Association between somatic cell count early in the first lactation and the lifetime milk yield of cows in Irish dairy herds

摘要: Change in lifetime milk yield is an important component of the cost diseases dairy cows. Knowledge likelihood and scale potential savings through disease prevention measures to evaluate how much expenditure on control rational. The aim this study was assess association between somatic cell count (SCC) at 5 30 d during parity 1 (SCC1), for cows Irish herds. data set studied included records from 53,652 5,922 This split into 2 samples 2,500 3,422 herds random. Linear models with first-lactation as outcomes random effects account variation were fitted first sample herds; second used cross-validation. developed a Bayesian framework include all uncertainty posterior predictions parameters estimated 10,000 Markov chain Monte Carlo simulations. final model good fit appeared generalizable other A unit increase natural logarithm SCC1 associated median decrease 864 kg, 105 kg. To clarify meaning results context, microsimulation trajectory individual cows, expected particular changes herd-level prevalence ≥ 400,000 cells/mL. Differences mean these multiplied by gross margin each cow give difference revenue. Results presented probabilities savings; example, 75% probability least€97 or€115/heifer calved herd existed if cells/mL reduced 20 <10 or <5%, respectively, least€71/heifer 10 <5%. indicate large differences yield, depending SCC early lactation findings can be where specific interventions heifer mastitis prepartum are likely effective.