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

## TL;DR

A compound of Chinese herbs improves growth, digestion, and immunity in a type of fish called Megalobrama amblycephala when added to their feed.

## Contribution

This study identifies a 2% optimal dosage of a compound Chinese herbal medicine for enhancing fish growth and immunity.

## Key findings

- The compound herbal medicine significantly increased intestinal enzyme activity and growth rates in fish.
- The T2 group (2% herbal addition) showed the highest immunity markers and lowest mortality after pathogen exposure.
- The 2% dosage was found to be optimal for improving digestive and immune functions in Megalobrama amblycephala.

## Abstract

As a natural and environmentally friendly feed additive, compound Chinese herbal medicine has a significant promoting effect on the growth of fish and enhances immunity. In this study, four Chinese herbal medicines, Lycium barbarum, Astragalus membranaceus, Panax ginseng and Rhizoma phragmitis, were prepared into a compound Chinese herbal medicine, which was added to the basic feed of Megalobrama amblycephala for breeding experiments to explore its effects on the growth, immunity and digestive function of this species. The aim of this was to provide a valuable basis for the sustainable and healthy breeding of Megalobrama amblycephala. 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 Megalobrama amblycephala. The appropriate addition amount of this compound Chinese herbal medicine in the basic feed of Megalobrama amblycephala was 2%.

Chinese herbal medicine is rich in active ingredients that can promote growth and enhance immune function. In this study, Lycium barbarum, Panax ginseng, Astragalus membranaceus and Phragmitis rhizoma were crushed and mixed to prepare a compound Chinese herbal medicine. The basic feed of Megalobrama amblycephala 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 Aeromonas hydrophila, the cumulative mortality rate of M. amblycephala 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 M. amblycephala. The appropriate addition amount of this compound Chinese herbal medicine in the basic feed of M. amblycephala was 2%.