|Finck, Derek - Texas Tech University|
|Ribeiro, Flavio - Texas Tech University|
|Parr, Sandy - Texas Tech University|
|Carroll, Jeffery - Jeff Carroll|
|Young, Tanner - Texas Tech University|
|Bernhard, Bryan - Texas Tech University|
|Corley, Jimmie - Lesaffre Yeast|
|Estefan, A - Lesaffre Yeast|
|Rathmann, Ryan - Texas Tech University|
|Johnson, Bradley - Texas Tech University|
Submitted to: Professional Animal Scientist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2014
Publication Date: 6/1/2014
Citation: Finck, D.N., Ribeiro, F.R., Sanchez, N.C., Parr, S.L., Carroll, J.A., Young, T.R., Bernhard, B.C., Corley, J.R., Estefan, A.G., Rathmann, R.J., Johnson, B.J. 2014. Yeast supplementation alters the performance and health status of receiving cattle. Professional Animal Scientist. 30(3):333-341.
Interpretive Summary: A collaborative study was completed with researchers with the USDA-ARS-LIRU, Texas Tech University, and Lesaffre Feed Additives to determine the effect of yeast product supplementation on performance and health of receiving cattle. This study utilized 184 corssbred steers that were assigned to one of four treatments receiving either a control diet, a diet supplemented with live yeast, a diet supplemented with yeast cell wall, or a diet supplemented with both live yeast and yeast cell wall. Performance data was collected on morbidity and mortality recorded for 56 days. Following 39 days on feed, a subset of 24 steers was used to determine the effect of yeast supplementation on the response of steers to a provocative lipopolysaccharide (endotoxin) challenge. Steers that were supplemented with live yeast or yeast cell wall displayed a 7% numerical increase in average daily gain, and cumulative dry matter intake was greater for all yeast-supplemented groups compared to control steers. Prior to administration of endotoxin, interferon-gamma concentrations tended to be greater in control compared to yeast-supplemented steers. Additionally, rectal temperatures were greater in control steers than yeast-supplemented steers prior to administration of endotoxin. Following the challenge, rectal temperature increased, with control steers having greater rectal temperature than yeast-supplemented steers. Cortisol concentrations following the administration of endotoxin were greater in control steers than those supplemented with both live yeast and yeast cell wall. These data suggest that the use of yeast products can be used to increase the amount of total feed consumed and enhance immune function during the receiving period at a feedlot. This information is of interest to researchers and producers who are seeking antimicrobial feed additive alternatives to maintain growth and the health status of cattle upon entrace to the feedlot.
Technical Abstract: Weaned crossbred steers (n = 184; initial BW = 203 ± 1 kg) were blocked by BW and randomly assigned to pen (4 pens/block; 5 to 6 hd/pen). Pens within a block were randomly assigned to one of four treatments (9 pens/treatment): 1) control (CON; no yeast additive); 2) live yeast (LY; 5 g.hd-1.d-1 live yeast), 3) yeast cell wall (YCW; 5 g.hd-1.d-1 yeast cell wall); and 4) live yeast + yeast cell wall (LY+YCW; 5 g.hd-1.d-1 LY and 5 g.hd-1.d-1 YCW). Daily DMI was recorded and individual BW was collected every 14 d for 56 d. Data were analyzed using a randomized complete block design with the fixed effect of treatment and random effect of block. A subset of 24 steers (n=6/treatment) was utilized on d 38 for a lipopolysaccharide (LPS) challenge. Calves were fitted with jugular catheters and indwelling rectal temperature measuring devices that measured rectal temperature at 1-min intervals, and were moved into individual stanchions. On d 39, blood samples were collected at 30-min intervals (-2 to 8 h and then at 24 h) relative to LPS administration (0.25 µg/kg BW) at 0 h. Serum isolated from blood samples and was used to determine serum interferon-' (IFN-y) and cortisol concentrations. Whole blood samples were used to calculate neutrophil:lymphocyte (N:L) ratios. Data from the LPS challenge were subjected to analysis of variance specific for repeated measures using Statview with sources of variation including treatment, time, and their interaction. Specific time point comparisons within treatment group were conducted using a paired t-test to compare pre-challenge values with specific time points post-challenge. Cumulative DMI increased (P = 0.05) for the LY, YCW, and LY+YCW treatments compared to CON (5.47, 6.02, 5.96, and 5.89 kg/d, respectively). In response to LPS challenge, basal RT prior to LPS tended (P = 0.06) to differ among groups with CON calves having higher RT compared to LY+YCW (P = 0.01) and LY (P = 0.04) calves. Peak cortisol concentrations post-LPS administration were 26.5 ng/mL greater (P = 0.04) in CON calves compared to LY+YCW calves. Concentrations of IFN-tended (P = 0.06) to be greater in CON calves compared to YCW-fed calves prior to LPS exposure. Collectively, these data indicate yeast supplements increased total feed consumed and tended to improve cattle health during the receiving period.