Efeitos da suplementação de glutamina na ração de tilápia do Nilo sobre o desempenho e resistência à infecção bacteriana / Effects of glutamine supplementation in the ration of Nile tilapia on performance and resistance to bacterial infection

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

23/06/2010

RESUMO

The current study was aimed at evaluate the effect of dietary glutamine supplementation in diets of Nile tilapia adults (Oreochromis niloticus) on the performance and resistance to infection by Streptococcus agalactiae. Two trials were carried out at the fish nutrition laboratory of the Animal Science Department of the Federal University of Viçosa. In the first experiment, aimed at evaluate the effect of L-glutamine supplementation in the diet. Three hundred reverted Nile tilapia (Oreochromis niloticus), thailand line (201 1.51g), were allotted at a completely randomized design, with five treatments (0, 1, 2, 3 and 4% of glutamine supplementation in the diet), all of then were isoenergetic and digestible isolysinic, and minimum ratios between the other amino acids with the lysine, five replicates by treatment and twelve fishes per experimental unit. Fishes were maintained in 25 aquariums of 320 liters supplied with single-pass flow-through water and aeration, controlled temperature and they were fed six daily meals during 32 days. Performance, corporal composition, corporal protein and fat deposition and nitrogen retention efficiency of the fishes were evaluated. L-glutamine supplementation in the diet does not affect weight gain, specific growth rate, the amount of body protein, fat and protein deposition rates, fat:protein ratio, nitrogen retention efficiency, feed:gain ratio, lysine and protein efficiency for growth, body water and fat. In the second one, aimed at investigate effects of dietary supplementation of glutamine on resistance to infection caused by Streptococcus agalactiae, 144 adults reverted Nile tilapia (Oreochromis niloticus), of the Thailand line, with initial weight of 201 1.51 g were used in an experiment with completely randomized design, six treatments, two replicates and 12 animals per experimental unit. Fishes were fed during 32 days with five experimental diets isonitrogenous, isoenergetic, and five levels of glutamine supplementation (0, 1, 2, 3 and 4%). At the end of this period all fish were challenged by an intraperitoneal injection with 0.1 mL inoculum of S. agalactiae 4x105 CFU / mL, except for the control group, which was inoculated with 0.1 ml of sterile Brain Heart infusion (BHI) and fed a diet containing 0% supplementation. The infected fish continued to receive diets with five levels of glutamine supplementation. The animals were observed during twenty-three days after infection. Fishes were maintained in 12 aquariums of 320 liters supplied with single-pass flow-through water and aeration, controlled temperature and they were fed six daily meals during 55 days. During the feeding period was recorded animals feeding behavior and the occurrence of clinical symptoms of meningoencephalitis, such as lethargy, anorexia, erratic swimming and exophthalmia. The level of 2% L-glutamine supplementation in diet provids the lowest mortality rate and greater reduction of symptoms of infection caused by Streptococcus agalactiae in adults of Nile tilapia.

ASSUNTO(S)

oreochromis niloticus aminoácido nutricao e alimentacao animal oreochromis niloticus amino acid

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