Location: Livestock Issues Research
Title: Yeast cell wall supplementation alters the metabolic responses of crossbred heifers to an endotoxin challenge Authors
|Young, Tanner -|
|Corley, Jimmie -|
|Rathmann, Ryan -|
|Johnson, Bradley -|
Submitted to: Innate Immunity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 29, 2013
Publication Date: N/A
Interpretive Summary: This research represents a collaborative effort by scientists from the Livestock Issues Research Unit, Texas Tech University, and Lesaffre Feed Additives to determine the effect of supplementing newly-received heifers with yeast cell wall products on the metabolic response to a lipopolysaccharide (LPS) challenge. Live yeast and (or) yeast cell wall supplementation has been demonstrated to modulate the immune response to LPS. Specifically, a previous study by our group demonstrated that feeding yeast cell wall to heifers reduced the vaginal temperature, cortisol, and interleukin-6 response to LPS challenge. It was hypothesized that the differences observed in the acute phase response may be due to differences in metabolism, as the immune response has a high energy demand. Therefore, we utilized newly-received beef heifers to determine the effect of supplementing yeast cell wall products on the glucose, insulin, non-esterified fatty acid (NEFA), and blood urea nitrogen (BUN) responses to LPS challenge. Data from this study suggest that yeast cell wall supplementation can modulate the metaboic hromone and metabolite response to administration of LPS. Specifically, there was a trend for yeast cell wall-supplemented heifers to have greater average daily gain in the time periods before and after challenge. Additionally, yeast cell wall supplementation altered concentrations of glucose, insuline, NEFA, and BUN relative to control heifers throughout the pre- and post-challenge period. These data inidicate that certain yeast cell wall products can enhance the energy metabolism during an immune challenge without causing lipolysis or muscle catabolism. Therefore, alterations in energy utilization during an immune challenge due to yeast cell wall supplementation may modulate the energy demand, thus potentially enhancing recovery. These data will be of interest to scientists in the fields of stress physiology, nutrition, and metabolism, as well as cattle producers, and can be used to enhance the health and performance of newly-received feedlot cattle.
Technical Abstract: This study examined the effect of feeding yeast cell wall (YCW) products on the metabolic responses of newly-received heifers to endotoxin challenge. Heifers (n = 24; 219 ± 2.4 kg) were separated into treatment groups receiving a Control diet (n = 8), YCW-A (2.5 grams/heifer/d; n = 8) or YCW-C (2.5 grams/heifer/d; n = 8) and were fed for 52 d. Heifers were weighed on d 0, 14, 36, 38, and 52. On d 37, heifers were challenged intraveneously with lipopolysaccharide (LPS; 0.5 ug/kg body weight), and blood samples were collected relative to LPS challenge. Heifer weight increased from d 0 to 36 and from d 38 to 52, but was not affected by treatment. Post-LPS, YCW-A heifers lost more weight than Control and YCW-C heifers. Post-LPS, glucose concentrations increased and were less in YCW-A than Control and YCW-C heifers. Pre-LPS, insulin concentrations were greater in YCW-A and YCW-C than Control heifers. Post-LPS, insulin concentrations increased with YCW-C and YCW-A having greater insulin than Control heifers. Pre-LPS, non-esterified fatty acid (NEFA) concentrations tended to be less in YCW-C than Control and YCW-A. The difference in NEFA concentrations were significant post-LPS. Pre-LPS, blood urea nitrogen (BUN) concentrations were greater in YCW-A than Control. Post-LPS, BUN concentrations were greater in YCW-A than Control and YCW-C. These data indicate that certain YCW products can enhance the energy metabolism during an immune challenge without causing lipolysis or muscle catabolism.