Effects of dietary supplementation of punica granatum L. and alpinia officinarum extracts on the innate immunity of red tilapia (oreochromis sp.)

Abstract

Red tilapia (Oreochromis sp.) is well known for its appealing taste, short cultured period, and high tolerance to adverse environmental stimulants. However, due to the intensification of aquaculture and environmental degradation, tilapia farming has been threatened by diseases such as Streptococcosis, which results in high mortality. Herbal extracts are now recognized for their medicinal activities in combating pathogens for both human and animals. Besides, due to the high availability in nature, ease of preparation and administration, and role as immunostimulants, these herbs can be considered as antibiotics alternatives. This study was carried out to determine the effectiveness supplemented schedule of Punica granatum L. and Alpinia officinarum extracts in order to improve the innate immunity of red tilapia. The experiment lasted for eight weeks and was divided into five treatments with three replications each. In these treatments, P. granatum L. (T1 of 1%) and A. officinarum (T2 of 1%) extracts were mixed separately with commercial pellets then alterated to control diet, fed for two weeks intervals (T1-2 and T2-2), and four weeks intervals (T1-4 and T2-4), and commercial feed without additives (Control diet). Fish of each treatment was sampled for blood, plasma at the 2nd, 4th, 8th week to check for the immune responses of experimental fish. There was significant different (P<0.05) with positive effects for all additives added treaments on haematological parameters, lysozyme activity, immune related genes expression, and Streptococcus agalactiae resistance in fish, with two weeks feeding alteration interval exhibited better result, especially for A. officinarum extract.