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Phosphorus Requirement (phosphorus + requirement)

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Earth and Environmental Science100%

Selected Abstracts

Phosphorus requirement of common carp (Cyprinus carpio L) based on growth and mineralization

AQUACULTURE RESEARCH, Issue 3 2010
L C Nwanna
Abstract The effect of diets supplemented with varied levels of inorganic phosphorus (P) (NaH2PO4) on the growth, body composition, nutrient digestibility and mineralization in common carp (Cyprinus carpio L) was evaluated to determine the optimum P requirements. The six diets used were DPO, as the basal diet with a total P content of 1.30 g kg,1, and DP1, DP2, DP3, DP4 and DP5, which contained 4.10, 6.70, 11.6, 14.9 and 23.4 g P kg,1 respectively. Weight gain, SGR, apparent digestibility coefficient of organic matter and P, whole body ash, P, Ca and Mg increased significantly with increasing dietary P levels while dry matter (DM), fat and Zn content decreased. Feed conversion ratio was the poorest (P<0.05) in fish fed DPO, suggesting P deficiency. The apparent digestibility coefficient of P was 18% in the DPO-fed group, which increased from 69% in DP1 to 92% in DP5 after P supplementation, revealing lower digestibility of the native P than that in NaH2PO4. Broken-line analyses based on weight gain, P content of fish bones and whole body against total dietary and digestible P (data in brackets) contents showed the optimum P requirement for the growth of common carp to be 6.87 (5.55) g kg,1 DM, and the requirement for optimum mineralization in bones and whole body to be 9.10 (7.62) and 14.7 (13.2) g kg,1. [source]

Phosphorus requirement of Catla (Catla catla Hamilton) fingerlings based on growth, whole-body phosphorus concentration and non-faecal phosphorus excretion

AQUACULTURE RESEARCH, Issue 2 2009
Krishna Sukumaran
Abstract A 120-day feeding trial was conducted to determine the dietary requirement of phosphorus for Indian major carp, catla (Catla catla) fingerlings. Four hundred and eighty fingerlings (mean body weight: 4.23±0.87 g) were randomly distributed among eight treatment groups with three replicates each. Eight isonitrogenous and isocaloric semi-purified diets (crude protein: 35% and crude lipid: 8.5%) were formulated with graded levels of phosphorus using KH2PO4 (T1: control, 0.1%; T2: 0.3%; T3: 0.5%; T4: 0.7%; T5: 0.9%; T6: 1.1%; T7: 1.3%; T8: 1.5%) and fed to the respective groups. Twenty fish were stocked in 150 L plastic tanks and fed to apparent satiation twice a day. Specific growth rate (SGR) significantly (P<0.05) increased with increasing dietary phosphorus concentration from 0.73% to 1.27%, after which there was a slight decline in growth at 1.1% available phosphorus (aP) and remained constant thereafter. The quadratic broken-line model based on growth was Y=317.5,581(0.64,x) (0.64,x); R2=0.73. Moisture and crude protein contents of whole body were similar among all the treatments. However, the ether extract in T1 group was significantly (P<0.05) higher than all the other treatments. The whole-body phosphorus content increased significantly (P<0.05) with an increase in phosphorus in the diets. The one-slope broken-line model based on whole-body phosphorus concentration was Y=4.07,1.63 (0.71,x); R2=0.48. The one-slope broken-line model for non-faecal phosphorus excretion as inorganic phosphorus (Pi) for 24 h revealed a trend of Y=12.67+73.96 (x,0.6); R2=0.81. Minimum aP requirements based on weight gain (%), whole-body phosphorus content and phosphorus excretion were 0.64%, 0.71% and 0.6%, respectively. Hence, the dietary aP requirement of catla fingerlings ranges from 0.6% to 0.71%. [source]

Phosphorus requirements and optimum calcium/phosphorus ratio in the diet of mrigal Cirrhinus mrigala (Ham.) fingerlings

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2004
B. N. Paul
Summary An experiment was conducted to investigate phosphorus requirements and the optimal calcium/phosphorus (Ca/P) ratio on growth and carcass tissue composition of mrigal Cirrhinus mrigala (c. 6 g). Five purified diets were formulated to contain Ca/P ratios of 1 : 0 (0.35 : 0), 1 : 1 (0.35 : 0.35), 1 : 2 (0.31 : 0.63), 1 : 3 (0.24 : 0.71), and 1 : 4 (0.19 : 0.75), respectively. Growth performance and feed conversion ratio of mrigal responded significantly (P < 0.01) to the Ca =0.19 : P = 0.75 diet. Carcass protein, lipid, and P percentage also increased significantly with the higher P level. Based on this study, it may be concluded under the given conditions that the optimum Ca : P ratio in mrigal feed is 0.19 : 0.75. [source]

Phosphorus requirements of gilthead sea bream (Sparus aurata L.) juveniles

AQUACULTURE RESEARCH, Issue 2001
A M Pimentel-Rodrigues
Abstract A trial was conducted to evaluate the phosphorus requirements of gilthead sea bream juveniles. Seven semipurified diets were formulated to contain 54% crude protein and 15% lipids and phosphorus (di-calcium phosphate) levels ranging from 0.37% to 1.5% (DM basis). Each diet was fed to duplicate groups of 25 fish with an initial average weight of 5 g over 42 days. The fish were fed by hand to visual apparent satiety twice daily, six days a week. At the end of the trial growth rate was not significantly different in groups fed diets containing 0.75% phosphorus or higher, while growth rate of fish fed the 0.37% phosphorus diet was significantly lower than all the other diets. Feed efficiency ratio, protein efficiency ratio and N retention were significantly lower in fish fed the 0.37% phosphorus diet than in those fed diets with 0.75% and higher phosphorus levels. Phosphorus content of the fish averaged 2% (on a dry weight basis) and was not significantly affected by dietary phosphorus content. Phosphorus retention averaged 6.6 g kg,1 weight gain and was not statistically different among groups. Phosphorus retention (% phosphorus intake) decreased with the increase of dietary phosphorus content, being even higher than 100% in groups fed diets with 0.37% and 0.57% phosphorus, indicating phosphorus absorption from the water. The results of this study indicate that phosphorus requirements of gilthead sea bream juveniles were satisfied with a diet including 0.75% phosphorus. [source]

Phosphorus requirements and optimum calcium/phosphorus ratio in the diet of mrigal Cirrhinus mrigala (Ham.) fingerlings

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2004
B. N. Paul
Summary An experiment was conducted to investigate phosphorus requirements and the optimal calcium/phosphorus (Ca/P) ratio on growth and carcass tissue composition of mrigal Cirrhinus mrigala (c. 6 g). Five purified diets were formulated to contain Ca/P ratios of 1 : 0 (0.35 : 0), 1 : 1 (0.35 : 0.35), 1 : 2 (0.31 : 0.63), 1 : 3 (0.24 : 0.71), and 1 : 4 (0.19 : 0.75), respectively. Growth performance and feed conversion ratio of mrigal responded significantly (P < 0.01) to the Ca =0.19 : P = 0.75 diet. Carcass protein, lipid, and P percentage also increased significantly with the higher P level. Based on this study, it may be concluded under the given conditions that the optimum Ca : P ratio in mrigal feed is 0.19 : 0.75. [source]

Phosphorus requirements of gilthead sea bream (Sparus aurata L.) juveniles

AQUACULTURE RESEARCH, Issue 2001
A M Pimentel-Rodrigues
Abstract A trial was conducted to evaluate the phosphorus requirements of gilthead sea bream juveniles. Seven semipurified diets were formulated to contain 54% crude protein and 15% lipids and phosphorus (di-calcium phosphate) levels ranging from 0.37% to 1.5% (DM basis). Each diet was fed to duplicate groups of 25 fish with an initial average weight of 5 g over 42 days. The fish were fed by hand to visual apparent satiety twice daily, six days a week. At the end of the trial growth rate was not significantly different in groups fed diets containing 0.75% phosphorus or higher, while growth rate of fish fed the 0.37% phosphorus diet was significantly lower than all the other diets. Feed efficiency ratio, protein efficiency ratio and N retention were significantly lower in fish fed the 0.37% phosphorus diet than in those fed diets with 0.75% and higher phosphorus levels. Phosphorus content of the fish averaged 2% (on a dry weight basis) and was not significantly affected by dietary phosphorus content. Phosphorus retention averaged 6.6 g kg,1 weight gain and was not statistically different among groups. Phosphorus retention (% phosphorus intake) decreased with the increase of dietary phosphorus content, being even higher than 100% in groups fed diets with 0.37% and 0.57% phosphorus, indicating phosphorus absorption from the water. The results of this study indicate that phosphorus requirements of gilthead sea bream juveniles were satisfied with a diet including 0.75% phosphorus. [source]