Concepedia

Abstract

SIXTY wethers were used in a fasted and refeeding schedule to determine enzyme adaptations important in the long term control of metabolite flux through pathways of gluconeogenesis and lipogenesis. After a 30% reduction in empty body weight; liver glucose-6-phosphatase was reduced and after refeeding a concentrate ration, it was increased 2.5 fold. In general, when sheep were refed a concentrate ration, enzyme adaptations in both liver and adipose tissues were more dramatic than when refed hay. Enzymes normally associated with high rates of lipogenesis were elevated in adipose tissue of sheep receiving the concentrate ration. Long term adaptations to fasting in ruminants are characterized by a decrease in gluconeogenic and lipogenic enzymes. The type of diet refed has a profound influence on the enzyme profile of liver and adipose tissues.