The disease conditions, which are attributable to an imbalance between rates of input of dietary nutrients and the output of production, are defined as production diseases. These conditions, previously known as metabolic diseases, occur more commonly and assume greatest importance in dairy cows and buffaloes, and pregnant ewes. Parturient paresis (milk fever), ketosis (acetonaemia), downers cow syndrome, lactation tetany of mares, hypomagnesaemic tetanies, pregnancy toxaemia in sheep, fat cow syndrome and post-parturient haemoglobinuria in cattle and buffaloes are commonly encountered production diseases.
Production or metabolic diseases may be predisposed by the genetic factors. However, they are associated largely to production and management factors. In most cases increased demand for a specific nutrient that has become deficient under certain conditions is the primary cause of development of production diseases. High yielding dairy cows and buffaloes generally verge on abnormal homeostasis, and their feeding and management for enhanced milk production make them more susceptible to metabolic diseases.