Abstract

Effect of dietary �������¢-glucan on growth and immunity of Ancherythroculter nigrocauda

Author(s): Hai-Cheng Yin, Jun-Jun Guan1, Guo-Hao Yang, Feng Jia, Jin-Shui Wang

The Ancherythroculter nigrocauda juveniles had been feeded with â- glucan from brewerÂ’s yeast for 50 days in order to observe their growth performance and serumimmunoglobulin levels.With the addition level of â(1,3) -glucan from 0 to 1000 mg/kg, the weight gain rate (WGR), the specific growth rate (SGR) and protein efficiency ratio (PER) increased (< 500 mg/ kg) first, and then appeared to decline (> 500 mg/kg), while the feed conversion ratio (FCR) showed the opposite trend. Moreover, A2 group (500 mg/kg) presented the highest WER, SGR and PER, and the lowest FCR. There were significant differences (P <0.05) between the control and treatments in lysozyme (LZM) activity, superoxide dismutase (SOD) activity, acid phosphatase (ACP) activity, alkaline phosphatase (ALP) activity, plasma complement C3 and the phagocytic index (PI), and also the lowest immune parameters were found in the control. For LZM, SOD,ACP,ALP and PI, the highest values (P <0.05) were obtained at the addition level of 500mg/kg (A2) or 750mg/kg (A3). In addition, although the highest plasma complement C3was inA4 (1000mg/kg), no significant difference (P >0.05) appeared betweenA3 andA4. In conclusion, lower doses of â(1,3)-glucan addition to the diet could increase appetite, promote growth, improve the efficiency of feed utilization, and so reduce the feed conversion ratio.And Immune parameters indicated that â (1,3) -glucan could boost their immune systems and the immune enhancement was dose-dependent. Therefore a suitable addition of â(1,3)-glucan to the diet might be inferred: 500 mg/kg.