The wool growth of Merino sheep receiving an exponential pattern of methionine infusion to the abomasum

Abstract

The wool grown by Merino wethers infused with equal daily amounts of DLmethionine was compared with the wool grown by the same wethers while they were receiving the same quantity of methionine in an exponential pattern of infusion repeated every 6 days. The exponential pattern (8 g down to 0.5 g on the sixth day) of infusion was designed to simulate the expected flow of a once weekly dose of 'protected' methionine from the rumen to the abomasum. Initially, the wool growth of the wethers was measured while they were consuming the basal diet of oaten hay without any methionine infusion. In comparison the exponential and equal daily patterns of methionine infusion were associated with increases in wool growth of 37 and 36% respectively. Although the digestibility of the basal ration was relatively unaffected during the periods of methionine infusion both methods of infusion resulted in average nitrogen retentions greater than that from the basal ration alone.