Physical properties and nutritive values of shell meal derived from different shellfish species and habitats

Abstract

Background and Objective: The province of West Sumatra is rich in various species of shellfish that live in salt water and fresh water bodies, including the ocean, estuaries, lakes and rivers. This study aimed to evaluate the physical properties and nutritive values of shell meals produced from different shellfish species living in various habitats. Materials and Methods: Samples of shellfish were collected from 12 locations in 4 different water body types: Lakes, rivers, estuaries and oceans. Shell parts were separated, dried and weighed. The dried shells were then ground or subjected to open-air burning to produce 3 meal products: Raw coarse meal, raw fine meal and roasted meal. The products were weighed and analyzed for physical properties (bulk density, angle of response and particle size) and content of crude ash, Ca and P. The nutritive values of the meals were evaluated by mixing 3% shell meal with basal diet that was fed to 200 laying quails in a completely randomized design. There were four dietary treatments: Control diet (P0), basal diet+3% roasted meal (P1), 3% raw fine meal (P2) and 3% raw coarse particles (P3). The quail were divided into 20 experimental units of 10 birds each, so that each treatment consisted of 5 replications. Parameters measured include feed intake, egg production, feed conversion ratio (FCR) and egg shell quality. Results: The dried shells represented between 47 and 56% of the total body weight of the shellfish, with lake mussels having the highest percentage of shell parts (p<0.05). Raw coarse ground meal had the highest percentage of meal yield (98.7%), followed by raw fine meal (95.8%) and roasted meal (86.8%) (p<0.01). Raw coarse meals had higher bulk density and lower angle of response due to the higher percentage of large particles (p<0.05). The Ca content of roasted meal was significantly higher (p<0.05) than that of the raw meals. There was no significant effect of the different shell meal products on feed intake, egg production or FCR. However, quail fed a diet containing raw coarse ground shell (P3) had significantly better egg shell quality (p<0.05) than those fed the control diet (P0), P1 or P2. Conclusion: Shell meal that had coarse particles showed the best physical properties and nutritive values.