An evaluation of milk recording, somatic cell counts and reproductive performance in a large cohort of dairy herds in England and Wales

摘要: Milk recording consists in the regular, usually monthly, collection of a milk sample from all lactating cows dairy herd. A large data collected England and Wales between 2004 2006 was used this thesis. 8,211,988 recordings 2,128 herds, representing 16 % herds activity December 2006, were described analysed. Calvings followed seasonal pattern with 80 more calving September than May. production highest May (26.5 kg) lowest October (24.1 kg). Butterfat stable, close to 4 March reached minimum at 3.7 June July. Protein stayed 3.2 3.3 year. Geometric mean somatic cell count 177 180 205,000 cells/mL July August. At individual cow level, yield, percentage butterfat, protein, fat protein ratio (geometric mean) 26.4 kg, 3.96 %, 3.29 1.21 90,000 cells/mL, 5 305 days milk. Changes counts around threshold 200,000 consecutive dates predict bulk both herd-year test-day levels. The main contributors staying above for 2 test-days. yields composition start lactation conception interval. Higher lower lactose, higher butterfat associated probabilities before 145