Table 1.
No. herds | End of one year study period | Herd size Cow years/year | Calculated bulk tank somatic cell count | Milk production Kg ECM/day | Mastitis treatments % cows treated/cow year | % of cows with infection risk > 50% | |
Conventional | 20 | 03–2000 | 83 | 283 | 25.7a | 74a | 42 |
Organic before 1995 | 18 | 03–2000 | 88 | 296 | 22.1c | 48b | 38 |
Converting herds before conversion | 19 | 04–1999 or 04–2000 | 87 | 317 | 24.6a,b | 61a,b | 42 |
Converting herds first year after conversion | 19 | 04–2000 or 04–2001 | 101 | 337 | 23.3c | 52a,b | 44 |
Converting herds second year after conversion | 19 | 04–2001 or 04–2002 | 107 | 327 | 23.8* | 48a,b | 45 |
Conventional herds in full research project | 109 | 03–2000 | 85 | 309 | 24.4b | 55* | 43 |
Different letters: P < 0.05
*No comparison made