Changes in plasma concentrations of glucose, free fatty acids, ketone bodies, thyroxine and insulin of lactating beef cows in relation to time of feeding and energy status

Abstract

The economic implications of sub-standard performance in animal production which result from the increased incidence of metabolic disorders such as bovine ketosis and ovine pregnancy toxaemia, and accompanying reduced reproductive performance, plus the detrimental effects of undernutrition, are well known. Together they pinpoint the desirability of being able to assess the adequacy of rations in supplying nutrients, particularly energy, to provide an appropriate diet. The assessment of nutritional status is becoming increasingly important as farmers attempt to maintain enterprise profitability by either reducing feed costs and maintaining production, or by maintaining feed costs and increasing overall production, or by a combination of these two procedures.