• Journal of Nutrition and Health
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• v.30 no.4
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• pp.406-414
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• 1997

It has been known that dietary phytate decreases the absorption of body zinc pool which is composed of the dietary and endogenous zinc in the body. The purpose of this study was to examine the effect of phytate on the absorption of total bodyzinc in Zn-depleted rats. Rats were Zn-depleted with either low(0.8%) or high(1.6%) Ca diet containing sodium phytate for 4 weeks. After zinc depletion, rats were assigned into phytate or non-phytate dietary groups within each low-or high-Ca dietary group. ant feces were collected for 2 weeks of the initial collection and 1 week after dietary crossover, during which the phytate and the non-phytate diet was switched over within the same Ca group. The content of Zn and Ca measured by atomic absorption spectrophotometer and phytate content was analyzed. food intake was higher in the high Ca group than in the low Ca group(p <0.0001), and was also higher in the non-phytate group than in the phytate group(p <0.0001). Food intake and phytate level affected body weight gain in rats(p <0.0001). Zinc excretion in the total feces was higher in the phytate group than in the non-phytate group at both low and high Ca level(p <0.0001), except during the crossover collection period in high Ca group. Calcium, however, didn't show any synergistic effect on phytate effect(p <0.05). This study showed that phytate decreased the absorption of total body zinc at both low and high Ca levels in Zn-depleted rats. A large portion of total body zinc originated from the endogenous zinc pool in these rats. The results of the present study showed the same effect of phytate on the endogenous zinc in Zn-depleted rats as in a previous study, confirming that phytate adversely affects zinc bioavailability, especially under marginal and poor zinc nutrition.

• Journal of Nutrition and Health
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• v.30 no.4
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• pp.394-405
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• 1997

Endogenous zinc is important for maintaining zinc homeostasis because the size of endogenous zinc pool is almost 3-4 times bigger than that of dietary zinc. The purpose of this study was to examine the phytate effect on the reabsorption of endogenous zinc and the additional Ca effect on the phytate effect. Rats were fed a casein-based diet with added sodium phytate containing either high(1.6%) or low(0.8%) Ca concentrations for 4 weeks to reduce the body zinc pool. After the depletion period, $^{65}$ Zn was given by intraperitoneal injection to label the endogenous zinc pool. Rats were then assigned into phytate or non-phytate group within the same Ca group. feces were collected for 2 weeks of the initial collection period and 1 week after dietary crossover. The ratios of excreted fecal $^{65}$ Zn radioactivity of phytate group non-phytate group were determined as a measure of the phytate effect on the endogenous zinc. Mean fecal $^{65}$ Zn radioactivity was higher in the phytate group than in the non-phytate group during the entire 3 weeks of the collection period in the low Ca group, and during the initial collection period in the high Ca group(p <0.0001). This study showed an adverse phytate effect on endogenous zinc at both high and low dietary Ca levels. Elevated dietary Ca levels showed a synergistic effect on the phytate effect on endogenous zinc(p <0.05). These results imply greater phytate effect on zinc homeostasis rather than on zinc bioavailability through complexing with the endogenous zinc which is larger portion than the dietary zinc on zinc homeostasis.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.250-257
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• 2001

An experiment was conducted to determine the effects of phytase supplementation to the diets containing different levels of non-phytate phosphorus (NPP). A $3{\times}2$ factorial arrangement of treatments was employed. There were three dietary NPP levels of control (C) (0.45% for starter diet and 0.35% for grower diet), C-0.1% NPP (0.35% for starter diet and 0.25% for grower diet), and C-0.2% NPP (0.25% for starter diet and 0.15% for grower diet) and two phytase levels (0 and 500 U/kg). Reduced dietary NPP decreased feed intake and weight gain and increased mortality whereas dietary phytase increased feed intake and weight gain and decreased mortality. Supplemental phytase improved availabilities of dry matter, crude fat, ash, P, Zn, Mg, and Cu whereas dietary NPP level did not affect availabilities of nutrients except decreased Zn availability and increased Cu availability in reduced NPP diets. Nutrient retention of N, ash, Ca, P, Mg, and Zn were linearly decreased as dietary NPP levels reduced but dietary phytase increased their retention. Reduced dietary NPP increased ash excretion but decreased P and Cu excretion while dietary phytase decreased N excretion. Weight, length, girth and contents of ash, Ca, P and Mg of tibia linearly decreased as dietary NPP levels reduced. Dietary phytase increased length and ash content of tibia. It is concluded that dietary phytase can reduce P excretion and alleviate adverse affects caused by feeding low dietary NPP. Effects of phytase were greater in the lower NPP diets.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1642-1649
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• 2003

An experiment was conducted to evaluate the effects of phytase supplementation on the growth performance, nutrients utilization and bone mineralization in broiler chickens. Day-old broiler chicks (n=480) were equally devided into eight treatment groups and fed maize or wheat based isocaloric, isonitrogenous and isocalcium diets having two non phytate phosphorus (NPP) concentrations (0.50% and 0.30%) and two phytase levels (0 and 500 phytase units/kg diet) in a 42 days growth trial. Maize based dietary treatments were MC (NPP 0.50%, MN (NPP 0.30%), MNP (MN+500 units of phytase) and MCP (MC+500 units of phytase), whereas wheat based experimental diets were WC (NPP 0.50%), WN (NPP 0.30%), WNP (WN+500 units of phytase) and WCP (WC+500 units of phytase). The NPP levels were maintained by dicalcium phosphate. Reduction in dietary NPP depressed live weight gain and feed intake and increased feed conversion ratio (FCR). Phytase supplementation to low NPP (0.30%) diets significantly (p<0.05) improved the growth performances of broilers. The supplementation to low NPP diets allowed complete, safe and economic replacement of dietary inorganic P (dicalcium phosphate) to reduce feed cost per kg live weight gain of broilers. Reduction in dietary NPP did not affect retention of nutrients except phosphorus (P) but had a significant (p<0.05) depression in tibia ash and minerals (Ca, P) concentration in serum and tibia ash. Phytase supplementation at low NPP level was effective (p<0.05) in improving the retention of dry matter, Ca and P and Ca and P concentration in serum and tibia ash. However, the supplementation was not effective at high level of NPP (0.50%). There were no significant (p>0.05) differences in carcass quality among dietary treatments. The response of phytase was greater in low NPP and maize based diets as compared with high NPP and wheat based diets, respectively. The results show that phytase supplementation to low NPP (0.30%) diets improved the growth performance, relative retention of nutrients (N, Ca and P) and minerals (Ca, P) status of blood and bone in broiler chickens, with a better efficacy in maize based diets.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.933-938
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• 2007

An experiment was conducted to study the laying performance, shell quality, bone mineralization, hatchability of eggs and performance of progeny (weight at day one and 14 d of age, P content in day old chick, leg score and survivability of chicks) of synthetic broiler breeders fed different levels of non-phytate phosphorus (NPP). Six levels of NPP (1.2, 1.8, 2.4, 3.0, 3.6 and 4.2 g/kg diet) at a constant calcium (Ca) level (30 g/kg) in a maize-soya-deoiled rice bran based diet were tested. Levels of dicalcium phosphate, shell grit and deoiled rice bran were adjusted to achieve the desired levels of NPP and Ca. Each level of NPP was fed with a weighed quantity of feed (160 g/b/d) to 40 female broiler breeders from 25 to 40 weeks of age housed in individual cages. Each bird was considered as a replicate. Egg production, feed/egg mass, body weight, egg weight, shell weight, shell thickness, egg specific gravity, serum Ca content and tibia breaking strength were not influenced (p>0.05) by the variation in dietary NPP levels tested. Increasing the dietary levels of NPP did not influence the hatchability of eggs, phosphorus (P) contents both in egg yolk and day old chick, chick body weight at day one and 14 d of age, leg score and survivability of chicks up to 14 d of age. Maximum response ($p{\leq}0.01$) in shell breaking strength, tibia ash and serum inorganic P contents were observed at NPP levels of 2.09, 2.25 and 3.50 g per kg diet, respectively. The retention of Ca increased, while the P retention decreased ($p{\leq}0.01$) with increasing dietary levels of NPP. Though maximum responses in shell breaking strength, bone ash and serum inorganic P were observed at NPP higher than 1.2 g/kg diet, the broiler breeder performance in terms of egg production, shell quality, hatchability of eggs and progeny performance and their survivability was not influenced by dietary NPP concentrations. It is concluded that synthetic broiler breeders maintained in cages do not require more than 1.2 g NPP/kg diet with a daily intake of 192 mg NPP/b/d during 24 to 40 weeks of age.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1299-1304
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• 2005

An experiment was conducted to study the production performance of broiler breeder females (25 to 40 weeks of age) fed either reference diet or low non-phytate phosphorus (NPP) diet with or without microbial phytase (500 FYT/kg) supplementation. A weighed (160 g/b/d) quantity of feed from each diet was offered daily to 40 replicates of one bird each housed in California type cage having individual feeders. Each cage was considered as a replicate. A continuous 16-h light per day was provided using incandescent bulbs. Body weight, egg production, egg weight, feed per egg mass, egg specific gravity, egg breaking strength, shell thickness, tibia ash and serum Ca and protein concentrations were not affected by reducing the NPP level from 0.30 to 0.18% in the broiler breeder diet. Supplementation of phytase (500 FYT/kg) enzyme to the diet containing 0.18% NPP had no added advantage on any of the above production parameters. The serum inorganic P was increased significantly (p<0.05) by either enhancing the NPP content from 0.18 to 0.30% or supplementing phytase @500 FYT/kg to the diet containing low P which were found comparable. Retention of Ca and P was positive on all the diets. P retention decreased significantly (p<0.05) with either increase in NPP content or phytase supplementation in the diet. Neither NPP nor phytase supplementation influenced bone mineralization in terms of tibia ash and strength. The hatchability was not influenced by either increasing the NPP content or supplementing the enzyme phytase. Similarly, the P concentration in the egg yolk and day old chick, day old and 14th day body weight and leg score was not altered by increasing the level of NPP or supplementing phytase enzyme. The mortality was within the normal limits in all the three dietary groups. Thus, it can be concluded that 0.18% NPP (288 mg NPP intake/b/d) in the broiler breeder' diet is adequate in sustaining the optimum performance from 25 to 40 wks of age. Enhancing the NPP content or supplementation of phytase (500 FYT/kg diet) to diet containing 0.18% NPP had no added advantage on performance.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.8
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• pp.1171-1175
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• 2005

An experiment was conducted (28 to 44 weeks) to study the laying performance, shell quality, and nutrient retention of White Leghorn layers fed different levels of non-phytate phosphorus (NPP). Six levels of NPP (0.15, 0.18, 0.21, 0.24, 0.27 and 0.30%) at a constant calcium (Ca) level (3.5%) in maize-soya-deoiled rice bran based diets were formulated, and each experimental diet was offered ad libitum for 16 weeks to five replicates with five birds in each replicate. The body weight of WL layers fed diet containing 0.15% NPP was significantly (p<0.05) lower than those fed diet with 0.30% NPP, at 44 weeks of age. However, the hen day egg production, egg weight, daily feed intake and feed consumed per dozen eggs were not influenced by the variation in the NPP levels in the diet. The bone ash content was significantly (p<0.05) higher in the birds fed 0.30% NPP as compared with those fed diets up to 0.24% NPP. Bone ash content was intermediate in the birds fed diet containing 0.27% NPP. The tibia strength followed the same trend as that of bone ash. Dietary NPP content had no influence on serum Ca and protein concentration and activity of alkaline phosphatase. However, serum inorganic P concentration increased linearly with NPP content in the diet. The concentration of P was significantly (p<0.05) higher in the birds fed 0.27% NPP or higher as compared with those fed 0.15% NPP. Levels of dietary NPP had no influence on egg quality parameters like shell wt, shell thickness, shell strength and specific gravity. The retention of nutrients such as DM, N and Ca were comparable among the WL layers fed different levels of NPP. However, the retention of P decreased linearly with increase in the level of NPP in the diet. The retention of P in the birds fed diets up to 0.24% NPP in the diet was comparable, however further increasing the content of NPP (either 0.27% or 0.30%) reduced the retention of P. Based on the results of the present study, 0.15% NPP (180 mg/b/d) in the diets of WL layers is adequate for optimum production performance during 28 to 44 weeks of age, however, WL layers require 0.27% NPP (324 mg /b/d) in the diet for optimum production with better bone mineralization.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.2
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• pp.237-246
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• 2014

Two experiments were conducted to evaluate the efficacy of feeding an Escherichia coli (E. coli) derived phytase to pigs fed P deficient, corn-soybean meal diets. In Exp. 1, one hundred and twenty crossbred piglets ($9.53{\pm}0.84$ kg) were allocated to one of five treatments which consisted of four low P diets (0.61% Ca, 0.46% total P and 0.24% non-phytate P) supplemented with 0, 500, 1,000, or 20,000 FTU/kg E. coli phytase as well as a positive control formulated to be adequate in all nutrients (0.77% Ca, 0.62% total P and 0.42% non-phytate P). The treatments were applied to six pens with four pigs per pen for 28 days. In Exp. 2, ten crossbred pigs ($19.66{\pm}1.16$ kg) fitted with ileal T-cannula were used in a nutrient balance study. The pigs were assigned to treatments similar to those used in Exp. 1 in a doubly replicated $5{\pm}4$ incomplete Latin square design (5 diets with 4 periods). Each period consisted of a 5-d adjustment period followed by a 3-d total collection of feces and urine and then a 2-d collection of ileal digesta. Supplementation with phytase linearly increased (p<0.05) weight gain, feed intake, feed efficiency, bone breaking strength and fat-free dry and ash bone weight. There were linear increases (p<0.01) in the apparent ileal digestibility (AID) of DM, GE, CP, Ca, total P, inositol hexaphosphate ($IP_6$) and some AA with increasing dose of E. coli phytase. Pigs fed 20,000 FTU/kg had a greater (p<0.05) AID of IP6 (80% vs 59% or 64%, respectively) than pigs fed diets with 500 or 1,000 FTU/kg phytase. There were linear increases (p<0.05) in the total tract digestibility of Ca, total P, Na, K, Mg, and Zn as well as in the retention of Mg and Zn with increased phytase dose. The retention and utilization of Cu, and the total tract digestibility of CP and Cu quadratic increased (p<0.05) with increased phytase dose. In conclusion, supplementation of 500 FTU of phytase/kg and above effectively hydrolyzed phytate in low-P corn-soybean diets for pigs. In addition, a super dose of phytase (20,000 FTU/kg) hydrolyzed most of the IP6 and consequently further improved mineral use, protein utilization and performance.

• Korean Journal of Poultry Science
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• v.27 no.3
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• pp.169-179
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• 2000

An experiment was conducted to measure the effect of crude phytase supplementation on the growing performance, blood concentrations of some minerals and tibia characteristics of broiler chickens. Day-old 240 male broiler chickens (Avian) were randomly allotted to four treatments. There were six replicates per treatment, and ten chicks per replicate. Treatments consisted of two levels of crude phytase (0 and 600U/kg) made from Aspergillus ficuum and two levels of non-phytate P (0.45 and 0.35% NPP for the starter period, and 0.35 and 0.25% NPP for the grower period), making the experiment 2$\times$2 factorial. The starter period was from hatch to 21 d of age, and grower period was from 22 to 35 d of age. Feed intake and weight gain of chicks fed diet containing phytase were higher(P〈0.05) than those of chicks fed diets without phytase, however, no differences was found in feed/gain. mortality, and nutrient availabilities regarding the phytase supplementation. Chickens fed diets with low NPP and phytase excreted lower P than did birds fed diets containing normal NPP without phytase. The level of NPP and phytase did not affect N excretion. The Ca availability was increased by feeding low NPP diet. Dietary phytase increased the availabilities of P and Mg, but decreased those of Fe and Zn. There was interactions between dietary NPP level and phytase addition on mineral availability. Tibia was lighter and shorter in low NPP groups, and heavier in phytase treated groups. The tibial contents of Ca, P and Mg decreased in low NPP treated groups, but increased in phytase treated groups. The ash content of tibia of chickens fed diet with phytase was higher than that of birds fed diets without phytase. These data suggest that the crude phytase supplementation to broiler diets containing low NPP level improves growth performance and mineral availability and, reduces fecal P excretion.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.673-680
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• 2000

An experiment was conducted with day-old 300 commercial male broiler chicks (Arbor Acres$^{(R)}$) to evaluate the efficacy of crude phytase preparerations produced from a culture of Aspergillus ficcum. The experiment consisted of five dietary treatments; T1, com-soy control diet with 0.45% non-phytate phosphorus (NPP) for starter period and 0.35% NPP for grower period; T2, control - 0.1% NPP; T3, control 0.2% NPP; T4, T3+600 U of crude phytase (broth+cell); and T5, T3+600 U of crude phytase (broth). The body weight gain, feed intake, and feed/gain of chickens fed T1 diet was highest (p<0.01) among treatments. BW gain and feed intake of T4 and T5 were greater than those of T3 but were less than those of T1 and T2. T3 was highest in mortality among treatments. Decreasing the NPP level lowered availability of DM, crude ash, ether extract, crude fiber, Zn, and Fe but supplementation of crude phytase preparations improved the availability of these nutrients as well as those of Ca, P and Cu. Excretion of P and Cu significantly decreased as the NPP level in the diet decreased. Further reduction of P and Cu excretion and reduction of Ca, Mg and Fe excretion were achieved by supplementation of crude phytase preparations. The serum concentrations of Ca, P, Mg, Zn, Fe, and Cu were significantly increased by crude phytase supplementation. The weight and length of tibia, and contents of crude ash, Ca, P, Mg, and Zn were adversely affected by lowering NPP level but partially recovered by supplementation of crude phytase preparations. In conclusion, lowering NPP level in the broiler diet significantly depressed the performance. Supplementation of crude phytase preparations produced from Aspergillus ficuum could partially recover the depression.