Protein-energy status and 15N-glycine kinetic study of child a cirrhotic patients fed low- to high-protein energy diets

In five male cirrhotic patients (Child A) and in four age- and sex-matched healthy control subjects, whole-body protein turnover was measured using a single oral dose of N-15-glycine as a tracer and urinary ammonia as end product. Subjects were studied in the fasting and feeding state, with different levels of protein and energy intake. The patients were underweight and presented lower plasma transthyretin and retinol-binding protein levels. When compared with controls, the kinetic studies showed patients to be hypometabolic in the fasting (Do) state and with the control diet [D-1 = (0.85 g of protein/154 kJ). kg(-1). day(-1)]. However, when corrected by body weight, the kinetic differences between groups disappeared, whereas the N-retention in the feeding state showed better results for the patients due mainly to their efficient breakdown decrease. When fed high-level protein or energy diets [D-2 = (0.9 g protein/195 kJ) and D-3 = (1.56 g protein/158 kJ). kg(-1). day(-1)], the patients showed D-0 = D-1 = D-2 < D-3 for N-flux and (D-0 = D-1) < D-3 (D-2 is intermediary) for protein synthesis. Thus, the present data suggest that the remaining mass of the undernourished mild cirrhotic patients has fairly good protein synthesis activity and also that protein, rather than energy intake, would be the limiting factor for increasing their whole-body protein synthesis.

Apparent digestibility of protein, energy, and amino acids in some selected feed ingredients for pacu Piaractus mesopotamicus

The apparent digestibility coefficients (ADCs) of amino acids (AA), protein, and energy in six feed ingredients (Brazilian fish meal, soybean meal, corn gluten meal, alcoholic yeast, corn, and wheat bran) we evaluated for pacu juveniles. In general, all ingredients showed high digestibility values for all AA, and differences among ADCs of individual amino acid were detected (P < 0.01). Corn gluten, soybean, and fish meals had the highest ADCs of AA. The ADCs of protein in fish meal, yeast, and corn gluten meal should not be used as AA digestibility indicators, because those showed differences up to 6.7% between the ADCs of protein and AA. All ingredients had lower ADCs of energy than corn gluten meal (P < 0.01). Lysine was the first limiting amino acid in fish meal, corn gluten meal, wheat bran, and corn, and the second limiting amino acid in soybean meal, as methionine was the first limiting amino acid in soybean meal and yeast. However, the soybean meal was the best quality protein source, as it had the highest digestible essential amino acid index. This demonstrated that digestible amino acid values can be used to formulate practical diets for pacu, preventing potential deficiencies or excess that might cause environmental and economic losses.

Apparent digestible energy and nutrient digestibility coefficients of diet ingredients for pacu Piaractus brachypomus

The digestible energy and apparent nutrient digestibility coefficients of common diet ingredients were determined for pacu Piaractus brachypomus (370.21 ± 17.56 g). Fish were fed with pelleted practical diets to apparent satiation and the feces were collected by siphoning. The digestibility value for each ingredient was determined by comparison of the digestibility of a test diet with a reference diet (24.5% crude protein and 1% chromic oxide). The digestible energy values of soybean meal (SBM), fish meal (FM), corn (CN), and wheat bran (WB) were 2382, 3826, 3353, and 1784 kcal/kg, respectively. The apparent dry matter digestibility coefficients were 83.72, 90.14, 89.13, and 82.05% for SBM, FM, CN, and WB, respectively. The apparent crude protein digestibility coefficients were 75.88, 90.49, 85.06, and 61.62% for SBM, FM, CN, and WB, respectively. The apparent lipid digestibility coefficients were 63.03, 77.00, 83.01, and 82.45% for SBM, FM, CN, and WB, respectively. The digestibility of protein, lipid, and energy from SBM were somewhat low compared to values for other warmwater omnivorous fishes, but similar to values reported for pacu-caranha P. mesopotamicus. Otherwise, the nutrient and energy availability of the ingredients to P. brachypomus was similar to that of other fish. This information will be useful in formulating nutritious, economical diets for pacus. © by the World Aquaculture Society 2004.