This experiment aimed to analyze the amino acid digestibility of Clostridium autoethanogenum protein in growing pigs. A total of 16 healthy growing pigs fitted with a T?cannula，with an average body weight of（38.2±4.4） kg，were selected for the trial. The experiment lasted 7 days（5?day adaptation period + 2?day trial period）. The pigs were assigned to two treatments，with 8 replicates per group，and were fed either a standardized ileal digestibility （SID）diet formulated with Clostridium autoethanogenum protein or a nitrogen?free diet. The results showed that The crude protein content of Clostridium autoethanogenum protein is 88.57%，with a total energy of 5514 kcal/kg. Among the essential amino acids，the contents of lysine，methionine，and threonine are 8.12% ，1.78% ，and 3.73% ， respectively. The apparent ileal digestibility of crude protein，lysine，methionine，and threonine in Clostridium autoethanogenum protein is 71%，72%，73%，and 74%，respectively，while the standardized ileal digestibility is 82%，87%，85%，and 89%，respectively.

To investigate the effects of dietary adding compound enzyme preparation and seaweed oligosaccharides on growth performance，and pork quality of Huaxiang black pigs，120 pigs with the average body weight of 80 kg were selected and randomly divided into 3 groups with 4 replicates per group and 10 pigs per replicate. The treatments were control group （feeding a basal diet），enzyme preparation group （feeding the basal diet supplemented with 200 mg/kg complex enzyme preparation），and oligosaccharide group（feeding the basal diet supplemented with 400 mg/kg algal oligosaccharide）. The experiment lasted for 40 days. The results showed that compared to the control group，adding complex enzyme preparation increased the average daily gain（P<0.05）， increased the content of flavoring amino acids in longissimus dorsi muscle，and reduced the drip loss（P<0.05）. Compared to the control group，addition of oligosaccharides increased the redness，intramuscular fat content，and flavor amino acid content of longissimus dorsi muscle（P<0.05）. In conclusion，the compound enzyme preparation can improve the performance of pigs，and the addition of compound enzyme preparation and oligosaccharides can improve the meat quality of pigs.

B vitamins（VB）are important nutrients to maintain the health and metabolism of host. It is widely used as feed additives in livestock and poultry. Due to the complex composition and extremely low content of VB in the serum，it is difficult to accurately monitor the dynamic changes of VB in serum by existing methods. In this study，five kinds of VB including VB1，VB2，VB3（Nicotinamide），VB6（Pyridoxal）and VB9 in the serum of weaned piglets at different age were successfully detected using the targeted metabolomics technique of ultra performance liquid chromatography?tandem mass spectrometry?multi?reaction monitoring（UPLC?MS/MS?MRM）. This results showed that the content of VB in the serum of weaned piglets were increased in varying degrees with the increase of age. The content of VB in serum of weaned pigs at 35 days old were higher than that at 28 days old and at 63 days old，which showed a trend of rising first and then decreasing. The content of nicotinamide in serum of weaned piglets was the highest，and the detection range was 422.95 ? 1 805.58 ng/mL；The content level of VB2 in the serum was followed nicotinamide，with the detection range ranged from 182.33 to 561.33 ng/mL；The detection range of VB1 in the serum was from 23.36 to 72.95 ng/mL；The detection range of pyridoxal in the serum was from 3.48 to 27.90 ng/mL. The content of VB9 in serum was the lowest，and the detection range was from 5.22 to 22.72 ng/mL. In conclusion，5 kinds of VB in the serum of weaned piglets were detected efficiently and quantitatively by the targeted metabolomics with ULPC?MS/MS?MRM technology in this study，which provided a reference for subsequent research on VB in livestock and poultry.