Effects of One-Step Laparoscopic Abomasopexy and Laparotomic Omentopexy Treatments of Left Displaced Abomasum on Metabolic and Inflammatory Stress Responses, Liver Health and Milk Yield in Multiparous Cows

Metabolic and inflammatory stress during the postoperative period following left displaced abomasum (LDA) correction poses significant risks to dairy cows’ health and productivity. This study aimed to evaluate the differences in metabolic and inflammatory responses between LDA cows treated with laparoscopic abomasopexy in one-step and left paralumbar fossa omentopexy, focusing on myeloperoxidase (MPO), metabolic- and liver-related biochemical markers, antioxidative response, and milk yield. Sixteen LDA cows were randomly assigned to one-step laparoscopic abomasopexy (LPS, n = 8) or left laparotomic omentopexy (LPT, n = 8), matched by parity and days in milk with healthy cows (CON, n = 8), and evaluated for blood indices and milk production during lactation. Blood samples were collected before (D0) surgery and 1 (D1), 3 (D3), 10 (D10), and 30 (D30) days following surgery, while milk yield was recorded monthly. MPO activity exhibited significantly higher values in both LPS (p < 0.001) and LPT (p < 0.001) cows compared to CON on D1, but also significantly lower values in LPS than in LPT cows (p < 0.001). In addition, both LPS and CON cows displayed significantly lower MPO levels than LPT cows on D3 (p < 0.001; p < 0.001; respectively), D10 (p < 0.001; p < 0.001; respectively), and D30 (p < 0.001; p = 0.008; respectively). Serum paraoxonase-1 (PON1) activity was significantly suppressed on D1 in both the LPS and LPT groups compared to CON cows (p < 0.05); however, overall PON1 activity remained significantly lower in the LPT group throughout the monitoring period (p = 0.016), despite a non-significant treatment × day interaction (p = 0.099). Significant treatment × day interactions were found for total bilirubin concentrations (p = 0.019), aspartate aminotransferase (AST, p < 0.001), and gamma-glutamyl transferase (GGT, p = 0.011) activities. Compared to control, AST and GGT activities were significantly elevated on D1 in both LPS (p = 0.037; p = 0.028, respectively) and LPT (p = 0.007; p = 0.045, respectively), while total bilirubin concentrations showed marked elevation on D1 in the LPT group compared to both CON and LPS cows (p = 0.031). Non-esterified fatty acids, beta-hydroxybutyrate and total bilirubin showed more favorable patterns in the LPS compared to LPT group too. Compared to LPT cows, milk yield was higher in LPS cows on days 30 (p < 0.001), 60 (p = 0.016), and 90 (p = 0.005) of lactation. In conclusion, this study underlines the benefits of laparoscopic abomasopexy in one step during the postoperative period, as it reduced the inflammatory response, could positively impact recovery of milk production, and eventually enhanced liver metabolism in LDA cows. In addition, our results suggest that MPO shows potential for use as an exploratory biomarker for monitoring the scale of postoperative tissue damage in dairy cows.