3993 AABP 2021 Conference Proceedings Text V2.Indd

Investigation of the relationship between method of processing recycled manure solids bedding and udder health and production on Midwest dairy farms

S. M. Godden, DVM, DVSc1; F. P. Mosca, DVM, MS1; E. Royster, DVM, MS1; B. Crooker, MS, PhD2; J. Hadrich, MS, PhD3; P. Raynor, MS, PhD ; R. Singer, DVM, MPVM, PhD5; K. Janni, MS, PhD6 1 4 2 3Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN 55108 Department of Animal Science, University of Minnesota, St. Paul, MN 55108 45Department of Applied Economics, University of Minnesota, St. Paul, MN 55108 6Division of Environmental Health Sciences, University of Minnesota, Minneapolis, MN 55455 Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN 55108 Department of BioproductsIntroduction and Biosystems Engineering, Universitytests, of and Minnesota, the proportion St. Paul, ofMN cows 55108 with a chronic infection

There has been a rapid increase in adoption of recycled manure solids (RMS) as bedding in Midwest dairy herds over (CRON) where chronic was defined as a LS ≥4.0 on the last 2 the past 10 to 15 years due to perceived advantages such as tests. The monthly cumulative incidence of clinical mastitis the(CLXM) relationship was also between recorded bedding for the processing30-d period system preceding and sample day. Mixed linear regression was used to describe herdscost and using availability. RMS as Severalcompared studies to inorganic have reported or organic increased non- bedding bacteria counts (BBC) and increased mastitis risk in the following dependent variables: AVLS, IMI, NIMI, CRON, ventilationCLXM, and quality,305ME. beddingOther covariates and manure offered management into models, prac if- anmanure anaerobic materials. methane Although digester many (DIG), RMS some dairies herds use have either ad- significant, included herd size, avg DIM, avg parity, season, green/raw (GRN) solids or solids first processed through tices, and mastitis control practices. Herd was controlled for opted mechanical composters (COM) or dryers (DRY) in an as a random effect. Overall significance was set at P < 0.05, effort to lower BBC and control mastitis. Research is needed with a trend at 0.05 ≤ P < 0.10. However, the critical P value udderto evaluate health, potential air quality, benefits antimicrobial and costs resistance of adopting in solids, these was adjusted for multiple Resultscontrasts. andtechnologies. economics, This for research herds usingteam initiated different a studyRMS processingto evaluate

investigate if method of processing RMS is associated with and clinical mastitis treatment records were available for methods. The objective of this portion of the study was to Of 56 herd visits conducted, DHIA test day information

udder health and Materialsmilk production and Methods on Midwest dairy farms. varied43 and by39 processing visits, respectively. method, TheRMS median processing (range) system number was of cows milking was 1,261 (235 – 5,467). Although results This observational study was conducted with a con- associated with AVLS, IMI, CRON, and 305ME, but not CLXM. Specifically, the adjusted mean AVLS (± SE) was lower in herds venience sample of 29 free-stall premises in MN and WI. using DRY, and tended to be lower in COM, as compared to Farms were recruited to achieve a representative sample herds using GRN solids, but with no difference between DRY twice,of different once processingin Aug-Sept, systems 2019, andincluding again inGRN January (n=7), 2020, COM and COM (DRY = 2.12 [0.17], COM = 2.15 [0.26], DIG = 2.63 to(n=4), collect DIG bedding (n=6), andsamples, DRY electronic(n=12). Premises herd records, were visitedand to [0.22], GRN = 2.89 [0.16], Type 3 P = 0.006). The percent of complete a management questionnaire describing facilities cows with IMI was lower in herds using DRY, and tended to and management, including but not limited to manure and be lower in COM, as compared to GRN solids, but with no bedding management, milking procedures, and mastitis difference between COM and DRY, or between DIG and GRN (DRY = 17.31 [2.32], COM = 14.46 [4.64], DIG = 23.82 [2.97], captured from the DHIA test day preceding each herd visit GRN = 25.92 [2.15], Type 3 P = 0.015). The percent of cows control practices. Udder health and performance metrics with CRON was lower in herds using DRY, and tended to be lower in COM, as compared to DIG or GRN solids, but with no included average 305ME (kg/cow), test day average linear difference between COM and DRY, or between DIG and GRN- score (AVLS), the proportion of cows with an intramammary (DRY = 8.66 [1.61], COM = 8.59 [3.28], DIG = 14.95 [2.06], infection (IMI) where infection was defined as LS ≥ 4.0, the GRN = 16.10 [1.50], P = 0.003). Though NIMI was numeri proportion of cows with a new IMI (NIMI) where a new IMI cally lower for herds using DRY or COM as compared to GRN was defined as LS changing from < 4.0 to ≥ 4.0 in the last 2 solids, differences were not significant (DRY = 9.02 [1.55],

384 AABP ANNUAL CONFERENCE PROCEEDINGS — VOL. 53 — NO. 2 — SEPTEMBER 2020

Drs. Harold Amstutz —

Veterinary Veterinary College, attending Board of Directors Collinge (vice president), Emporia, KS; and Francis (secretary-treasurer), Purdue University; Irwin Fox Fox (1st District representative), New State York AABP officers (right to left) meeting.

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Chicago, Illinois Chicago, November 2 4 -2 6 1st A n nual Convention “This was the first was“This the convention in yearsrecent where a bovinepractitioner could elbow to the right or to Dr. Knappenberger expressed concern over the sluggishness of new product development, due to the the to due development, product new of sluggishness the over concern expressed Knappenberger Dr. One of the highlights of every AABP Convention has been the Practice Tips Session. At the Chicago the At Session. Tips Practice the Convention been AABP every has of highlights the ofOne practicing the veterinarians’ He spoke of guest was speaker. President, a Joe AVMA Knappenberger, Dr. JAVMA, February 1, 1969 had a report on the First Annual AABP Convention at the LaSalle Hotel, LaSalleAABP Hotel, the AnnualConvention at First the on report had a JAVMA, February 1969 1, registrants, AABPregistrants, the findofficers delightedwere to themselves hostsmore to 350than veterinarians. Exhibi House House of Delegates. tors, speakers andguests swelledthe attendance to 425. the the left and find everywhere a newly made friend to talk to about cattle. Hoping and praying for at least 200 meeting there descriptionswere lively gadgetsnovel of and procedures. future,the in role trends which would lessen the physical strain practitioner on the by using improved tech niques and specially trainedassistants. defined He veterinarians futurethe of role supervisors as instead of skilled laborers. Chicago on November24-26, Hitherto, 1968. the annual meetings hadbeen heldconjunction in AVMA with the stated: Meetings. Annual The report stringent regulations imposed by the Food AdministrationDrug & Veterinary and Biologicalsthe Division prac animal offood engagedin veterinarians of percentage diminishing the concerned with also was USDA. He urged He memberstice. representativedirect activities their the AVMA take state’s a interestof in to the in held in Chicago, Nov. 24 -26, 1968. Left to right: Dr. Don Williams, Ada, Ada, OK, Williams, Don Dr. right: to Left -26, 1968. 24 Nov. Chicago, in held AABP AABP and AVMA counterparts join forces at AABP's first annual meeting Dr. R. A. B. /vie, president-elect A. John Follett, Dr. R. andAABP; Texas, Dr. of Herrick, Herrick, Ames, /A, president-elect Dr. AVMA of /vie took over as president of president of AABP; Dr. presidentJoe AABP; Knappenberger, Dr. of Olathe, president AVMA; KS, of AABP for 1969. systems to process RMS generally had improved udder health

COM = 9.78 [2.88], DIG = 13.10 [2.02], GRN = 12.84 [1.47], orType DIG 3 Psolids, = 0.15). respectively, Finally, Avg305ME but with (kg/cow) no difference was higherbetween or udderand, for health DRY, improvedor production milk differences production, may compared be explained to herds by tended to be higher for herds using DRY as compared to GRN using digested or green solids. Future analysis will explore if investigated, and will evaluate the economics of adopting DRY versus COM, or between DIG versus GRN (DRY = 13,781 differences in bedding hygiene for the 4 processing systems [402], COM = 12,752 [804], DIG = 12,517 [510], GRN = 11,689 [430], Type 3 P = 0.02).Significance different RMS processing systems.

In conclusion, preliminary results show that Midwest herds using mechanical drying or mechanical composting

Investigation of the relationship between method of processing and bacteria counts in ready-to-use recycled manure solids bedding on Midwest dairy farms

There has been a rapid increase in adoption of recycled health and milk production as compared to GRN. In this ab manure solids (RMS) as bedding in Midwest dairy herds over stract, we explore if these benefits are likely to be explained the past 10 to 15 years due to perceived advantages such as portionby differences of the study in bedding is to investigate characteristics, if method such of asprocessing BBC, for the 4 processing systems investigated. The objective of this

mastitiscost and riskavailability. in herds However, using RMS several as compared studies to have inorganic reported or RMS is associated with BBC in ready-to-use (RTU) RMS on increased bedding bacteria counts (BBC) and increased Midwest dairy farms.Materials and Methods

throughorganic non-manurean anaerobic materials. methane Althoughdigester (DIG),many RMSsome dairies herds This observational study was conducted with a conve- use either green/raw (GRN) solids or solids first processed were recruited to achieve a representative sample of different have adopted mechanical composters (COM) or dryers (DRY) nience sample of 29 free-stall premises in MN and WI. Farms in an effort to lower BBC and control mastitis. Research is evaluateneeded to udder evaluate health, potential air quality, benefits antimicrobial and costs of resistance adopting inprocessing Aug-Sept, systems 2019, and including again in GRNJanuary (n=7), 2020, COM to collect(n=4), bedDIG- inthese solids, technologies. and economics, This researchfor herds teamusing initiated different a RMS study pro to- ding(n=6), samples, and DRY electronic (n=12). Premisesherd records, were andvisited a management twice, once questionnaire describing facilities, manure and bedding man-

cessing methods. In a companion abstract, we determined that use of COM or DRY was associated with improved udder agement, and other practices. At each visit, post-processed

SEPTEMBER 2020 — VOL. 53 — NO. 2 — AABP ANNUAL CONFERENCE PROCEEDINGS 385

Drs. Harold Amstutz —

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