ABSTRACT At inadequate stocking density, fish generally show different physiological responses. The effects of stocking density on Arapaima gigas larvae productive parameters have been determined in a previous study. This study aimed to evaluate the effect of the stocking density on the water quality, hematological and biochemical profile, and productive performance of juvenile A. gigas. One hundred and eighty twelve months old, A. gigas were distributed into tanks using initial densities of 103.90, 157.95 and 220.11 kg m-3 with three replicates. Ammoniacal nitrogen, carbon dioxide, dissolved oxygen pH, alkalinity, and hardness were determined using a LaMotte Fish Farm 9, AQ-2 model, Maryland, USA, freshwater test kit. Blood samples were taken at 13, 14, and 15 months old by pricking the caudal vein and profiles of glucose (Glu), total protein (TP), albumin, aspartate transaminase (AST), alanine transaminase (ALT), and urea, were determined in blood serum. Rearing water was saturated in ammoniac nitrogen, carbon dioxide, and dissolved oxygen but have not changed with the increase of stocking density (P < 0.05), Erythrocyte's count (EC) diminished (P < 0.05), nonetheless, hemoglobin, mean concentration hemoglobin (MCH) and mean cell volume (MCV) increased (P < 0.05). Albumin, AST, ALT and urea diminished at 220.11 kg m-3 stocking density (P < 0.05). The feed intake increased, final biomass gain was 100.26 ± 19.00, 119.10 ± 13.95, and 130.24 ± 08.07 kg m-3, but did not change as density increased (P < 0.05). Juveniles of A. gigas showed no variation in productive performance with an increase in the stocking density. Furthermore, hematological and biochemical adapting profile to high stocking densities characterized this species.

Eggs are sources of high nutritious value; however, their intake is associated with hypercholesterolemia in consumers. Stevia rebaudiana, among other properties, has a hypoglycemic and hypocholesterolemic effect in humans, rats and broilers chicken. The objectives of this research were to determine the effect of the inclusion of 0, 1, 2 and 3% of Stevia rebaudiana leaves powder in the diet on the lipid profile and productive parameters of Isa Brown hens. One hundred, 17-24 week old, Isa Brown laying hens were used and distributed in a completely randomized design with four treatments and five repetitions. The increase in the levels of powder from Stevia leaves decreased the cholesterol profile (p < 0.05), without changing other profiles and the productive parameters (p > 0.05). Additionally, the triglyceride profile and weight gain showed quadratic and negative linear tendencies, respectively associated with the increase of powder from Stevia leaves in the diet. It is concluded that the levels of cholesterol, triglycerides, final weight and total weight gain of Isa Brown laying hens has a tendency to decrease when the levels of powder from Stevia leaves is increased in the diet.

Um estudo foi conduzido para avaliar os efeitos de microminerais inorgânicos e orgânicos na dieta em dois níveis de suplementação, sobre desempenho, ocorrência de diarreia, parâmetros hematológicos, excreção dos minerais nas fezes e retenção dos minerais nos metacarpos e fígado de leitões desmamados. Setenta leitões desmamados aos 21 dias de idade com peso médio inicial de 6,70 ± 0,38 kg foram distribuídos em cinco tratamentos: dieta controle (sem adição de premix micromineral); 50% ITMP (dieta controle contendo premix micromineral inorgânico atendendo a somente 50% da exigência em microminerais); 50% OTMP (dieta controle contendo premix micromineral orgânico atendendo a somente 50% da exigência em microminerais); 100% ITMP (dieta controle contendo premix micromineral inorgânico atendendo a 100% da exigência em microminerais); e 100% OTMP (dieta controle contendo premix micromineral orgânico atendendo a 100% da exigência em microminerais). Consumo de ração e o ganho diário de peso não foram afetados pelos tratamentos, entretanto, os leitões suplementados com microminerais apresentaram melhor eficiência alimentar. Não foram observadas diferenças para as quantidades de cálcio, fósforo, potássio, magnésio, sódio e enxofre excretados nas fezes por quilograma de alimento consumido. Os tratamentos não afetaram os teores de cálcio, fósforo, magnésio, enxofre e ferro nos metacarpos. A suplementação com microminerais, independente dos níveis e da fonte, melhorou o desempenho dos leitões.

A study was conducted to evaluate the effects of dietary inorganic and organic trace minerals in two levels of supplementation regarding performance, diarrhea occurrence, hematological parameters, fecal mineral excretion and mineral retention in metacarpals and liver of weanling pigs. Seventy piglets weaned at 21 days of age with an average initial body weight of 6.70 ± 0.38 kg were allotted in five treatments: control diet (no added trace mineral premix); 50% ITMP (control diet with inorganic trace mineral premix supplying only 50% of trace mineral requirements); 50% OTMP (control diet with organic trace mineral premix supplying only 50% of trace mineral requirements); 100% ITMP (control diet with inorganic trace mineral premix supplying 100% of trace mineral requirements); and 100% OTMP (control diet with organic trace mineral premix supplying 100% of trace mineral requirements). Feed intake and daily weight gain were not affected by treatments, however, piglets supplemented by trace minerals presented better gain:feed ratio. No differences were observed at calcium, phosphorus, potassium, magnesium, sodium and sulfur excreted in feces per kilogram of feed intake. Treatments did not affect calcium, phosphorus, magnesium, sulfur and iron content in metacarpals. Trace mineral supplementation, regardless of level and source, improved the performance of piglets.