ABSTRACT
Avaliou-se o efeito de diferentes níveis do composto enzimático Natugrain Blend L®, que contém endo-xilanase e endo-beta-glucanase, sobre a digestibilidade dos nutrientes e a energia do triticale pela tilápia-do-nilo. O método para a determinação da digestibilidade foi o indireto, utilizando-se o óxido de crômio III (0,10 por cento). O delineamento experimental foi inteiramente ao acaso, com cinco tratamentos e três repetições. O nível de substituição da dieta-referência foi 50,0 por cento pelo triticale. Os tratamentos foram 0,0; 150,0; 300,0; 450,0 e 600,0mg kg-1 de Natugrain Blend L, que contém 800 unidades g-1 de endo-1,3(4)-β-glucanase (BGU) e 36.600 unidades g-1 de endo-1,4-β-xylanase (EXU). Os coeficientes de digestibilidade aparente foram: da matéria seca, 76,42; 74,01; 83,39; 82,97 e 78,34 por cento; da proteína bruta 88,19; 88,39; 90,52; 92,05 e 88,34 por cento, da energia bruta 75,93; 71,31; 81,78; 80,27 e 78,62 por cento, respectivamente, para os níveis de inclusão na dieta 0,0; 150,0; 300,0; 450,0 e 600,0mg kg-1 de Natugrain Blend L.Os resultados demonstram que 300mg kg-1 do complexo de enzimas foi suficiente para aumentar o coeficiente de digestibilidade aparente da matéria seca. O composto de enzimas pode ser utilizado para aumentar a eficiência de aproveitamento dos nutrientes do triticale.
The effects of different levels of Natugrain Blend L® enzymatic compound on triticale nutrients and energy digestibility by Nile tilapia were evaluated. The digestibility was indirectly determined with chromic oxide III (0.10 percent) as an external marker. The level of substitution by triticale in the reference diet was 50 percent. The treatments were 0, 150, 300, 450, and 600g kg of Natugrain Blend L, which contains 800 units g-1 of endo-1,3(4)-β-glucanase (BGU) and 36.600 units g-1 of endo-1,4-β-xylanase (EXU). The apparent digestibility coefficients were: dry matter 76.42, 74.01, 83.39, 82.97, and 78.34 percent; crude protein 88.19, 88.39, 90.52, 92.05, and 88.34 percent; crude energy 75.93, 71.31, 81.78, 80.27, and 78.62 percent, respectively to inclusion levels of 0.0, 150.0, 300.0, 450.0, and 600.0mg kg-1 of Natugrain Blend L in diet. Results demonstrated that 300mg kg-1 of enzymes were enough to increase the dry matter apparent digestibility coefficient and energy. The enzyme compound can be used to increase the efficiency of triticale feed utilization.
Subject(s)
Animals , Food Analysis/methods , /administration & dosage , /administration & dosage , Cichlids , Edible Grain/adverse effectsABSTRACT
Avaliou-se a digestibilidade aparente de cinco rações isoproteicas e isoenergéticas contendo 0; 0,1; 0,2; 0,3 e 0,4g do complexo enzimático Bioenzimaplus (lipase, protease e carboidrase)/kg de ração na alimentação da tilápia-do-nilo. Foram utilizados 100 peixes distribuídos em cinco aquários de alimentação e cinco aquários de coleta de fezes. Os cinco tratamentos foram arranjados em delineamento inteiramente ao acaso com cinco repetições. Houve efeito linear de tratamento sobre a digestibilidade aparente (CDa) para proteína bruta e extrato etéreo. O CDa da proteína bruta e do extrato etéreo variaram de 81,60 por cento a 84,93 por cento e de 74,19 por cento a 82,69 por cento, respectivamente. Para carboidrato e energia bruta, o maior nível de suplementação resultou em maior CDa, 57,85 por cento e 63,78 por cento, respectivamente( P<0,05). Não foi observada diferença entre tratamentos no CDa da matéria seca, apresentando valores de 49,47 por cento a 58,55 por cento. A inclusão de complexo enzimático - lipase, protease e carboidrase - em dietas para tilápia-do-nilo melhorou a digestibilidade da proteína, do extrato etéreo, do carboidrato e da energia das rações.
Apparent digestibility (ADC) of five isoproteic and isoenergetic diets containing 0, 0.1, 0.2, 0.3, and 0.4g/kg of enzymatic complex Bioenzimaplus (lipase, protease, and carbohydrase) for Nile tilapia was evaluated. A hundred fish were randomly assigned in five feeding aquaria, and five collecting feces ones. Treatments were composed by five enzymatic complex levels arranged in a completely randomized design in five repetitions. Significant differences (P<0.05) were observed with the inclusion of enzymatic complex in the diets for ADC of crude protein and fat (linear effect). ADC of crude protein and fat varied from 81.60 percent to 84.94 percent and 74.19 percent to 85.69 percent, respectively. The highest enzyme supplementation level showed better digestibility values for carbohydrate and gross energy (57.85 percent and 63.78 percent, respectively). No difference was observed for ADC of dry matter showing values between 49.47 percent and 58.55 percent. The use of enzymes in Nile tilapia diets improved the digestibilities of protein, fat, carbohydrate, and gross energy digestibility.
Subject(s)
Animals , Cichlids , Enzymes/administration & dosage , Animal Feed/adverse effects , Rumen/physiology , Nutritive ValueABSTRACT
The effects of grain-based diets from C3 or C4-cycle plants on muscle delta(13)C change process in Nile tilapia (Oreochromis niloticus) fingerlings were investigated. Two groups of sex reversal males Nile tilapia fingerlings were fed with isoproteic (32.0% DP) and isocaloric (3200 kcal DE/kg) diets, differing from each other by their delta(13)C. Muscle samples were collected and the carbon isotopic composition was measured. For C4 diet, the formula for the muscle delta(13)C change related to the intake time of a new diet was delta(13)C=-14.88-9.21e(-0.0209t) and the half-life (T) of the muscle carbon was 33.2 days. For C3 diet, the formula was delta(13)C=-25.43+8.59e(-0.0533t) with T=13 days. The C3 diet was considered more appropriate based on its palatability and consequent larger food intake than the C4 diet, resulting in an increased muscle delta(13)C change rate. However, for future studies, would be necessary to mix both the C3 and C4 feedstuffs to formulate diets nutritionally appropriated, with contrasting stable isotopes signatures. Tissue delta(13)C change rate is therefore indicated as a promising tool to better understand the biotic and abiotic factors that influence nutrients utilization from the diet and animal growth.
Subject(s)
Animal Feed , Cichlids/metabolism , Diet , Edible Grain/chemistry , Edible Grain/metabolism , Muscles/metabolism , Animals , Body Weight , Carbon Isotopes , Feeding BehaviorABSTRACT
The contribution of growth and turnover to the muscle delta(13)C change process was investigated using mathematical models which associate delta(13)C change to time of intake of a new diet or increase in body mass. Two groups of Nile tilapia (Oreochromis niloticus) were fed on diets based on C3 (delta(13)C=-25.64+/-0.06 per thousand) or C4 (delta(13)C=-16.01+/-0.06 per thousand) photosynthetic cycle plants to standardize the muscle delta(13)C. After establishing the carbon isotopic equilibrium, fish (mean mass 24.12+/-6.79 g) then received the other treatment diet until a new carbon isotopic equilibrium could be established, characterizing T1 (C3-C4) and T2 (C4-C3) treatments. No significant differences were observed in fish productive performance. Good fits were obtained for the models that associated the delta(13)C change to time, resulting in carbon half-life values of 23.33 days for T1 and 25.96 days for T2. Based on values found for the muscle delta(13)C change rate from growth (0.0263 day(-1) and 0.0254 day(-1)) and turnover (0.0034 day(-1) and 0.0013 day(-1)), our results indicate that most of the delta(13)C change could be attributed to growth. The application of model that associated the delta(13)C change to body mass increase seems to produce results with no apparent biological explanation. The delta(13)C change rate could directly reflect the daily ration and growth rate, and consequently the isotopic change rates of carbon and other tissue elements can be properly used to assess different factors that may interfere in nutrient utilization and growth.
Subject(s)
Carbon/metabolism , Cichlids/growth & development , Cichlids/metabolism , Muscles/metabolism , Animal Feed , Animals , Body Weight , Carbon Isotopes , Models, Theoretical , Weight GainABSTRACT
The effects of diets with variable zinc levels on the midgut epithelial cells were studied in Oreochromis niloticus L. One hundred and twenty fry of tilapia were apportioned into 4 experimental groups (I, II, III and IV groups), with 30 fish in each treatment, 5 replicate aquaria per treatment containing 6 fish each. The animals of the 4 groups were fed with isonitrogenous (30% crude protein) and isoenergetic (3000 Kcal/Kg of digestible energy) diets with increasing quantities of zinc (44.59; 149.17; 309.93; 599.67 mg Zn/kg of diet), twice a day, for 93 days. Three fish from each group were sacrificed at 36, 66 and 93 days and samples of midgut were removed for ultrastructural analysis. After 93 days of treatment, 3 animals of each experimental group were used for the analysis of zinc concentration by atomic absorption spectrophotometry. The comparative relative index (CRI) revealed that the animals in groups II, III and IV contained, respectively, 1.99%, 34.67% and 22.78% more zinc than the mean concentration in animals from group I. The ultrastructural analysis showed enterocytes with swelling of smooth surfaced endoplasmic reticulum and dilated mitochondria with variable matrix rarefaction and cristae number reduction in the fish exposed to 599.67 mg Zn/Kg of diet at 66 and 93 days of treatment.
