Influence of inclusion of pigeon pea ( Cajanus cajan ) leafmeal on growth, physio‐metabolic and immune parameters, and expression of IGF‐1, IGF‐1R and IGFBP‐1 genes in Labeo rohita (Hamilton, 1822) fingerlings

Abstract

A feeding trial was conducted with inclusion levels of Cajanus cajan leafmeal (CCLM) in the diet of Labeo rohita to study the growth, haematological indices, digestive enzyme, physio-metabolic changes and molecular expression of insulin-like growth factor-1 (IGF-1), insulin-like growth factor-binding protein-1 (IGFBP-1), insulin-like growth factor-1 receptor (IGF-1R) genes. Four practical diets with CCLM, control, T20 (20%), T30 (30%) and T40 (40%) were prepared. Weight gain%, SGR, FER and PER were significantly (p < 0.05) higher when 30% de-oiled rice bran (DORB) was replaced by CCLM whereas the treatment group 40% registered with lower FCR value. The protease and amylase activities were higher in the T30 group. T20 showed significantly higher (p < 0.05) hepatic and muscular lactate dehydrogenase and serum glucose was also higher, whereas, WBC content was found significantly (p < 0.05) higher in control. The hepatic IGF-1 gene expression was significantly higher (p < 0.05) in T40 followed by the T30 group but the weight gain was not significantly (p > 0.05) higher in T30 from the T40 group. Results reveal that the response of IGF-1, IGF-1R and IGFBP-1 genes was complementary to the biological growth parameters and hence were used as an indicator to evaluating growth. The study also demonstrates that CCLM can replace 100% DORB in the diet of L. rohita without any antinutritional or adverse growth effects.