RESUMEN
ABSTRACT: This study evaluated the effect of low, medium, and high-water salinity (5, 35, and 50 ppt) on the apparent dry matter, protein, and energy digestibility of two formulated and six commercial diets for juvenile whiteleg shrimp, Litopenaeus vannamei, in a 120-day trial. Digestibility was determined in vivo using chromic oxide as an inert diet marker. Hydrostability in pellets varied from 86.8% to 99.9%; dry matter digestibility varied from 49.1% to 64.1%; protein digestibility showed greater variations at all salinities (56.9%-85.8%); and energy digestibility ranged from 70.1 to 86.4%. Salinity had a significant effect on dry matter, protein, and energy digestibility. Using a principal component analysis (PCA) with a covariance matrix, our findings suggested that the E2 (fishmeal-based formulation) diet and 35 ppt salinity provided optimum hydrostability and digestibility to Pacific white leg shrimp juveniles.
RESUMO: Nós medimos o efeito de baixa, normal e alta salinidade (5, 35 e 50ppt) na digestibilidade aparente da matéria seca, proteína e energia em duas dietas formuladas e seis comerciais para camarão juvenil do Pacífico, Litopenaeus vannamei. Os coeficientes de digestibilidade aparente da matéria seca, proteína e energia foram determinados in vivo utilizando o óxido crômico como marcador inerte nas dietas (peso inicial médio de 4g), em um teste de 120 dias. Hidrostabilidade na dieta de 86,8% a 99,9%, os coeficientes de digestibilidade da matéria seca variaram de 49,1 a 64,1%, os coeficientes de digestibilidade da proteína apresentaram maiores variações em todas as salinidades (56,9-85,8%), enquanto os coeficientes de digestibilidade da energia variaram de 70,1 a 86,4%. Efeito significativo da salinidade na digestibilidade da matéria seca, proteína e energia foi encontrado. Esses resultados, usando a análise de componentes principais (PCA) com a matriz de covariância, sugerem que a dieta E2 (fórmula à base de farinha de peixe) e salinidade a 35 ppt é ideal para a hidrostabilidade e digestibilidade das dietas para juvenis de camarão-branco-do-Pacífico.
RESUMEN
In this study, an attempt was made to substitute maize (Zea mays L.) content of broiler starter feed with ground cassava (Manihot esculenta Crantz) peels enzymatically improved with amylaseproducing fungi with a view to having a cost-effective yet nutritious and health-friendly feed. The biochemical components of the formulated feeds were determined as well as the effect of the feeds on some biochemical parameters in the broiler chicks. Six starter feeds tagged Control Feed, 20%CPFG, 40%CPFG, 60%CPFG, 80%CPFG and 100%CPFG were formulated with respect to variations in maize and cassava peel contents. The results showed a significant (p<0.05) increase in total polysaccharide contents of Feeds 20%CPFG, 60%CPFG, 80%CPFG and 100%CPFG compared to the Control Feed (191.4±14.5 mg/g of feed). Total soluble protein and reducing sugar contents were statistically different in most of the feeds (p<0.05). All the feeds contain relatively high amounts of total phenol (>70 mgCE/g of feed) and most of them comparatively high in anthocyanin relative to the control feed anthocyanin content (225.4±12.2 mg/g of feed). The highest weight gain (108.0±3.0 g) was observed in broiler chicks fed the feed ration containing 60% cassava peels improved with amylase-producing fungi and 40% maize (60%CPFG). Broiler chicks fed the formulated feeds, including the control, exhibited over 40% inhibition against 2, 2-diphenyl-1- picrylhydrazyl (DPPH) radical. The serum activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in birds fed the compounded feeds and control slightly differed except in group 60%CPFG. It was concluded that the maize content in broiler feed can be replaced with cassava peels improved with fungal amylase upto a maximum of 60%. This would significantly decrease the overall cost of broiler feed production without compromising the nutritional, antioxidant and health-friendly potentials of the feed.