Effect of alternate day feeding strategy of sub-optimal protein level on haemato-biochemical responses in Labeo rohita (Hamilton) juveniles

A feeding trial was conducted for 60 days to delineate the effect of alternate day feeding strategy of sub‐optimal protein level on haematological parameters, serum parameters and phagocyte respiratory burst activity (NBT) in Labeo rohita juveniles. One hundred and thirty‐five fingerlings (1.87 ± 0.01–2.26 ± 0.05 g) were distributed in triplicate groups of each treatment, and fish were fed at 5% body weight daily. Three experimental isocaloric (401.32–410.28 kcal/100 g) diets of 30%, 25%, and 20% crude protein designated as diet A, diet B, and diet C respectively, were prepared, using locally available feed ingredients. Three different feeding schedules of normal protein diet continuously (diet A‐30%), alternate feeding of 1‐day diet A followed by 1‐day diet B (1A/1B) and alternate feeding of 1‐day diet A followed by 1‐day diet C (1A/1C) were tested. The total erythrocyte count and haemoglobin content was significantly (p < 0.05) enhanced in the group T1 fed (1A/1B), and the lowest count was recorded in the group T2 fed (1A/1C). Total leucocyte counts, total serum protein, and serum globulin were higher in the group T1 fed (1A/1B) and lower in the group T2 fed (1A/1C) as compare to control. The respiratory burst activity (NBT) of blood phagocytes and serum A‐to‐G ratio was recorded significantly difference in among the treatment groups. Based on the results of the present study, it is concluded that alternate feeding of 1‐day diet A followed by 1‐day diet B (1A/1B) is equally effective and promote the immunity in Labeo rohita juveniles.