Teat Skin Research Articles

The effect of early colonized gut microbiota on the growth performance of suckling lambs.

The early colonized gut microbiota during the newborn period has been reported to play important roles in the health and immunity of animals; however, whether they can affect the growth performance of suckling lambs is still unclear. In this study, a total of 84 newborn lambs were assigned into LF-1 (top 15%), LF-2 (medium 70%), and LF-3 (bottom 15%) groups according to their average body weight gain at 30 days of age. Fecal samples of lambs (LF) as well as feces (MF), vagina (VAG), colostrum (COL), teat skin (TEAT) samples of ewes, and the air sediment (AIR) in the delivery room were collected 72 h after birth, and then the 16S rRNA gene was sequenced on the Illumina MiSeq platform. The results showed that the early colonized gut microbiota had a significant effect on the growth performance of suckling lambs with alpha and beta diversity (p < 0.05), and we observed that the contribution of early colonized bacteria on the growth performance of lambs increased with age (from BW30 at 25.35% to BW45 at 31.10%; from ADG30 at 33.02% to ADG45 at 39.79% by measuring the relative effects of factors that influence growth performance). The early colonized gut microbiota of suckling lambs with high growth performance was similar to that in VAG, MF, and AIR (p < 0.05). With the RandomForest machine learning algorithm, we detected 11, 11, 6, and 4 bacterial taxa at the genus level that were associated with BW30, BW45, ADG30, and ADG45 of suckling lambs, respectively, and the correlation analysis showed that Butyricicoccus, Ruminococcus_gnavus_group, Ruminococcaceae_Other, and Fusobacterium could significantly affect the growth performance (BW30, BW45, ADG30, and ADG45) of suckling lambs (p < 0.05). In conclusion, the early colonized gut microbiota could significantly affect the growth performance of suckling lambs, and targeting the early colonized gut microbiota might be an alternative strategy to improve the growth performance of suckling lambs.

Short-milking-tube thermograms: An alternative to udder thermograms for mastitis detection in Sahiwal cows

Mastitis is a multi-etiological production disease that causes substantial financial loss to dairy farmers. In this context, early detection of mastitis using thermograms can aid the dairy sector in managing mastitis efficiently, and this technology could be a supportive tool in precision dairy farming. Infrared cameras can detect minor temperature changes on the udder surface by taking multiple images of the udder and teat. In the current study, a thermogram of the short milking tube (SMT) of the milking machine, as well as the udder and teat of lactating Sahiwal cow (n = 100 quarters of 25 Sahiwal cows), was captured using a hand-held digital infrared thermal camera (DarviDTL007) during morning milking to assess the mastitis status. CMT and SCC of milk samples were carried out for further confirmatory diagnosis of healthy, sub-clinical (SCM), and clinical mastitis (CM). Cut-offs for short milking tube temperature were developed using the receiver operating characteristics analysis. Results of thermal image analysis revealed that the pre-milking, milking, and post-milking parameters of the udder and the teat skin surface temperatures showed a significant difference in the healthy, SCM, and CM-affected quarters. The thermogram analysis showed a significant increase (p < 0.05) of 1.11 and 2.04°C in the mean values of SMT surface temperature among SCM and CM quarters compared to healthy quarters, respectively. In addition, the values of CMT and SCC revealed a significant increase (p < 0.05) in SCM and CM samples and a positive correlation to SMT surface temperatures. Short milking tube thermograms can be a useful assessment tool for detecting sub-clinical mastitis in dairy animals.

Antibacterial efficacy of essential oil spray formulation for post-milking disinfection in dairy cows.

Mastitis is an essential issue in dairy cows. Post-milking teat dips can help reduce this problem, but they employ harsh disinfectants, and many bacteria are becoming increasingly tolerant. This study aimed to investigate the antibacterial activity of clove, citronella, and sweet basil essential oils against the common bovine mastitis causative agents Staphylococcus aureus, Streptococcus agalactiae, and Escherichia coli and to develop an antiseptic post-milking teat spray for use in dairy cows. The in vitro antimicrobial activity of the essential oils was determined by broth microdilution and time-kill assays. Essential oil-based post-milking teat sprays were developed. The bacterial eradication efficacy of the formulations was determined by time-kill assays and their stability was tested by repeated freeze-thaw cycles. The most effective formulation was tested in dairy cows. The minimum inhibitory concentrations and minimum bactericidal concentrations of the tested essential oils against S. aureus, S. agalactiae, and E. coli were in the range of 0.78-6.25 μL/mL. The time-kill tests indicated that the essential oils' antibacterial activity depended on concentration and contact time. All three essential oil-based post-milking teat spray preparations showed good stability. The citronella spray formulation showed the highest antibacterial potency. In in vivo testing, the citronella spray eradicated aerobic bacteria on the teat skin of cows (99.9% or 3-log10 reduction) within 1 min, which was non-inferior to a standard 0.54% iodine solution teat dip. Clove, citronella, and sweet basil essential oils were effective against S. aureus, S. agalactiae, and E. coli in vitro. Of these, citronella essential oil is the most promising to be developed as a post-milking teat spray with high antibacterial activity and excellent bacterial eradication properties in vivo.

Transmission of fungi and protozoa under grazing conditions from lactating yaks to sucking yak calves in early life

Microbiota from mothers is an essential source of microbes in early-life rumen microbiota, but the contribution of microbiota from different maternal sites to the rumen microbiota establishment in neonates needs more data. To fill this gap, we collected samples from the mouth, teat skin, and rumen of lactating yaks and from the rumen of sucking calves concomitantly on seven occasions between days 7 and 180 after birth under grazing conditions. We observed that the eukaryotic communities clustered based on sample sites, except for the protozoal community in the teat skin, with negative correlations between fungal and protozoal diversities in the rumen of calves. Furthermore, fungi in the dam’s mouth, which is the greatest source of the calf’s rumen fungi, accounted for only 0.1%, and the contribution of the dam’s rumen to the calf’s rumen fungi decreased with age and even disappeared after day 60. In contrast, the average contribution of the dam’s rumen protozoa to the calf’s rumen protozoa was 3.7%, and the contributions from the dam’s teat skin (from 0.7 to 2.7%) and mouth (from 0.4 to 3.3%) increased with age. Thus, the divergence in dam-to-calf transmissibility between fungi and protozoa indicates that the foundation of these eukaryotic communities is shaped by different rules. This study provides the first measurements of the maternal contribution to the fungal and protozoal establishment in the rumen of sucking and grazing yak calves in early life, which could be beneficial for future microbiota manipulation in neonatal ruminants.Key points• Dam to calf transfer of rumen eukaryotes occurs from multiple body sites.• A minor proportion of rumen fungi in calves originated from maternal sites.• The inter-generation transmission between rumen fungi and protozoa differs.

Comparison of the effectiveness of the means “Oxy Foam” and “Pre-Dip” in reducing the causative agents of mastitis on the skin of cows' teats

Although teat disinfection before milking has advantages, some producers believe the use of disinfectants to be unprofitable compared to qualitative teat processing using warm water with skin drying using paper towels. The aim of the work was to compare the effect of pre-milking treatment of cows' udders with Oxy Foam and Pre-Dip on the reduction of mastitis pathogens on the skin of teats cows on large dairy farms. The study was conducted in the winter-spring period on two dairy plants with a stable-free range cow breeding system. In the first group of animals: the right anterior and the right posterior teats of the udder were processed using disinfectant Oxy Foam and the left anterior and the left posterior teats were washed using warm water (control). Pre-milking treatment of the studied teats using disinfectant included foam application, keeping it for 30 seconds, and further wiping dry using disposable paper towels. In the second group of animals: the right teats were treated with Pre-Dip with the help of a cup by immersion with a subsequent exposure of 15 seconds. Swish from the skin of udder teats were taken using sterile tampons before the processing before milking and repeatedly after the end of the milking process. The ordinary treatment using warm water and drying using paper towels was found to reduce the number of microorganisms on the teat skin by 2.5 times (Р ≤ 0.001), while the use of disinfectant Oxy Foam – by 6.4 times (Р ≤ 0.001), and Pre-Dip – 4.8 times (Р ≤ 0.001). Herewith, treatment with water reduced the amount of hemolytic staphylococci on the teat skin – by 1.9 times (Р ≤ 0.01), disinfection using Oxy Foam – by 4.4 times (Р ≤ 0.001) to 13.2 ± 3.14 CFU/cm3 of the wash, and with Pre-Dip – 4 times (Р ≤ 0.001) to 14.6 ± 3.05 CFU/cm3 of wash. After using warm water, the number of pathogenic streptococcus reduced by 1.8 times (Р ≤ 0.01), and by 2.5 times (Р ≤ 0.001), when using Oxy Foam and Pre-Dip – 2.1 times (Р ≤ 0.001) to 7.5–8.9 CFU/cm3 of the wash. Microorganisms of Escherichia kind were well-removed with the use of ordinary -pre-milking treatment and were distinguished from the cow teat skin in single cases in the number of only a few cultures. Therefore, Oxy Foam based on hydrogen peroxide and lactic acid turned out to be a more effective means for treating the udder of cows before milking, compared to Pre-Dip with a content of 0.15 % of free iodine. Further research will be aimed at creating new domestic ecologically safe means for the pre-milking treatment of cow udders.

Teat open lesions can lead to challenges at milking time on dairies in the Northeast United States.

During evaluations of teat skin by the authors using National Mastitis Council procedures, teat open lesions (TOL) have been more commonly identified in dairies in the Northeast United States over the last 10 years. The TOL described here are found in all stages of lactation and in any age lactating cow, which is unique from TOL that present mainly in first lactation animals just after calving. Cows with these TOL exhibit more abnormal cow behaviors during the milking event. Based on the authors' subjective field evaluations, dry teat skin condition appears to be a significant risk factor. Although there is a paucity of published literature, the other risk factors that the authors have observed are exposure to wind and significant temperature fluctuations, wet bedding, certain bedding additives, and occasionally mechanical, chemical, or thermal trauma. Teat open lesions have been observed in herds with all the common types of bedding. Treatment and preventative measures have focused on supporting skin conditions through higher emollients in the postmilking teat disinfection (PMTD) and controlling the environmental conditions to which the teat is exposed. This includes an evaluation of cow positioning in the stall as well as bedding levels, which influence bedding contamination. The accuracy of PMTD application can also have an influence. The objective of this narrative review was to search the current literature describing TOL, identify knowledge gaps, describe the authors' field experience with TOL on dairy operations in the Northeast United States, and identify opportunities for future research.

Emergence of livestock-associated Mammaliicoccus sciuri ST71 co-harbouring mecA and mecC genes in Brazil

The discovery and tracking of antimicrobial resistance genes are essential for understanding the evolution of bacterial resistance and restraining its dispersion. Mammaliicoccus sciuri (formerly Staphylococcus sciuri) is the most probable evolutionary repository of the mecA gene, that later disseminated to S. aureus. In this study, we describe the first double mecA/mecC homologue-positive non-aureus staphylococci and mammaliicocci (NASM) from the American continent, also representing the first report of mecC-positive NASM in Brazil. Two clonally related methicillin-resistant M. sciuri strains co-carrying mecA and mecC genes were isolated from the teat skin swab and milk sample collected from an ewe’s left udder half. Both M. sciuri strains belonged to the sequence type (ST) 71. Besides mecA and mecC genes, the M. sciuri strains carried broad resistomes for clinically important antimicrobial agents, including β-lactams, tetracyclines, lincosamide, streptogramin, streptomycin, and aminoglycosides. Virulome analysis showed the presence of the clumping factor B (clfB), ATP-dependent protease ClpP (ClpP) and serine-aspartate repeat proteins (sdrC and sdrE) virulence-associated genes. Phylogenomic analysis revealed that these M. sciuri strains are part of a globally disseminated branch, associated with farm and companion animals and even with food. Our findings suggest that M. sciuri is likely to emerge as a pathogen of global interest, carrying a broad repertoire of antimicrobial resistance genes with a remarkable co-presence of mecA and mecC genes. Finally, we strongly encourage to monitor M. sciuri under the One Health umbrella since this bacterial species is spreading at the human-animal-environment interface.

Importance of Pre-Milking Udder Hygiene to Reduce Transfer of Clostridial Spores from Teat Skin to Raw Milk.

Butyric acid producing clostridia (BAPC) cause the so-called late-blowing defect, a serious quality problem in semi-hard and hard cheeses. Late-blown cheeses are characterized by undesired slits and cracks, irregular eyes, and off-flavors due to excessive amounts of gas and organic acids produced by clostridia. Clostridial transfer to raw milk can occur during milking through dirty teats. Therefore, teat cleaning before milking is a key factor in preventing clostridial contamination of the milk. However, different cleaning methods are used, and little information is available on the efficacy of routine teat cleaning in reducing clostridial endospores. The main objectives of this study were to assess the extent of udder contamination with BAPC spores and to investigate the efficacy of routine teat cleaning on BAPC spore counts in milk. In a longitudinal study, eight dairy farms were visited during five sampling events. Clostridial spore counts were quantified from teat skin before and after routine teat cleaning, in pooled quarter milk samples from individual cows, and in bulk tank milk samples using a most probable number method. In addition, farm management data were collected periodically through a survey, and average cow cleanliness was assessed by a veterinarian. On average, teat cleaning resulted in a 0.6 log unit reduction in BAPC spores on teat skin, and a strong positive correlation was found between BAPC spore concentrations on teat skin after cleaning and in pooled quarter milk samples. Seasonal variations and the potential influence of differences in farm management were also noted. Interestingly, average cow cleanliness correlated strongly with BAPC spore levels in milk, suggesting the potential for a quick and rough estimation method of clostridial contamination that could be implemented by farmers.

Intramammary infections and risk factors in freshly calved heifers in Swedish dairy herds

Subclinical mastitis can be common among freshly calved heifers (FCH), but the prevalence differs between herds, possibly due to variation in risk factors. The aims of this observational study were to identify differences in occurrence of intramammary infection (IMI) in FCH between herds with documented good or poorer first-parity udder health based on cow somatic cell count (CSCC) in early lactation, and to study herd differences in animal factors important for udder health, such as udder and hock skin lesions and animal cleanliness. Three groups of herds were included: those with high proportions of FCH with low CSCC (≤75,000 cells/mL) at the first 2 milk recordings after calving (LL), herds with high proportions of FCH with high CSCC (>100,000 cells/mL) at the first and low CSCC at the second recording (HL), and herds with high proportions of FCH with high CSCC at both recordings (HH). Thirty-nine herds (13 LL, 11 HL, 15 HH) were visited 3 times during a 12-mo period for observation of cleanliness and hock lesions, and sampling of udder and teat skin using swab cloths of milk-fed calves, early-pregnant heifers, and late-pregnant heifers. In 25 (9 LL, 9 HL, 7 HH) udder quarter samples from colostrum and milk on d 3 to 4 after calving were taken by the farmers from FCH during one year. The farmers also provided information on calving (individual or group), use of restraint and oxytocin at milking, and presence of teat and udder skin lesions. Bacterial growth in swab samples and quarter samples was investigated by culturing, and a selection of isolates was genotyped using whole-genome sequencing. Cleanliness, hock and udder skin lesions other than udder-thigh dermatitis, and growth of bacteria in swab samples did not differ between herd groups. It was more common that FCH from LL herds, compared with FCH in HH and HL herds, calved in a group of animals. Use of restraint at milking was more common in LL herds than in HH herds, whereas presence of udder-thigh dermatitis was lowest in LL herds. Specific infection was found in 14% of 5,593 quarter samples from 722 FCH. The most common IMI was Staphylococcus chromogenes. Growth of Staphylococcus simulans was more common in HH than in LL and HL herds. In colostrum samples, Staphylococcus haemolyticus was more common in HL and HH than in LL herds. The proportion of quarters with the same specific infection at both samplings was higher in HH than in LL herds and tended to be higher in HH than in HL herds. The proportion of quarters with Staph. chromogenes IMI at both samplings tended to differ between herd groups and was highest in HH herds. Whole-genome sequencing found the same sequence type of Staph. chromogenes and Staphylococcus aureus in both samples in almost all quarters with the same infection at both samplings. The differences in IMI between herd groups were in line with the higher somatic cell count in HH herds. The reasons for the predominance of Staph. chromogenes IMI in FCH need further studies.

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.

Dietary Live Yeast Supplementation Influence on Cow’s Milk, Teat and Bedding Microbiota in a Grass-Diet Dairy System

The supplementation of animal feed with microbial additives remains questioning for the traditional or quality label raw milk cheeses with regard to microbial transfer to milk. We evaluated the effect of dietary administration of live yeast on performance and microbiota of raw milk, teat skin, and bedding material of dairy cows. Two balanced groups of cows (21 primiparous 114 ± 24 DIM, 18 multiparous 115 ± 33 DIM) received either a concentrate supplemented with Saccharomyces cerevisiae CNCM I-1077 (1 × 1010 CFU/d) during four months (LY group) or no live yeast (C group). The microbiota in individual milk samples, teat skins, and bedding material were analysed using culture dependent techniques and high-throughput amplicon sequencing. The live yeast supplementation showed a numerical increase on body weight over the experiment and there was a tendency for higher milk yield for LY group. A sequence with 100% identity to that of the live yeast was sporadically found in fungal amplicon datasets of teat skin and bedding material but never detected in milk samples. The bedding material and teat skin from LY group presented a higher abundance of Pichia kudriavzevii reaching 53% (p < 0.05) and 10% (p < 0.05) respectively. A significant proportion of bacterial and fungal ASVs shared between the teat skin and the milk of the corresponding individual was highlighted.

Maternal rumen and milk microbiota shape the establishment of early-life rumen microbiota in grazing yak calves

Early-life gut microbial colonization and development exert a profound impact on the health and metabolism of the host throughout the life span. The transmission of microbes from the mother to the offspring affects the succession and establishment of the early-life rumen microbiome in newborns, but the contributions of different maternal sites to the rumen microbial establishment remain unclear. In the present study, samples from different dam sites (namely, oral, rumen fluid, milk, and teat skin) and rumen fluid of yak calves were collected at 6 time points between d 7 and 180 postpartum to determine the contributions of the different maternal sites to the establishment of the bacterial and archaeal communities in the rumen during early life. Our analysis demonstrated that the dam's microbial communities clustered according to the sites, and the calves' rumen microbiota resembled that of the dam consistently regardless of fluctuations at d 7 and 14. The dam's rumen microbiota was the major source of the calves' rumen bacteria (7.9%) and archaea (49.7%) compared with the other sites, whereas the potential sources of the calf rumen microbiota from other sites varied according to the age. The contribution of dam's rumen bacteria increased with age from 0.36% at d 7 to 14.8% at d 180, whereas the contribution of the milk microbiota showed the opposite trend, with its contribution reduced from 2.7% at d 7 to 0.2% at d 180. Maternal oral archaea were the main sources of the calves' rumen archaea at d 14 (50.4%), but maternal rumen archaea became the main source gradually and reached 66.2% at d 180. These findings demonstrated the potential microbial transfer from the dam to the offspring that could influence the rumen microbiota colonization and establishment in yak calves raised under grazing regimens, providing the basis for future microbiota manipulation strategies during their early life.

Characterization and spoilage potential of Bacillus cereus isolated from farm environment and raw milk.

Bacillus cereus sensu lato (B. cereus sl) is important spoilage bacteria causing milk structure and flavor changes and is ubiquitous in the environment. This study addresses the biodiversity, toxicity, and proteolytic activity of B. cereus sl from 82 environmental samples and 18 raw bovine milk samples from a dairy farm in the region of Tianjin. In sum, 47 B. cereus sl isolates were characterized through biochemical tests, 16S rRNA gene sequencing, and panC gene analysis. Fourteen sequence types (STs) of B. cereus sl were found in raw bovine milk samples, and five new STs (ST2749, ST2750, ST2751, ST2752, and ST2753) were identified in this study. ST1150 was the dominant ST, associated with fecal, air, drinking water, teat skin, teat cup, and teat dip cup. The results of toxin gene analyses showed that 12.77% and 8.51% of isolates carried hblACD and nheABC operons, respectively. In addition, the detection rate of emetic cesB gene was 21.28%. B. cereus sl demonstrated high spoilage potentials even at 7°C, which has the proteolytic activity of 14.32 ± 1.96 μmol of glycine equivalents per ml. Proteolytic activities were significantly (p < 0.05) decreased after the heat treatment. The residual activity of protease produced at 7°C was significantly higher than that produced at 25°C and 37°C after treatment at 121°C for 10 s and 135°C for 5 s (p < 0.01). Together, the results provide insights into the characteristics of B. cereus sl from farm environment and raw bovine milk and revealed that B. cereus sl contamination should also be monitored in raw milk for ultra-high temperature (UHT) products. This knowledge illustrates that strict cleaning management should be implemented to control B. cereus sl and assure high-quality milk products.

Evaluation of Usefulness of Infrared Thermography for the Detection of Mastitis Based on Teat Skin Surface Temperatures in Dairy Cows

Given the severe economic losses due to mastitis, the identification of a diagnostic tool that can rapidly screen cows suspected of mastitis immediately before milking would be especially advantageous for farmers owning a large number of dairy cows. It is important to detect mastitis at an early stage to ensure effective and successful prevention and management of intramammary infections. Therefore, this study evaluated utility of Infrared Thermography (IRT) as a diagnostic tool for mastitis based on the heat patterns of thermal images. We found that 49 (1–4 teats in 16 cows) of the 252 teats were suspected of mastitis and 203 teats appeared normal. Our results showed that cows suspected of mastitis presented teat skin surface temperature (TSST) values that were 5.05°C higher, on average, then those of healthy cows. Moreover, TSST values were well correlated with both high somatic cell count values (r=0.99; P&lt;0.001) and California mastitis test scores (r=0.59; P&lt;0.001), indicating that TSST temperature monitoring using IRT could represent an easy and reliable method for screening for mastitis in dairy cows breeding farms.

Immunolocalization of antibacterial peptide S100A7 in mastitis goat mammary gland and lipopolysaccharide induces the expression and secretion of S100A7 in goat mammary gland epithelial cells via TLR4/NFκB signal pathway

The antimicrobial peptide S100A7, with antimicrobial activities for a broad spectrum of bacteria, has attracted more and more attention for the prevention and treatment of mastitis. However, there is little information about the expression and regulation mechanism of S100A7 in mastitis goats. This study revealed that S100A7 was mainly expressed in the stratified squamous epithelium of teat skin and streak canal, and S100A7 was present weakly in the healthy goat alveolus yet densely in the mastitis goat collapsed alveolus. Goat mammary epithelial cells (MECs) were isolated and treated with 2.5, 5, 10 and 20 µg/mL lipopolysaccharide (LPS) respectively for a different time, S100A7 mRNA expression and protein secretion were upregulated significantly with LPS treatment for 3 h, and the secretion level of S100A7 descended after 48 h treatment for all of these four groups. Moreover, after treatment with LPS, the mRNA levels of Toll-like receptor 4 (TLR4) and MyD88 were up-regulated, and the phosphorylation of p65 was up-regulated markedly. However, adding TLR4 inhibitor TAK-242 or/and NF-κB inhibitor QNZ significantly suppressed the phosphorylation of p65, and then inhibited the expression and secretion of S100A7 induced by LPS treatment. In conclusion, LPS induced the expression and secretion of S100A7 in goat MECs via TLR4/NF-κB signaling pathway.

Effectiveness of detergents and disinfectants in the production of cow’s milk

The relevance of this study is conditioned upon the need to improve the hygiene of milking cows by selecting detergents and disinfectants with different component compositions that ensure the quality and safety of dairy products. The purpose of this paper was to investigate the effectiveness of solutions of modern chlorine-containing and chlorine- free detergents and disinfectants on the test cultures of microorganisms, the sanitary and hygienic condition of the milking parlour, parts of milking equipment, and the skin of the udder teats of cows. The total number of bacteria was determined according to the requirements of DSTU ISO 15214:2007, by inoculating 1 cm3 of the test material on meat-peptone agar followed by incubation at an average temperature of 36°C for 24-48 h. Cultivation was performed in a thermostat at 37°C. After incubation, colonies of grown microorganisms were counted, and the number of colony-forming units was determined. Detergents and disinfectants “Chloramine B”, “Sanalcalin” and “Neochlor” have a detrimental effect on the growth of test cultures of E. coli, S. aureus and P. aeruginosa. “Desmol” suppresses the growth of test cultures of E. coli and P. aeruginosa after 20 minutes. The number of colonies of microorganisms in the air of the milking parlour is minimal at the beginning and greatest at the end of milking. 0.5% solution has a detrimental effect on E. coli and S. aureus, and slightly affects the growth of Salmonella spp. At the same time, this product is effective against microbial contamination of the skin of the udder teats of cows for its use in pre-milking disinfection. During the treatment of milking equipment with a 0.5% “Gralan Gel” solution, the total bacterial inoculation of the milking gum is reduced by 94.1%, the collector – by 98.4%, the milk hose – by 96.5%, the tank of the milking machine – by 97.4% compared to the indicators before processing the milking equipment with detergents and disinfectants. According to the results of the study, the best efficiency in reducing the general bacterial contamination of milking equipment, the harmful effect on opportunistic microflora and microbial contamination of the skin of the udders of cows when used in pre-milking disinfection at milk production enterprises shows a 0.5% solution of the alkaline detergent and disinfectant “Gralan Gel”. Thus, it is advisable to use a 0.5% solution of alkaline detergent and disinfectant “Gralan Gel” for producers of cow’s raw milk to reduce the total bacterial contamination of milking equipment and cow udders

Bacterial Composition and Interactions in Raw Milk and Teat Skin of Dairy Cows

The microbiota in raw milk plays an important role in the health of dairy cows and the safety of dairy products, which might be influenced by that in teat skin. However, the microbiota composition in raw milk and teat skin, as well as the bacterial interaction between the two adjacent spatial locations, remains elusive. Here, we investigated the composition, diversity, and co-occurrence network of the bacterial communities in raw milk and on teat skin, as well as the shift of bacterial communities during the teat bath using 469 samples from 156 individual cows. We observed that raw milk and teat skin harbored significantly different bacterial communities according to an assessment of the genera numbers (p &lt; 0.05) and PCoA analysis (ANOSIM p &lt; 0.05). The microbiota in raw milk was dominated by Proteobacteria (58.5% in relative abundance) at the phylum level and by Pseudomonas (51.2%) at the genus level, while that in teat skin was dominated by Firmicutes (46.9%) at the phylum level and by Pseudomonas (11.0%) at the genus level. We observed a massive difference between the bacterial subnetworks in raw milk and teat, and the bacterial abundance in these two adjacent spatial locations was positively correlated (p &lt; 0.05). Using Bayesian algorithms, we identified that 92.1% of bacteria in raw milk were transferred from teat skin, while 63.6% of bacteria on teat skin were transferred from raw milk. Moreover, microbiota composition in teat skin could be affected by the teat bath with iodine disinfectant, which tended to be more similar to that in raw milk after the teat bath (p &lt; 0.05), while the abundance of the dominant genus Pseudomonas significantly increased (p &lt; 0.05). These findings expand our knowledge on the microbiota composition in teat skin and raw milk, as well as the interaction between these two adjacent spatial locations.

Distribution of staphylococcal and mammaliicoccal species from compost-bedded pack or sand-bedded freestall dairy farms

The purpose of this prospective observational study was to determine whether dairy cattle housing types were associated with staphylococcal and mammaliicoccal populations found on teat skin, bedding, and in bulk tank milk. Twenty herds (n = 10 sand-bedded freestall herds; n = 10 compost-bedded pack herds) were enrolled. Each herd was visited twice for sample collection, and at each visit, 5 niches were sampled, including bulk tank milk, composite teat skin swab samples collected before premilking teat preparation, composite teat skin swab samples collected after premilking teat preparation, unused fresh bedding, and used bedding. All samples were plated on Mannitol salt agar and Columbia blood agar and staphylococcal-like colonies were selected for further evaluation. Bacterial colonies were speciated using MALDI-TOF mass spectrometry. All species were grouped into 4 categories included host-adapted, opportunistic, environmental, and unclassified. Absolute numbers and proportions of each genus and species were calculated. Proportional data were compared between groups using Fisher's exact test. Data representing 471 staphylococcal-like organisms were analyzed. Overall, 27 different staphylococcal and mammaliicoccal species were identified. Staphylococcus chromogenes was the only species identified from all 20 farms. A total of 20 different staphylococcal-like species were identified from bulk tank milk samples with the most prevalent species being S. chromogenes, followed by Staphylococcus aureus and Mammaliicoccus sciuri. Overall, more staphylococcal and mammaliicoccal isolates were identified among used bedding than unused bedding. The increased numbers of isolates within used bedding were primarily from used sand bedding samples, with 79% (76/96) of used bedding isolates being identified from sand bedding and only 20.8% (20/96) from used compost-bedded pack samples. When comparing categories found among sample types, more unclassified species were found in used sand bedding than in used compost-bedded pack samples. This finding is possibly related to the composting temperatures resulting in reduced growth or destruction of bacterial species. The prevalence of S. aureus was high in bulk tank milk for all herds, regardless of herd type, which may represent the influence of unmeasured management factors. Overall, staphylococcal and mammaliicoccal species were highly prevalent among samples from both farm types.

Influence of Post-Milking Treatment on Microbial Diversity on the Cow Teat Skin and in Milk

In dairy cattle, teat disinfection at the end of milking is commonly applied to limit colonization of the milk by pathogenic microorganisms via the teat canal. The post-milking products used can irritate the teat skin and unbalance its microbial population. Our study aimed to assess the impact of different milking products on the balance of the microbial communities on the teat skin of cows and in their milk. For 12 weeks at the end of each milking operation, three groups of seven Holstein dairy cows on pasture received either a chlorhexidine gluconate-based product (G) or a hydrocolloidal water-in-oil emulsion (A), or no post-milking product (C). The composition of the bacterial and fungal communities on the teat skin and in the milk were characterized using a culture-dependent method and by high-throughput sequencing of marker genes to obtain amplicon sequence variants (ASVs). The individual microbiota on the cows’ teat skin was compared for the first time to that of a cow pool. In contrast to the milk, the post-milking treatment influenced the microbiota of the teat skin, which revealed a high microbial diversity. The water-in-oil emulsion appeared to slightly favour lactic acid bacteria and yeasts and to limit the development of undesirable bacteria such as Pseudomonas and Staphylococcus.

Efficacy of bacteriocin-based formula for reducing staphylococci, streptococci, and total bacterial counts on teat skin of dairy cows

The use of teat dips is one of the most effective strategies to control mastitis by preventing new intramammary infections. Reducing bacterial load on teat skin helps control the spread of pathogens and spoilage and improves the quality of milk. The objective of this study was to evaluate the reduction of bacterial populations through the application of bacteriocin-based teat formulas. Teats of 12 Holstein cows received 2 different concentrations of bactofencin A, nisin, and reuterin alone or in combination, as well as iodine (positive control) and saline (negative control). Teat swabs were collected before and after application of teat formulas and analyzed for staphylococci, streptococci, and total bacteria counts. There were no differences for staphylococci, streptococci, and total bacterial counts for samples collected before application throughout the entire experiment. Reuterin-low and reuterin-high treatments reduced total bacterial count by 0.47 and 0.36 logs, respectively, whereas bactofencin A had no effect on any tested bacterial groups. Nisin-low treatment reduced staphylococci, streptococci, and total bacterial counts by 0.47, 0.30 and 0.50 logs, respectively. Nisin-high treatment resulted in 0.50, 0.50, and 0.47 log reduction for staphylococci, streptococci, and total bacterial counts. The bacteriocin consortium showed the highest reduction rates with 0.91, 0.54, and 0.90 log reductions obtained for staphylococci, streptococci, and total bacteria counts, respectively, for the low-concentration consortium. Similarly, the high-concentration consortium showed reduction rates with 0.95, 0.60, and 0.82 log reductions obtained for staphylococci, streptococci, and total bacteria counts, respectively. Thus, nisin and the bacteriocin consortium showed the most promise as a teat disinfectant by reducing staphylococci, streptococci, and total bacteria counts.