Optimization of de-oiled rice bran inclusion level in the diet ofLabeo rohita: Effect on growth performance, nutrient utilization, insulin-like growth factors I and II gene expression

Abstract

A 60‐day feeding trial was conducted to optimize the inclusion level of de‐oiled rice bran (DORB) in the diet of Labeo rohita fingerlings. Six iso‐nitrogenous (260g/kg), iso‐lipidic (70g/kg) and iso‐energetic (15 MJ/Kg) diets were prepared with different inclusion level of DORB viz., T33, T38, T43, T48, T53 and T58. One hundred and eighty fingerlings (9.8 ± 0.5 g) were randomly distributed in seven experimental groups in triplicates following a completely randomized design. The weight gain %, specific growth rate, protein efficiency ratio and feed efficiency ratio were found similar in 33%, 38% and 43% DORB fed groups. The expression of both insulin‐like growth factors I and II (IGF‐I and II) was significantly (p < 0.05) higher in T33, T38 and T43 groups. Based on second order polynomial regression analysis (y = −0.0059x2 + 0.4573x − 4.8404, R2 = 0.95), the expression of IGF‐I was found to be maximum at 39.5% inclusion level of DORB. Significantly (p < 0.05) lower muscle RNA content, RNA‐DNA ratio and higher feed conversion ratio were found in T58 group. Hence, from these results, it can be concluded that the optimum inclusion of DORB in the diet (260g/kg CP and 70g/kg lipid) of L. rohita should be 39.5% to support maximum nutrient utilization and growth performance.

Effects of Dietary Protein-to-Energy Ratios on Growth, Immune Response, Antioxidative Capacity, Liver and Intestinal Histology, and Growth-Related Gene Expression in Hybrid Yellow Catfish (Pelteobagrus fulvidraco ♀ × Pelteobagrus vachelli ♂ )

“…A number of animal organs (the gut, liver, or kidney) synthesize IGF-I. But in fish, liver IGF-I is thought to be one of the most important growth mediators [ 91 , 92 ]. The nutritional condition of numerous fish species has a significant impact on hepatic IGF-1 levels [ 91 , 93 ].…”

“…But in fish, liver IGF-I is thought to be one of the most important growth mediators [ 91 , 92 ]. The nutritional condition of numerous fish species has a significant impact on hepatic IGF-1 levels [ 91 , 93 ]. In current research, hepatic IGF-I expression was directly correlated with the optimum P/E ratio; however, as the P/E ratio increases or decreases further, the expression level of IGF-I diminishes.…”

“…Studies on a variety of fish, including GIFT [ 92 ] and salmonids [ 95 ], demonstrated a substantial link between growth hormone IGF-I and growth. Related findings indicated that the IGF-I expression followed a pattern that was similar to WG% [ 91 ]. It was found that the combined effects of crude protein, fat, and carbohydrate considerably influenced IGF-I.…”

Substitution of de‐oiled rice bran with Khejri pod meal and groundnut oilcake with Khejri seed meal in the diet of Labeo rohita (Hamilton, 1822)

“…As DORB is widely distributed, easily available and cheapest, it is most commonly incorporated in fish farm‐made feed along with different oilcakes (Meshram et al, 2018; Ranjan et al, 2017, 2018, 2019). However, recent studies indicated that 33–40% inclusion of DORB in the carp diet does not affect the growth in rohu fingerlings (Kumar et al, 2018, 2018, 2019). Moreover, the growing competitions with livestock feed and human food sector would lower the availability of DORB in near future to aquafeed sector (FAO, 2017).…”