Dietary protein:lipid ratio changes growth, digestive enzyme activity, metabolic profile and haematological parameters in hybrid surubim (Pseudoplatystoma fasciatum × Leiarius marmoratus)

Abstract

Studies investigating improved protein:lipid ratios based on their effects on growth, nutrient utilization, digestive enzyme activities, blood metabolites and erythogram in tropical carnivorous fish are very scarce. This study evaluated the effect of different protein:lipid ratios on these parameters in the hybrid surubim Pseudoplatystoma corruscans × Leiarius marmoratus. Juvenile fish (8.90 ± 0.94 g initial weight) were fed 3% of total biomass for 60 days using four isoenergetic experimental diets with different protein:lipid ratios (9.00, 4.60, 3.54 and 1.78). Higher growth performance parameters were observed at higher protein:lipid ratios. The activities of intestine total alkaline protease, trypsin and lipase (U/mg protein) were not affected by dietary treatments. Chymotrypsin (U/mg protein) was higher in the 4.60 protein:lipid ratio group. Amylase (U/mg protein) was higher in intermediate groups. Blood glucose, total plasma protein, triglycerides, cholesterol and free amino acids decreased as the protein:lipid ratio decreased. Haematocrit was higher at the 9.00 and 4.60 protein:lipid ratios. Hybrid surubim showed metabolic adaptation to the different protein:lipid ratios tested. These results suggest that the 4.60 protein:lipid ratio showed the best protein‐sparing effect of lipids.

Atividade das enzimas digestivas frente a restrição alimentar de peixes ornamentais

“…O estudo bioquímico-enzimático das enzimas digestivas torna-se imprescindível para o melhor entendimento da fisiologia da digestão e do metabolismo dos nutrientes. Essas informações geram subsídios para trabalhos na área de nutrição e possibilitam ajustes mais precisos na elaboração de dietas (Campeche et al, 2018). Ressalta-se, no entanto, que o primeiro passo neste ramo é avaliação da atividade das enzimas digestivas frente a presença de alimento no trato digestório.…”

Revisión: necesidades nutricionales de peces de la familia Pimelodidae en Sudamérica (Teleostei: Siluriformes)

“…Las proteínas son péptidos de elevado peso molecular, compuestas por carbono, hidrógeno, de la relación proteína:lípidos no han sido estudiados frecuentemente en peces tropicales carnívoros (Campeche, Andrade, Souza, Melo, & Bezerra, 2018).…”

“…Cuando los niveles de lípidos en la dieta están por encima de los requisitos metabólicos, podría ser almacenado como grasa visceral. Dietas con altos valores de lípidos pueden afectar la actividad de la lipasa, los niveles de colesterol y triglicéridos y causar disminución del crecimiento (Campeche et al, 2018).…”

Dietary lipid level and source affect metabolic responses in hybrid catfish (Pseudoplatystoma reticulatum × Leiarius marmoratus)

“…Given its fillet quality and important commercial value, studies to improve nutritional requirement knowledge of hybrid catfish ( P. reticulatum × L. marmoratus ) have been carried out (Fortes‐Silva et al, ; Prieto‐Guevara et al, ). Recently, it was also established that the growth performance of hybrid catfish juveniles was improved with a dietary protein: lipid ratio of 4.6 than with lower ratios (Campeche, Andrade, Souza, Melo, & Bezerra, ). In respect of dietary lipids level, inclusion ranges from 44 to 250 g/kg, and an optimal oil level in surubim catfish diets is unclear (Arslan, Dabrowski, Ferrer, Dietrich, & Rodriguez, ; Asrlan et al, ; Bernardes, Navarro, Guerra‐Santos, & Fortes‐Silva, ; Campeche et al, ; Martino, Cyrino, Portz, & Trugo, , , ).…”

“…. In respect of dietary lipids level, inclusion ranges from 44 to 250 g/kg, and an optimal oil level in surubim catfish diets is unclear (Arslan, Dabrowski, Ferrer, Dietrich, & Rodriguez, 2013;Asrlan et al, 2008;Bernardes, Navarro, Guerra-Santos, & Fortes-Silva, 2016;Campeche et al, 2018;Martino, Cyrino, Portz, & Trugo, 2002a, 2002b. Studies evaluating the effect of this range and oil source on are scarce.…”