Short communication: Effect of yeast cell wall supplementation on peripheral leukocyte populations and mRNA expression of cytokines in lactating dairy cows

摘要

This study was designed to examine the effect ofyeast cell wall (YCW) supplementation on peripheralleukocyte populations and mRNA expression of cytokinesin lactating dairy cows. Fourteen Holstein lactatingcows were assigned to 1 of 2 treatments; thecontrol group (n = 7) were fed a total mixed rationwithout supplementation and cows in the YCW group(n = 7) were fed a total mixed ration supplementedwith YCW (SafMannan; Phileo, Lesaffre Animal Care,Lille, France; 10 g/cow per day). Blood samples werecollected 3 times during the experimental period [wk0 (before any treatment), wk 4, and wk 8]. Peripheralleukocyte populations and cytokine mRNA expressionof peripheral blood monocular cells were measured usingflow cytometry and real-time PCR, respectively.Among the peripheral leukocyte populations, TcR1-N12 + and CD14~+ T cells increased at wk 4, and CD4~+T cells and CD8~+ T cells increased at wk 4 and wk8 with YCW supplementation. The mRNA level ofIL8 tended to be increased in the YCW group at wk4. Expression of IL12A was lower in the YCW groupthan in the control group before the experiment (wk 0)but no differences were observed at later time points(wk 4 and wk 8). Expression of IL12A decreased inthe control group and increased in the YCW group.Expression of CCR2 increased at wk 4, and CCL2 andCCL3 were increased at wk 8 in the YCW group. Thus,YCW supplementation increased the mRNA expressionof cytokines in peripheral blood mononuclear cells oflactating dairy cows.