• Journal of Nutrition and Health
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• v.31 no.6
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• pp.1031-1038
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• 1998

The present study was carried out to investigate the effects of magnesium supplement levels and periods on calcium, magnesium, and phosphorus metabolism in male Sprague-Dawley rats given low protein and magnesium deficient diets for 2 weeks. Serum calcium content was significantly lower in the magnesium supplement group than in the magnesium-deficient group, but calcium excretion in urine and feces was significantly increased as magnesium level and period was increased. Increasing the dietary magnesium level and periods raised serum content and excretion of magnesium in urine k feces. Urinary excretion of phosphorus in two week group was significantly lower in the magnesium supplement group than in the magnesium-deficient group. fecal phosphorus excretion in supplement group (Mg 800mg/kg diet) was significantly higher than that of other group. (Korean J Nutrition 31(6) : 1031-1038, 1998)

• Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.30-37
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• 2006

We performed experiments on the uptake and excretion of dissolved organic phosphorus (DOP) using two toxic dinoflagellates, Alexandrium tamarense Lebour (Balech) and Gymnodinium catenatum Graham, isolated from Hiroshima Bay, Japan. ATP (adenosine triphosphate), UMP (uridine-5-monophosphate), G-6-P (glucose-6-phosphate) and Glycero-P (glycerophosphate) were used as DOP sources in preliminary uptake experiments. ATP was selected as the DOP species for the short-tenn uptake experiment because preliminary experiments showed it to be the DOP source used by both species. Although the $K_s$ values of A. tamarense and G. catenatum (5.63 and $7.61{\mu}M$, respectively) obtained from the short-term experiments for ATP were only slightly higher than those reported for dissolved inorganic phosphorus (DIP), the ${\rho}_{max}$ values (5.04 pmol/cell/h and 13.4 pmol/cell/h, respectively) were much higher. The DOP excretion rate in batch-culture experiments was estimated at 0.084 pmol/cell/h for A. tamarense and 0.012 pmol/cell/h for G. catenatum, accounting for about 30% and 25%, respectively, of the assimilated phosphorus. Our results suggest that the DIP-depleted conditions of Hiroshima Bay favor these two species by supporting their ability to use DOP.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.651-656
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• 1999

In current animal production in Japan, a large surplus of nitrogen and phosphorus is given to animals as their feed which are mostly imported from outside of our own country. Today, an excess of nitrogen and phosphorus from animal manure has been spread out of the area of animal production and the surroundings. These components have become the major reason for eutrophication of ground, surface and inland water. Nutritional studies for the reduction of nitrogen and phosphorus from animal waste has been done by many researchers. The reduction of excess protein in animal feed and the supplementation of deficient essential amino acids to feed have a possibility to increase the biological value of feed and to reduce nitrogen excretion, especially, via urine. The use of phytase activity to degrade phytate and to release utilizable inorganic phosphorus make it possible to cut an excess supply of feed additive inorganic phosphorus and to reduce phosphorus excretion from animal waste.

• Journal of Nutrition and Health
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• v.38 no.1
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• pp.40-47
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• 2005

This study was performed to determine the effect of three different concentrations of soy-isoflavones on calcium and phosphorus balance in either sham-operated or ovariectomized female rats. Seventy-two 16-week old Sprague-Dawley rats underwent sham operation or bilateral ovariectomy. They were provided diets containing different levels of soy iso-flavones for 6 weeks: 50 ppm (Jow isoflavone intake; LI) , 250 ppm (medium isoflavone intake; MI) and 500 ppm (high isoflavone intake; HI). The subsequent fecal and urinary excretions of calcium and phosphorus were then measured. In the sham-operated rats, body weight gains and food efficiency ratio of the MI and HI groups were significantly lower than the control group while food intake was not different. However, there was no significant difference in the ovariectomized rats. The fecal excretion of calcium was significantly lower in the LI, MI and HI groups than the control group in sham operated rats, and significantly lower in the HI group than the control group in ovariectomized rats. Also, apparent ab-sorption rate of calcium and phosphorus did not show any significant difference among groups. Urinary excretion of calcium and phosphorus was significantly lower in the HI group than the LI group in the sham-operated rats. Urinary excretion of calcium was significantly higher in the control ovariectomized rats than in the control sham-operated rats. Retention of calcium and phosphorus did not show any significant difference in both groups. From the above result, we see that isoflavone intake increases calcium retention through an increase in calcium absorption and also suppresses the increase of calcium excretion in urine in ovariectomy. Therefore, it is suggested that isoflavone intake is recommended for menopausal women who experience sharp bone loss due to the decrease in estrogen honnone.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.3
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• pp.432-444
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• 2001

In this manuscript, several effective feeding and management systems to reduce environmental pollution in swine production have been briefly introduced. It is logical that reducing the excretion of nutrients in manure should be the first step to reduce the environmental impact of pig production. it is evident that the excretion of nitrogen and phosphorus can be reduced when more digestible or available feedstuffs are used. Also, it is well known that proper feed processing can reduce anti nutritional factors (ANF) and improve nutrient digestibilities. Supplementation of effective feed additives can reduce excretion of nitrogen and phosphorus due to efficient feed utilization. These include enzymes (e.g., phytase), antibiotics, probiotics, organic acids and growth hormones ($\beta$-agonists and porcine somatotropin). One of the most effective ways to reduce pollutants from swine manure is to use synthetic amino acids in feed manufacturing. Many studies showed that reduction of 2 to 4% unit (U) of dietary protein with supplemental amino acid (AA) could dramatically reduce (15 to 20%) nitrogen excretion. Regarding feeding strategies, it has been recognized that phase feeding regimen could be used to reduce nitrogen and phosphorous excretion by feeding pigs in better agreement with age and physiological state. Feeding barrows and gilts separately, known as split sex feeding, can also decrease excretion of nitrogen and phosphorus. With the increasing concerns on the negative impact of animal production systems on the environment, animal nutritionists and producers should be aware that sustainability of animal agriculture is as important as high production performance. Therefore, some feeding and management strategies described in this manuscript will help to reduce environmental pollution in swine production. Proper combination of feeding regimen and environment-friendly diet formulation through nutritional approach will be more effective to reduce nutrient excretion in swine production system compared to single approach to do so.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.124-135
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• 2003

In order to prevent pollution from animal waste, the excretion of nutrients should be reduced through proper nutritional management. Among the many nutrients of concern, such as N, P, Cu, Zn and K, P is one of the most concerned nutrients to be managed. Seven feeding trials, three with layers and four with broilers, were conducted to determine if microbial phytase supplementation can reduce non-phytate phosphorus (NPP) level in diets and results in concomitant reductions of P excretion. The results showed that microbial phytase can be successfully used to achieve these purposes. Activity of natural phytase in certain plant feedstuffs is high enough to be considered in feed formulation. Three experiments have been conducted to study the characteristics of plant phytase and its application to feeding of broilers. Selected brands of wheat bran could be successfully used as a source of phytase in broiler feeding.

• Journal of Animal Environmental Science
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• v.3 no.2
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• pp.97-104
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• 1997

This research was carried out to determine the effect of dietary calcium(Ca) levels(low : 0.29, medium : 0.65 and high : 1.07%) on the digestibility, excretion and retention of nitrogen(N) phosphorus (P) in pigs fed diets supplemented with phytase(750U/kg). Twelve growing-finishing pigs(average body weight: 35kg) were divided into 3 groups and these pigs were reared in metabolism cage. After 10 days adaptation period, N and P balance experiments were carried out for 4 days. The results were summarized as follows ; 1. The High-Ca group was lower than the others in digestibility of P(Low-Ca and Medium-Ca group). 2. The amount of daily excretion of urinary N were 19.6g in Low-Ca group and 16.7g in high-Ca group. The High-Ca group was the lowest(22.71%/d) in the total N excretion. 3. The High-Ca group was the highest and the Low-Ca group the lowest in fecal P excretion. The urinary P excretions per day were 1.90g in Low-Ca group and 0.04g in High-Ca group. The medium-Ca group showed the lowest total P excretion(4.57g/d). 4. The N retention of the High-Ca group(20.50g) was greater than that of the Low-Ca group and Medium-Ca(5.02)g was the highest and the Low-Ca groups(3.92g) was the lowest in the P retention. These results indicate that dietary Ca level was an important factor influencing N and P utilization in pigs.

• Journal of Nutrition and Health
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• v.26 no.9
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• pp.1118-1128
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• 1993

This study was undertaken to investigate the acute effect of caffeine consumption on the change of mineral concentration in serum and urinary mineral excretion in healthy young females. On two separate mornings at one week intervals, each subject drank a coffee which contained no caffeine and 3mg/kg body weight caffeine. To obviate dietary effects on mineral concentration in serum and urine, each subject fasted at least ten hours before consuming the test beverage. At one, two, three and four hours, serum and urine production collected seperately for measurement of sodium, potassium, calcium, phosphorus and magnesium concentration. The results were as following : 1) Mean age of subjects was 20.6$\pm$0.32, Mean body mass index of subjects was 21.64$\pm$0.89, which was within $\pm$10% of ideal body weight. 2) Total urine volume of caffein groups for 4 hour after caffeine consumption was higher than that of decaffeine one, but urine pH was unchanged after caffeine consumption. Total urinary four hour excretion of creatinine was not affected by caffeine consumption and creatinine clearance also was not different from the control value. 3) In serum, mean three hour content of sodium(p<0.01) and phosphorus was higher in the subject given the caffeine. Mean serum magnesium and calcium contents were lower in caffeine group than that of decaffeine one. Mean serum magnesium content for three hour after caffeine ingestion was affected by caffeine consumption(p<0.001). Mean serum content of potassium was unaffected by caffeine consumption. 4) Total urinary four hour excretion of sodium, increased significantly after caffeine consumption(p<0.05), while total urinary four hour excretion of potassium, calcium, phosphorus and magnesium was unchanged after caffeine intake. Urinary excretion of Na, Ca, P and Mg was greatest at one hour after caffeine consumption, especially urinary sodium and potassium excretion was significantly high(p<0.05, p<0.01). The above results show that only 3mg caffeine per kg body weight increase the urinary macro mineral excretion in healthy young females.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.720-726
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• 2006

In an attempt to develop an artificial diet for growing olive flounder (Paralichthys olivaceus), weight gain, feed utilization and nutrient retention were investigated in fish fed moist (MP), semi-moist (SMP) and extruded pellets (EP). Excretion of nitrogen and phosphorus was also estimated based on their whole body gain and intake. EP and MP composed of raw fish and SMP made of formulated powder feed with water were prepared to have the same energy contents on a dry matter basis. A total of 240 fish with an average initial weight of 120 g were randomly distributed to each (20 fish/tank) of 12 circular plastic tanks (4 tanks/treatment) and fed experimental diets for 8 weeks. Fish groups fed EP (209 g) or SMP (209 g) recorded higher final weight than those fed MP (176 g), while dry feed consumption was highest in SMP groups (106 g), followed by MP (71 g) and EP groups (62 g). As a consequence, fish groups fed EP showed much lower feed conversion ratio than the other two groups. Protein efficiency ratio was also significantly higher in fish groups fed EP (2.55) than in those fed MP (1.44) and SMP (1.31). Fish groups fed EP, which showed the highest nitrogen retention of 43.9%, resulted in the lowest excretion of nitrogen of 35.5 g per kg gain. Also, the lowest phosphorus excretion of 6.0 g per kg gain was found in the EP groups with the highest P retention (37.0%) among treatments. Although the EP groups had the lowest dietary energy intake, they retained the highest energy in the whole body among treatments. The present results showed that EP could be more advantageous than MP or SMP in terms of growth, feed utilization and excretion of nitrogen and phosphorus for olive flounder.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.505-510
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• 1992

The experiments were carried out to study the effect of physical forms of hay diet on phosphorus metabolism by offering sheep roughage diets containing a low phosphorus content. The sheep were fed coarse hay, short hay or finely ground pelleted hay. The physical forms of hat diet had little effect on the pathway of phosphorus excretion. In all groups, the most of phosphorus was excreted in feces and urinary phosphorus excretion was negligible. Duodenal fluid flow, rumen fluid outflow and estimated salivary flow appeared to be relatively high in sheep fed the coarse hay diet as compared to those in sheep fed the finely ground diet. The amount of phosphorus flow to the duodenum tended to be high in the coarse diet group as compared to those in other two groups. On the other hand, phosphorus concentrations in the duodenal fluid and the rumen fluid were lower in sheep fed the coarse hay diet than those in sheep fed the ground hay. Net intestinal phosphorus absorption tended to be higher in sheep fed the coarse hay than that in sheep fed the ground hay or pelleted hay. However, a negative phosphorus balance was observed in the coarse hay diet group although a positive phosphorus balance was found in other two groups. It was considered that salivary phosphorus secretion was greater than the amount of salivary phosphorus reabsorbed from the intestine, resulting in the negative of phosphorus balance in sheep fed the coarse hay.