Effects of body condition score in liver proinflammatory state and insulin-signaling of dairy cattle during the transition period

ANGELI E; BARCAROLO D; NOTARO U; MATILLER V; REY F; ORTEGA HH; HEIN GJ

Mar del Plata

Congreso; LXIV Reunión Científica Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2019

SAIC

The transition period (last 3 weeks of prepartum until 3 weeks postpartum)is the most critical stage in the lactation of a dairy cow, characterized by lipidmobilization, proinflammatory state and insulin resistance during peripartum.The aim of this study was to evaluate the insulin-signaling pathway and certainproinflammatory factors in the liver and metabolic biomarkers in plasma duringthe transition period in cows with different body condition score (BCS). Sixteengrazing dairy cows from a commercial dairy farm were classified according toBCS using the 5-point scale as high BCS (HBCS, ≥ 3.5, n = 8) and low BCS(LBCS, < 3.5, n = 8). Blood and liver biopsies were sampled at -14, 4, 14and 28 days relative to parturition. The concentrations of non-esterified fattyacids (NEFA), beta-hydroxybutyrate (BHB), glucose, triglycerides,insulin and liver triglycerides content were spectrophotometrically measured.Also, liver protein expression of relevant insulin signaling components: insulinreceptor (IR), insulin receptor substrate 1 (IRS-1), total and phosphorylated proteinkinase B (Akt and p-Akt); along with tumor necrosisfactor alpha (TNF-alpha), interleukin-6 (IL-6), and nuclear factor-κB (NF-κB)were measured by Western blot. The obtained results shown that cows with HBCShad greater BHB concentration than LBCS (p < 0.05); an interaction effect (BCSx time, p < 0.05) for NEFA and TNF-alpha was determined; protein abundance ofTNF-alpha was greater at day 4 postpartum in HBCS group (p < 0.05). Inaddition, cows with HBCS had a tendency to have a greater p-Akt/Akt than thosewith LBCS (p = 0.08). These results suggest that the proinflammatory state inliver of dairy cows with HBCS during postpartum could affect the insulin signalingin agreement with reports of other researchers. This knowledge could help tounderstand the metabolic behavior and to optimize the health and milkproduction of dairy cattle during this period.