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

ANGELI E; BARCAROLO D; NOTARO US; 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

The transition period (TP) is the most critical stagein the lactation of a dairy cow, characterized by lipid mobilization, proinflammatorystate and insulin resistance during peripartum. Theaim of this study was to evaluate the insulin-signaling pathway and certain pro-inflammatoryfactors in the liver and metabolic biomarquers in plasma during the TP in cowswith different body condition score (BCS). Sixteen grazing dairy cows from acommercial dairy farm were classified according to BCS using the 5-point scale as highBCS (HBCS, ≥ 3.5, n = 8,) and low BCS (LBCS, < 3.5, n = 8). Bloodand liver biopsies were sampled at -14, 4, 14 and 28 days relative to parturition.The concentrations of NEFA, BHB, glucose, triglycerides,insulin and liver triglycerides 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 necrosis factor alpha (TNFα), interleukin-6 (IL-6),and nuclear factor-κB (NF-κB) were measured by Western blot. Resultsobtained shown that cows with HBCS had greater BHB concentration than LBCS (p< 0.05); an interaction effect (BCS x time, p < 0.05) for NEFA and TNFαwas determined; protein abundance of TNFα was greater at day 4 postpartum inHBCS group (p < 0.05). In addition, cows with HBCS had a tendency to have a greaterp-Akt/Akt than those with LBCS (p = 0.08). These results suggest that the proinflammatorystate in liver of dairy cows with HBCS during postpatum could affect the insulinsignaling in agreement with reports of other researchers. Thisknowledge could help to understand the metabolic behavior and to optimize thehealth and milk production of dairy cattle during this period.