Serous metabolite levels of early lactation dairy cows supplemented with different lipid sources

Abstract

Eight Jersey cows in early lactation with mean liveweight of 380 kg were distributed into two 4 x 4 latin squares with 21-day experimental periods, and fed corn silage, alfalfa hay, and four concentrates (control and with three different sources of fat: tallow, commercial protected fat, and ground whole soybeans, so as to provide 6.3% EE in the total dietary DM vs. 3.7% in the control). The objective was to evaluate effects of the lipid supplementation on blood composition. Blood samples were collected on days 17 and 21 of each experimental period via jugular vein puncture using vacutainer tubes with a separator gel, followed by centrifugation. The sources of fat did not influence serous levels of glucose, the enzyme GGT, and Ca; however, differences (P<0.05) were found in the serous concentrations of cholesterol, triglycerides, non-esterified fatty acids and urea. The values found in this study are within normal ranges according to the literature on serous levels of the evaluated metabolites.