Ketosis and fatty liver in cattle

PROBABLY two‐thirds of nutritional problems in cattle centre on energy balance. Energy deficiency, particularly in early lactation, leads to fat mobilisation, the degree of which appears to be related to the level of milk production, the magnitude of the energy deficit and/or the cow's body condition score at calving. All these factors can result in increased fat utilisation and raised plasma fatty acids and ketone body levels, which in turn can lead to diseases such as clinical ketosis or fat cow syndrome. More frequently, however, there are no overt signs of disease, but the deficit has knock‐on effects such as an increased incidence of metabolic and infectious disease, excessive loss of condition, and poor fertility including poor conception rates, anoestrus, suboestrus and cystic ovarian disease. In every case there will be some increase in the fat content of the liver. Thus, the development of fatty liver appears to precede ketosis and contribute to its onset and that of a number of other energy deficiency syndromes, as described in this article.