Uso do complexo enzimático solid state fermentation (SSF) em rações para tilápia do Nilo

• Autor(a) principal: Moura, Guilherme de Souza
• Data de Publicação: 2011
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1782
• topic: Oreochromis niloticus; Enzimas; Fisiologia de peixes; Oreochromis niloticus; Enzyme; Fish physiology; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL

In the first experiment aimed to evaluate the stability of the enzyme complex SSF (solid state fermentation) during the feed processing and storage time. Two diets were formulated with the same nutritional composition, being a diet free of SSF and the other containing 50g of SSF/kg of diet. The samples were collected during the following processing steps: mixing, after pelleting and then dried. To evaluate the storage time, was considered as day one, ready to feed after drying. On this day, two samples were being kept in a room with ambient temperature of 25oC and another kept in a freezer at-18oC. Sub-samples were taken in the 15th, 30th, 45th and 60th day. All samples from the processing stage and storage period were sent to the laboratory, measured the activity of the following enzymes: α-galactosidase, endoglucanase (carboxy-methyl-cellulase), xylanase, sucrase, amylase, lipase and trypsin. For all control samples, were not observed activities of the enzymes analyzed. Among the steps of mixing and post oven there were no differences, except for α-galactosidase and lipase activities that were observed reduction and sucrase that was observed increase in activity. There were no effects for the activities of endoglucanase, sucrase, xylanase, amylase and trypsin between the first (after oven) and the 60th day of the trial for the storage temperature of 25°C. For the storage temperature of -18°C, no differences were observed only in relation to the activities of endoglucanase and xylanase between the first and last day. Comparison between the two treatments (-25oC and 18oC) was only observed effect on the activity of galactosidase and trypsin at 60 days. For all enzymes of the SSF there was no difference in the period from 30 to 45 days of storage. It is concluded that the enzymes studied the SSF enzyme complex remain stable during the processing of pelleted feed at 55°C, maintaining activity for at least 60 days when stored at temperatures up to 25oC. For the second trial aimed to evaluate the effects of enzyme complex SSF in diets for Nile tilapia and the availability of sucrose and monosaccharides in these chime. We used 360 fish with an average weight ranging from 4.43 ± 70g in a completely randomized design with six treatments (0, 50, 100, 150, 200 and 250 ppm), six replicates, totaling 10 fish per experimental unit. At 60 days of the experiment was evaluated: initial weight, final weight, weight gain, feed conversion, specific growth rate and survival. For evaluation of sucrose, glucose and fructose present in the chyme, every 15 days, it was sacrificed a fish of each experimental unit. The levels of these carbohydrates were measured by HPLC. There was a linear effect of treatment according to final weight and weight gain. For the other performance parameters, no effect was observed. For sucrose and glucose levels of chime was observed quadratic effect as a function of treatment, while levels of fructose increased linearly. It is concluded that the enzyme complex SSF improves performance and increases the availability of sucrose and monosaccharides in the chime of Nile tilapia. The third trial evaluated the effects of the enzyme complex SSF on nutrient and gross energy digestibility in diets for Nile tilapia. A total of 72 males of Nile tilapia with average weight of 204.30 ± 17.2 g were randomly assigned to six tanks adapted for digestibility trial. The experimental diets were isonitrogenous (30% CP) and isocaloric (3,000 kcal DE / kg), supplemented with the enzyme complex SSF levels of 0, 50, 100, 150, 200 and 250 ppm. The apparent digestibility was measured by the indirect method using chromium oxide (Cr2O3) as an indicator of digestibility. Each tank received a treatment and stool collections were performed during the night (19:00, 11:00, 02:00 and 05:00). The study was conducted during nine days, with six treatments and three replicates. It is concluded that the addition of the enzyme complex in the diet improves the apparent digestibility of dry matter, crude protein, gross energy, calcium and phosphorus.