effects of dietary iodine content, milking system, and farming practices on milk iodine concentration and quality traits

Various management practices can influence milk quality traits in dairy cattle. As an example, an increasing investment in automatic milking system to substitute milking parlors has been observed in the last 2 decades in dairy farms which could have affected certain bulk milk quality traits. What is more, milking practices can also affect certain milk parameters; as an example, teat disinfectants containing I are used in commercial farms where pre- or postdipping is performed, leading to presence of some I in the bulk milk. However, this trace mineral is also supplied in cows' diet to fulfill their nutritional requirements, partly contributing to the milk I final concentration. Therefore, the aim of this study was to evaluate the sources of variation of milk I along with other traditional milk quality traits. A total of 91 dairy farms in northeastern Italy were enrolled in the study. In each farm, diet and bulk milk samples were collected on the same day for chemical analysis. Concentration of I, in particular, was determined in both milk and feed with gold standard. Pearson correlations were calculated among the traits available for milk and diet, and a general linear model was used to test significance of fixed effects (feeding system, milking system, farming system, herd size, herd stage of lactation, and sampling month) on milk quality traits including the I concentration. In the case of milk I, diet I and presence of I-based predipping and postdipping teat disinfect application were also tested as fixed effects. Results showed a positive linear correlation between milk and diet I content (correlation coefficient [r] = 0.78). Although milk I was also positively correlated with lactose content (r = 0.25), dietary I was not correlated with other milk traits. Milk I content was significantly affected by dietary I, I-based predipping teat disinfectant application, and herd composition. Compared with conventional farms, organic farms showed lower protein content and greater somatic cell score (SCS) but similar milk I. Milking system significantly affected only lactose content and SCS of milk. Sampling month was only significant for milk urea nitrogen and herd composition, feeding system, herd size, and herd average days in milk did not modify milk gross composition and SCS. In conclusion, dietary supply of I is the main factor affecting milk I concentration and findings suggest that I level in milk can be naturally improved in dairy cows by modulating the I content in the diet administered. However, further research is needed to evaluate the effect of I-based sanitizers on milk I.

Infectious Bovine Rhinotracheitis Post-Eradication Program in the Autonomous Province of Bolzano, Italy: A Retrospective Study on Potential Bovine Herpesvirus Type 2 Cross-Reactivity.

Bovine alphaherpesviruses, BoAHV, can cause respiratory, genital and neurological disorders. In particular, bovine alphaherpesvirus type 1 (BoAHV1) is one of the most significant ruminant pathogens worldwide and it can heavily damage the livestock industry. BoAHV1 can cause infectious bovine rhinotracheitis (IBR) along with fertility disorders. Bovine alphaherpesvirus type 2 (BoAHV2) can cause two different conditions as well: pseudo-lumpy skin disease (PSLD) and bovine herpetic mammillitis (BHM). The autonomous province of Bolzano (Italy) has adopted several strategies to control and eradicate IBR, and it was declared in 2000 to be IBR-free by the European Commission. Since 2001, a post-eradication monitoring program has overseen the serological analysis of bulk milk and, in the presence of a positive result, a follow-up examination is performed on the individual blood serum of all bovines older than 24 months that belong to bulk milk-positive herds. Despite the detection of positives in both bulk milk and serum samples, South Tyrol has been declared IBR-free, as these positives have never been confirmed through seroneutralization. Between 2014 and 2022, approximately 41,000 bulk milk (averaging 4300 samples/year) and 3229 serum samples were tested for BoAHV1. The aim of this study was to evaluate the post-eradication program for IBR with a particular focus on the potential cross-reactivity with BoAHV2; for this reason, serum samples were also tested for BoAHV2 antibodies. This study could be of great importance for those countries that submit herds to an IBR monitoring and eradication program; performing further analyses to confirm and explain false positive outcomes would increase the reliability of the obtained results.

Use of Cyanobacterium Spirulina (Arthrospira platensis) in Buffalo Feeding: Effect on Mozzarella Cheese Quality.

The high demand for PDO buffalo mozzarella cheese is leading to the use of new strategies for feeding supplementation. Spirulina is acknowledged as a valuable source of protein with antioxidant and immune-modulatory effects in humans and animals. This investigation aimed to examine the effect of Spirulina integration in buffalo diets on mozzarella cheese quality, sensory profile, consumer acceptability, and willingness to pay (WTP). The trial was carried out on two groups of 12 buffaloes that differed in Spirulina integration: 50 g/head/d before calving (1 month) and 100 g/head/d after calving (2 months). Both the bulk milk and mozzarella cheese samples from the two groups did not differ in chemical composition. However, Spirulina inclusion influenced the sensory quality of mozzarella cheese, which resulted it being externally brighter, with a higher butter odour and whey flavour and greater sweetness, bitterness, juiciness, tenderness, oiliness, and buttermilk release than the control. The consumer test showed that information about Spirulina affected consumer liking, causing them to be in favour of the Spirulina group, leading to a higher price for it. In conclusion, Spirulina inclusion in buffalo diets affected the sensory quality of mozzarella cheese. The provision of product information to consumers can be a crucial factor in determining their liking and WTP.

Grazing management practices on Waikato and Canterbury dairy farms diverging in bulk milk urea content

New Zealand dairy farmers have little realtime information on surplus nitrogen (N) in their herd’s diet to help manage farm-scale N loss. By understanding the influence of management on bulk milk urea (BMU), farmers could potentially use milk components to identify changes in dietary N surplus. Our study examined the relationships between grazing management and BMU concentration on 38 dairy farms selected for low or high BMU in Canterbury and Waikato. Measurements included pre- and post-grazing herbage mass, perennial ryegrass leaf stage at grazing, and botanical and chemical composition (crude protein (CP) and metabolisable energy (ME) content) of herbage on four occasions over a year. Herds with Low BMU tended to graze pastures with a greater pre-grazing herbage mass (+153 kg DM/ha), a more advanced leaf stage (+0.13 number of leaves), and longer grazing intervals (+11 days). Consistent with this, herbage on Low BMU farms had lower CP (-2.7%) compared with High BMU farms. We identified grazing management differences between Low and High BMU groups, which could be linked to reductions in N surplus in the herd’s diet through the lower CP% of pasture offered. Future work should determine the importance of this in relation to other farm management factors such assupplement and N fertiliser use.

Cladodes of Opuntia ficus-indica (L.) as a source of bioactive compounds in dairy products

Recently, the interest in improving livestock product nutraceutical profiles through sustainable feeding systems has increased. In this context, the overall quality and nutraceutical profiles were examined in dairy products obtained from 16 lactating Cinisara cows given an integrated feed in dry season with Opuntia ficus-indica cladodes. Two homogeneous groups of cows (milk yield: 6.3 ± 1.5 kg; body weight: 213 ± 55 kg) were fed with 2 different diets (CON: pasture and wheat bran; OFI: pasture, wheat bran, and cladodes), according to a 2 × 2 Latin square design. The bulk milk produced during the study was used to make Caciotta cheese and was analyzed at 0, 15, and 30 storage days. Milk and cheese samples were analyzed for chemical, physical, and microbiological traits. The nutraceutical and sensorial profiles, as well as the antioxidant capacity, were also determined in the final products. For milk, the urea content in individual samples was reduced in OFI but not in CON. In the cheese, integration of cladodes did not influence the starter cultures development with 2 strains of Streptococcus thermophilus, but it caused a higher content of polyphenols and a consequent greater antioxidant capacity and a change in the fatty acids profile. In particular, the caprylic, capric, lauric, myristic, and palmitic fatty acids were higher, as were the petroselinic, vaccenic, rumenic, and α-linolenic fatty acids. In contrast, the oleic and the γ-linolenic fatty acids were lower for OFI. The cheese from the OFI group showed better overall acceptability, and a higher yellow color, odor intensity, and butter flavor. The multivariate analysis well distinguished the cheeses belonging to the 2 groups. Further investigations should be conducted to formulate well-balanced diets that include cladodes for Cinisara lactating cows, but also to determine the content of other important bioactive compounds in fresh and treated cladodes, as well as their effects on animal welfare and production.

Computational quality-by-design strategy to validate high-performance liquid chromatography method for the estimation of meloxicam in bulk dosage forms and milk samples.

Bovine clinical mastitis has significant repercussions for farmers across the globe. Meloxicam, a COX-2 inhibitor, attenuates mastitis symptoms and is also approved for veterinary use. An RP-HPLC (Reverse Phase-High Performance Liquid Chromatography) method development and validation is essential in the pharmaceutical industry to assess API (Active Pharmaceutical Ingredient) quantity present in the pharmaceutical dosage forms. RP-HPLC method of meloxicam was developed and optimized with the aid of QbD (Quality by Design) using Box-Behnken design (BBD). The pH of the aqueous mobile phase, acetonitrile (ACN) percentage, and column temperature were chosen as influence variables, and retention time (RT) and tailing factor (Tf) were selected as response variables. The optimum experimental conditions were selected as pH ~ 3 of the aqueous mobile phase, 65% v/v ACN, and 30˚C as column temperature. The drug was eluted at 6.02min RT with 1.18 as Tf. The method was subjected to validation for accuracy, linearity, precision, range, sensitivity, and robustness and was found to comply with ICH Q2 (R1) guidelines. The in vitro bioequivalent studies were performed in hydrochloric acid, pH ~ 1.2; acetate buffer, pH ~ 4.5; and phosphate buffer, pH ~ 6.8 for two veterinary brands of meloxicam tablets, and their release profiles were compared by mathematical models. Both the brands, brand 1 and 2 exhibited significant (Unpaired t-test, P < 0.05) differences in dissolution efficiency (DE) and mean dissolution time (MDT) except DE at pH 1.2. However, brands 1 and 2 showed similarity (f2 > 50) in terms of release of meloxicam except at pH 6.8 (f2 = 47.01). The in vitro release of meloxicam followed Peppas kinetics except for brand 2 at pH 6.8, where it followed the Higuchi model. Moreover, the recovery of meloxicam extracted with ACN in the milk sample was estimated to be 99.67 ± 0.58% significantly (Unpaired t-test, P < 0.05) higher than 90.34 ± 6.77% extracted with methanol. In conclusion, the optimized and validated RP-HPLC method of meloxicam may further be used for the analysis of drug content in pharmaceutical dosage forms in addition to biological fluids.

Effect of bovine subclinical mastitis on milk production and economic performance of Brazilian dairy farms

This review summarized the significant results from Brazilian studies published in peer-reviewed scientific papers about the effect of bovine subclinical mastitis (SM) on economic performance and milk production. Different approaches were considered for (i) disease detection (indirect measurement of somatic cell count (SCC) and directly using microbiological culture) and (ii) milk sampling strategy (mammary quarters, composite cow samples, and bulk milk tank). Globally, bovine mastitis is the most common disease of dairy herds, and the subclinical presentation is the most frequent. Dairy farmers usually underestimate the economic losses associated with SM because no visual changes in milk and quarters, udder, and systemic symptoms are observed. SM reduces milk yield and quality, reducing dairy herds’ profitability. The estimation of losses depends on the causative pathogen, the lactation stage, and the parity of affected cows. Thus, estimating the economic caused by SM in milk production and economic performance in dairy herds can be used to decide which mastitis control strategies to adopt. Mastitis control involves adopting specific measures associated with the characteristics of each herd, the period of the highest frequency of cases, the transmission form, and the profile of the pathogens involved in cases of intramammary infection. Thus, using individual SCC, the microbiological identification of pathogens causing SM, adopting efficient drying-off protocols, and other management practices are essential for mastitis control, improved milk quality, and greater profitability of dairy herds.

The use of milk Fourier-transform infrared spectra for predicting cheesemaking traits in Grana Padano Protected Designation of Origin cheese

The prediction of the cheese yield (%CY) traits for curd, solids, and retained water and the amount of fat, protein, solids, and energy recovered from the milk into the curd (%REC) by Bayesian models, using Fourier-transform infrared spectroscopy (FTIR), can be of significant economic interest to the dairy industry and can contribute to the improvement of the cheese process efficiency. The yields give a quantitative measure of the ratio between weights of the input and output of the process, whereas the nutrient recovery allows to assess the quantitative transfer of a component from milk to cheese (expressed in % of the initial weight). The aims of this study were: (1) to investigate the feasibility of using bulk milk spectra to predict %CY and %REC traits, and (2) to quantify the effect of the dairy industry and the contribution of single-spectrum wavelengths on the prediction accuracy of these traits using vat milk samples destined to the production of Grana Padano Protected Designation of Origin cheese. Information from 72 cheesemaking days (in total, 216 vats) from 3 dairy industries were collected. For each vat, the milk was weighed and analyzed for composition (total solids [TS], lactose, protein, and fat). After 48 h from cheesemaking, each cheese was weighed, and the resulting whey was sampled for composition as well (TS, lactose, protein, and fat). Two spectra from each milk sample were collected in the range between 5,011 and 925 cm-1 and averaged before the data analysis. The calibration models were developed via a Bayesian approach by using the BGLR (Bayesian Generalized Linear Regression) package of R software. The performance of the models was assessed by the coefficient of determination (R2VAL) and the root mean squared error (RMSEVAL) of validation. Random cross-validation (CVL) was applied [80% calibration and 20% validation set] with 10 replicates. Then, a stratified cross-validation (SCV) was performed to assess the effect of the dairy industry on prediction accuracy. The study was repeated using a selection of informative wavelengths to assess the necessity of using whole spectra to optimize prediction accuracy. Results showed the feasibility of using FTIR spectra and Bayesian models to predict cheesemaking traits. The R2VAL values obtained with the CVL procedure were promising in particular for the %CY and %REC for protein, ranging from 0.44 to 0.66 with very low RMSEVAL (from 0.16 to 0.53). Prediction accuracy obtained with the SCV was strongly influenced by the dairy factory industry. The general low values gained with the SCV do not permit a practical application of this approach, but they highlight the importance of building calibration models with a dataset covering the largest possible sample variability. This study also demonstrated that the use of the full FTIR spectra may be redundant for the prediction of the cheesemaking traits and that a specific selection of the most informative wavelengths led to improved prediction accuracy. This could lead to the development of dedicated spectrometers using selected wavelengths with built-in calibrations for the online prediction of these innovative traits.

Associations between the Bacterial Composition of Farm Bulk Milk and the Microbiota in the Resulting Swedish Long-Ripened Cheese.

The maturation of a traditional Swedish long-ripened cheese has shown increasing variation in recent years and the ripening time is now generally longer than in the past. While the cheese is reliant on non-starter lactic acid bacteria for the development of its characteristic flavour, we hypothesised that the observed changes could be due to variations in the microbiota composition and number of bacteria in the raw milk used for production of the cheese. To evaluate associations between microbiota in the raw milk and the resulting cheese, three clusters of commercial farms were created to increase variation in the microbiota of dairy silo milk used for cheese production. Cheese production was performed in three periods over one year. Within each period, milk from the three farm clusters was collected separately and transported to the cheese production facility. Following pasteurisation, the milk was processed into the granular-eyed cheese and matured at a dedicated cheese-ripening facility. For each cheese batch, farm bulk and dairy silo milk samples, a starter culture, early process samples and cheese samples from different stages of maturation (7-20 months) were collected and their microbiota characterised using 16S rRNA amplicon sequencing. The microbiota in the farm bulk milk differed significantly between periods and clusters. Differences in microbiota in dairy silo milk were observed between periods, but not between farm clusters, while the cheese microbiota differed between periods and clusters. The top 13 amplicon sequence variants were dominant in early process samples and the resulting cheese, making up at least 93.3% of the relative abundance (RA). Lactococcus was the dominant genus in the early process samples and, together with Leuconostoc, also dominated in the cheese samples. Contradicting expectations, the RA of the aroma-producing genus Lactobacillus was low in cheese during ripening and there was an unexpected dominance of starter lactic acid bacteria even at the later stages of cheese ripening. To identify factors behind the recent variations in ripening time of this cheese, future studies should address the effects of process variables and the dairy environment.

Milk as diagnostic fluid for udder health management.

Mastitis is the major disease affecting milk production of dairy cattle, and milk is an obvious substrate for the detection of both the inflammation and its causative infectious agents at quarter, cow, or herd levels. In this review, we examine the use of milk to detect inflammation based on somatic cell count (SCC) and other biomarkers, and for the detection of mastitis pathogens through culture-based and culture-free methods. The use of SCC at a cow or bulk milk level to guide udder health management in lactation is well-established, and SCC is increasingly used to guide selective dry cow treatment. Other markers of inflammation include electrical conductivity, which is used commercially, and markers of disease severity such as acute phase proteins but are not pathogen-specific. Some pathogen-specific markers based on humoral immune responses are available, but their value in udder health management is largely untested. Commercial pathogen detection is based on culture or polymerase chain reaction, with other tests, for example, loop-mediated isothermal amplification or 16S microbiome analysis still at the research or development stage. Matrix-assisted laser desorption ionisation time of flight (MALDI-ToF) is increasingly used for the identification of cultured organisms whilst application directly to milk needs further development. Details of test sensitivity, specificity, and use of the various technologies may differ between quarter, cow, and bulk milk applications. There is a growing array of diagnostic assays that can be used to detect markers of inflammation or infection in milk. The value of some of these methods in on-farm udder health improvement programs is yet to be demonstrated whilst methods with proven value may be underutilised.

Virulence Potential, Biofilm Formation, and Disinfectants Control of Escherichia coli from Raw Milk Bulk Tanks in the Southeast of Brazil

Escherichia coli is a major player in foodborne illnesses, capable of forming biofilms on dairy facilities, leading to milk contamination. Thus, we examined the capacity of E. coli strains from raw milk bulk tanks to form biofilms on surfaces made of polystyrene, stainless steel, and silicone; the potential links between biofilm formation with genes responsible for fimbriae and virulence factors of extra-intestinal E. coli (ExPEC); and the susceptibility of biofilm-forming isolates to iodine and chlorhexidine digluconate. Out of 149 E. coli strains, 42.28% (63/149) formed biofilm on polystyrene, 56.38% (84/149) on silicone, and 21.48% (32/149) on stainless steel. The frequency of genes was: fimH (100%), hlyA (5.4%), irp2 (2.7%), sitA (10.7%), ompT (43.6%), and traT (98%). No biofilm developed when disinfectants were used prior to biofilm formation. However, iodine and chlorhexidine digluconate allowed 25.40% (16/63) of isolates displaying growth after a mature biofilm was formed. The presence of biofilm on different surfaces emphasizes the vital need for thorough equipment cleaning, both in farms and in industrial dairy settings. Rapid disinfection is crucial, given the reduced susceptibility of potentially pathogenic E. coli after biofilm maturity.

Antioxidant Potential of Yogurts Produced from Milk of Cows Fed Fodder Supplemented with Herbal Mixture with Regard to Refrigerated Storage

The aim of the study was to assess the potential of milk from herbal blend-fed cows to be used for the production of yogurts exhibiting increased antioxidant potential with regard to the duration of refrigerated storage of the products. Bulk milk (control—CM and experimental—EM) intended for the production of yogurts was provided by a dairy cattle breeding farm. The milk samples were analyzed to determine their basic chemical composition (the content of dry matter, fat, and total protein including casein), hygienic status (somatic cell count (SCC) and total microbial count (TMC)), and antioxidant activity (FRAP, DPPH, and ABTS assays). Pasteurized milk was used to manufacture natural yogurts with the use of starter cultures YC-X11 (Chr. Hansen, Hørsholm, Denmark). Changes in physicochemical traits (acidity, nutritional value, and water activity) and antioxidant activity (FRAP, DPPH, and ABTS assays) occurring during 21-day refrigerated storage of the yogurts were determined. The analyses revealed that the yogurts had higher antioxidant potential than the milk, irrespective of the determination method. Additionally, the experimental yogurts produced from milk obtained from the cows fed fodder supplemented with an herbal mixture exhibited significantly higher antioxidant activity than the control yogurts. The antioxidant potential of the yogurts changed during the refrigerated storage. It should be emphasized that their antioxidant activity significantly increased during the first two weeks (until day 14) but decreased by 15–20% in the following week.

Explaining farmers’ adoption of mastitis control practices using psychological constructs from the theory of planned behavior

Mastitis control options (MCOs) are management actions that are adopted to prevent mastitis in dairy herds. In this study, the psychological constructs attitude, subjective norms and perceived behavioral control are used to explain farmers’ adoption of MCOs. So far, little research has used psychological constructs to explain adoption of MCOs. Based on recommendations by a Swedish dairy association (Växa) aimed at farmers, a total of 15 different management areas, representing MCOs for contagious and environmental bacteria, were used to characterize adoption behaviors. A total of 286 Swedish full-time farmers specializing in dairy production participated in the survey. Four different farmer groups were identified through a cluster analysis of similarities in how farmers adopted MCOs together with data on bulk milk somatic cell count and subjectively evaluated somatic cell counts on the farms. Regression analyses were performed to test whether the psychological constructs could explain differences in adoption across the MCO groups. Results revealed that farmers’ decisions about which set of mastitis control options to adopt as preventive actions were explained by the farmers’ perceived behavioral control of the situation and by differences in subjective norm. The attitude construct did not contribute to predicting the adoption of mastitis control options. Results suggest that work aimed at implementing MCOs should be complemented by programs specifically designed to improve the ability of farmers to use and/or combine MCOs to both alleviate and prevent mastitis. They also suggest that there is little to gain from programs aimed at fostering attitudes to prevent mastitis. We interpret the findings as indicating a need to strengthen perceived behavioral control as well as subjective norms among Swedish farmers’ regarding their preventive work with mastitis. Understanding how to affect farmers’ behavior, and thus reducing and controlling mastitis, will have positive effects on animal health and welfare in general.

Chlorinated water as a source of chlorate contamination in farm bulk milk

The potential for chlorinated water to cause chlorate contamination of milk was evaluated at both laboratory and field level. It was found that for such contamination to occur, direct contact of water and milk was necessary. To minimise the opportunity for chlorinated water to cause chlorate contamination of milk, it is vital to ensure that milk handling equipment is engineered to provide for proper drainage of water and that all necessary steps are taken to prevent the adulteration of milk with water.

An In-House ELISA for Treponema Antibodies in Bulk Milk as Part of a Monitoring Tool for Claw Health in Dairy Herds.

Digital dermatitis (DD) is a painful inflammation at the coronary band of the claws, a major cause of lameness in cattle and associated with infections with several Treponema spp. Clinical inspection of the feet is the best way to diagnose DD, but this is laborious and stressful for cattle. A simple diagnostic tool was developed to monitor DD prevalence at the herd level. An antibody ELISA based on antigens from four different Treponema spp. has been developed and validated in two field studies. In one study, bulk milk and individual milk samples of seven dairy herds, of which clinical claw scores were obtained, were tested. In the second study, bulk milk was tested from 110 herds of which clinical scores were obtained. A weak correlation between clinical scores of cows and the ELISA results in individual milk samples was observed. The ELISA response in bulk milk was higher in herds with higher mean clinical scores. Using the ELISA results in bulk milk, herds with a low or high proportion of cattle with DD lesions could be distinguished. This ELISA is useful to obtain insight into the DD status at the herd level, and is nowadays being used in a claw health monitoring program for dairy cattle in the Netherlands.

Milk volatilome as affected by somatic cell count in Holstein cows

The aim of the current trial was to study the impact of a high somatic cell count (SCC) on milk volatilome of fresh raw milk, and its evolution during storage of processed fluid milk. Six Holstein cows were selected from our research dairy herd based on test-day SCC records. Three cows were used to produce low-SCC milk (20 × 103 cells/mL). The three other cows had one-quarter infected by Staphylococcus aureus. Infected and healthy udder halves were milked separately, and high-SCC milk was standardized to 400 × 103 cells/mL by mixing these two milks. The profile of milk volatile organic compounds (VOCs) was determined on raw milk and during the storage of processed milk. The processing included a standardization to 3.25% fat, followed by homogenization, and thermization (65 °C/30 min). This procedure was repeated four times over a period of 7 days. A total of 40 VOC were identified using the solid-phase microextraction technique followed by gas chromatography separation, mass spectrometry analysis, and database search. These VOC were grouped into seven different families, including alcohols (n = 4), free fatty acids (n = 5), sulfur compounds (n = 3), esters (n = 7), ketones (n = 7), aldehydes (n = 12), and aromatic hydrocarbons (n = 2). In raw milk, high SCC was associated with a tendency for lower concentrations of ethyl-hexanoate (P = 0.07), acetone (P = 0.06), and benzaldehyde (P = 0.07) and lower concentrations of trans-2 hexenal (P = 0.04). On the contrary, high SCC was associated with a tendency for greater concentrations of acetic acid (P = 0.09) and hexanoic acid (P = 0.07) and greater concentrations of 2-nonanone (P = 0.02) and pentanal (P = 0.01). Concentrations of most VOC increased during the storage of processed milk. Lower concentrations of butanoic acid (P = 0.09; tendency) and ethyl hexanoate (P = 0.04), and greater concentration of 1-ocen-3-ol (P < 0.01) were observed in high-SCC milk at all times of storage evaluated. Increases in concentrations over time were less pronounced for ethanol (P < 0.01), ethyl butanoate (P = 0.05), and propanal (P = 0.10) in high SCC as compared with low SCC milk. In conclusion, an increase in SCC has a limited effect on milk volatilome, when a SCC standard of 400 × 103 cells/mL for bulk milk is respected.

Relationships between chemical and physical parameters of bulk milk from Valle del Belice sheep

In this study, we aimed to evaluate the relationships between the constituents of bulk milk of Valle del Belice sheep. During two years of investigation, 693 milk samples were collected and analysed to assess the major physicochemical parameters. Comparative analysis of partial and simple correlations revealed a strong correlation between milk constituents without the effect of third-party parameters.