Animal Feeding

The use of purified vitamins and vitamin premixes as supplements to animal feeds has increased the economy of animal feeding. Vitamin premixes are composed of required vitamins and a suitable carrier and are given to animals together with feedstuffs providing energy and protein. Vitamin E is generally added to premixes for most domestic and laboratory animals (Combs, 1998). They are added as esters, because they are more stable than free tocopherols. Free tocopherols are known to stabilize other vitamins such as vitamin A in premixes. As an example, practical diets for chicks contain 5500 pg a-tocopherol equivalents/g (Combs, 1998). 

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Figure 15.4 A plant for the production of animal feed. The heat pump encroaches into a pocket in the gremd composite curve. (From Smith and Linnhojf, Trans. IChemE, ChERD, 66 195, 1988 reproduced by permission of the Institution of Chemical Engineers.)...

Enzymes are used in baking, cheese manufacture, wine-making, brewing and distillation, pharmaceuticals, leather tanning, paper manufacture, adhesives, sewage disposal, animal feeds and in detergents. 

Hydrogen selenide in a concentration of 1.5 ppm is intolerable to man. Selenium occurs in some solid in amounts sufficient to produce serious effects on animals feeding on plants, such as locoweed, grown in such soils. Exposure to selenium compounds (as Se) in air should not exceed 0.2 mg/m3 (8-hour time-weighted average - 40-hour week). 

The following data were collected as part of a study to determine the effect of sampling variance on the analysis of drug animal-feed formulations.2... 

Typical examples of solid samples include large particulates, such as those found in ores smaller particulates, such as soils and sediments tablets, pellets, and capsules used in dispensing pharmaceutical products and animal feeds sheet materials, such as polymers and rolled metals and tissue samples from biological specimens. 

Animal dmg controls Animal fat Animal fats Animal feed... 

M. S. Ash., Animal Feeds Compendium, Agricultural Fconomic Report No. 656, U.S. Dept, of Agriculture, Economic Research Service, Washington, D.C., 1992. 

Nonnutrient Additives. Nonnutritional dietary additives provide antioxidants to preserve freshness, flavor enhancers to stimulate food selection, color to meet the owner s expectations, pellet biaders to minimi2e fine particles, mycostats to minimi2e mold growth, and iagredient-flow enhancers. Pet foods do not iaclude coccidiostats, antibiotics, added hormonal materials, and fly-larval iasecticides used ia other animal feeds. 

Sodium chloride is relatively inexpensive and is provided either free or incorporated directly into animal feed to prevent sodium and chloride deficiencies. Potassium is usually not deficient because most forages have adequate quantities. Therefore, it should be supplemented only when animals consume poor quaHty roughages or a high concentrate diet, or when they are under stress, dehydrated, or suffering from diarrhea (5). Potassium deficiency usually is alleviated by changing the diet or by supplementing with potassium sulfate. 

When PET is extracted with water no detectable quantities of ethylene glycol or terephthaUc acid can be found, even at elevated extraction temperatures (110). Extractable materials are generally short-chained polyesters and aldehydes (110). Aldehydes occur naturally iu foods such as fmits and are produced metabohcaHy iu the body. Animal feeding studies with extractable materials show no adverse health effects. 

Modem technology for produciag microbial cells for human food or animal feed emerged ia Germany duriag World War I. Baker s yeast,... 

Most of the bacteria, yeasts, molds, and higher fungi of interest for SCP production are deficient in methionine and must be supplemented with this amino acid to be suitable for animal feeding or human food appHcations. Also, lysine—arginine ratios should be adjusted in poultry rations in which yeast SCP is used (62). Human feeding studies have shown that only limited quantities of yeast such as Candida utilis can be added to food products without adverse effects on flavor (63). 

The 1993 market for LPC-type products in the United States was for dried alfalfa meal for animal feed. This product is sold for both protein and carotenoid content. The USDA Pro-Xan product attempts to obtain improved xanthophyU contents for use in egg-laying rations in addition to protein contents. The limitations to commercial development of LPC products for human food use are high capital costs as compared with the low yields of protein, seasonal availabihty of raw materials, and the need in the United States for FDA approval of the products. 

Lupine seed, though used primarily in animal feeds (see Feeds AND FEED ADDITIVES), does have potential for use in human appHcations as a replacement for soy flour, and is reported to contain both trypsin inhibitors and hemagglutenins (17). The former are heat labile at 90°C for 8 minutes the latter seem much more stable to normal cooking temperatures. Various tropical root crops, including yam, cassava, and taro, are also known to contain both trypsin and chymotrypsin inhibitors, and certain varieties of sweet potatoes may also be impHcated (18). 

The antagonisms that exist between unsaturated fatty acids, and carotene and vitamin E are compHcated and largely undefined. Linoleic acid acts as an antivitamin to i7/-a-tocopherol [59-02-9, 1406-18-9, 10191-41-0] (vitamin E) by reducing availabiHty through direct intestinal destmction. Various Hpoxidases destroy carotenes and vitamin A (73). Dicoumarol [66-76-2] (3,3 -methylenebis(4-hydroxycoumarin)) is a tme antimetaboHte of vitamin K [12001 -79-5] but seems to occur only in clover and related materials that are used primarily as animal feeds (74). 

Formic acid can also be used as an antisalmoneUa additive in animal feeds, for decontamination of feed raw materials, and prevention of flock infection in the poultry industry by treatment of the finished feed. 

The nutrient sparing effect of antibiotics may result from reduction or elimination of bacteria competing for consumed and available nutrients. It is also recognized that certain bacteria synthesize vitamins (qv), amino acids (qv), or proteins that may be utilized by the host animal. Support of this mode of action is found in the observed nutritional interactions with subtherapeutic use of antibiotics in animal feeds. Protein concentration and digestibiHty, and amino acid composition of consumed proteins may all influence the magnitude of response to feeding antibiotics. Positive effects appear to be largest... 

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