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Dietary P (dietary + p)
Selected AbstractsPreparation of phosphorus and carbohydrate microcapsules for manipulating dietary C : P ratio for aquatic suspension-feedersFRESHWATER BIOLOGY, Issue 2 2003Daniel A. Kreeger SUMMARY 1.,Dietary phosphorus can be limiting for aquatic animals such as suspension-feeders. However, our understanding has been limited by the difficulty of manipulating dietary P without altering other aspects of food quality. We microencapsulated various forms of bioavailable P with carbohydrate to manipulate dietary C : P ratio for suspension-feeders. 2.,Calcium phosphate, sodium hexametaphosphate, sodium tripolyphosphate and tetrasodium pyrophosphate were each mixed with a concentrated solution of a carbohydrate base (either maltodextrin or potato starch) and microencapsulated using an interfacial polymerisation technique. Each of the 10 types of capsules produced had a particle size ideal for suspension-feeders (3,10 ,m). 3.,Leakage rates were low (<12% of capsule weight per day). Relative enzymatic breakdown in vitro by carbohydrases (amylase or cellulase) was similar among the 10 capsule types and was always at least 15 times the comparable leakage rate. 4.,Release of dissolved P from enzyme-treated capsules varied depending on capsule P content. Liberation of P from capsules prepared from 20% w/w sodium hexametaphosphate in maltodextrin (molar C : P = 1.8) was three times greater than all other types, and this combination appears most suitable as a dietary supplement for zooplankton. 5.,Although P content and capsule integrity were greatly influenced by choice of carbohydrate, choice of P compound, and the mixing ratio of the two, P-rich artificial microparticles can be produced that have low leakiness, high digestibility, and a physical size suitable for aquatic suspension-feeders. Therefore, microcapsules represent promising tools for manipulating dietary C : P for suspension feeders. [source] Mineral absorption in tapirs (Tapirus spp.) as compared to the domestic horseJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 6 2009M. Clauss Summary To test whether mineral recommendations for horses are likely to guarantee adequate mineral provision for tapirs (Tapirus spp.), we investigated the apparent absorption (aA) of macro and micro-minerals in 18 tapirs from five zoological institutions in a total of 24 feeding trials with total faecal collection. Samples of feeds and faeces were analysed for Ca, P, Mg, Na, K, Fe, Cu and Zn. The resulting aA coefficients and the linear relationships of apparently absorbable dietary mineral content to total dietary mineral content (per 100 g dry matter) were compared with data for domestic horses. While there were no apparent differences in the absorption patterns for P, K, Na, Fe, Cu or Zn, the absorption of both Ca and Mg was distinctively higher in tapirs than in horses. Tapirs are browsers that are adapted to a diet of higher Ca content and higher Ca:P ratio than equids, and high absorptive efficiency for Ca might have evolved to ensure that high dietary Ca concentrations do not lead to the binding of dietary P in the intestine, making it unavailable for hindgut microbes. Similar to other hindgut fermenters, in tapirs, absorption coefficients for Ca increased with dietary Ca:P ratio, and urinary Ca:creatinine ratios increased with dietary Ca. Several zoo diets used were deficient in one or more minerals. When compared with faeces of free-ranging animals, faeces of zoo animals had higher concentrations of most minerals, probably indicating a lesser diluting effect of indigestible fibre in zoo animals. [source] Effects of dietary phosphorus level on non-faecal phosphorus excretion from yellowtail (Seriola quinqueradiata Temminck & Schlegel) fed purified and practical dietsAQUACULTURE RESEARCH, Issue 2 2009Pallab Kumer Sarker Abstract Non-faecal phosphorus (P) was determined for large yellowtail to estimate a minimum available P requirement (Experiment 1) and to justify inorganic P supplementation in a fish meal-based diet (Experiment 2). In Experiment 1, purified diets with incremental P concentrations were fed to yellowtail (mean weight 917 g) at a feeding rate of 1.5% of body weight. The peaks of non-faecal P excretion appeared 5,6 h after feeding in fish fed more than 4.5 g available P kg,1 dry diet. Broken-line analysis indicated that the minimum available P requirement was 4.4 g kg,1 dry diet. In Experiment 2, a purified diet (PR) containing 6.5 g available P kg,1 and a fish meal-based diet with (F1) and without (F0) additional phosphorus were fed to yellowtail (mean weight 1.1 kg) at 1.5% (PR) and 2% (F0 and F1) feeding rates respectively. There was no significant difference in P excretion between fish fed the F0 (5.5 g soluble P kg,1 dry diet) and the PR diet. However, significantly higher (34.5%) amounts of non-faecal P excretions (7.4 g soluble P kg,1 dry diet) were found in fish fed F1 compared with the F0 diet. This suggested that there was an excess of dietary P in the F1 diet and that supplementation is not needed in fish meal-based diets for large yellowtail. [source] Effect of supplemental phytase on growth, phosphorus digestibility and bone mineralization of common carp (Cyprinus carpio L)AQUACULTURE RESEARCH, Issue 10 2007Lawrence C Nwanna Abstract The effect of dietary phytase on phosphorus (P) digestibility, growth, bone mineralization and plasma P of common carp (Cyprinus carpio) was investigated. Five diets, D0, DP, PHYT1, PHYT2 and PHYT4, were used. D0 contained no supplement. DP was supplemented with 2.6 g P (Na2HPO4× 2H2O) kg,1. PHYT1, PHYT2 and PHYT4 comprised 1000, 2000 and 4000 U phytase [Ronozyme P (CT)] kg,1. D0, PHYT1, PHYT2, PHYT4 had average of 7.95 g P kg,1; DP contained 10.3 g P kg,1. After 126 days of feeding, fish grew from 115 to 347 g (D0), 583.7 g (DP), 352.6 g (PHYT1), 393.3 g (PHYT2) and 406.4 g (PHYT4). Addition of phytase significantly increased daily feed intake, but only led to a marginal improvement in the weight gain, SGR and FCR of fish fed PHYT2 and PHYT4 compared with fish fed D0. Fish fed DP showed the best (P<0.05) growth performances. Fish fed DP and PHYT4 significantly digested dietary P more than the fish fed D0. Fish fed D0, PHYT1, PHYT2 and PHYT4 retained higher (P<0.05) Zn in their bones than fish fed DP. However, there was no further effect on bone mineralization. Plasma P scarcely improved by between 14% and 26% in fish fed PHYT2 and PHYT4 relative to fish fed D0. P concentration of the faeces was reduced by about 9,22% in fish fed PHYT1 and PHYT4 compared with fish fed D0. [source] Formulation of low phosphorus loading diets for carp (Cyprinus carpio L.)AQUACULTURE RESEARCH, Issue 2001P Jahan Abstract This study focuses on reducing total phosphorus loading (T-P) from carp culture through improved feed formulation. Since phosphorus (P) contained in fish meal (FM) mainly in the form of tricalcium phosphate is not available to carp, which lack a stomach, the reduction of FM from their diets is effective for lowering T-P. Thus in this experiment, six diets (crude protein < 35%, digestible energy > 3.5 kcal g,1) were designed by substituting FM (10%,25%) with alternate protein ingredients such as poultry feather meal (PFM; 5%,10%), blood meal (BM; 5%,7%) and defatted soybean meal (dSBM; 4%,9%). All diets followed the Kasumigaura ,Feed Standard'. The total dietary P was 1.0%,1.4% and water extractable P available to carp was 0.66%,0.71%, the levels meeting the dietary requirement of carp. A feeding trial was conducted with juvenile carp (4.6 ± 0.7 g) for 12 weeks at a mean water temperature of 23.7°C. The T-P loading from fish fed the different diets was estimated based on absorption and retention of dietary P. Growth performance corresponded to increasing levels of FM inclusion, being highest in the fish fed 25% FM diet; however, the decrease in T-P was achieved at the lower FM levels. The T-P (based on P retention) ranged from 8.9 to 11.7 kg t,1 production, much lower than that from the commercial diets (9.1,26.4 kg t,1 production). These results indicated that the reduction of FM levels in carp diets to 15%,20% through the combined use of PFM, BM and dSBM effectively lowered T-P. Moreover, the formulated diets were also found to be better than commercial diets in lowering the N loading from carp culture. [source] Immunohistochemical analysis of heme oxygenase-1 in preneoplastic and neoplastic lesions during chemical hepatocarcinogenesis,INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 4 2004Fabiana Caballero Summary Heme oxygenase (HO) breaks down the pro-oxidant heme into carbon monoxide, iron and the antioxidant biliverdin. The isoform HO-1 plays an effective role to counteract oxidative damage and to control inflammation. Prolonged cellular damage due to chronic inflammation is one of the reasons leading to the development of tumours. The aim of this work was to investigate HO-1 expression and localization along the different stages of chemically induced hepatocarcinogenesis (HCC) and the occurring morphological changes. To provoke sustained oxidative stress and chronic inflammation, CF1 mice received dietary p -dimethylaminoazobenzene (DAB, 0.5%, w/w) during a whole period of 14 months. HO-1 expression increased along the experimental trial in morphologically normal hepatocytes in DAB-treated animals. HO-1 expression diminished in altered hepatic foci (AHF) and oval cells and early preneoplastic lesions. Otherwise, marked HO-1 overexpression was detected in Kupffer cells and macrophages surrounding necrotic and nodular areas. Adenomas showed decreased HO-1 immunostaining. In hepatocellular carcinomas, an inverse relationship was found between the immunohistochemical expression of HO-1 and the degree of tumour differentiation, being negative in poorly differentiated tumours. In our experimental model, down modulation of HO-1 expression correlated with malignancy progression. Thus, our data point to activation of HO-1 as a potential therapeutic tool. [source] | ||||||||||