Effects of Artemisia ordosica Crude Polysaccharide on Antioxidant and Immunity Response, Nutrient Digestibility, Rumen Fermentation, and Microbiota in Cashmere Goats

SIMPLE SUMMARY: Semi-intensive and extensive captive rearing systems for cashmere goats have been gradually adopted due to the limited availability of pasture and the seasonal imbalance of nutrients in grazing pastures in China. However, intensive rearing increases cashmere goat oxidative stress risk while improving lamb productivity and economic efficiency. Crude polysaccharide from Artemisia ordosica has excellent hydrophilicity and various biological activities. It can alleviate oxidative stress with its antioxidant, antitumor, and immunity-enhancing effects. In this laboratory, the addition of 0.3% Artemisia ordosica crude polysaccharide (AOCP) improved rumen fermentation in cashmere goats, as confirmed by in vitro rumen fermentation analysis. This experiment investigated the effect of AOCP supplementation in the ration on the antioxidant and immune functions of the cashmere goat. The results of the study indicated that the addition of 0.3% AOCP to the ration improved rumen fermentation, antioxidant and immune functions, nutrient digestibility, and growth performance of cashmere goats by altering rumen flora distribution, promoting beneficial bacterial colonization, and decreasing the colonization of potentially pathogenic bacteria. Therefore, AOCP may be a viable source of antioxidants for cashmere goats. ABSTRACT: The objective of this experiment was to investigate the effect of dietary supplementation with Artemisia ordosica crude polysaccharide (AOCP) on growth performance, nutrient digestibility, antioxidant and immunity capacity, rumen fermentation parameters, and the microbiota of cashmere goats. A total of 12 cashmere goats (2 years old) with similar weight (38.03 ± 2.42 kg of BW ± SD) were randomly divided into two dietary treatments with six replicates. The treatments were as follows: (1) control (CON, basal diet); and (2) AOCP treatment (AOCP, basal diet with 0.3% AOCP). Pre-feeding was conducted for 7 days, followed by an experimental period of 21 days. The results showed that the ADG; feed/gain (F/G); and the digestibility of DM, CP, and ADF of cashmere goats in the AOCP group were greater than in the CON group (p < 0.05). Still, there was no significant effect on the digestibility of EE, NDF, Ca, and P (p > 0.05). Compared to the CON group, AOCP increased BCP, propionate, butyrate, isobutyrate, valerate, isovalerate, and TVFA concentrations (p < 0.05), but it reduced the protozoa numbers of acetate and A/P (p < 0.05). The serum CAT, GSH-Px, T-SOD, 1L-6, and NO levels were higher in AOCP than in the CON group (p < 0.05). The addition of AOCP increased the Sobs and Ace estimators (p < 0.05) and reduced the Simpson estimator in the ruminal fluid compared to the CON group (p < 0.05). Additionally, the AOCP group increased the colonization of beneficial bacteria by positively influencing GSH-Px and IL-6 (norank_f__F082, unclassified_p__Firmicutes), as well as bacteria negatively associated with F/G (norank_f__norank_o__Bacteroidales, unclassified_p__Firmicutes, and norank_f__F082). It decreased the colonization of potential pathogenic bacteria (Aeromonas and Escherichia-Shigella) (p < 0.05) compared to the CON group. In conclusion, 0.3% AOCP improves the growth performance, nutrient digestibility, antioxidant status, immune function, rumen fermentation, and microflora of cashmere goats.