Effects of Mineral pitch (Asphaltum punjabianum) supplemented diet on rohu (Labeo rohita): growth performance, immunological indices, antioxidant enzymes, and expression levels of immunity and growth- related genes

Abstract A 60 day completely randomized feeding experiment in triplicate was designed to evaluate the effect of a Mineral pitch supplemented diet on the growth performance and overall health status of Labeo rohita. Uniform-sized 240 rohu (average weight 60.2 ± 0.02g) were evenly distributed in 12 concrete rectangular tanks (1250 L) at a stocking density of 1g L− 1. Fish were divided into 4 groups i.e., the control group (C; provided with 32% CP basal diet), while other experimental groups were reared on Mineral pitch supplemented diet i.e., 2g (T2), 4g (T4), and 6g (T6) Mineral pitch kg− 1 diet. Results indicated a significant effect of Mineral pitch supplementation on the growth performance of fish i.e., improved weight gain (%WG), specific growth rate (% SGR) and protein efficiency ratio (PER) with maximum response observed in T6 group of fish followed by T4. Moreover, proximate analysis of muscle followed the same trend with increased levels of crude protein, lipids, and ash in the T6 group of fish. Also, significantly (p ≤ 0.05) improved immunological indices (WBC, total plasma protein, IgM, lysozyme, respiratory burst, and phagocytic activity), hemato-biochemical indices (RBC, HCT, Hb, MCH, MCV, MCHC, AST, ALT) and anti-oxidant enzyme activities (CAT, SOD, POD, LPO) was observed in T6 group of fish followed by T4. Furthermore, nutrigenomic studies also indicated increased mRNA level of growth response genes (MyoD and MyoG) in muscle and immune genes (Lysozyme C and TNF-α) in the liver of the experimental group of fish with maximum levels in the T6 group followed by T4 group. Overall results of the study revealed Mineral pitch supplementation in L. rohita as potential growth and an immune booster at a dosage level of 6 g kg− 1 in the diet.