摘要 : In the present study, lifetime milk-, fat-, protein yield and efficiency of lifetime milk-, fat- and protein were analysed. Analysis of variance for systematic effects was employed using a mixed linear model for an uncensored data... 展开 In the present study, lifetime milk-, fat-, protein yield and efficiency of lifetime milk-, fat- and protein were analysed. Analysis of variance for systematic effects was employed using a mixed linear model for an uncensored dataset including 524,190 German Brown cows born between 1990 and 2001. Date of birth, date of culling and age at first calving were registered for all cows under analysis. On average, lifetime milk, fat and protein yield were 22,127 kg, 924 kg and 789 kg and average efficiency of lifetime milk, fat and protein were 8.34 kg, 0.35 kg and 0.30 kg. Relative herd production level of the cow contributed the largest variance on lifetime milk production and its efficiency. Cows with lifetime milk yield and efficiency of half a standard deviation from the mean relative herd production level had least-squares (LS) means between 16,688 and 28,217 kg milk and an efficiency between 7.31 and 10.04 kg milk. From the birth years 1990-1993 to 1998-2001, LS-means for lifetime milk yield and efficiency decreased from 21,773 kg and 8.15 kg to 20,554 kg and 7.91 kg milk. Cows with Brown-Swiss proportions of 41-50% showed the highest LS-means for lifetime milk yield and efficiency with 21,830 kg milk, respectively 8.11 kg milk. The relationships among the age at first calving and lifetime milk production as well as efficiency were curvilinear. The higher the age at first calving the higher was lifetime milk production but efficiency of lifetime decreased. Approximately 20% of all German Brown cows reached a lifetime milk, fat and protein yield of 30,000 kg, 1,200 kg and 1,000 kg, respectively. For these lifetime records, cows had to be in milk for at least five lactations within seven years of life. 收起