Phosphorus body content

Sodium, potassium and chloride are the primary dietary ions that influence the electrolytic balance and acid-base status, and the proper dietary balance of sodium, potassium and chloride is necessary for growth, bone development, eggshell quality and AA utilization. Potassium is the third most abundant mineral in the body after calcium and phosphorus, and is the most abundant mineral in muscle tissue. It is involved in electrolyte balance and neuromuscular function. The content of potassium in poultry diets is usually adequate. Chloride is present in gastric juice and chlorine is part of the HC1 molecule which assists in the breakdown of feed in the proventriculus. Sodium is essential for nerve membrane stimulation and ionic transport across cell membranes. Signs of sodium, potassium or chloride deficiency include reduced appetite, poor growth, dehydration and increased mortality. 

A normal adult has a total body phosphorus content of 700-800 g [1]. The majority of phosphate is present in bone, although approximately 15% is distributed outside of the skeleton where it is present in the form of inorganic phosphate in extra-cellular fluid and organic phosphates within cells, such as adenosine triphosphate (ATP), nucleic acids, and membrane phospholipids. As such, phosphorus plays a vital role in numerous cell processes including cell energetics, cell membrane formation, and DNA RNA synthesis, to name a few. Within blood, phosphate exists mainly in two forms, HPO and HjPO. These two anions are important serum buffers and their relative concentrations are determined by the serum pH. 

Like nitrogen, phosphorus is an element that is essential to life. It constitutes only about 1 percent by mass of the human body, but it is a very important 1 percent. About 23 percent of the human skeleton is mineral matter. The phosphorus content of this mineral matter, calcium phosphate, Ca3(P04)2, is 20 percent. Our teeth are basically Ca3(P04)2 and Ca5(P04)30H. Phosphates are also important components of the genetic materials deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). 

Tab. 4.6 Phosphorus content in various organs of the human body...

It has been observed that when a body of water becomes eutrophic due to large inputs of phosphorus, diatom populations increase, and this results in a decline in the dissolved silica content of the water, especially the surface water(66). If this process continues until the available silica becomes depleted below the limiting concentration for diatoms, they are replaced by obnoxious green and blue-green algal species which have much lower requirements for silicon(67). Thus, it is beneficial to maintain an adequate supply of soluble silica in a phosphorus-rich body of water in order to promote diatoms as... 

Phosphorus fertilizers may contain impurities among those are some heavy metals that are of concern. In particular, cadmium (Cd) has received attention during the past few years. The level of cadmium content in fertilizers has been more or less arbitrarily limited to the concentration of 50 mg Cd/kg of P2O5 [7]. WHO has limited the daily intake of Cd to 1 microgram Ag of body weight per day [7]. The current average intake in Europe is lower than this limit [8]. 

Determination of the ratio of end-groups to monomeric units in systems of another type must be mentioned. Suppose that the end-group contains an element readily detected by NMR, such as fluorine or phosphorus, and that the bodies of the macromolecules are free from that element. Clearly, determination of, say, the fluorine content of the whole polymer could lead to a value of the required ratio. It is necessary to use as a standard a properly... 

Phosphorus has more known fimctions than any other mineral element in the animal body. The close association of phosphorus with calcium in bone has already been mentioned. In addition, phosphorus occms in phosphoproteins, nucleic acids and phosphohpids.The element plays a vital role in energy metabolism in the formation of sugar-phosphates and adenosine di- and triphosphates (see Chapter 9). The importance of vitamin D in calcimn and phosphorus metabolism has already been discussed in Chapter 5. The phosphorus content of the animal body is considerably less than that of calcimn content. Whereas 99 per cent of the calcium found in the body occurs in the bones and teeth, the proportion of the phosphorus in these structures is about 80-85 per cent of the total the remainder is in the soft tissues and fluids, where it serves the essential fimctions mentioned above. The control of phosphorus metabolism is different from that of calcium. If it is in an available form, phosphorus is absorbed well even when there is an excess over requirement. The excess is excreted via the kidney or the gut (via sahva). In monogastric animals, the kidney is the primary route of excretion. Plasma phosphorus diffuses into saliva and in ruminants the large amount of chewing during rumination results in saliva being the major input of phosphorus into the rumen rather than the food. 

The residual oil of the cake or meal is highly unsaturated and may result in soft body and milk fat if consumed in excessive amounts and may also impart a disagreeable flavour to milk. The oil rapidly becomes rancid and unpalatable, and meals containing it have been implicated in cases of vitamin E deficiency. The meal has a high content of phytic acid, which makes much of its phosphorus unavailable rations containing the meal may also need extra supplementation with calcium. 

Phytin content of whole seeds and protein bodies varies with species and cultivar. Examples of the chemical composition of the aleurone grains of rice and protein bodies (and isolated globoids) of cotton seed are shown in Table 2.7. Note, in particular, the higher phosphorus but lower protein content of the cereal aleurone grain in comparison with the dicot protein body. The concentration of the associated macronutrient elements can also be seen to differ. Qualitative as well as quantitative differences occur between the macronutrient compositions of different seeds, e.g. in C. maxima the globoid is rich in phosphate, potassium... 

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