Johne's Flashcards

Question

what tests are useful to establish herd status

Answer 1

Bulk tank ELISA: * Useful starting point in dairy herds but insensitive especially in low prevalence herds * False negatives Blood serology: * 30 cow screen * Select based on age/ICSCC * All animals \>2yr

Answer 2

**1. not infected** to remain free from MAP **2. infected, low prevalence** to eliminate MAP from the herd as fast as possible **3. infected, moderate or high prevalence of infected animals** to prevent the spread of MAP to incoming stock (including homebred replacements) in order to reduce prevalence over time

Answer 3

bioexclusion

Answer 4

bioexclusion test and cull

Answer 5

bioexclusion test and cull possibly breed to terminal sire initially buy in replacements from accredited-free source, keep separate

Answer 6

**ELISA-based:** * Blood test all animals \>2yrs old annually * Milk ELISA quarterly **Cull positives at convenient time** **Manage positive cattle as ‘leper colony’** * Beef cows in separate group * Dairy cows calve in separate groups * Don’t retain offspring for breeding **Johne’s accredited free = 3 x annual clear tests**

Answer 7

Level 1: there have been 3 clear annual herd tests. This is the lowest level of risk Level 2: there has a current clear herd test, but has not yet gained level 1 status Level 3: at the most recent herd test there are reactors in the herd at the level of 3% or fewer Level 4: there has been more than 3% reactors at its most recent herd test Level 5: those herds without a health plan for Johne’s disease and that do not adhere to the mandatory elements of the health plan are risk level 5. This is the highest level of risk and additionally applies to herds that carry out no testing

Answer 8

Calf rearing Cleanliness Colostrum Replacement milk Pasture/slurry

Answer 9

1. Identify status of breeding cattle 2. Separate into negative and positive groups 3. Biosecurity: establish (herd-level) status of animals coming into herd 4. Keep replacements from negative-test cows and from calves that have had less infection-pressure (ex. calves calved at grass) 5. Slurry and/or manure management

Answer 10

Less ability to manage transmission between infected dam/adults and young calves than dairy Possibly increased chance of calves being exposed to other host (sheep/deer) as more likely to be outside during critical period (first month) Environmental management probably most feasible (fencing off standing water etc)

Answer 11

as for beef plus: Don’t pool colostrum in herds with known Johne’s disease from cows with unknown/positive test status ‘Herdwise’ testing scheme

Answer 12

Quarterly individual milk antibody testing used as a tool to control the disease within a herd Traffic light system is used to categorize cows, and inform management decisions about which milk to collect for replacement feeding and animals testing positive are put into separate calving facilities All cattle are re-tested every 3 months when in milk, so deacons are less based on a single antibody result Repeat positives are culled as they are likely to have reduced milk yield and will be contributing to environmental contamination

Answer 13

antibody results used to inform management decisions Milk/colostrum for replacements = green * Group calving Calving facilities = yellow * Individual Culling repeat positives prior to next calving = red * Environmental contamination * Minimize milk and slaughter losses

Answer 14

only available by import ## Footnote Only available by import Needs Animal Health Office approval Interferes with TB testing Does not stop cases Should also use all aforementioned hygiene practices