Effects of disease on milk production in the dairy cow: a review

Estimates of milli losses consequent to dystocia, stillbirth, milk fever, r etained placenta, metritis, cystic ovaries, ketosis, displaced abomasum and locomotor disorders were reviewed. Papers were selected if they provided q uantitative estimates of losses based on data collected after 1965, with a sample size resulting in a minimum number of disease cases of 25. Thirty-fi ve papers fulfilled the selection criteria. Milk losses were expressed in k g/day over the period under study to allow comparison of results. Milk feve r and cystic ovaries were not associated with yield losses (six studies for each disease). Less than half of the studies found losses associated with dystocia, retained placenta, and metritis, with, respectively, five studies out of 13 (0.3-2.3 kg/day across the lactation), five studies out of 13 (0 .8 kg/day across the lactation to 2.5 kg/day across 100 days in milk), and two studies out of 10 (0.4 kg/day across the lactation, and 2.3 kg/day acro ss 119 days in milk). More than half of the studies found losses associated with stillbirth, clinical ketosis, ketosis evidenced by a diagnostic test, and locomotor disorders, with, respectively, three studies out of five (0. 7-1.3 kg/day across the lactation), seven studies out of 11 (2.6-5.7 kg/day short-term, and 1.2 kg/day across the lactation), five studies out of seve n (1-7 kg/day on the day of diagnosis, and around 1 kg/day across 200 days in milk), and six studies out of 11 (0.3-3.3 kg/day across the lactation). All the five studies, investigating effects of displaced abomasum, found lo sses (3.5-10.9 kg/day across 80 days in milk, or 0.8-2.5 kg/day across the lactation). (C) 1999 Elsevier Science B.V. All rights reserved.