The Effects of Compound Chinese Herbal Medicine on the Growth and Digestive and Immune Systems of Megalobrama amblycephala

Chinese herbal medicine is rich in active ingredients that can promote growth and enhance immune function. In this study, <i>Lycium barbarum</i>, <i>Panax ginseng</i>, <i>Astragalus membranaceus</i> and <i>Phragmitis rhizoma</i> were crushed and mixed to prepare a compound Chinese herbal medicine. The basic feed of <i>Megalobrama amblycephala</i> was supplemented with 0 (control group), 1% (T1), 2% (T2) and 4% (T3) of this compound medicine. After raising for 90 days, in the T1 and T2 experimental groups, the length and width of intestinal villi and the activities of amylase, trypsin and lipase in the intestine were significantly higher than those in the control group. The weight gain rate and specific growth rates were highest and the feed coefficient was lowest in the T2 experimental group. In the control group, a large number of dilated hepatic sinusoids were detected, while this number significantly decreased in the T1 experimental group and they were not detected at all in the T2 and T3 experimental groups. The spleen and liver body indices were highest in the T2 experimental group. In all experimental groups, the Lys content and the activities of T-SOD, CAT, ACP, AKP and GSH-PX in serum were significantly higher than those of the control group. The expression of IgM, C3, TNF-ɑ and IL-1β in the head kidney; C3, TNF-ɑ and IL-1β in the spleen; C3 and IL-1β in the gills; IgM, C3 and IL-1β in liver; and IL-1β in the intestine was highest in the T2 experimental group. After challenge with <i>Aeromonas hydrophila</i>, the cumulative mortality rate of <i>M. amblycephala</i> was lowest in the T2 experimental group. The results of this study indicated that this compound Chinese herbal medicine could significantly enhance immunity, increase the activity of intestinal digestion-related enzymes and promote the growth of <i>M. amblycephala</i>. The appropriate addition amount of this compound Chinese herbal medicine in the basic feed of <i>M. amblycephala</i> was 2%.