Feed additives commercialization

Commercially, urea is produced by the direct dehydration of ammonium carbamate, NH2COONH4, at elevated temperature and pressure. Ammonium carbamate is obtained by direct reaction of ammonia and carbon dioxide. The two reactions are usually carried out simultaneously in a high pressure reactor. Recendy, urea has been used commercially as a catde-feed supplement (see Feeds and feed additives). Other important appHcations are the manufacture of resins (see Amino resins and plastics), glues, solvents, and some medicinals. Urea is classified as a nontoxic compound. 

The FDA first approved use of a polyether ionophore as a feed additive for catde ia 1975. Ionophores were first isolated from bacteria generally of the Streptomjces genus, but are produced commercially by bacterial fermentation (qv). Monensia [17090-79-8] and other ionophores are being fed to over 90% of feedlot cattle grown for beef (53) to enhance efficiency of gain improvements of 5—10% are common. Ionophores also are used as anticoccidial dmgs ia poultry production and have similar, but lesser, effects ia mminants (54). 

Only three dalbaheptides are commercialized vancomycin (39) and teicoplanin (18—22) for human health, and avoparcin (63—65) for animal usage. Vancomycin, the main trademark of which is EH Lilly s Vancocin had 1990 sales around 160 million. Total annual production is in the vicinity of 8 t. Teicoplanin, trademarked Targocid, had 1990 sales of 35 million corresponding to 200 kg. Teicoplanin is commercialized in Europe, Hong Kong, Korea, and the Middle East. It is at the late developmental clinical phase in North America and Japan. Avoparcin is used as a growth promoting feed additive (see... 

The polyether antibiotics were first recognized as a separate class with the pubHcation of the structure of monensia ia 1967 (1). Several members of the group have siace found commercial appHcation as anticoccidials ia poultry farming and ia improvement of feed efficiency for mmiaants (see Feeds and FEED additives). 

The commercial uses of arsenic compounds in 1988, measured in terms of elemental arsenic, are wood (qv) preservatives, 69% agricultural products (herbicides (qv) and desiccants (qv)), 23% glass (qv), 4% nonferrous alloys and electronics, 2% and animal feed additives and pharmaceuticals (qv), 2% (see Feeds AND feed additives). Chromated copper arsenate (CCA) [11125-95-4] is the most widely used arsenic-based wood preservative. The Environmental Protection Agency has, however, restricted the use of arsenical wood preservatives to certified appHcators. 

Thiopeptin is a sulfur-containing peptide antibiotic complex produced by Streptomyces tateyamensis. It is composed of five closely related components, the thiopeptins Ai, A2, A3, A4, and B (8). Commercially available thiopeptin is primarily composed of thiopeptins B. This antibiotic is active against gram-positive bacteria and is used exclusively as a feed additive for pigs. 

The industrially important acetoxylation consists of the aerobic oxidation of ethylene into vinyl acetate in the presence of acetic acid and acetate. The catalytic cycle can be closed in the same way as with the homogeneous Wacker acetaldehyde catalyst, at least in the older liquid-phase processes (320). Current gas-phase processes invariably use promoted supported palladium particles. Related fundamental work describes the use of palladium with additional activators on a wide variety of supports, such as silica, alumina, aluminosilicates, or activated carbon (321-324). In the presence of promotors, the catalysts are stable for several years (320), but they deactivate when the palladium particles sinter and gradually lose their metal surface area. To compensate for the loss of acetate, it is continuously added to the feed. The commercially used catalysts are Pd/Cd on acid-treated bentonite (montmorillonite) and Pd/Au on silica (320). 

Canthaxanthine (53) has a reddish color, is somewhat more stable than (1-carotene, and was introduced commercially as a feed additive in 1964. 

Since keratinase is a versatile protease that digests all kinds of proteins, it is possible that supplementation of the enzyme in feed may improve the feed digestibility. In 2001 keratinase was tested as a feed additive. The first test in young chicks was positive, and reproduced by many more experiments 0.1% of crude keratinase in a regular corn-soy diet improved the body weight gain, the feed conversion ratio (FCR), or feed efficiency in broiler chickens. Numerous experiments included the cage tests of chicks to 3-4 weeks of age (Odetellah et al., 2003), pen trials on a research farm to 6 week market age (Odetellah et al, 2005), and the commercial tests conducted by private com-... 

The development of a novel production system for D-pantoyl lactone (which is a lactone compound carrying a chiral hydroxy group and a chiral intermediate for the commercial production of D-pantothenate) by microbial asymmetric reduction has been undertaken. D-pantothenate is mainly used in various pharmaceutical products and as an animal feed additive, the current world production of calcium pantothenate being about 6,000 tons per year. Conventional commercial production of D-pantoyl lactone has depended exclusively on chemical synthesis involving optical resolution of a chemically synthesized racemic pantoyl lactone, which is the most troublesome step of the pantothenate synthesis process. 

R)-Pantothenic acid (vitamin B5) is synthesized by microbes and plants, but not by mammals, who require it as a nutritional factor. Only the (R)-enantiomer is physiologically active. (R)-Pantothenic acid is produced as its calcium salt on a 6 kt a-1 scale, 80% of which is applied as an animal feed additive major suppliers are Roche, Fuji and BASF. Pantothenic acid is produced via chemical methods [110] but a fermentative procedure has recently been commercialized. 

Moving on from therapeutic antibacterials to feed additive antibacterials, the chart shows that swine and poultry are the largest commercial sectors. 

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