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The effect of 1,25-dihydroxycholecalciferol [1,25-(OH)2 D3 ] supplementation on laying hen diets was evaluated using diets high and low in Ca (3.0% and 1.8% ) and high and low in P( 0.52% and 0.33% ). Since two levels of 1,25- (OH)2 D3 supplementation (0 and 5 µg/kg diet ) were applied, the experiment was a 2 X 2 X 2 factorial arrangement in a com-pletely randomized design using nine individually housed hens per each 8 treatments (72 in total). The hens were fed the diets for 28 days and records were kept on body weight, egg production, feed intake, egg weight, and egg specific gravity. At the end of the ex-periment, the hens were bled for plasma Ca and P determination and after being eutha-nased the left tibia removed for bone ash measurement. The corn-soybean meal based diet contained 0.1% Cr2O3 as an indicator for determining Ca, P and phytate phosphorus re-tention at 14 and 28 days. 1, 25-Dihydroxycholecalciferol supplementation had no effect on hen weight, egg production or feed intake. However, large increases in egg specific gravity were obtained when 1, 25-(OH)2 D3 was fed to hens receiving the low Ca diet. All of the treatments had significant effects on bone ash. The greatest effect of 1, 25-(OH)2 D3 on bone ash was obtained in those hens fed the high Ca and P diet that was then supple-mented with 1,25-(OH)2 D3 (49.3% vs 53.9% bone ash). At day 14, the high Ca diets de-creased phytate P retention while at d 28 the high P diets decreased phytate P retention.

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This study was carried out to determine the effect of fermentation, hydrothermal treatment, soda (Na2CO3), and table salt (NaCl) addition on the extent of phytase activity and phytate degradation in three Iranian wheat cultivars, namely, Mahdavi, Ghods, and Roshan. The samples were milled to three different extraction rates, i.e. whole, 85%, and 75% flours and three kinds of leavening procedure (fermented, soda, and control), and four NaCl percentages (0.0, 0.5, 1.0, 1.5%) were used for preparing dough in three replications. To evaluate the effect of heat treatment on phytic acid breakdown, baking was also done. The results indicated that among the wheat varieties, Mahdavi had the highest level of phytase activity and phytic acid content followed by Ghods and Roshan; in which‚ most of the phytate was concentrated in bran fractions. Fermentation (1% yeast at 37ºC for 3 hours), hydrothermal treatment (pH 4.8 at 55ºC for 12 hours) and salt addition (0 to 1.5%) to the dough samples resulted in an increased phytase activity, whereas soda addition (1%) decreased the enzyme activity. Heat treatment reduced phytic acid content significantly.

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 The present research was conducted to study the effect of NPK fertilization on wheat grain yield, minerals concentration, grain quality, gluten, pentosan, and phytate phosphorous (phy-P) content, and the influence of maternal plant NPK fertilization on the seed physiological attributes during the germination period. NPK treatments comprised a control, where no fertilizer was applied (T₀), and two levels of NPK fertilizer: T₁ (110 kg N+60 kg P₂O₅+55 kg K₂O ha^-1), and T₂ (200 kg N+120 kg P₂O₅+100 kg K₂O ha^-1). Winter wheat was grown in a greenhouse during the growing season of 2015-16, following randomized complete block design with 4 replicates. The results indicated that a high level of NPK (T₂) fertilization increased the grain yield, crude protein, water-soluble pentosan, and dry gluten, up to 151.6, 65.3, 40.5, and 408.9% compared to the control, respectively. It also enhanced the grain mineral concentration, but did not affect the grain starch significantly. Grain phy-P was increased with a high NPK fertilization and, interestingly, the level of phytase enzyme was also increased up to 46% in T₂ compared to the control. Moreover, maternal plant NPK fertilization enhanced seed germination percentage, seedling fresh weight, phytase activity, inorganic phosphorus, and phy-P metabolism during the germination period. From the results of this study, it was concluded that grain nutritional quality was improved with increasing NPK rates, but antinutritional compound phy-P was also increased, while it may enhance seed viability, germination, and seedling vigor.
 

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This experiment was conducted to determine whether 6-phytase has a positive effect on zinc requirements, production performance, and zinc content of tissues in broiler breeders at the end of their production cycle. One hundred and twenty-eight obese Cobb-500 broiler breeder hens (>v4.9 kg) were weighed at 58 weeks of age and assigned to various treatment groups. To deplete the zinc reserves in hens, they were given a zinc-deficient diet (9.5 mg kg^-1 of zinc) and drank water with 35 μg L^-1 zinc for two weeks. Then, hens were randomly allocated to 8 dietary treatments in a factorial arrangement of two levels of phytase (0, 300 FTU kg^-1) and four levels of dietary zinc (30, 60, 90, 120 mg kg^-1) with four replicates of 4 hens in each. Bodyweight, egg production, egg weight, and egg quality were measured during the five-week experimental period. Added zinc significantly increased yolk weight and zinc content of yolk (P< 0.05) and plasma (P< 0.0001). Egg weight was significantly increased by adding phytase (P< 0.05). As the results of this experiment show, adding exogenous phytase can decrease the zinc requirement of broiler breeder hens by releasing 16.9% of the zinc bound to phytate.