Table 1 List of variables included in GLMSELECT procedure to produce final multivariate model
Variable | Type | Description |
|---|---|---|
Production | Binary | Organic or Conventional |
State | Nominal | NY, OR, or WI |
Herd size | Ordinal | < 100, 100 to 200, or > 200 |
Parity | Continuous | The average lactation of all lactating cows at the time of the survey |
Average yield | Continuous | Average annual milk production per cow |
Calf housing | Nominal | Always housed in individual pens or areas; sometimes housed in groups or with contact to cows; always housed in groups or with contact to cows |
Description of calving area | Nominal | Dedicated calving area; area shared with lactating cows; or area sometimes shared with sick cows |
Heifer and cow contact on pasture | Nominal | Heifers grazing a pasture with or after the cows; before the cows; or heifers and cows do not graze the same pasture |
Jersey | Binary | Mostly Jersey or not mostly Jersey herd |
Johne’s procedures | Nominal | Procedures for MAP-positive cows: cull after calving or dry off; cull immediately; keep; never observed clinical Johne’s disease |
Johne’s program | Binary | Participation in Johne’s program |
Open farm | Binary | Some or no entering animals |
Seasonality sine | Continuous | , where day is a continuous variable from 1 to 365 |
Seasonality cosine | Continuous | , where day is a continuous variable from 1 to 365 |
Source of drinking water | Nominal | Primary source of drinking water for 60 days prior to survey: well; municipal water; or surface water |
Spreading manure | Binary | Manure spreading on pasture or fields that will be consumed by animals |
Written plan for Johne’s disease | Binary | Written herd plan for managing Johne’s disease |