Biotechnology in nutrition, physiology and animal health

*INRA UMR Veau et Porc Rennes (FRA) Diffusion du document : INRA UMR Veau et Porc Rennes (FRA)International audienc

Biotechnology in animal nutrition, physiology and health

Biotechnology is already widely used in animal production and there are numerous other potential applications. Application of biotechnology can be envisaged for improving the performance of animals through better nutrition, enhanced production potential or improved health status. Nutrients (i.e. amino acids) can be produced and/or protected, resulting in improved formulation of diets that more accurately meet specific needs for productive functions. Enzymes can improve the nutrient availability from feedstuffs, lower feed costs and reduce output of waste into the environment. Pre- and pro-biotics or immune supplements can inhibit pathogenic gut microorganisms or make the animal more resistant to them. Plant biotechnology can produce crops with improved nutritional value or incorporate vaccines or antibodies into feeds that will cheaply and effectively protect the animals against diseases. Transgenic manipulation of commensal gut or rumen microorganisms has considerable potential for improving nutrition, gut development and health in animals. Administration of recombinant somatotropin (ST) results in accelerated growth and leaner carcasses in meat animals and increased milk production in dairy cows. The effects on meat or milk quality are limited. Immunomodulation can also be used for enhancing the activity of endogenous anabolic hormones. Transfer of the ST gene has the same effects as use of exogenous ST. However, unless the expression of the gene is controlled with ad-hoc promoters, the health status of the transgenic animals is severely impaired. There are numerous applications of biotechnology that aim to improve the health and welfare of animals. The generation of disease-resistant transgenic farm animals is still a long-term goal. On the other hand recombinant vaccines are widely in use. New advancements such as DNA-based vaccines and genetically engineered vaccine adjuvants hold much promise for improving animal health. Monoclonial antibodies and nucleic acid probes are used widely in diagnostic tools. Neutralization approaches, including immunological and antisense DNA, can offer interesting alternatives to surgical castration and the traditional prevention of broodiness in breeder birds. Acceptance of biotechnology in livestock production is difficult, and depends heavily on the perception of risks and benefits by the general public. Information is critically important in order that lay citizens can make an educated choice. The acceptance of biotechnology applied to animal production will depend on social and cultural aspects, and on the perceived benefits for consumers and society in general

Biliary and plasma copper and zinc in pregnant Simmental and Angus cattle

Three each of 3-year-old Angus and Simmental heifers, surgically modified to collect bile, were used to measure the effects of pregnancy and breed on bile flow, biliary copper and zinc excretion and plasma copper and zinc concentrations. Bile copper excretion was significantly higher at 7-mo of pregnancy when samples from both breeds were pooled. From then onwards it declined to its lowest, one week post-partum. During pregnancy, plasma copper concentration increased slightly, reaching its highest level at 7-mo of pregnancy and then decreased slightly until full term. In pooled samples from both breeds, the correlation between increase in bile copper excretion and plasma copper concentration from 0 to 7-mo of pregnancy was high (r = 0.85) and significant (p < 0.05). Plasma zinc concentration decreased to the lowest level around 6-mo of pregnancy but increased thereafter until full term. In cows that were dried off one week after parturition, major shifts in bile and plasma copper and zinc parameters occurred at one week following and these coincided with a marked decline of bile flow and bile copper and zinc excretion. By 3-mo post-partum, biliary copper and zinc excretion and plasma copper and zinc concentrations had reached levels observed prior to pregnancy. When the data from all samples were pooled, the bile flow and bile copper excretion were significantly (p < 0.05) higher in Simmental, and plasma copper and zinc concentration higher in the Angus

Rotavirus Particles Function as Immunological Carriers for the Delivery of Peptides From Infectious Agents and Endogenous Proteins

A major problem in the development of useful animal subunit vaccines has been the generation of immune responses to weakly immunogenic molecules. For this purpose a new and effective delivery system has been devised. This system is based upon the inner capsid of bovine rotavirus. Under the appropriate conditions, the inner capsid protein, designated BP6, can be made to self-assemble in vitro and from spherical particles. These particles possess an inherent capacity to target to cells of the immune system