Hematological parameters of Brazilian sardines (Sardinella brasiliensis Steinachner, 1879) fed different concentrations of fatty acids in their diet

ABSTRACT This study aimed to evaluate the effect of different levels of omega-3 polyunsaturated fatty acids (n-3 PUFA) in the diet of Sardinella brasiliensis on their hematological parameters. A total of 375 fish were distributed in 15 experimental units to evaluate the effects of the diet on their blood for 45 days. The levels of n-3 PUFA added in the diet were 0, 0.3, 0.6, 0.9, and 1.2% of the lipid fraction. These values represent the total percentage of n-3 PUFA in the lipid fraction of the diet, and 0% n-3 PUFA was used as the negative control. Five fish from each experimental unit were sampled at the end of the experiment for hematological analysis, and the parameters measured include the total number of erythrocytes, hematocrit percentage, hemoglobin and glucose concentration and differential leukocyte count. Higher numbers of circulating eosinophils were observed in fish fed 0.3% and 1.2% n-3 PUFA. Although no significant differences were observed in several of the parameters, the results demonstrate that the health of the sardines was not affected by the addition of n-3 PUFA in their diet. It should be emphasized that this is the first study with emphasis on the blood analysis of S. brasiliensis.