Effects Of Spirulinaplatensison The Growth Performance, Nutrition, Digestibility And Immunity Of Cranoglanis Multiradiatus

In order to study the effects of Spirulinaplatensison the growth performance, muscle nutrition, digestibility and immunity, 750 Cranoglanis multiradiatus with 5.78±0.01 g weight were chosen for the experiment. They weredivided into 5 groups randomly after 7 days' being fed with basal diet, with 3 replicates for each group. Diets for each group were supplemented with 0, 0.5%, 1%, 2%, 3% S.platensispowder, respectively. The experiment lasted for 60 days. Growth performance, muscle conventional nutrients, amino acids, fatty acids, blood physiological and biochemical indexes, digestive enzymes and HSP70 expression were measured at the end of the experiment.The result showed that: there were no significant differences in survival rate(SR), condition factor(CF), viscerosomatic indexes(VSI) and hepatosomatic indexes(HIS) among the five groups(p>0.05), the final weight, the weight gain rate(WGR), the specific growth rate(SGR) of 1% group improved significantly with 27.50%,45.87% and 26.14%(p<0.05) comparing with the control group, respectively. Feed conversion ratios(FCR) in 1% group was significantly reduced 29.71%(p<0.05). Adding Spirulina or not showed no significant difference on muscle conventional nutrients(p>0.05). The crude protein improved and crude fat decreased as the amount of S. platensisincreased. 2% group ran the first in total amino acids(TAA), essential amino acids(EAA), non-essential amino acids(NEAA), delicious amino acids(DAA) and DAA/TAA. EAAI in this experiment ranked: 2%> 3%> 0.5%> 1%> 0%. The lowest content of saturated fatty acids was in 3% group, which decreased by 1.55% than the control group. Unsaturated fatty acid in 3% group was higher than other groups. Monounsaturated fatty acids ranked: 0.5%> 0%> 2%> 1%> 3%. As S. platensisadditivecontentincreased,polyunsaturated fatty acids in test groups improved gradually. Superoxide dismutase(SOD), catalase(CAT), total protein, albumin and alkaline phosphatase increased in test groups, when glucose changed little in each group. It showed downward trends on malondialdehyde(MDA), total cholesterol and triglycerides in test groups. As to SOD and CAT in liver, they were higher than those in serum, but MDA presented the opposite. There were no significant differences with the control group of amylase in liver and intestine, and trypsin in liver(p> 0.05). Compared with the control group, trypsin activity in intestine of 1% group increased by 47.53%(p<0.05).Compared with the control group, lipase of liver increased by 58.18%in 3% group(p<0.05), and increased by 40.88% and 38.29% of intestine in 2% group and 3% group(p<0.05). Expression of HSP70 intest groups improved by 85.03%?93.30%?117.51% and 136.94%, respectively(p<0.05).In conclusion: a certain amount of S. platensis can accelerate growth efficiency, save feed, improve the composition of amino acid and fatty acid, improve muscle nutritional value, enhance digestion and absorption of dietary protein, enhanced antioxidant activity, reduce blood lipid levels, improve tolerance to adverse environmental of Cranoglanis multiradiatus.