Biotechnologies for improving animal metabolism and growth - A review

Biotechnology will play critical role in improving animal productivity. Animal growth rate and muscle deposition potential can be greatly improved by the application of biotechnology and biotechnological products. Administration of recombinant somatotropin (ST) or other compounds such as IGF-l and growth hormone-releasing peptides (GHRPs) can enhance growth rate and carcass lean percentage. Gene transfer offers a powerful approach to manipulate endocrine system and metabolic pathways toward faster growth and better feed efficiency. Biotechnology is also extensively used for improving metabolism and activity of gut microorganisms for better nutrient digestibility. Knockout of growth-inhibiting genes such as myostatin results in considerable acceleration of body weight and muscle growth. Animal growth can also be improved by the use of gene therapy. Immunomodulation is another approach for efficient growth through controlling the activity of endogenous anabolic hormones. All the above aspects will be discussed in this review.