IMMUNE-MODULATION OF HORMONES CONTROLLING GROWTH

Consumer discrimination against meat products from animals treated wit h hormones has provided the impetus to investigate alternative ways of boosting feed conversion efficiency and growth rates of animals and t o manipulate the reproductive capacity of animals. In view of the long evity of the immune response to specific antigens and the realization that antibodies are capable of neutralizing or mimicking the actions o f hormones, vaccination techniques have been explored as alternatives to hormone administration to boost animal productivity. To date, only two commercial vaccines are available to improve the efficiency of pro duction, although neither is related to the stimulation of growth effi ciency: Fecundin (registered product, Glare Pty Ltd) is designed to im prove lambing percentages, and Vaxstrate (registered product, Arthur W ebster and Co.) to prevent reproductive activity. In this review, rece nt advances in vaccine development are explored together with some of the problems encountered in research in this field.