Body composition and growth in lambs: The effect of the myostatin g+6723G>A mutation and the β-adrenergic agonist ractopamine

Abstract

This thesis reports two experiments designed to evaluate the effect of the myostatin g+6723G>A mutation on production in meat lambs, with emphasis on traits such as: growth, lean meat yield, meat quality and feed efficiency. Chapter 1 provides an introduction and background information on the current knowledge of the function and mechanism of myostatin, results of preliminary research on the myostatin g+6723G>A mutation in lambs and the β-adrenergic agonist, ractopamine. Chapters 2, 3 and 4 present the results of the first experiment and Chapter 5 presents the results of the second experiment. Chapter 6 is the general discussion which summarises the major findings and important implications identified during the studies. Chapter 7 is a consolidated reference list. Chapter 8 consists of appendices and is divided into two parts. The first part is a list of published or submitted peer reviewed journal manuscripts and abstracts. The second part is detailed materials and methods of myofibre and computer tomography.