ABSTRACT
The effects of Ca:P total ratio and particle size of oyster shell meal (OSM) were evaluated in broiler diets. In Experiment 1, 800 broilers (22-42 days old) were distributed in a 2×2 factorial design, with two Ca:P ratios (1.7 and 2.0:1) and two OSM particle sizes (coarse = 1,354 µm and fine = 428 µm), totaling four treatments with 10 repetitions with 20 broilers. Feed intake, weight gain, and feed conversion ratio were calculated. In Experiment 2, 1,280 broilers were distributed in a 2×2×2 factorial design (1.7 and 2.0:1 Ca:P ratios; coarse and fine OSM; male and female broilers), with eight treatments and 16 repetitions with 10 broilers. Apparent metabolizability of dry matter, Ca, P, and apparent metabolizable energy (AME), as well as bone resistance, bone weight, ash, Ca, and P content in the tibia were assessed. Growth performance was not affected (P > 0.05). Coarse OSM increased tibia Ca content in male broilers (P < 0.001), and higher Ca:P ratio improved bone ash and bone resistance in both sexes (P < 0.001), but reduced P content in male broilers (P < 0.05); male broilers displayed heavier bones with higher ash content than females (P < 0.05). Metabolizability of Ca was improved with coarse OSM (P < 0.05); whereas metabolizability of DM, P, and AME was not affected (P > 0.05). In conclusion, diets with a Ca:P total ratio of 2.0:1 containing coarser OSM improved bone mineral composition, particularly in male broilers, and coarse OSM improved the metabolizability of Ca in broilers regardless of the Ca:P total ratio or broiler sex.
Dois experimentos foram conduzidos para avaliar os efeitos do tamanho de partícula da farinha de ostras (FO) e relação Ca:P total em dietas para frangos de corte. No primeiro experimento, 800 frangos (22 a 42 dias) foram distribuídos em um delineamento fatorial 2x2: 2 relações Ca:P (1,7 e 2,0:1) e dois tamanhos de partícula da FO (grossa = 1354 µm e fina = 428 µm), totalizando quatro tratamentos com 10 repetições de 20 aves. O consumo de ração, o ganho de peso e a conversão alimentar foram calculados. No segundo experimento, 1.280 frangos foram distribuídos em um fatorial 2x2x2 (relações Ca:P 1,7 e 2,0:1; FO grossa e fina; aves machos e fêmeas) com oito tratamentos e 16 repetições de 10 aves. Foram avaliados: metabolizabilidade aparente da matéria seca, Ca e P, energia metabolizável aparente (EMA), peso e resistência óssea, conteúdo de cinzas, Ca e P na tíbia. As variáveis de desempenho não foram afetadas (P > 0,05). O uso de FO grossa aumentou o conteúdo de Ca na tíbia de frangos machos (P < 0,001), e a relação Ca:P de 2,0:1 aumentou o conteúdo de cinzas e aprimorou resistência óssea em ambos os sexos (P < 0,001), porém reduziu P na tíbia dos machos (P < 0,05); frangos machos também tiveram ossos mais pesados e maior conteúdo de cinzas do que fêmeas (P < 0,05). A metabolizabilidade de Ca foi melhorada com FO grossa, enquanto a metabolizabilidade da matéria seca, P, e EMA não foram afetadas (P > 0,05). Conclui-se que as dietas com relação Ca:P de 2,0:1 e com FO grossa resultaram em melhor composição mineral óssea - particularmente em frangos machos - e a FO grossa melhorou a metabolizabilidade de Ca independentemente da relação Ca:P ou do gênero das aves.
Subject(s)
Animals , Particle Size , Calcification, Physiologic , Calcium, Dietary/administration & dosage , Chickens , Phosphorus, Dietary/administration & dosage , Animal Feed/analysis , OstreidaeABSTRACT
OBJECTIVE： To study the effects of superfine grinding on the powder properties and dissolution of oyster shell， and to provide experimental basis for its comprehensive exploitation. METHODS： Oyster shells were firstly prepared into ordinary powder by grinder. Then the ordinary powder was prepared into micro-powder Ⅰ （crushing 5 min） and Ⅱ （crushing 10 min） by ultrafine pulverizer. The differences of micromeritic properties were investigated before and after superfine grinding from the aspects of particle size distribution， specific surface area and porosity， angle of repose， bulk density， hygroscopicity， etc. Scanning electron microscope （SEM）， Fourier transform infrared spectroscopy （FTIR） and X-ray powder diffraction （XRD） techniques were used to analyze the morphological characteristics and chemical structure of oyster shell before and after superfine grinding. The dissolution were investigated. RESULTS： Compared with ordinary powder， micropowder Ⅰ and micropowder Ⅱ’s were small in particle size and uniformly distributed， but the particles were easy to adhere and aggregate； the specific surface area， porosity and the angle of repose increased， while bulk density decreased； the hygroscopicity increased. FTIR and XRD showed no significant change in chemical structure of oyster shell after superfine grinding. The dissolution rate of micropowder Ⅱ and micropowder Ⅰ was 18.5％ and 10.3％ at 10 min， and the dissolution of ordinary powder was only 6.4％ at 60 min. CONCLUSIONS： Compared with ordinary powder， oyster shell show obvious differences in powder properties after superfine grinding； the dissolution rate of the powders increases， and there is no significant change in chemical structure.
ABSTRACT
Objective To verify the feasibility of applying hydrothermal synthesis for preparing oyster hydroxyapatite(HA) and to develop a preparation method of oyster HA porous material for bone repair.Methods Hydrothermal synthesis was applied for preparing oyster HA,and the reaction condition was 220 ℃ for 6 h.Then,the prepared oyster HA was used as the raw material for porous scaffold preparation by sponge-soaking and sintering,successively.The porosity and compressive strength of the scaffold were adjusted by controlling the soaking time and absorbed HA slurry of the sponges.Results Hydrothermal synthesis was an effective method for preparing oyster HA.When the volume of the sponge cube was 1 cm3,the material absorbed by one to three times sponge-soaking were 0.184 8 g,0.318 1 g and 0.426 1 g,respectively,the corresponding porosity were 91.5％,82.9％ and 78.5％,and the compressive strength were 1.06 MPa,3.99 MPa and 8.49 MPa.Conclusion The oyster shell powder can be effectively converted into HA under the hydrothermal reaction condition of 220 ℃ for 6 h.The preparation of HA porous bone repair material by sponge-soaking method can obtain ideal porosity and mechanical strength.However,in this preparation process,the number of sponge-soaking and the weight of the absorbed HA slurry should be exactly controlled in order to obtain desired properties.
ABSTRACT
[Objective]To prepare a new porous composite artificial bone substitute and evaluate its properties.[Method]Thermally induced phase separation was adopted to prepare the artificial bone made from oyster shell powder and PLLA which were proportionally mixed and its properties as porosity rate,pore size and mechanical strength were assessed.Meanwhile the related variation parameters were examined every 2 weeks in a course of 14 weeks after the slices of CAB and pure PLLA were immersed in NS of 37℃ in vitro,the results of which were compared in statistics.[Result]The average porosity rate of artifical bone with TIPS method was 85.1% and pore sizes ranged 100-300 ?m under the SEM,with better pore connectivity and regulation shape.The average compressive strength was 2.12 MPa.As the immersion prolonged,the regular variation was observed about the mass loss of CAB and the pH alteration of solution,there was statistically difference in the indexes between the two groups(P﹤0.05).[Conclusion]The porosity rate,pore size,mechanical strength and degradation performance in vitro of the artifical bone made by TIPS method can satisfy the requirement of bone substitute.