Evaluation of metabolic status in Simmental dairy cows during late pregnancy and early lactation

Abstract

The objective of this experiment was to evaluate the metabolic status of late pregnant and early lactation dairy cows based on changes in characteristic blood metabolites. Blood samples were collected from 15 late pregnant cows and 15 early lactation cows to measure beta-hydroxybutyrate (BHB), non-esterifified fatty acids (NEFA), triglycerides (TG), glucose, total protein (TP), albumin, total bilirubin, urea and the activity of aspartate transaminase (AST) and gamma-glutamyl transferase (GGT). Cows in early lactation had signififi cantly higher (P lt 0.05) levels of serum BHB and NEFA, and lower (P lt 0.05) glycaemia compared to the late pregnant cows. High lipomobilization (NEFA>0.4 mmol/L) was detected in 6 (40%) of early lactation cows but in none of the late pregnant cows, while subclinical ketosis (BHB>1.2 mmol/L) was detected in 14 (94.4%) of the early lactation cows and 4 (26.6%) of the late pregnant cows. AST activities above 100 U/L were detected in 2 early lactation cows and in none of the late pregnant cows. TG levels below 0.12 mmol/L and glucose below 2.5 mmol/L were found in 7 (44%) and 10 (66.6%) of the early lactation cows, respectively, and in none of the late pregnant cows. Early lactation cows were found to have lower blood serum levels of TG (P lt 0.05), albumin (P lt 0.05) urea (P lt 0.05) and GTT (P>0.05) activities and higher concentrations of total bilirubin (P>0.05) TP (P>0.05) and AST activities (P lt 0.05) compared to the late pregnant cows. The results of blood serum levels of glucose, TG, BHB, NEFA and AST in early lactation cows suggest metabolic disorders associated with ketosis, and some degree of hepatic lesions, probably due to fat infifiltration. These serum parameters may have a key role in evaluating metabolic status in late pregnant and early lactation dairy cows.