[Efficiency of a herd health program in Swiss dairy herds]

A retrospective analysis of the reproductive parameters was conducted in 15 dairy farms using a herd health monitoring system between 1995 and 1998. Five of these farms have used this monitoring process for many years (group 1) while 10 of them only initiated the process in 1996 (group 2). It was the aim of this study to evaluate the economic gain of the farms in each group due to the herd health monitoring program throughout the three year study period, by using Value Based Management (VBM), a model from the economic sciences. The mean calving to conception interval decreased from 93.3 to 84.0 days and from 104.9 to 86.7 days throughout the study period in groups 1 (P>0.05) and 2 (P < 0.05), respectively. The mean percentage of cows with calving to conception intervals below 115 days varied between 68.2% and 82.0% in group 1, while there was an increase form 65.2% to 78.6% in group 2 (P<0.05). There were no apparent trends in the reproductive culling rate throughout the study period (P>0.05), and the majority fell below 10%. Likewise, the first service conception rate varied between 52.7% and 56.6% and between 41.2% and 50.0%, in group 1 and 2, respectively. The number of services per conception varied between 1.6 and 1.8 and between 1.8 and 1.9, in groups 1 and 2, respectively. The number of days between calving and first service varied between 62.7 and 64.8 days in group 1, while it decreased significantly from 69.2 to 59.2 in group 2 (P<0.05). The time between first service and conception decreased from 30.6 to 22.0 days, and from 35.7 to 28.0 days in groups 1 and 2, respectively (P<0.05). Although there was an apparent increase of the detection rate of oestrus from 57.8% to 68.2% throughout the study period in group 1, it was not significant (P > 0.05). In group 2, however, the oestrus detection rate increased significantly from 53.0% to 69.9% (P < 0.05). The percent of detected oestrus within 42 days post partum increased from 33.1% to 38.1%, and from 24.1% to 40.9% in groups 1 and 2, respectively (P < 0.05). By 1998, four out of five farms in group 1, and five out of the eight farms where information was avail- year study period of CHF 25.- to CHF 609.- per cow and year. The calving to conception interval and the reproductive culling rate were the two most important parameters to determine the reproductive performance of the herd and the economic benefit of the herd health monitoring program. These findings support the implementation of a herd health monitoring program.