Direct-Fed Microbial PrimaLac and Salinomycin Modulate Whole-Body and Intestinal Oxygen Consumption and Intestinal Mucosal Cytokine Production in the Broiler Chick

The current study investigated whole-body O2 consumption, intestinal O2 consumption, and intestinal inflammation status through mucosal cytokine production on broiler chicks fed the direct-fed microbial PrimaLac. One hundred twenty 1-d-old broiler chicks were randomly assigned to 1 of 3 experimental diets: standard starter diet (control), standard starter diet with added salinomycin (SAL), and standard starter diet with added PrimaLac (DFM). Birds were housed in 2 separate rooms, the control and SAL treatments in one room and the DFM in another. Intact ileal and cecal samples were collected on d 19, 20, and 21 after measuring whole-body O2 consumption using indirect calorimetry. The O2 up-take of ileal tissue was measured using an in vitro O2 monitor. Analysis of intestinal immune status of broilers was measured by the relative differences in mRNA of both pro- and antiinflammatory cytokines: interleukin-(IL) 1beta, IL-6, and IL-10 using real-time reverse transcription-PCR. Broilers exhibited a 6 to 16% decrease in whole-body energy expenditures and up to a 47% decrease (P<0.05) in ileal energy expenditures in the DFM group compared with other treatments. The reverse transcription-PCR data demonstrated that DFM consortium numerically altered both pro- and antiinflammatory cytokines within the ileum of 19-d posthatch broilers. These data suggest that direct-fed microbials like PrimaLac increase metabolic efficiency via changes in intestinal physiology and metabolism.