Use of gene profiling to evaluate the effects of a feed additive on immune function in periparturient dairy cattle

Abstract

Summary Objectives were to investigate mechanisms by which a nutritional supplement alters immunity in dairy cattle. Our hypothesis was that feeding this product to dairy cattle altered neutrophil gene expression. Eight periparturient Jersey cattle were randomly assigned to one of two treatments: control and treated. Control animals were fed a dry cow ration for 1 month prior to calving. The treated cows were fed the same ration supplemented with OmniGen‐AF. Following calving, blood samples were taken and neutrophils were prepared after which RNA was extracted. Gene expression in neutrophils of treated versus control‐fed animals was then assessed using bovine‐total leukocyte (BOTL‐5) arrays. Eighteen genes were differentially regulated in the experimental group and of these, twice as many were up‐regulated as down‐regulated. Patterns of changes indicated that the additive might alter neutrophil apoptosis, signaling and sensitivity. Two of the regulated genes [interleukin‐1β converting enzyme (ICE) and interleukin‐4 receptor (IL‐4R)] were investigated in more detail using quantitative reverse transcriptase‐polymerase chain reaction (QRT‐PCR). Each was found to be elevated by the feeding of experimental product. Increased expression of ICE indicates potential for enhanced neutrophil expression of interleukin‐1β (IL‐1β), a cytokine which plays roles in the inflammatory response and which stimulates adaptive immunity following innate immune activation. Altered expression of IL‐4R indicates potential for changes in neutrophil apoptosis. The experiment identified mechanisms by which the additive altered neutrophil gene expression. While many nutrients support the immune system, we have shown that a non‐traditional nutritional approach may also have utility in modulating immune function.

Effects of an immunomodulatory feed additive on the development of mastitis in a mouse infection model using four bovine-origin isolates

“…These data are supported by earlier studies (e.g. Wang et al, 2007 and2009) in which the additive increased the expression of neutrophil markers in sheep and dairy cattle.…”

“…Mechanisms by which the additive reduced mammary accumulations of pathogen DNA were examined in this and in other studies (Wang et al, 2007 and2009). In this study, the additive increased mammary concentrations of MPO and MHC mRNAs.…”

“…Wang et al (2007 and2009) examined effects of this additive on markers of neutrophil function in immunosuppressed sheep and in periparturient dairy cattle. The studies revealed that the additive altered expression of neutrophil function markers -E-mail: nforsberg@omnigenresearch.com (including L-selectin (CD62L)) and interleukin-1b (IL-1b)) and that immunomodulatory actions of the product were preserved following pelleting.…”

“…The studies revealed that the additive altered expression of neutrophil function markers -E-mail: nforsberg@omnigenresearch.com (including L-selectin (CD62L)) and interleukin-1b (IL-1b)) and that immunomodulatory actions of the product were preserved following pelleting. In peri-parturient dairy cattle (Wang et al, 2009), gene profiling techniques were used to identify a broader spectrum of genes that were differentially expressed in neutrophils of cows fed the additive. The additive altered concentrations of several messenger RNA (mRNA) including IL-1b converting enzyme (ICE), IL-4 receptor-a, IL-8 receptor and thymopoeitin-a.…”

Effet immunostimulant de quatre additifs alimentaires contre les maladies de Gumboro et de Newcastle chez le poulet de chair (<em>Gallus gallus</em>)

“…Chez ce dernier, les pathologies virales, en l'occurrence la maladie (Herich et Levkut, 2002 ;Yin et al, 2007). Dans ce dernier cas, des suppléments à base d'extraits microbiens, de plantes, de champignons ou des substances d'origine animale ont été expérimentés chez les animaux de compagnie (Chabanne, 2006 ;Desenclos, 2012), les ruminants (Wang et al, 2009 ;Yang et al, 2007), les poissons (Gabor et al, 2012 ;Nya et Austin, 2009) et les volailles (Bouzoubaa et Krull, 2008 ;Awaad et al, 2010 ;Ajakaiye et al, 2010). Cette pratique serait d'autant plus intéressante au niveau de la production de volailles de chair, chez qui les cycles de production courts ne permettent pas l'acquisition d'une immunité active et efficace (Rauw et al, 2009 …”