Interacting effects of dietary lipid level and temperature on growth, body composition and fatty acid profile of rohu, Labeo rohita (Hamilton)

Abstract

Three isonitrogenous (320 g kg−1 crude protein, casein and gelatine) semi‐purified diets with 80 (L8), 130 (L13) and 180 (L18) g kg−1 lipid (sunflower oil at increasing levels and cod liver oil fixed at 50 g kg−1) at three digestible energy levels (12 096, 13 986 and 15 876 kJ kg−1 dry weight) and were tested, in triplicate, on rohu fingerlings (3.2 ± 0.08 g) at two different temperatures (21 and 32 °C). Fish were fed to apparent satiation, twice daily, at 09.00 and 15.00 h, 7 days a week for 56 days. Maximum growth was obtained at a lipid level of 80 g kg−1 (L8) at 21 °C (439.37%) and 130 g kg−1 (L13) at 32 °C (481.8%). In general growth rate was higher at 32 °C than at 21 °C at all lipid levels. Tissue monounsaturated fatty acid (MUFA) contents decreased with increasing lipid level at 32 °C, but the reverse occurred at 21 °C. At 21 °C, Polyunsaturated fatty acid (PUFA) level increased significantly (P > 0.05) over initial values, but was affected insignificantly by dietary lipid level. At 32 °C, fish fed diet L13 had more n‐3 fatty acid (FA) in liver and muscle than the other two dietary groups while at 21 °C, both liver and muscle FA profiles exhibited significant change (P > 0.05) in n‐3 and n‐6 FA content which corresponded to variation in percent addition of dietary lipid. However, n‐3/n‐6 ratio was higher for fish fed diet L13 at 32 °C and diet L8 at 21 °C and may be correlated with fish growth.

Effect of Algae Based Diets on Growth Performance, Body Composition and Fatty Acid Profile of Indian Major Carp, Rohu Labeo Rohita, Hamilton)

“…Thus in the present study four individual algae were incorporated in the diet replacing 40% of the control diet and one complete algal meal mixture were tested to find out their suitability for inclusion in the rohu diet. Mishra and Samantaray (2004) observed maximum growth of 481.8% in rohu using 32% protein at 3 digestible energy level (12 096, 13 986 and 15 876 kJ/kg of feed). Chittem and Kunda (2013) used 20 g protein and 337 kcal/100 g of feed to study the effect of n-3 fatty acid on rohu and observed maximum weight gain of 127.4%.…”

“…From the present study it appears that the level of n-3 PUFA available from some algal diets, particularly WS and NS, is sufficient to meet the requirement of the same in rohu. In rohu an increased level of accumulation of EPA and arachidonic acid (20:4n6) over their respective initial level in liver and muscle at 21°C and 32°C suggested bio-transformation of the parent FAs of these series (Samantaray and Mishra, 2004). Karanth et al (2009) reported high deposition of linolenic acid (18:3n3) and EPA in rohu liver feeding with high linolenic acid diet.…”

“…In both these studies rohu FA profile is found to be affected by the diet. Samantaray and Mishra (2004) reported changes in rohu FA profile due to change in experimental temperatures and dietary lipid levels. In the present study, algal meal diets also found to affect the rohu liver and muscle FA.…”

“…Then optimum lipid level resulted in improved growth, FCR, nutrient utilization and reduced nitrogen excretion (Martins et al, 2007). Mishra and Samantaray (2004) for each diet ± SE).…”

Growth performance, body composition and fatty acid profile of liver and muscle in tilapia, Oreochromis mossambicus (Peters, 1852) fed algal meal incorporated diets

“…Several research works carried on marine fish species have confirmed that the dietary levels directly influence the fatty acid profile of fish (Stickney and Hardy, 1989;Brown et al, 1997). However, very little information is available on the same aspect in case of freshwater fish species (De Silva et al, 1997;Mishra, 2000;Mishra and Samantaray, 2004).…”