Effects of health disorders on feed intake and milk production in dairy cows

The purpose of this study was to quantify feed intake decreases and associated milk production losses related to health disorders in dairy cows. Daily individual records of feed intake, milk production and health disorders were available in an experimental farm (107 328 daily records on 1050 lactations from 551 Holstein cows less than 140 DIM). Milk production losses and feed intake decreases were estimated for each health disorder, from 5 days before to a maximum of 140 days after its diagnosis, in comparison to a cow without the disorder, using two separate mixed linear models. On the day of diagnosis, diarrhoea, systemic mastitis, ketosis and milk fever were associated with high reduction in milk production (4.1-25.7 kg) and feed intake (6.7-14.7 kg DM). High cumulated decreases occurred in milk production (109-160 kg) after systemic mastitis, teat injuries and twin calving and in feed intake (46-72 kg DM) after ketosis, systemic mastitis and hock lesions. The average estimated effect of health disorders is a 1.94-kg milk yield loss per kg DM feed intake decrease. This suggests that economical evaluation of health control actions should include associated feed intake decreases. (C) 2003 Elsevier B.V. All rights reserved.