This study analyzed the performance, antioxidant status, hepatopancreatic lipoperoxidation, and proximate composition of Macrobrachium rosenbergii juveniles fed diets supplemented with clove basil (Ocimum gratissimum) essential oil (EO-OG). A total of 360 M. rosenbergii (initial weight 0.028 g ± 0.004) were randomly divided into four experimental groups with six replications each (n = 6). The prawns were fed diets with different EO-OG inclusion levels: 0.0, 1.0, 2.0, and 3.0 g kg⁻¹ EO-OG. After a 42-day feeding trial, dietary EO-OG showed no significant effect on prawn performance or carcass proximate composition, except on final antenna length. Prawns fed 3.0 g kg⁻¹ EO-OG displayed a 1.2- to 1.3-fold longer final antenna length than prawns from all other experimental groups. Likewise, prawns fed 3.0 g kg⁻¹ EO-OG presented a 2.6- to 3.2-fold higher catalase activity than prawns from all other experimental groups. Prawns fed EO-OG, regardless of the inclusion level, showed a 1.6- to 1.7-fold decreased hepatopancreatic lipoperoxidation compared to the control group. Therefore, EO-OG has been demonstrated to be a potential management tool as a non-nutritional dietary immunostimulant and animal welfare promoter for freshwater prawn farming, without affecting animal performance. This study recommends the dietary inclusion level of 3.0 g kg⁻¹ EO-OG for M. rosenbergii juveniles.

In prawn farming, the main protein source used in aquafeed formulations is fishmeal. Nevertheless, one estimates that in the coming years, this protein source will no longer be able to meet the demand for the activity. The search for new ingredients is important to meet the increasing demand and minimize environmental impacts, such as the reduction in fish stocks and the eutrophication of aquatic systems. The objective of this study was to determine the apparent digestibility coefficients of dry matter (DM), crude protein (CP), gross energy (GE), and ether extract (EE) of fishmeal, poultry co-products (viscera and hydrolysed feather), and insect meal (Gromphadorhina portentosa) for giant river prawn (Macrobrachium rosenbergii) juveniles. To determine the apparent digestibility coefficients (ADCs), 90 prawns (average weight, 15 g) were randomly distributed among three experimental units. The reference feed was formulated according to the requirements of the giant river prawn, with 35% crude protein and a gross energy of 3600 kcal kg⁻¹. The test diets comprised 70% of the reference diet and 30% of the respective test ingredients. Prawns were fed three times a day until apparent satiety. Faeces were collected using the indirect siphoning method, twice a day at the same feeding site (at 7:30 a.m. and 6:30 p.m.). The water parameters were temperature (27 °C), dissolved oxygen (6.65 mg L⁻¹) and pH (7.76). The ACDs of DM, CP, EE, and GE were, respectively, 61.48; 88.28; 99.89 and 88.25 for fishmeal; 76.48; 81.55; 97.29 and 85.13 for poultry viscera meal; 73.82; 75.21; 73.17 and 76.42 for hydrolysed feather meal; and 52.35; 59,48; 87.95 and 67.64 for G. portentosa meal. The values of protein (%) and digestible energy (kcal kg⁻¹) were 55.20 and 3711 for fishmeal; 47.27 and 4285 for poultry viscera’s meal; 65.03 and 4145 for hydrolysed feather meal; and 47.72 and 3616 for G. portentosa meal. These results showed the potential use of insect meals and poultry co-products as ingredients for the diets of M. rosenbergii juveniles, as they present digestible values close to those found for fishmeal, the main raw material used in aquaculture diets.

The objective was to evaluate the effects of partial replacement of fish meal with protein hydrolysates and a commercial product in the diets of Penaeus vannamei post-larvae on zootechnical performance, proximate chemical composition, digestive enzyme activity, and total hemocyte count. The experiment was conducted in a clear water recirculation system comprising 24 experimental units, each with 30 shrimp with an average weight of 0.2 g. The treatments were control, chicken protein hydrolysate (CPH), enzymatic hydrolysate of chicken feathers, Aquabite^®, CPH + maltodextrin, and CPH + yeast, with four replicates each. The inclusion level of the different protein sources evaluated was 6%. At the end of the experiment, all shrimp were counted, weighed, and measured to determine the zootechnical performance. The body and feed chemical compositions, as well as the enzymatic activities of the hepatopancreas and the total hemocyte count in the hemolymph, were analyzed. The data obtained were subjected to ANOVA and Tukey’s test. There was no statistical difference between the treatments in any of the analyzed parameters. The results showed that all the evaluated protein hydrolysates can be used as partial substitutes for fish meal in P. vannamei diets during the nursery phase, maintaining equivalent and adequate digestive enzyme activities, health, growth, and body composition of the shrimp, in addition to being ecologically sustainable ingredients.