Progress 10/01/12 to 09/30/17
Outputs
Target Audience:Veterinarians, dairy farmers, dairy farm employees and other industry professionals were the target audiences for our efforts for the past 5 years. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Educational programs were conducted for producers and their advisors to share the results of the study assessing milk quality on PA dairy farms using Automated Milking Systems, and management practices associated with good milk quality and udder health, and to encourage the adoption of effective risk-reduction practices. A conference was also held to share the results of the study, with raw milk producers attending from Pennsylvania, Ohio, Indiana, and other states. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
OBJECTIVE 1: Characterization of host mechanisms associated with mastitis susceptibility and resistance. In 2014, a Campylobacter outbreak occurred among consumers of raw milk in Pennsylvania and Maryland. The outbreak was traced from to a permitted raw milk producer in Pennsylvania, where the organism was isolated from milk samples. Dr. Hovingh was contacted to help investigate this issue. A farm visit was carried out to assess potential sources for the introduction of bacteria into the milk. Records were also investigated to determine the udder health status of the cows within the herd. Repeated sampling and anaerobic culturing was carried out of cows with elevated somatic cells. An individual animal with subclinical mastitis was found to be positive for Campylobacter. After removal of this animal no further bulk milk samples were positive. The isolate from the cow was found, by PFGE analysis @ CDC, to be similar to the bulk milk isolates, as well as the organisms isolated from human cases. No further assessment of the positive cow was possible, since she was immediately removed from the herd. OBJECTIVE 2: Characterization and manipulation of virulence factors of mastitis pathogens for enhancing host defenses. In 2015-2016, small cell variant phenotype analysis of Staph aureus was performed, and resistance to 10 antimicrobials was assessed. MLST analysis was used to track S. aureus within a given cow, a herd and between herds, as was the presence of enterotoxin and leukocidin genes. Preliminary analysis suggests that the small cell variant may play a role in the persistence of Staphylococcus aureus infection. OBJECTIVE 3: Assessment and application of new technologies that advance mastitis control, milk quality, and dairy food safety. In FFY 2013-2014 a study examined milk quality on PA dairy farms using Automated Milking Systems (AMS), and management practices associated with good milk quality and udder health. Some studies have reported an increase in mastitis associated with the use of AMS, in spite of quarter-based milking, and the availability of technologies to monitor milk quality. Nine dairy farms with 1-5 AMS units/farm participated in the study. Bedding type, manure management, feed management, and other factors varied between farms. Farms had from less than one year to over six years of experience with AMS. Bulk tank milk samples were collected once a week for four consecutive weeks and analyzed for: Somatic Cell Count (BTSCC), Standard Plate Count (SPC), Preliminary Incubation Count (PIC), Laboratory Pasteurization Count (LPC), Staphylococcus aureus (SA), Streptococcus agalactiae (SAg), Coagulase Negative Staphylococci (CNS), Environmental and non-environmental Streptococci (SS), and Coliform and Non-coliform counts. Teat cleanliness, udder preparation, cow hygiene, and stall hygiene were visually evaluated. During each observation period milkings were observed for 2 hours, or 15 successful milking-events. Teats were scored for cleanliness as the cow entered the robot and again following cleaning by the robot, each teat was assigned a cleanliness score from 0 (very clean) to 4 (very dirty). Technical success (efficiency) of teat cleaning was scored as 'successful' or 'unsuccessful' depending on whether or not the cleaning device made contact with the teat. A questionnaire was completed to provide additional information about management practices. Average daily milk production across the farms averaged 75 pounds, with an average of 2.6 milkings per cow per day. On average, there was an average of 56 cows per AMS unit. Average BTSCC across all farms was 247,806. SPC averaged 3,911cfu/ml, and SA was found on all farms. For most farms technical success (the cleaning device made contact with the teats) ranged between 90 and 97% successful. Only one farm achieved 100% success for all teats during the study period.On one farm the AMS successfully contacted the front right teat only 53% of the time, while success for the front left teat was 96%. A project was undertaken to investigate factors associated with the presence of zoonotic pathogens (E. coli O157:H7, Listeria, Campylobacter, Salmonella) in the milk of permitted raw milk producers in Pennsylvania. Milk samples ("as sold") were collected on a monthly basis, and assessed for the presence of pathogens. At the beginning of the project, an assessment of milking practices, mastitis management practices, bulk milk cooling and storage temperatures, wash temperatures and other potential risk factors was conducted. The monthly samples yielded only two positive pathogen tests - a surprisingly low prevalence (~0.035%), and an insufficient number to detect any statistically-significant associations with risk factors. A study was also conducted to evaluate Trek Aris(r) 2x Sensititre (ARIS), API(r) (API) and Bruker MALDI-TOF MS (BMALDI) bacterial species identification systems using 132 diverse bacterial isolates from quarter or composite milk samples received at Penn State Animal Diagnostic Laboratory. The results were compared with 16s rRNA gene sequence analysis which served as the reference method for species identification. As compared to 16s rRNA gene sequencing data, the ARIS, API and BMALDI systems were able to respectively identify 0%, 40% and 50% of species classified as gram positive rods (n=6 isolates belonging to genera Arthrobacter, Bacillus, Brachybacterium, Brevibacterium, Corynebacterium).With regard to catalase-negative gram-positive cocci (n=33; Aerococcus, Enterococcus, Lactococcus, Streptococcus), 57.5%, 78.7% and 96.9% of the isolates were correctly identified to their species by ARIS, API and BMALDI systems respectively; while 26.6%, 80% and 95.5% of catalase-positive gram-positive cocci (n=45; Kocuria, Staphylococcus) were correctly identified by ARIS, API and BMALDI systems, respectively. A total of 48 isolates (Acinetobacter, Citrobacter, Enterobacter, Escherichia, Klebsiella, Pantoea, Pasteurella, Providencia, Pseduomonas, Serratia)of gram-negative bacteriawere examined of which 83.3%, 91.6%, and 95.8% of the isolates were correctly identified to their species by ARIS, API and BMALDI systems, respectively. In our laboratory the cost for supplies and consumables was the least for BMALDI ($2.00), followed by Aris(r) 2x ($5.95), 16s rRNA ($6.80), and API(r) systems ($9.90-$13.10) identification methods. Identification of bacterial species (primary plating to identification) was accomplished in 22-26h, 36-38h, 44-48h, and 48-64h using BMALDI, 16s rRNA, ARIS and API identification systems, respectively. A study was conducted in 2016-2017 to determine the bacterial species associated with contamination of milk samples received at the Animal Diagnostic Laboratory, and if diluting the milk sample would allow identification of mastitis pathogens. From 01/15 to 12/16, 1 to 2 milk samples/month (total=38) that were identified as contaminated were diluted ten-fold to obtain isolated colonies for bacterial speciation by MALDI-TOF MS. The bacterial counts averaged 175,390 cfu/ml, and ranged from 98,450 to 850,230 cfu/ml. The number of aerobic bacterial species identified in the contaminated milk samples ranged from 2 to 8, with the predominant ones being Pseudomonas spp. (52%), Bacillus spp. (48%), Proteus spp. (34%), Enterobacter spp. (31%), Alcaligenes spp. (10%), and Pantoea spp. (8%). Five of the 38 samples included mastitis pathogens including; 1) Streptococcus dysgalactiae, 2) Staphylococcus chromogenes, 3) Staphylococcus hyicus, 4) Escherichia coli, and 5) Klebsiella oxytoca. This study suggests that serial dilution could possibly be used to for isolating mastitis pathogens from "contaminated" milk samples.
Publications
- Type:
Other
Status:
Under Review
Year Published:
2017
Citation:
Savage E, S. Chothe, V. Lintner, T. Pierre, T. Matthews, S. Kariyawasam, D. Miller, D. Tewari, B. Jayarao. Evaluation of Three Bacterial Identification Systems for Species Identification of Bacteria Isolated from Bovine Mastitis and Bulk Tank Milk Samples. 2017. Foodborne Pathog Dis. 14(3):177-187.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2014
Citation:
Hovingh, E. Lessons from the PA Raw Milk Project. The Raw Milk Workshop at Penn State. State College, PA. 11/14/14.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2014
Citation:
Hovingh, E., B. Jayarao. Raw Milk Is It Safe? American Dairy Science Association Annual Meeting. Kansas City, MO. 7/21/14.
- Type:
Other
Status:
Other
Year Published:
2015
Citation:
Poster Presentations
Chothe, S., E Savage, V Linter, T Pierre, T Matthews, S Kariyawasam, D Tewari and B Jayarao. Evaluation of Bacterial Identification Systems for Species Identification of Bacterial Isolates from Milk Samples. 58th AAVLD/119th USAHA Annual meeting, Providence, Rhode Island. October 23, 2015.
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Hovingh, E. Mastitis Identification and Management . Dairy Summit. Lancaster, PA. 2/12/14.
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Hovingh, E. Udder Health and Raw Milk Safety. Pennsylvania Association for Sustainable Agriculture. University Park, PA. 2/7/14.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Hovingh, E. Lessons from Bulk Milk. American Board of Veterinary Practitioners (Dairy) Annual Meeting. Knoxville, TN. 11/1/13.
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Progress 10/01/15 to 09/30/16
Outputs
Target Audience:Veterinarians, dairy farm owners/managers/employees, dairy industry professionals, undergraduate students, graduate students. Changes/Problems:A graduate student who was assisting with project activities went on unexpected, extended medical leave. In addition to losing one member of the Veterinary Extension/Applied Research Team to retirement in mid-2016, the Team's laboratory and offices were relocated to a building which required substantial renovation and retro-fitting. These changes presented some challenges to the team during the 2015-2016 reporting period. What opportunities for training and professional development has the project provided?Udder health lectures and laboratory sessions were delivered to undergraduate students at Penn State University. A 3-day training module (May 19-21, 2016) was conducted for veterinarians. Approximately 18 individuals from Pennsylvania, Florida, Georgia, New York and Canada participated and learned about "Intelligent Mastitis Management", mastitis bacteriology, records analysis, etc. A series of six 2-hour training sessions were also held across Pennsylvania with veterinarians to teach them about the use of VaDia® data to evaluate the adequacy of udder preparation routines, equipment function and parlor efficiency. Individual farm visits were also conducted on ~60 farms to evaluate udder health status, milking procedures, equipment function and other udder health risk factors. Results of the assessments were communicated to the herd owner, manager(s), and herd veterinarians. How have the results been disseminated to communities of interest?Results have been disseminated to communities of interest during the activities outlined. In addition, materials have been prepared for distribution on the "new" Penn State Extension website, which is scheduled for unveiling in early 2017. What do you plan to do during the next reporting period to accomplish the goals?Plans are to continue work on the small cell variant of Staphylococcus aureus. Investigation of the intra- and inter-operator agreement of VaDia® data analysis will also be continued.
Impacts
What was accomplished under these goals?
An investigation was undertaken using Staphylococcus aureus isolates from diagnostic quarter and bulk milk samples submitted to Penn State University in 2008, 2013, 2014, and 2015. Small cell variant phenotype analysis and resistance to 10 antimicrobials were assessed, as was the presence of enterotoxin and leukocidin genes. Multilocus sequence typing (MLST) was also carried out. Eighty percent of isolates were sensitive to all 10 antimicrobials, and no Methicillin Susceptible Staphylococcus Aureus (MRSA) strains were isolated. MLST analysis was used to track S. aureus within a given cow, a herd and between herds. Preliminary analysis suggests that the small cell variant may play a role in the persistence of Staphylococcus aureus infection. Ongoing work to evaluate the correlation of VaDia® recordings and Lactocorder® milk flow curves was undertaken. Work was also initiated to assess the level of intra-operator and inter-operator agreement of VaDia® vacuum analyses with multiple VaDia users. The use and interpretation of VaDia data were also explored in on-farm settings.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Schewe, R.L., J. Kayitsinga, G.A. Contreras, C. Odom, W.A. Coats, P. Durst, E.P. Hovingh, R.O. Martinez, R. Mobley, S. Moore, R.J. Erskine. Herd management and social variables associated with bulk tank somatic cell count in dairy herds in the eastern United States. 2015. J. Dairy Sci. 98(11).7650-7665.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Hovingh, E.P. Use of a four-channel vacuum recording device for monitoring and diagnosing milk equipment and milking procedures abnormalities. Florida Dairy Summit, Gainesville, FL. February 11, 2016. (Conference presentation)
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:Veterinarians, dairy farmers, dairy farm employees, and industry professionals. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?A workshop was presented to diplomates of the American Board of Veterinary Practitioners - Dairy Practice Specialty (11/1/14); workshops were held for milking equipment specialists (March 3 & 4, 2015); and results also were shared in face-to-face interactions/farm visits, on the web, at extension meetings, and with undergraduate students in lectures and laboratories. What do you plan to do during the next reporting period to accomplish the goals?The plan is to continue to investigate new methods of diagnosing, managing and monitoring mastitis and milk quality in dairy herds, with the goal to determine the best method of improving udder health and optimizing antimicrobial usage. We also plan to investigate the reliability and repeatability of VaDia® units. We also will provide educational and training opportunities for veterinarians, dairy producers, industry professionals, and students.
Impacts
What was accomplished under these goals?
Research was undertaken to assess the utility and validity of a compact vacuum recording device (VaDia®) which is designed to measure claw, mouthpiece and pulsator vacuum levels during milking. Units were attached to claws in various milking parlors on commercial farms in PA, along with other vacuum recording devices (TriScan®, QuadVac®) to measure the level of agreement. The VaDia® unit recordeds also were compared with milk flow recordings obtained using a Lactocorder® device. A study was conducted to evaluate the TREK Diagnostic Systems Sensititre Aris® 2x, the API® ID Strip, and Bruker martix-assisted lasar desorption/ionization time of flight mass spectrometer (MALDI-TOF MS, or "BMALDI") bacterial species identification systems using 132 diverse bacterial isolates from quarter or pooled milk samples received at Penn State Animal Diagnostic Laboratory. The results were compared with 16s rRNA gene sequence analysis, which served as the reference method for species identification. As compared to 16s rRNA gene sequencing data, the ARIS, API and BMALDI systems were able to identify, respectively, 0%, 40% and 50% of species classified as gram-positive rods (n=6 isolates belonging to genera Arthrobacter, Bacillus, Brachybacterium, Brevibacterium, and Corynebacterium). With regard to catalase-negative, gram-positive cocci (n=33; Aerococcus, Enterococcus, Lactococcus, and Streptococcus), 57.5%, 78.7% and 96.9% of the isolates were identified correctly to their species by ARIS, API and BMALDI systems, respectively; while 26.6%, 80% and 95.5% of catalase-positive. gram-positive cocci (n=45; Kocuria and Staphylococcus) were correctly identified to their species by ARIS, API and BMALDI systems, respectively. A total of 48 isolates (Acinetobacter, Citrobacter, Enterobacter, Escherichia, Klebsiella, Pantoea, Pasteurella, Providencia, Pseduomonas, and Serratia) of gram-negative bacteria were examined of which 83.3%, 91.6%, and 95.8% of the isolates were correctly identified to their species by ARIS, API and BMALDI systems, respectively. In our laboratory the cost for supplies and consumables was the least for BMALDI ($2.00), followed by Aris 2x ($5.95), 16s rRNA ($6.80), and API systems ($9.90-$13.10) identification methods. Identification of bacterial species (primary plating to identification) was accomplished in 22-26h, 36-38h, 44-48h, and 48-64h using BMALDI, 16s rRNA, ARIS and API identification systems, respectively. The findings of the study suggest that the BMALDI system accurately speciated most of the isolates from milk, as compared to ARIS and API systems. Although only a few isolates of (n=6) gram-positive rods were examined, it is suggested that the BMALDI database needs to include more profiles of gram-positive rods. In conclusion, BMALDI is a faster, cheaper, and more accurate method for routine 7seven species identification of isolates from milk samples.
Publications
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Progress 10/01/13 to 09/30/14
Outputs
Target Audience: Dairy farmers, veterinarians, dairy farm employees and other industry professionals. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? The Penn State Mastitis & Milk Quality Conference was held on March 25-26 in Grantville, PA. This conference, along with pre-conference workshops, provided information and practical skills to veterinarians, dairy producers, allied dairy industry personnel, with the aim of improving udder health, milk quality and milk safety. How have the results been disseminated to communities of interest? Results have been disseminated by means of conferences and workshops, newsletters, websites, face-to-face interactions, and presentations at outside meetings. Results were also shared with undergraduate students in lectures and laboratories. What do you plan to do during the next reporting period to accomplish the goals? We plan to continue to investigate novel methods of diagnosing, managing and monitoring mastitis and milk quality, with a goal to improving udder health and reducing unnecessary antimicrobial usage. We will also provide educational and training opportunities for veterinarians, dairy producers, industry professionals, and students.
Impacts
What was accomplished under these goals?
A study was conducted to document milk quality on Pennsylvania dairy farms using automated milking systems (AMS) and to identify management practices that contribute to good milk quality and udder health. A number of studies have reported a decrease in udder health and milk quality associated with the use of AMS, in spite of quarter-based milking, and the availability of electrical conductivity and other technologies to monitor milk quality, which are common on AMS. Despite the general decrease in milk quality with AMS, some farmers are able to consistently achieve good milk quality using AMS. Nine Pennsylvania dairy farms participated in the current study evaluation milk quality on dairy farms using AMS. Bulk tank milk samples were collected during August-September 2014. Farms ranged in size from one to five robots. Six farms utilized Lely® robots, the remaining three utilized Delaval® robots. Bedding type, manure management, feed management, and other factors varied between farms. The farms had from less than one year to over six years of experience with AMS. Bulk tank milk samples were collected once a week for four consecutive weeks; samples were transported to the Penn State Animal Diagnostic Lab for analysis. Samples were analyzed for: Bulk-tank Somatic Cell Count (BTSCC), Standard Plate Count (SPC), Preliminary Incubation Count (PIC), Laboratory Pasteurization Count (LPC), Staphylococcus aureus (SA), Streptococcus agalactiae (SAg), Coagulase Negative Staphylococci (CNS), Environmental and non-environmental Streptococci (SS), and coliform and non-coliform counts. Twice during the month in which bulk tank milk samples were collected, teat cleanliness, udder preparation, cow hygiene, and stall hygiene were visually evaluated. During each observation period, milkings were observed for two hours, or 15 successful milkings. Teats were scored for cleanliness as the cow entered the robot and again following cleaning by the robot, each teat was assigned a cleanliness score from zero (very clean) to four (very dirty). Technical success (efficiency) of teat cleaning was scored as ‘successful’ or ‘unsuccessful’ depending on whether or not the cleaning device made contact with the teat. Dairy producers also completed a questionnaire to provide additional information about management practices. Average daily milk production across the farms averaged 75 pounds, with an average of 2.6 milkings per cow per day. On average, there was an average of 56 cows per AMS unit. Average BTSCC across all farms was 247,806 cells/mL. SPC averaged 3,911cfu/mL-, and SA was found on all farms. For most farms, technical success (the cleaning device made contact with the teats) ranged between 90 and 97% successful. Only one farm achieved 100% success for all teats during the study period. On one farm the robot successfully contacted the front right teat only 53% of the time, while success for the front left teat was 96%.
Publications
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