title: Subclinical ketosis: prevalence and associations with production and disease.
abstract: Cows in 32 southern Ontario Holstein herds were monitored for subclinical ketosis for a period of two and one half years. Milk samples were routinely collected and the level of milk ketone bodies determined by the use of a commercial nitroprusside based test powder (reactions scored as negative, +1 or +2). Approximately 92% of positive reactions were observed in the first 65 days of lactation and for that time period the prevalence of ketosis was 12.1%. Based on this prevalence, the minimum possible duration of subclinical ketosis would be 7.9 days and the minimum possible lactational incidence rate would be 12.1%. The prevalence during the first 65 days of lactation in individual herds ranged from 0 to 33.9%. Subclinical ketosis was more likely to be found in cows experiencing metritis than in unaffected cows. Detection of elevated levels of milk ketones also indicated that the cow had a significantly higher risk of having clinical ketosis, metritis or cystic ovaries diagnosed within the following four days. Milk ketone scores of +1 and +2 were found to be associated with a reduction in daily milk production of 1.0 and 1.4 kg of milk respectively.
mesh_terms: D000138:Acidosis / Q000662:veterinary*; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000378:metabolism; D005260:Female; D007657:Ketone Bodies / Q000032:analysis; D007662:Ketosis / Q000453:epidemiology / Q000378:metabolism / Q000662:veterinary*; D007774:Lactation; D008414:Mastitis, Bovine / Q000453:epidemiology; D008892:Milk / Q000378:metabolism; D009864:Ontario; D010048:Ovarian Cysts / Q000453:epidemiology / Q000662:veterinary; D011247:Pregnancy; D011644:Puerperal Disorders / Q000453:epidemiology / Q000378:metabolism / Q000662:veterinary*; D013997:Time Factors
chemical_list: D007657:Ketone Bodies