Protective efficacy of Shilajit enriched diet on growth performance and immune resistance against Aeromonas hydrophila in Oreochromis mossambicus.

We investigated the effects of dietary enriched with Shilajit in three dose levels: 2.0, 4.0, and 6.0 g kg-1 in the basal diet on growth rate, non-specific immune response, and disease resistance for 60 days in Oreochromis mossambicus against an opportunist pathogen, Aeromonas hydrophila. The results showed that the Shilajit enriched diets at 4.0 and 6.0 g kg-1 diets significantly (p < 0.05) enhance survival rate, weight gain (WG), protein efficiency ratio (PER), specific growth rate (SGR), and feed efficiency (FE), whereas it significantly decrease the feed conversion ratio (FCR) from weeks 1-4 when compared with control. The innate immune parameters, such as the phagocytic, complement, respiratory burst, and lysosome activities in infected fish fed with all Shilajit enriched diet were significantly (p < 0.05) enhances on weeks 2-4. A very low cumulative mortality, 8.0% and 12.0% were observed in the infected fish fed with 4.0 and 6.0 g kg-1 Shilajit enriched diets, whereas 18% mortality was found with 2 g kg-1 diet. In conclusion, 4.0 and 6.0 g kg-1 Shilajit enriched diets significantly increased the growth performance, innate immune response, and disease resistance in O. mossambicus against A. hydrophila infection.

Protective efficacy of Mucuna pruriens (L.) seed meal enriched diet on growth performance, innate immunity, and disease resistance in Oreochromis mossambicus against Aeromonas hydrophila.

The impact of Mucuna pruriens (L.) seed meal diet on growth performance, innate immune response, and disease resistance in Oreochromis mossambicus against Aeromonas hydrophila is reported for the first time. Infected O. mossambicus was fed with 2 g kg-1, 4 g kg-1, and 6 g kg-1 of M. pruriens seed meal diets significantly increased initial body weight (IBW) and final body weight (FBW) over control, for a period of 4 weeks. At 4 g kg-1 and 6 g kg-1 the enriched diet significantly (P < 0.05) enhanced the survival rate, weight gain (WG), protein efficiency ratio (PER), specific growth rate (SGR), feed conversion ratio (FCR), and feed efficiency (FE) when compared to the control; besides, from weeks 2-4 these diets significantly (P < 0.05) enhanced the complement activity, phagocytic activity, respiratory burst activity, and lysosome activity. On being fed with 4 g kg-1 and 6 g kg-1-enriched diets the cumulative mortality was lower (10% and 12%) than with 2 g kg-1 diet (24%). The present investigation suggests that the enriched diet at 4 g kg-1 and 6 g kg-1 improved the growth performance more than that of the control and negative control; it also positively enhanced the innate immunity and disease resistance against A. hydrophilla in O. mossambicus. Hence M. pruriens can be used as a feed additive to stimulate immunity for effective production of economically valuable freshwater fish, O. mossambicus.