Left displaced abomasum (LDA) leads to substantial changes in the metabolism of dairy cows. Surgical correction of LDA can rapidly improve the health of cows; however, changes in metabolism following surgery are rarely described. To investigate the changes of plasma metabolome in cows with LDA before and after surgical correction, blood samples were collected from 10 healthy postpartum cows and 10 cows with LDA on the day of diagnosis, then again from the LDA cows 14 d after surgery. Serum nonesterified fatty acid, β-hydroxybutyric acid, cortisol and histamine concentration, and antioxidant enzyme (superoxide dismutase and glutathione peroxidase) activities were evaluated, and the metabolic profile in plasma was analyzed using ultra-high-performance liquid chromatography timeof-flight mass spectrometry. The results demonstrated that cows with LDA experienced severe negative energy balance and oxidative stress, which can be improved by surgical correction. The metabolic profile was analyzed using multidimensional and univariate statistical analyses, and different metabolites were identified. In total, 102 metabolites differed between cows with LDA and healthy cows. After surgical correction, 65 metabolites changed in cows with LDA, compared with these cows during the LDA event. Following surgical correction, AA levels tended to increase, and lipid levels tended to decrease in cows with LDA. Pathway analysis indicated marked changes in linoleic acid metabolism, Arg biosynthesis, and Gly, Ser, and Thr metabolism in cows at the onset of LDA and following surgical correction. Surgical treatment reversed the changes in AA and lipid metabolism in cows with LDA.

In Southern China, distillers' grain is the main feed ingredient for small beef cattle farms. High intake of distillers' grain may lead to abomasum impaction, a disorder caused by the accumulation of solid content within the organ. For treatment, there are non-surgical and surgical options. In this study, we aimed to describe the clinical presentation, diagnosis, and treatment of beef cattle with abomasum impaction due to high intake of distillers' grain. Forty-nine Simmental beef cattle from 13 farms in Chongqing, China, were diagnosed with abomasum impaction. Animals were male, aged ≤2 years, and weighed between 200 and 350 kg. In this retrospective study, information on distillers' grain intake and clinical data were collected for 49 beef cattle diagnosed with abomasum impaction. The animals were treated between 2011 and 2019 with either non-surgical therapy or surgery. Animals diagnosed with mild abomasum impaction (n = 14) fully recovered after non-surgical treatment. Among moderate cases (n = 19), 12 cattle recovered after non-surgical treatment (63%), while the remaining seven did not respond well and underwent surgery. Three of those animals were subsequently cured (3/7). Among the severe cases (n = 16), four cattle were cured after non-surgical treatment (25%) (4/16). Of the remaining 12 cattle, six were slaughtered, and six died after surgery. Non-surgical treatment is efficient for mild abomasum impaction caused by a high intake of distillers' grain and may be considered for both moderate and severe cases. However, the treatment success rate for more severe cases decreases as the disease severity worsens.