title: Identification of dairy farm management practices associated with the presence of psychrotolerant sporeformers in bulk tank milk.
abstract: Some strains of sporeforming bacteria (e.g., Bacillus spp. and Paenibacillus spp.) can survive pasteurization and subsequently grow at refrigeration temperatures, causing pasteurized fluid milk spoilage. To identify farm management practices associated with different levels of sporeformers in raw milk, a bulk tank sample was obtained from and a management and herd health questionnaire was administered to 99 New York State dairy farms. Milk samples were spore pasteurized [80°C (176°F) for 12 min] and subsequently analyzed for most-probable number and for sporeformer counts on the initial day of spore pasteurization (SP), and after refrigerated storage (6°C) at 7, 14, and 21 d after SP. Management practices were analyzed for association with sporeformer counts and bulk tank somatic cell counts. Sixty-two farms had high sporeformer growth (≥3 log cfu/mL at any day after SP), with an average sporeformer count of 5.20 ± 1.41 mean log10 cfu/mL at 21 d after SP. Thirty-seven farms had low sporeformer numbers (<3 log cfu/mL for all days after SP), with an average sporeformer count of 0.75 ± 0.94 mean log10 cfu/mL at 21 d after SP. Farms with >25% of cows with dirty udders in the milking parlor were 3.15 times more likely to be in the high category than farms with ≤10% of milking cows with dirty udders. Farms with <200 cows were 3.61 times more likely to be in the high category than farms with ≥200 cows. Management practices significantly associated with increased bulk tank somatic cell count were a lack of use of the California mastitis test at freshening and >25% of cows with dirty udders observed in the milking parlor. Changes in management practices associated with cow cleanliness may directly ensure longer shelf life and higher quality of pasteurized fluid milk.
authors.affiliation: Milk Quality Improvement Program, Department of Food Science, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
authors.forename: S N
authors.initials: SN
authors.lastname: Masiello
authors.affiliation: Milk Quality Improvement Program, Department of Food Science, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
authors.forename: N H
authors.initials: NH
authors.lastname: Martin
authors.affiliation: Department of Animal Science, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
authors.forename: R D
authors.initials: RD
authors.lastname: Watters
authors.affiliation: Department of Animal Science, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
authors.forename: D M
authors.initials: DM
authors.lastname: Galton
authors.affiliation: Quality Milk Production Services, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
authors.forename: Y H
authors.initials: YH
authors.lastname: Schukken
authors.affiliation: Milk Quality Improvement Program, Department of Food Science, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
authors.forename: M
authors.initials: M
authors.lastname: Wiedmann
authors.affiliation: Milk Quality Improvement Program, Department of Food Science, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853. Electronic address: kjb4@cornell.edu.
authors.forename: K J
authors.initials: KJ
authors.lastname: Boor
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification* / Q000302:isolation & purification; D002417:Cattle / Q000382:microbiology*; D002452:Cell Count / Q000662:veterinary; D003612:Dairying / Q000379:methods*; D005260:Female; D008321:Mammary Glands, Animal / Q000382:microbiology; D064307:Microbiota; D008892:Milk / Q000382:microbiology*; D009518:New York; D061352:Pasteurization
keywords: Bacillus spp.; Paenibacillus spp.; management practice; spoilage