Dietary requirements

The P contents of most animal foodstuffs are not particularly high (Table 12.9) and the more restricted variety of their diet makes animals much more prone to P deficiency than humans (Chapter 11.2) -this applies particularly to grazing ruminant animals. Symptoms arising from such deficiency include osteomalacia, hypophosphataemia and pica (depraved appetite) and also rickets in the 

TABLE 12.9 Phosphorus Content of Animal Foodstuffs (wt% P Approximate)  

Beef molasses 0.03 Peanut kernels 0.43 Sugar beet 0.05 

Steamed bone meal 14.0 Wheat bran 1.22 Tobacco 0.3 

The desirable Ca/P ratio in most animal diets is between 1 1 and 2 1 - not very different from the estimated ideal for human diets. Adequate amounts of vitamin D are also required for the proper utilisation of both these elements (Chapter 11.1). 

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Prostaglandins arise from unsaturated C20 carboxylic acids such as arachidonic acid (see Table 26 1) Mammals cannot biosynthesize arachidonic acid directly They obtain Imoleic acid (Table 26 1) from vegetable oils m their diet and extend the car bon chain of Imoleic acid from 18 to 20 carbons while introducing two more double bonds Lmoleic acid is said to be an essential fatty acid, forming part of the dietary requirement of mammals Animals fed on diets that are deficient m Imoleic acid grow poorly and suffer a number of other disorders some of which are reversed on feed mg them vegetable oils rich m Imoleic acid and other polyunsaturated fatty acids One function of these substances is to provide the raw materials for prostaglandin biosynthesis... 

The essential mineral nutrients are classified either as principal elements or as trace and ultratrace elements. The distinction between these groups is the relative amounts ia the dietary requirement (see Table 1). 

The present (ca 1997) maximum safe level of vitamin for long-term feeding in most species is four to ten times the NRC dietary requirements. Short-term (<60 d), most species can tolerate 100 times their apparent dietary requirements (210). 

Haddock, S. H. D., Rivers, T. J., and Robison, B. H. (2001). Can coelenter-ates make coelenterazine Dietary requirement for luciferin in cnidarian bioluminescence. Proc. Natl. Acad. Sci. USA 98 11148-11151. 

Example 1.—A classical problem of linear programming is the diet problem. Given minimal needs for vitamins, iron, calcium, phosphorous etc., which are present in known proportions in a variety of possible foods with given prices, it is desired to determine a diet from these foods that meets the minimal needs for the vitamins and other ingredients at the lowest cost. To illustrate with a simple example and hypothetical figures, denote three types of food by Flt F2, F3, and two types of dietary requirements, e.g., vitamins by A and B. The table... 

Camitine deficiency can occur particularly in the newborn—and especially in preterm infants—owing to inadequate biosynthesis or renal leakage. Losses can also occur in hemodialysis. This suggests a vitamin-fike dietary requirement for carnitine in some individuals. Symptoms of deficiency include hypoglycemia, which is a consequence of impaired fatty acid oxidation and hpid accumulation with muscular weakness. Treatment is by oral supplementation with carnitine. 

This section is devoted to the definition and comparison of the three nonrodent animal models (dog, ferret, and monkey) in terms of experimental procedures, environmental and dietary requirements, as well as advantages and disadvantages of use in safety assessment testing. 

Environmental and Dietary Requirements. For reasons of environmental control, ferrets used in safety assessment studies should be housed indoors. It has been suggested that an optimal temperature range for the ferret is 40-65°F (4-18°C), while relative humidity should be maintained in the range of 40 to 65% (Fox, 1988). The ferret does not tolerate heat well due to its lack of well-developed sweat glands the primary method of regulating heat loss appears to be through panting (Moody et al., 1985). 

Environmental and Dietary Requirements. For most nonhuman primate species, room temperatures should be maintained in the range of 75 5°F with a relative... 

Table III. Dietary Required Amino Acids (mg/100 g Fresh Fruit) in Some Fruits...

Humans have a limited capacity to synthesize amino acids de novo, but extensive interconversions can occur. Those amino acids which cannot be formed within the body and must be supplied by the diet are called essential . Members of this group, which includes the branched chain amino acids leucine and valine, and also methionine and phenylalanine, are all dietary requirements. Such essential amino acids may be chemically converted, mainly in the liver, into the non-essential amino acids. The term non-essential does not equate with not biochemically important but simply means they are not strict dietary components. 

Maintenance and environmental control. While diet, breathing, temperature, and waste removal are virtually taken for granted in most rodent work, they form serious problems with aquatic animals. Knowledge of dietary requirements and prepared diets generally are nonexistent for most species oxygen must be supplied and toxic gases removed temperature maintenance and water composition are very important and the decay of food waste and excreta must be avoided. 

Essential fatty acid one of a family of polyunsaturated fatty acids that are essential dietary requirements. 

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