Reference | Habing2012 (10201) (Excluded)

**Data is not extractable as the study does not specify drug resistance. ** The objective of this cross-sectional study was to compare the use of management practices between Salmonella-positive and Salmonella-negative farms, and between AMR Salmonella-positive farms relative to farms where only pansusceptible Salmonella were isolated. The hypothesis tested by this research is that modifiable management practices are significantly associated with the recovery of Salmonella and AMR Salmonella on U.S. dairy farms. The 2007 National Animal Health Monitoring System (NAHMS) Dairy Study was conducted as a cooperative effort between the Animal and Plant Health Inspection Service (APHIS) and the National Agricultural Statistics Service (NASS). 17 states were chosen to represent 79.5% of the U.S. dairy operations and 82.5% of the dairy cow population. At the outset, a stratified random sample with unequal selection probabilities was used to select farms based on herd sizes of 1–99, 100–499, or>500 milking cows. In Phase I of Dairy 2007, NASS enumerators administered questionnaires to 2,194 operations between January 1 and January 31, 2007. Of 2,194 operations that completed Phase I, 1,077 consented to be contacted by veterinary medical officers for more information on the study. Of the 1,077 operations, 582 agreed to continue with Phase II of the study, and state and federal Veterinary Medical Officers (VMOs) and Animal HealthTechnicians (AHTs) administered two questionnaires between February 26 and August 31, 2007. Categories included cattle inventory, general management, health management, housing, biosecurity, antibiotic use, and nutrient management. A subset of eligible farms that participated in the both phases of the study was selected for composite fecal sampling. A subset that underwent composite fecal sampling was selected for individual collection. Farms were visited once by state and federal VMOs and AHTs between February 28, 2007 and August 30, 2007. Individual adult cow fecal samples and/or composite fecal samples were collected from 265 dairy herds in 17 states. Samples were cultured for Salmonella, and the MIC was determined for 15 antimicrobials. Herds were classified as Salmonella positive if at least one isolate was recovered, and AMR Salmonella positive if at least one resistant isolate was recovered.

Up to 35 individual samples (regardless of herd size) were collected via rectal retrieval, using individual sleeves. This sample size provides 95% confidence of detecting a positive animal assuming a prevalence not less than 8%. Up to five sick cows and five cows scheduled for culling were sampled, and the remainder were from cows with saleable milk. Composite samples were collected from adult cow areas where manure accumulated. Recommended sites included alleyways, pens, exits from parlors, floors of holding pens, flush water, gutter cleaner, lagoons or manure pits, and manure spreaders. The six composite fecal samples were collected from six different adult cow areas. Each composite fecal sample consisted of approximately 4 oz of manure/slurry from six different locations within a cow area. Samples were placed in sterile bags and placed on ice for shipment

AST Method: None

Reference explicitly reports AST breakpoints: True

Reference reports using a MIC table: False