Abstract: Metabolomics technology was used to analyze the changes of serum metabolites of suckling piglets in order to investigate the effects of increasing dietary energy level of suckling sows of Chuanxiang black pigs on the body metabolism of suckling piglets. Thirty-six sows of Chuanxiang black pigs were randomly divided into 3 groups with 12 pigs in each group. The digestible energy level of sows in control group was 13.81 MJ/kg, that in composite test Ⅰ group was 14.43 MJ/kg, and that in composite test Ⅱ group was 15.06 MJ/kg. The experiment lasted from 7 days before delivery to 28 days after delivery. After weaning, the serum of piglets was collected for metabolomics analysis. The results showed that compared with the control group, the main metabolic pathways in composite test Ⅰ group included glycerophospholipid metabolism, vitamin digestion and absorption, arachidonic acid metabolism, etc. The main metabolites involved in its metabolic pathway, acetylcholine, lysophosphatidic acid (LPA) (18:1), LPA (22:5), choline lysate (LPC) (22:4), thromboxane B2 and vitamin A were significantly up-regulated (P<0.05), vitamin B2 and LPC (18:3) were significantly down-regulated (P<0.05); When the dietary energy level of lactating sows was increased to 15.06 MJ/kg, the metabolism of arginine and proline metabolism, tyrosine metabolism, tryptophan metabolism, vitamin B6 metabolism, citrate cycle and linoleic acid metabolism were mainly affected, and the relative concentrations of main metabolites guanidinoacetic acid, α-methyldopa and levodopa were significantly decreased (P<0.05). The concentrations of pyridoxamine 5-phosphate ketone glutaric acid and 12,13-diHOME were significantly increased (P<0.05). In summary, when the dietary energy level of lactating sows is increased from 13.81 MJ/kg to 14.43 MJ/kg, the lipid metabolism of piglets will be abnormal. When the dietary energy level of sows is increased to 15.06 MJ/kg, protein and lipid catabolic metabolism of piglets is enhanced, neurotransmitter metabolism is disturbed, and tricarboxylic acid circulation is enhanced, which may lead to abnormal energy metabolism and neuroendocrine system imbalance.

Key words: energy level of diet, suckling piglets, serum metabolomics