Effects of Alfalfa Fermented Feed on Growth Performance, Meat Quality and Fecal Microflora of Taoyuan Black Pigs

Yongfei Zhu¹Xinyu Lei²Xiaoya Zhang³Yongmei Wu⁴Biguang Lv³Xuan Cheng³Haoqian Cheng³Li Wang³Yinghui Li¹Cong Li^5*Zhifei Zhang^6*Qian Lin^3*

• ¹Hunan Agricultural University College of Animal Science and Technology, Changsha, China
• ²Institute of Bast Fiber Crops and Center for Southern Economic Crops, Chinese Academy of Agricultural Sciences, Changsha, China
• ³Chinese Academy of Agricultural Sciences Institute of Bast Fiber Crops, Changsha, China
• ⁴Changsha Medical University, Changsha, China
• ⁵Key Laboratory of Swine Nutrition and Feed Science of Fujian Province, Key Laboratory of Swine Breeding in South China, Ministry of Agriculture and Rural Affairs, Aonong Group,, Zhangzhou, China
• ⁶Hunan Agricultural University College of Agronomy, Changsha, China

Abstract: This study investigated the effects of substituting 50% basal diet with alfalfa - fermented feed (AFF) on growth performance, meat quality, serum biochemical parameters, and gut microbiota in finishing-phase Taoyuan Black pigs. A total of 120 healthy pigs were randomly allocated to control (basal diet) and AFF groups (50% basal diet + 50% AFF), with 6 replicates per group (10 pigs/replicate). The experiment lasted 42 days. The results showed that compared with the control group, the AFF group exhibited no significant differences in growth performance (P>0.05), but significantly reduced serum TG, ALT, and MDA (P<0.05). In terms of meat quality, AFF substitution significantly increased muscle crude protein, energy level, and the contents of glutamic acid, alanine, isoleucine, lysine, tyrosine, proline, TAA, DAA, EAA, and UFA (P<0.05), while significantly decreasing the 45-min yellowness value (P<0.05) and markedly reducing SFA content (P<0.01). Regarding gut microbiota, at the phylum level, the relative abundances of Bacteroidetes, TenericutesFirmicutes, and Actinobacteria in the experimental group increased significantly (P<0.05), Spirochaetes rose markedly (P<0.01), and Proteobacteria dropped markedly (P<0.01). At the genus level, the relative abundances of Treponema, Ruminococcus, and Prevotella increased significantly (P<0.05). In conclusion, substituting 50% of the basal diet with AFF in late-stage Taoyuan Black pigs maintained growth performance while enhancing meat quality through improved muscle amino acid profiles and unsaturated fatty acid content. Additionally, it improved serum biochemical and antioxidant indicators, and cecal microbiota, promoting the overall health of the finishing pigs.