This study evaluated the histomorphometric characteristics of tambaqui intestinal mucous after using Bacillus spp based probiotics, incorporated in feed and dissolved in water during transport. It was used a completely randomized design, with three treatments and seven replications, and a control treatment (fish fed commercial feed without probiotic) was compared with two other treatments involving the use of commercial probiotic incorporated in the feed or in the transport water. A total of 510 juvenile tambaqui (average weight and total length 83.26±28.14g and 17.39±1.90cm, respectively) was distributed in three cement tanks. During 60 days, fish of two tanks were fed with commercial feed and fish of the third tank received commercial feed supplemented with probiotic. After this period, the fish from each tank were divided into plastic bags and transported for 4 hours according to the following treatments: T1 = feeding with commercial feed (control); T2 = feeding with commercial feed and probiotic dissolved in the water during transport (20mg/L); T3 = feeding with commercial feed supplemented with probiotic (1.0g/kg feed). Before transport (basaline), 24 and 96 hours after transport, eight fish of each treatment were submitted to euthanasia and the intestine was removed for weighing and length measuring to establish the relation between length/gut ratio. Then, the anterior and posterior portions of the intestine were collected for evaluation of morphological and histological characteristics of intestinal mucous. The use of probiotic during transport did not affect the intestine weight of tambaqui. Regardless of the treatment, the intestine length increased as the fish increased in size. The supplementation with probiotics (Bacillus spp.) had no effect on height and length villus of tambaqui’s intestine during transport challenge.
Bacillus spp.; Colossoma macropomum; intestinal villous
