Metabolic Responses of Lactating Goats to Feed Restriction and Dietary 1,3-Butanediol

Abstract

Feed restriction and dietary 1,3-butanediol were used with lactating goats in an attempt to induce metabolic changes characteristic of bovine lactation ketosis and fatty liver. In Experiment 1, midlactation goats were fed 80, 102, or 114% of metabolizable energy requirements and 0, 50, or 100 g/d of 1,3-butanediol. Concentration of β-hydroxybutyrate in blood plasma decreased with increasing metabolizable energy but was increased greatly at 2h after goats were fed 50 or 100g butanediol and remained elevated at 6h postfeeding with 100g of butanediol. Concentration of glucose in plasma was decreased at 2 and 6h postfeeding in goats fed 100g of butanediol. In Experiment 2, goats in early lactation were fed for ad libitum intake or were restricted to 70% of ad libitum intake with 1,3-butanediol included at 10% of diet DM. The treatment decreased milk production, increased concentrations of β-hydroxybutyrate and nonesterified fatty acids, and decreased the concentration of insulin and the insulin to glucagon ratio in plasma. Concentrations of glucose, acetate, and glucagon in plasma were not affected. After 28 d of treatment, concentration of total lipid in liver was increased, but concentrations of glycogen and triglyceride were unaffected. Changes caused in goats by feed restriction plus dietary 1,3-butanediol were characteristic of subclinical lactation ketosis in cows, but the response was more moderate than seen previously in cows.