An experiment was performed for evaluating calibration curve (CC) and comparing negative and posi... more An experiment was performed for evaluating calibration curve (CC) and comparing negative and positive controls (CNP) as a major method for estimating of phytase phosphorus equivalence for layer hens. Three hundred sixty 70-wk-old layer hens (W-36Hy-line) were used in a complete randomized design. Evaluated methods were setting the two regression equations for NPP-supplemented and phytase supplemented treatments with two sub-methods, include calibration curve (CC) or exclude phosphorus content of the basal diet (CC-BD) in calculation, and exploring enzyme equivalency by comparing phosphorus deficient diet as a negative and supplemented diet by inorganic phosphorus sources as a positive control group (CNP). Experiment included nine treatments (a phosphorus deficient basal diet contained 0.12% Av. P and 200, 300, 400 and 500 FTU/kg phytase was added to the basal diet, the rest four treatments were included basal diet supplemented with 0.20, 0.27, 0.35 and 0.43% Av. P). Each treatment i...
SUMMARYTwo experiments were performed for evaluating calibration curve (CC) and comparing negativ... more SUMMARYTwo experiments were performed for evaluating calibration curve (CC) and comparing negative and positive controls (CNP) as a major method for estimating of phytase phosphorus equivalence for layer and broiler chickens. In the first and second experiments, 360 Hy-line W-36 layer hens and 525 day-old Ross-308 broiler chickens were used in a complete randomized design, respectively. Evaluated methods were setting the two regression equations for NPP-supplemented and phytase supplemented treatments with two sub-methods, include calibration curve (CC) or exclude the amount of phosphorus content of basal diet (CC-BD) in calculation, and exploring enzyme equivalency by comparing phosphorus deficient diet as an negative and supplemented diet by inorganic phosphorus sources as a positive control group (CNP). Experiment one included nine treatments (200, 300, 400 and 500 FTU/kg phytase was added to a phosphorus deficient basal diet contained 0.12% AvP, the rest four treatments were inc...
An experiment with Leghorn laying hens was undertaken to determine the effect of oyster shell par... more An experiment with Leghorn laying hens was undertaken to determine the effect of oyster shell particle size and feeding time on different production variables, calcium retention, plasma calcium content and egg internal and external quality. Two hundred Leghorn layers (40 weeks old old) were allocated in five dietary treatments with four replicates during ten weeks. Two particle size combinations (wherein 50% of calcium substituted by medium or coarse particles (1-2 mm and 2-4 mm respectively) and two feeding time (8-pm or 9-am) were compared against a control diet (100% ground, <1 mm which fed with meal). Egg number, egg production, egg mass and feed conversion ratio did not differ among treatments (p > 0.05). Hens fed diets containing coarse Ca had significantly greater feed intake and calcium content of excreta (p > 0.05), whereas medium particle size reduced feed intake compared to control. Coarse particle size and feeding time at 9-pm significantly increased the calcium content of egg shell, egg shell thickness, egg surface area (ESA) and shell weight per unit surface area (SWUSA) (p < 0.05). Plasma calcium concentration, gizzard digesta calcium content and egg specific gravity were not affected by treatments (p > 0.05). Providing of calcium at 9-pm resulted an increase of egg shell (%), shell weight and thickness (p < 0.05). The results have shown that substitution of fine oyster shell with 50% coarse particles (2-4 mm) and feeding time at 9-pm have better effects on egg shell quality.
The effect of diets containing wheat and rice brans with or without phytase supplementation on pe... more The effect of diets containing wheat and rice brans with or without phytase supplementation on performance, intestinal carbohydrase activities and mRNA expression of sodiumglucose transporter-1 (SGLT-1) in layers was studied. A total of 96 23-wk-old Hy-line W-36 were allocated in a completely randomized experimental design at random with 6 treatments and 4 replicate cages of 4 birds each. A control diet was used in this experiment and then it was formulated to contain 10% wheat bran and 15% rice bran. Then phytase (2 g kg-1 ; 1000 FTU kg-1) was added to each diet. Feed intake, egg mass, feed conversion ratio, shell weight, shell thickness and Haugh units were not influenced by brans or phytase supplementation (p > 0.05). But egg production decreased in rice bran treatments (p < 0.05). In the jejunum, adding of phytase to control and diet containing wheat bran increased the concentration of sucrase (p ≤ 0.01). Also, addition of phytase to control diet increased (p ≤ 0.001) the mRNA expression of SGLT-1 in the duodenum. It was concluded that feeding layers with diets containing 10% wheat bran were practically feasible without compromising production performance, egg shell quality, and endogenous carbohydrase activity.
In this research the variation of mechanical and rheological properties of the composite as a fun... more In this research the variation of mechanical and rheological properties of the composite as a function of different processing parameters and ethylene propylene diene monomer (EPDM) rubber content was studied. The optimum amount of dicumyl peroxide (DCP) to achieve the highest percentage of grafting of maleic anhydride to EPDM was obtained by Fourier transform infrared (FTIR) spectroscopy. In general, immiscibility between nylon 66 and EPDM, and their high interfacial tension makes their blending difficult. Maleic anhydride was grafted to EPDM to reduce interfacial tension between two phases. Also the blends were prepared at highest possible speed of mixing (screw speed in extrusion) and lowest temperature to reach a well mixed sample which can be seen in scanning electron microscopy (SEM) images and impact strength results. Dynamic mechanical thermal analysis (DMTA) tests were conducted to evaluate the miscibility of the components and to measure the glass transition temperature of...
The present study was conducted to examine the effects of L-carnitine on pulmonary hypertensive r... more The present study was conducted to examine the effects of L-carnitine on pulmonary hypertensive response in broiler chickens reared at high altitude and exposed to hypobaric hypoxia. A total of 192 day-old male broilers (Cobb 500) were randomly assigned to 4 treatments and 4 replicates of 12 chicks. A basal diet composed of mainly corn and soybean meal was formulated and served as a control. Three additional treatments were made by supplementing graded levels of L-carnitine (50, 100, and 150 mg/kg). Chicks received dietary treatments at free access from 1 to 42 days of age. Results indicated that feeding L-carnitine at 100 mg/kg caused a significant increase in plasma nitric oxide (NO) with concomitant decrease in plasma malonedialdehyde (MDA). The Lead II electrocardiogram indicated reductions of S wave amplitude for all three doses of L-carnitine relative to the control and the difference between the birds that received L-carnitine at 50 mg/kg and the control was significant (P＜0.05). The right ventricular weight ratio (RV/TV) tended to decline when L-carnitine supplemented to diets. In conclusion, L-carnitine reduced ascites mortality in broiler chickens by increased NO production, reduced MDA concentration, and reduced right ventricular hypertrophy.
An experiment was performed for evaluating calibration curve (CC) and comparing negative and posi... more An experiment was performed for evaluating calibration curve (CC) and comparing negative and positive controls (CNP) as a major method for estimating of phytase phosphorus equivalence for layer hens. Three hundred sixty 70-wk-old layer hens (W-36Hy-line) were used in a complete randomized design. Evaluated methods were setting the two regression equations for NPP-supplemented and phytase supplemented treatments with two sub-methods, include calibration curve (CC) or exclude phosphorus content of the basal diet (CC-BD) in calculation, and exploring enzyme equivalency by comparing phosphorus deficient diet as a negative and supplemented diet by inorganic phosphorus sources as a positive control group (CNP). Experiment included nine treatments (a phosphorus deficient basal diet contained 0.12% Av. P and 200, 300, 400 and 500 FTU/kg phytase was added to the basal diet, the rest four treatments were included basal diet supplemented with 0.20, 0.27, 0.35 and 0.43% Av. P). Each treatment i...
SUMMARYTwo experiments were performed for evaluating calibration curve (CC) and comparing negativ... more SUMMARYTwo experiments were performed for evaluating calibration curve (CC) and comparing negative and positive controls (CNP) as a major method for estimating of phytase phosphorus equivalence for layer and broiler chickens. In the first and second experiments, 360 Hy-line W-36 layer hens and 525 day-old Ross-308 broiler chickens were used in a complete randomized design, respectively. Evaluated methods were setting the two regression equations for NPP-supplemented and phytase supplemented treatments with two sub-methods, include calibration curve (CC) or exclude the amount of phosphorus content of basal diet (CC-BD) in calculation, and exploring enzyme equivalency by comparing phosphorus deficient diet as an negative and supplemented diet by inorganic phosphorus sources as a positive control group (CNP). Experiment one included nine treatments (200, 300, 400 and 500 FTU/kg phytase was added to a phosphorus deficient basal diet contained 0.12% AvP, the rest four treatments were inc...
An experiment with Leghorn laying hens was undertaken to determine the effect of oyster shell par... more An experiment with Leghorn laying hens was undertaken to determine the effect of oyster shell particle size and feeding time on different production variables, calcium retention, plasma calcium content and egg internal and external quality. Two hundred Leghorn layers (40 weeks old old) were allocated in five dietary treatments with four replicates during ten weeks. Two particle size combinations (wherein 50% of calcium substituted by medium or coarse particles (1-2 mm and 2-4 mm respectively) and two feeding time (8-pm or 9-am) were compared against a control diet (100% ground, <1 mm which fed with meal). Egg number, egg production, egg mass and feed conversion ratio did not differ among treatments (p > 0.05). Hens fed diets containing coarse Ca had significantly greater feed intake and calcium content of excreta (p > 0.05), whereas medium particle size reduced feed intake compared to control. Coarse particle size and feeding time at 9-pm significantly increased the calcium content of egg shell, egg shell thickness, egg surface area (ESA) and shell weight per unit surface area (SWUSA) (p < 0.05). Plasma calcium concentration, gizzard digesta calcium content and egg specific gravity were not affected by treatments (p > 0.05). Providing of calcium at 9-pm resulted an increase of egg shell (%), shell weight and thickness (p < 0.05). The results have shown that substitution of fine oyster shell with 50% coarse particles (2-4 mm) and feeding time at 9-pm have better effects on egg shell quality.
The effect of diets containing wheat and rice brans with or without phytase supplementation on pe... more The effect of diets containing wheat and rice brans with or without phytase supplementation on performance, intestinal carbohydrase activities and mRNA expression of sodiumglucose transporter-1 (SGLT-1) in layers was studied. A total of 96 23-wk-old Hy-line W-36 were allocated in a completely randomized experimental design at random with 6 treatments and 4 replicate cages of 4 birds each. A control diet was used in this experiment and then it was formulated to contain 10% wheat bran and 15% rice bran. Then phytase (2 g kg-1 ; 1000 FTU kg-1) was added to each diet. Feed intake, egg mass, feed conversion ratio, shell weight, shell thickness and Haugh units were not influenced by brans or phytase supplementation (p > 0.05). But egg production decreased in rice bran treatments (p < 0.05). In the jejunum, adding of phytase to control and diet containing wheat bran increased the concentration of sucrase (p ≤ 0.01). Also, addition of phytase to control diet increased (p ≤ 0.001) the mRNA expression of SGLT-1 in the duodenum. It was concluded that feeding layers with diets containing 10% wheat bran were practically feasible without compromising production performance, egg shell quality, and endogenous carbohydrase activity.
In this research the variation of mechanical and rheological properties of the composite as a fun... more In this research the variation of mechanical and rheological properties of the composite as a function of different processing parameters and ethylene propylene diene monomer (EPDM) rubber content was studied. The optimum amount of dicumyl peroxide (DCP) to achieve the highest percentage of grafting of maleic anhydride to EPDM was obtained by Fourier transform infrared (FTIR) spectroscopy. In general, immiscibility between nylon 66 and EPDM, and their high interfacial tension makes their blending difficult. Maleic anhydride was grafted to EPDM to reduce interfacial tension between two phases. Also the blends were prepared at highest possible speed of mixing (screw speed in extrusion) and lowest temperature to reach a well mixed sample which can be seen in scanning electron microscopy (SEM) images and impact strength results. Dynamic mechanical thermal analysis (DMTA) tests were conducted to evaluate the miscibility of the components and to measure the glass transition temperature of...
The present study was conducted to examine the effects of L-carnitine on pulmonary hypertensive r... more The present study was conducted to examine the effects of L-carnitine on pulmonary hypertensive response in broiler chickens reared at high altitude and exposed to hypobaric hypoxia. A total of 192 day-old male broilers (Cobb 500) were randomly assigned to 4 treatments and 4 replicates of 12 chicks. A basal diet composed of mainly corn and soybean meal was formulated and served as a control. Three additional treatments were made by supplementing graded levels of L-carnitine (50, 100, and 150 mg/kg). Chicks received dietary treatments at free access from 1 to 42 days of age. Results indicated that feeding L-carnitine at 100 mg/kg caused a significant increase in plasma nitric oxide (NO) with concomitant decrease in plasma malonedialdehyde (MDA). The Lead II electrocardiogram indicated reductions of S wave amplitude for all three doses of L-carnitine relative to the control and the difference between the birds that received L-carnitine at 50 mg/kg and the control was significant (P＜0.05). The right ventricular weight ratio (RV/TV) tended to decline when L-carnitine supplemented to diets. In conclusion, L-carnitine reduced ascites mortality in broiler chickens by increased NO production, reduced MDA concentration, and reduced right ventricular hypertrophy.
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