Serum metabolomics assessment of etiological processes predisposing ketosis in water buffalo during early lactation

Metabolic disorders as ketosis are manifestations of the animal’s inability to manage the increase in energy requirement during early lactation. Generally, buffaloes show a different response to higher metabolic demands than other ruminants with a lower incidence of metabolic problems, although ketosis is one of the major diseases that may decrease the productivity in buffaloes. The aim of this study was to characterize the metabolic profile of Mediterranean buffaloes (MB) associated with 2 different levels of β-hydroxybutyrate (BHB). Sixty-two MB within 50 days in milk (DIM) were enrolled and divided into 2 groups according to serum BHB concentration: healthy group (37 MB; BHB <0.70 mmol/L; body condition score: 5.00; parity: 3.78; and DIM: 30.70) and group at risk of hyperketonemia (25 MB; BHB ≥0.70 mmol/L; body condition score: 4.50; parity: 3.76; and DIM: 33.20). The statistical analysis was conducted by one-way ANOVA and unpaired 2-sample Wilcoxon tests. Fifty-seven metabolites were identified and among them, 12 were significant or tended to be significant. These metabolites were related to different metabolic changes such as mobilization of body resources, ruminal fermentations, urea cycle, thyroid hormone synthesis, inflammation, and oxidative stress status. These findings are suggestive of metabolic changes related to subclinical ketosis status that should be further investigated to better characterize this disease in the MB. INTRODUCTION The transition period is defined as the period between 3 wk before to 3 wk after parturition, and it is critically important to the health and profitability of dairy cows as well as in buffaloes (Fiore et al., 2017). This phase is characterized by major physiological, nutritional, metabolic, and immunological changes (Raphael and Sordillo, 2013; Lisuzzo et al., 2022c). Buffaloes adjust their metabolism to deal with the considerable increase of energy and nutrient requirements needed for milk production which makes them susceptible to negative energy balance (NEB; Purohit et al., 2013). The metabolic adaptation to NEB requires interactions with different energy resources, and its failure may occur in various tissues such as the liver, adipose tissue, and others (Herdt, 2000).