Table 1 Progression in the percentage of milk shedders after vaccination (April 2011) in the different age groups of milking cows in the different samplings
March 2011 | October 2011 | April 2012 | October 2012 | April 2013 | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
N analyzed | % shedders | N analyzed | % shedders | N analyzed | % shedders | N analyzed | % shedders | N analyzed | % shedders | |
1st calving | 46 | 4.3 | 45 | 2.2 | 44 | 0.0 | 44 | 0.0 | 67 | 0.0 |
2nd calving | 47 | 0.0 | 34 | 2.9 | 35 | 0.0 | 33 | 0.0 | 33 | 0.0 |
≥ 3 calvings | 63 | 19.0 | 60 | 13.3 | 65 | 7.7 | 58 | 12.0 | 68 | 2.9 |
Total | 156 | 9.0 | 139 | 7.2 | 144 | 3.5 | 135 | 5.2 | 168 | 1.2 |