Respostas fisiológicas e qualidade do filé de híbrido tambatinga suplementado com mananoligossacarídeo na dieta e submetido a estresse por adensamento

Abstract

The intensification of fish production and routine practices, such as trawling, transport and biometrics, can lead to stress in fish. Therefore, the use of food additives, such as prebiotics, is an alternative to reduce the negative effects caused by this condition during the production cycle. In this sense, this work aimed to evaluate the effect of mannan oligosaccharide (MOS), added to the feed, on the physiological responses of the hybrid tambatinga (♀C. macropomum x ♂ P. brachypomus), subjected to compaction. For this, tambatinga juveniles (initial average weight of 118.16±5.54 g) were stored in 100 L polyethylene boxes (14 grams of fish/L) and fed for 90 days (before densification) with experimental diets containing different levels of MOS: without inclusion (T0 = 0.0 g/kg) and with inclusion of 2.0 and 4.0 g MOS/kg (T1 and T2, respectively). After this period, the volume of water in the boxes was reduced, increasing the stocking density from 14 g of fish/L of water to 38 g of fish/L of water for a period of 14 days, maintaining constant renewal of water and aeration in the system and also the feed with the different concentrations of MOS in the feed. Samplings occurred before the increase in stocking densities, 7 and 14 days later, evaluating the condition factor of the fish (Factor K) and performing out blood analyzes of responses to stress (cortisol, glycemia, triglycerides, total proteins, albumin, globulin, chloride, total number of erythrocytes, mean corpuscular volume – MCV and respiratory activity of leukocytes) and meat quality indicators (thiobarbituric acid reactive substances value – TBARS and water holding capacity - WHC).