02098naa a2200289 a 450000100080000000500110000800800410001902200140006002400430007410000200011724501550013726000090029252012160030165000190151765000130153665000090154965000180155865000290157665000200160565000100162565000130163570000220164870000250167070000250169570000240172077300640174421365082022-02-15       2022    bl uuuu     u00u1 u    #d  a1365-21097 ahttps://doi.org/10.1111/are.156802DOI1 aRAMOS, A. M. J.  aOptimizing methodological aspects of stool collection by sedimentation in digestibility studies with pirarucu (Arapaima gigas).h[electronic resource]  c2022  aThis study aimed at optimizing the sedimentation method for stool collection in digestibility tests in pirarucu. In the first trial, juvenile fish (435.26 ± 10.80 g) received the reference diet with chromium oxide to determine the gastrointestinal transit time (GITT). In the second, the fish were fed the reference and two test diets (corn and soybean meal) for 15 days. The apparent dry matter, protein and phosphorus digestibility coefficients (ADC) were determined to verify the time of acclimatization to the experimental diets. The stool pattern was visually analysed on day 5 and 10 of acclimatization. The third trial evaluated the maximum stool collection time for reduced nutrient leaching 30 min, 1, 6 and 12 h after evacuation as well as the stool collected directly from the rectum. GITT was 5.5 h. ADC varied during the initial acclimatization and stabilized between days 8 and 10, corroborating a consistent visual pattern on day 10 than on day 5. Nutrient ADC increased with increased stool collection time, except with a 30-min interval, which presented ADC similar to rectum samples. Pirarucu stool must be collected from day 10 for a 30-min interval about 30 min after the second daily meal.  aArapaima gigas  aChromium  aDiet  aDigestibility  aGastrointestinal transit  aDigestibilidade  aPeixe  aPirarucu1 aFRACALOSSI, D. M.1 aFREITAS, L. E. L. de1 aSANTOS, V. R. V. dos1 aRODRIGUES, A. P. O.  tAquaculture Researchgv. 53, n. 4, p. 1456-1467, Mar. 2022.