Objective: This experiment aimed to explore the effects of water extract of Artemisia annua L. (WEAA) on growth performance, blood parameters, and intestinal-related indices in mutton sheep, so as to evaluate its potential as a natural growth promoter. Methods: The experiment was conducted using a completely randomized design. Thirty-two 3-month-old Dorper × Han mutton sheep were randomly assigned to 4 groups (n = 8). The control group was fed only the basal diet, while the other groups were fed the basal diet supplemented with, respectively, 500, 1000, and 1500 mg/kg WEAA. The adaptation period lasted 15 days, followed by a 60-day experimental period. Results: Results showed that dietary supplementation of WEAA significantly reduced average daily feed intake (ADFI) and feed-to-gain ratio (F:G) of mutton sheep, significantly improved the apparent digestibility of crude protein (CP) and phosphorus (P), and optimized blood biochemical indices, such as significantly increasing the concentrations of total protein (TP), albumin (ALB), high-density lipoprotein cholesterol (HDL-C), and glucose (GLU), while significantly decreasing blood urea nitrogen (BUN) level (p < 0.05). Additionally, WEAA significantly improved intestinal morphology by reducing the crypt depth (CD) of the duodenum, jejunum, and ileum, increasing jejunal villus height (VH), and elevating the villus-to-crypt ratio (VH/CD) across intestinal segments (p < 0.05). It also significantly enhanced the activity of intestinal digestive enzymes, including α-amylase and trypsin in the duodenum, lipase and chymotrypsin in the jejunum, and α-amylase and chymotrypsin in the ileum, with the 500 mg/kg and 1000 mg/kg WEAA groups reaching better activity (p < 0.05). Furthermore, WEAA supplementation significantly increased the counts of beneficial bacteria (Bifidobacteria and Lactobacilli) and decreased the count of harmful bacteria (Escherichia coli) in rectal fecal samples (p < 0.05). Notably, most of these beneficial effects were dosage-dependent, with overall optimal performance observed in the 1000 mg/kg WEAA group. Conclusion: In conclusion, supplementing the diet with 1000 mg/kg WEAA exerted significant positive effects on the feed efficiency, nutrient digestibility, and intestinal health status of mutton sheep.
Gang et al. (Thu,) studied this question.