Calf mortality as a welfare indicator on British cattle farms.

The objective of this study was to test calf mortality as an indicator of on-farm welfare and its use for welfare targeted surveillance. Calf mortality data were retrieved for three UK counties to estimate calf mortality rates at holding and county level. A selection criterion based on upper quartiles of calf mortality for the county of concern was defined. Its predictive ability was tested in a field study. The death risk of calves less than 6 months of age in 2002 was 1.76% in Inverness, 5.83% in Cheshire and 4.8% in Norfolk. Fifty-two welfare inspections matched by parish were conducted between October 2004 and January 2005. The positive predictive value was 26.92% and the negative predictive value was 65.38%. The addition of herd type, county and membership to an assurance scheme improved the predictive value. This study shows that calf mortality can be the starting point to design targeted welfare inspections in countries with centralized animal data recording systems.