Compounding additive feeding

Insecticidal Activity. Adult houseflies and 3rd instar com earworm larvae were used to evaluate the light induced toxicity of a-T. Rose Bengal was used as the standard. Both species were treated with a series of doses of the test compounds by feeding. In addition, a-T was tested by topical application. Two sets of insects were treated, one of which was kept covered to serve as a dark control. 

From elemental analysis, IR and C-NMR spectroscopy and GC-MS investigations of pyrolysates, PRB B isolated from the B race ca 10% of dry biomass), exhibits very similar structural features when compared to PRB A only slightly more important methyl-branching is observed in the former (77). In addition, feeding experiments with radio-labelled compounds confirmed the involvement of long unbranched, hydrocarbon chains in the biopolymer network. Indeed, sodium DL [2- " C] mevalonate, a botryococcene precursor, was poorly incorporated, while [lO- C] oleic acid resulted in strongly labelled PRB B (69, 72) in this latter case radioactivity was recovered both in the hydrocarbons and the fatty acids released on pyrolysis. To date the origin of PRB B is still obscure, no ether lipids similar to those found in the A race have been so far isolated from the B race. 

FEEDS AND FEED ADDITIVES - RUMINANT FEEDS] (Vol 10) -organobromine as [BROMINE COMPOUNDS] (Vol 4)... 

Animals that do not readily accept pelleted feeds may be enticed to do so if the feed carries an odor that induces ingestion. Color development is an important consideration in aquarium species and some animals produced for human food. External coloration is desired in aquarium species. Pink flesh in cultured salmon is desired by much of the consuming pubHc. Coloration, whether external or of the flesh, can be achieved by incorporating ingredients that contain pigments or by adding extracts or synthetic compounds. One class of additives that imparts color is the carotenoids. 

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. 

Most commercial processes involve copolymerization of ethylene with the acid comonomer followed by partial neutralization, using appropriate metal compounds. The copolymerization step is best carried out in a weU-stirred autoclave with continuous feeds of all ingredients and the free-radical initiator, under substantially constant environment conditions (22—24). Owing to the relatively high reactivity of the acid comonomer, it is desirable to provide rapid end-over-end mixing, and the comonomer content of the feed is much lower than that of the copolymer product. Temperatures of 150—280°C and pressures well in excess of 100 MPa (1000 atm) are maintained. Modifications on the basic process described above have been described (25,26). When specific properties such as increased stiffness are required, nonrandom copolymers may be preferred. An additional comonomer, however, may be introduced to decrease crystallinity (10,27). 

Most of the phosphoms produced as the element is later converted to high purity phosphoric acid and phosphate compounds the remainder is used in direct chemical synthesis to produce high purity products. In contrast, phosphoric acid produced by the wet process is used in lower purity apphcations, especially in fertiliser and to a lesser degree in animal feed (see Feeds AND FEED ADDITIVES). More recendy, a small portion of wet acid is purified in a second process and then also used in high purity acid and phosphate compound apphcations. 

Organophosphoms compounds, primarily phosphonic acids, are used as sequestrants, scale inhibitors, deflocculants, or ion-control agents in oil wells, cooling-tower waters, and boiler-feed waters. Organophosphates are also used as plasticizers and flame retardants in plastics and elastomers, which accounted for 22% of PCl consumed. Phosphites, in conjunction with Hquid mixed metals, such as calcium—zinc and barium—cadmium heat stabilizers, function as antioxidants and stabilizer adjutants. In 1992, such phosphoms-based chemicals amounted to slightly more than 6% of all such plastic additives and represented 8500 t of phosphoms. Because PVC production is expected to increase, the use of phosphoms additive should increase 3% aimually through 1999. 

Selenium plays a dual role in a living organism, depending on the compound and the amount adsorbed. Controlled small doses of some compounds are used in medicine and as diet supplements, for example, ca 0.1 ppm of diet dry matter for Hvestock (see Feed additives Mineral nutrients). Larger amounts can be toxic. 

By-products from EDC pyrolysis typically include acetjiene, ethylene, methyl chloride, ethyl chloride, 1,3-butadiene, vinylacetylene, benzene, chloroprene, vinyUdene chloride, 1,1-dichloroethane, chloroform, carbon tetrachloride, 1,1,1-trichloroethane [71-55-6] and other chlorinated hydrocarbons (78). Most of these impurities remain with the unconverted EDC, and are subsequendy removed in EDC purification as light and heavy ends. The lightest compounds, ethylene and acetylene, are taken off with the HCl and end up in the oxychlorination reactor feed. The acetylene can be selectively hydrogenated to ethylene. The compounds that have boiling points near that of vinyl chloride, ie, methyl chloride and 1,3-butadiene, will codistiU with the vinyl chloride product. Chlorine or carbon tetrachloride addition to the pyrolysis reactor feed has been used to suppress methyl chloride formation, whereas 1,3-butadiene, which interferes with PVC polymerization, can be removed by treatment with chlorine or HCl, or by selective hydrogenation. 

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. 

Additive inhibitors have been developed to reduce the contaminant coke produced through nickel-cataly2ed reactions. These inhibitors are injected into the feed stream going to the catalytic cracker. The additive forms a nickel complex that deposits the nickel on the catalyst in a less catalyticaHy active state. The first such additive was an antimony compound developed and first used in 1976 by Phillips Petroleum. The use of the antimony additive reportedly reduced coke yields by 15% in a commercial trial (17). 

Copper compounds are used as feed additives in Europe and the United States primarily for chickens and swine (see Feeds and feed additives) (90,91). Copper increases the rate of gain and feed efficiencies of the animals. It is unclear whether this results from overcoming animal deficiencies or by enhancing preservation of feedstuffs. 

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