AUTHOR=Xie Lingling , Jian Zhongling , Tang Mingyan , Li Chen , Huang Zhiyu , Wang Fu , Ou Ren , Lu Shengyong TITLE=Effects of summer supplementation of Houttuynia cordata extract on growth performance, anti-inflammatory properties, and rumen fermentation in Guizhou black goats JOURNAL=Frontiers in Veterinary Science VOLUME=Volume 12 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2025.1627331 DOI=10.3389/fvets.2025.1627331 ISSN=2297-1769 ABSTRACT=The aim of this study was to examine the effects of supplementing Guizhou black goats with Houttuynia cordata extract (HCE) during summer on growth performance, anti-inflammatory activity, and rumen fermentation parameters. A completely randomized single-factor experimental design was employed. Twenty-four healthy Guizhou black goats, with similar body weights (16.03 ± 0.79 kg), were randomly divided into three groups, with eight replicates per group and one goat per replicate. The control group (CON) was fed a basal diet, the LC and HC groups received the basal diet supplemented with 500 mg/kg and 1,000 mg/kg of HCE, respectively. The ADG in the HC group was significantly higher (p < 0.05) than that in the CON group. The digestibility of DM in both the LC and HC groups was significantly higher (p < 0.05) than in the CON group. Additionally, the digestibility of CP, GE, and NDF in the HC group was significantly higher (p < 0.05) than in the CON group. GSH-Px levels in both the LC and HC groups were significantly higher (p < 0.05) than in the CON group. T-AOC in the HC group was also significantly higher (p < 0.05) than in the CON group. MDA levels in the HC group were significantly lower (p < 0.05) than in both the LC and CON groups (p < 0.05). The TP content in the HC group was significantly higher (p < 0.05) than in the CON group. IgA levels in both the LC and HC groups were significantly higher (p < 0.05) than in the CON group. The levels of IL-6 and IL-8 in the HC group were significantly lower (p < 0.05) than in the LC and CON groups. Interestingly, the IL-10 level in the HC group was significantly higher (p < 0.05) than in the LC and CON groups. The TNF-α level in the HC group was significantly lower (p < 0.05) than in the CON group. The HCE had no significant (p > 0.05) effect on rumen pH, NH3-N, and VFAs. In conclusion, a high dose of HCE improved growth performance, apparent nutrient digestibility, and enhanced antioxidant, immune, and anti-inflammatory responses in goats.