Influência do tempo de armazenamento sob congelamento nas concentrações séricas de proteínas e metabólitos em amostras de bovinos da raça Bonsmara

Abstract

This study aimed to analyze the stability of proteins and serum metabolites of blood serum stored at different freezing periods (-20ºC). Were analized 80 serum samples from Bonsmara cattle from a farm in Uberlândia - MG. Blood samples were collected in tubes without anticoagulant (Vacutainer®) and processed in automated chemistry analyzer ChemWellTM calibrated (Calibra H) and gaged with universal control serum (Qualitrol) using commercial kits from Labtest Diagnostics®. The concentrations of total protein (PT), albumin (ALB), globulin (Glob) = PT-ALB, ALB:Glob ratio, creatinine (Crea), urea, cholesterol (COL) and triglycerides were determined in each serum sample on days 0, 30 and 60. Since the data did not meet normality, to compare the results obtained between the days of storage, we chose to use the medians and the nonparametric Kruskal-Wallis test. The values found for the analyzed constituents were, for day 0, 30 and 60, respectively: PT (g/dL) 7.79 ± 0.17, 6.72 ± 0.17, 6.82 ± 0.10; ALB (g /dL) 3.08 ± 0.03, 2.85 ± 0.05, 2.49 ± 0.09; Glob (g/dL) 4.64 ± 0.18, 3.72 ± 0.14, 4.49 ± 0.14; ALB:Glob ratio (g/ dL) 0.68 ± 0.02, 0.77 ± 0.03, 0.59 ± 0.03; Crea (mg/dL) 1.34 ± 0.03, 1.61 ± 0.05, 1.24 ± 0.06; urea (mg /dL) 25.3 ± 0.99, 24.4 ± 1.17, 18.85 ± 1.23; COL (mg/ dL) 109.08 ± 5.72, 108.75 ± 2.66, 88.25 ± 4.02 and TRI (mg/ dL) 34.4 ± 1.01, 21.3 ± 1.32, 25.95 ± 1.55. The largest reductions from day 0 to day 30 were observed for PT, Glob and TRI, and from 0 to 60 days were ALB, ALB:Glob ratio, Urea, COL and TRI. There was a statistical difference (p <0.05) in all parameters in at least one of the analyzed times. It was concluded that the stability of all constituents changed when the samples were stored under freezing, which indicates the importance of immediate processing of the samples after collection.