|Young, Tanner -|
|Corley, Jimmie -|
|Rathmann, Ryan -|
|Johnson, Bradley -|
Submitted to: Innate Immunity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 2, 2012
Publication Date: July 15, 2013
Citation: Sanchez, N.C., Young, T.R., Carroll, J.A., Corley, J.R., Rathmann, R.J., Johnson, B.J. 2013. Yeast cell wall supplementation alters the physiological and acute phase responses of crossbred heifers to an endotoxin challenge. Innate Immunity. 19:411-419. Interpretive Summary: This research represents a collaborative effort of scientists from the Livestock Issues Research Unit, Texas Tech University, and Lesaffre Feed Additives to determine the effect of feeding yeast cell wall products to newly-received cattle on the acute phase response to a lipopolysacharide (LPS) challenge. The receiving period at a feedlot is very stressful due to the handling associated with transportation and processing, and commingling with unfamiliar cattle. The stress associated with these events, as well as the transfer of pathogens between unfamilar cattle, can increase the risk for disease. Previous research from our group has demonstrated that feed live yeast and (or) yeast cell wall can modulate the acute phase response in steers. The current study utilized two different yeast cell wall products to determine their influence on vaginal temperature, sickness behavior, and cortisol and cytokine concentrations in response to LPS challenge. Data from this study suggest that supplementing yeast cell wall products can alter the response to an LPS challenge. Specifically, vaginal temperature was decreased in yeast cell wall-supplemented heifers compared to control heifers following challenge. Additionally, serum concentrations of cortisol and interleukin-6 were decreased in yeast cell wall-supplemented heifers than control heifers. These data suggest that yeast cell wall supplementation may enhance the overall health of heifers, resulting in a reduced response to subsequent infection. Therefore, yeast cell wall supplementation may be a viable feed supplement for newly-received heifers in order to reduce the negative effects of illness on productivity while at a feedlot. This data will be of interest to scientists in the fields of stress physiology, immunology, and nutrition, as well as cattle producers, and can be used to enhance the health of newly-received feedlot cattle.
Technical Abstract: A study was conducted to determine the effect of feeding yeast cell wall (YCW) products on the physiological and acute phase responses of crossbred newly-received heifers to an 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. On d 37 heifers were challenged interveneously with lipopolysaccharide (LPS; 0.5 microgram/kg body weight) and blood samples were collected relative to LPS challenge. There was an increase in vaginal temperature in all treatments post-LPS, with YCW-C maintaining lower vaginal temperature post LPS than Control and YCW-A treatments. Although low, sickness behavior scores increased post LPS but were not affected by treatment. Cortisol concentrations were greatest in Control heifers post LPS than YCW-A or YCW-C treatments. Concentrations of interferon-gamma and tumor necrosis factor-alpha increased post LPS but were not affected by treatment. Serum interleukin-6 concentrations increased post LPS and were greater in Control heifers than YCW-A and YCW-C heifers. These data indicate that YCW supplementation can decrease the physiological and acute phase responses of newly-received heifers to an endotoxin challenge.