J. Anim Sci. 2007. 85:233-239. doi:10.2527/jas.2006-216
© 2007 American Society of Animal Science
Feeding live cultures of Enterococcus faecium and Saccharomyces cerevisiae induces an inflammatory response in feedlot steers
D. G. V. Emmanuel*,
A. Jafari*,1,
K. A. Beauchemin
,
J. A. Z. Leedle
,2 and
B. N. Ametaj*,3
* Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada T6G 2P5;
and
Research Center, Agriculture and Agri-Food Canada, Lethbridge, Canada T1J 4B1; and
and
Chr. Hansen Inc., Milwaukee, WI 53214
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Abstract
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Two experiments were conducted to investigate the effects of oral supplementation of the lactic-acid-producing bacterium Enterococcus faecium EF212 alone or in combination with Saccharomyces cerevisiae (yeast) on mediators of the acute phase response in feedlot steers. Eight fistulated steers were used to study the effects of E. faecium alone or with yeast in a crossover design with 2 Latin squares, 4 steers within each square, and 2 periods. The length of each period was 3 wk, with a 10-d adaptation and an 11-d measurement period. The experimental diet contained 87% steam-rolled barley, 8% whole-crop barley silage, and 5% supplement (DM basis). In Exp. 1, treatments were control vs. the lactic-acid-producing bacterium E. faecium (6 x 1010 cfu/d). In Exp. 2, treatments were control vs. E. faecium (6 x 1010 cfu/d) and S. cerevisiae (6 x 1010 cfu/d). The bacteria and yeast supplements were blended with calcium carbonate to supply 6 x 1010 cfu/d when top-dressed into the diet once daily at the time of feeding (10 g/d). Steers fed the control diet received only carrier (10 g/d). Blood samples were collected from the jugular vein on d 17 and 21 of each period, and serum amyloid A (SAA), lipopolysaccharide binding protein (LBP), haptoglobin, and alpha1-acid glycoprotein (
1-AGP) were measured. Supplementation of feed with E. faecium had no effect on concentrations of SAA, LBP, haptoglobin, or 1-AGP in plasma compared with those of controls. However, feeding E. faecium and yeast increased (P = 0.02) plasma concentrations of SAA, LBP, and haptoglobin but had no effect on plasma 1-AGP. In conclusion, oral supplementation of E. faecium alone had no effect on the mediators of the acute phase response that were measured, whereas feeding of E. faecium and yeast induced an inflammatory response in feedlot steers fed high-grain diets. Further research is warranted to determine the mechanism(s) by which E. faecium and yeast stimulated production of acute phase proteins in feedlot steers.
Key Words: acute phase protein • direct-fed microbial • feedlot steer • probiotic • yeast
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INTRODUCTION
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There is growing interest in feeding direct-fed microbials (DFM) to cattle to improve digestion and enhance BW gain, as well as to prevent acidosis and outbreaks of foodborne pathogens. For example, Enterococcus faecium, a common DFM strain was reported to reduce the risk of acidosis when fed to dairy cows (Nocek et al., 2002
). In addition, E. faecium and other lactic acid-producing bacteria reduce fecal shedding of important enteropathogens like Escherichia coli O157:H7, Salmonella, shigella, and clostridia (Lewenstein, et al., 1979; Zhao et al., 1998; Ohya et al., 2000). Similarly, the yeast Saccharomyces cerevisiae stimulates cellulolytic and lactate-utilizing bacteria and improves weight gain in beef cattle (Yoon and Stern, 1996). Therefore, live cultures of E. faecium and S. cerevisiae might be useful to improve animal health.
Although the influence of DFM and other probiotic bacteria on blood chemistry, ruminal acidosis, ruminal microflora, BW gain, digestion, and feed intake has been studied in feedlot steers (Ghorbani et al., 2002; Beauchemin et al., 2003), little information is available concerning their effect on the immune system. Several studies performed in other animal models show that live DFM are capable of modulating the innate and acquired immunity at the local and systemic level (Isolauri et al., 2001). For example, oral administration of E. faecium stimulated the mucosal and systemic immune responses in young dogs with increased production of immunoglobulin A (Benyacoub et al., 2003). Similarly, a short-term oral administration of S. cerevisiae resulted in enhanced resistance of mice toward infections with Klebsiella pneumoniae, Streptococcus pneumoniae, and Streptococcus pyogenes (Bizzini and Fattal-German, 1990).
Activation of the immune system in conditions like inflammation, tissue injury, and infection is associated with release of acute phase proteins by the liver, known as the acute phase response (Suffredini et al., 1999). The acute phase proteins commonly studied in cattle are serum amyloid A (SAA), lipopolysaccharide binding protein (LBP), haptoglobin, and alpha1-acid glycoprotein (1-AGP; Ametaj et al., 2005; Gozho et al., 2005).
Although the favorable effects of DFM in modulating the different aspects of metabolism and production have been studied in feedlot cattle, little attention has been paid to their immunomodulatory effects. Therefore, the objective of this study was to investigate effects of feeding E. faecium alone or in combination with S. cerevisiae on selected mediators of acute phase response in beef cattle fed high proportions of grain.
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MATERIALS AND METHODS
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Animals and Treatments
As previously reported by Beauchemin et al. (2003), 8 cannulated steers (Exp. 1 BW = 507 ± 45 kg; Exp. 2 BW = 538 ± 46 kg) were used in 2 experiments. Steers were kept in individual stalls bedded with rubber mats and cared for according to the guidelines of the Canadian Council on Animal Care (1993). The experimental design was a 2 x 2 Latin square with 2 squares, 4 steers within each square, 2 periods, and 2 diets in each experiment. The squares within each experiment were conducted concurrently, and experiments were run consecutively. The length of each period was 21 d, which was divided into a 10-d adaptation and an 11-d measurement.
To minimize carry over effects from period to period, on the last day of periods 1 and 2, the rumen of each steer was emptied manually, and the contents were placed into the rumen of the next steer within the square that was to receive that treatment. Thus, each steer began the period with rumen contents corresponding to the same treatment it was fed.
In Exp. 1, steers were fed a diet that was top-dressed with the control treatment (carrier) or E. faecium EF212; and in Exp. 2, steers were fed a diet that was top-dressed with the control treatment (carrier) or E. faecium EF212 with S. cerevisiae (yeast). The bacteria and yeast were blended with calcium carbonate (carrier) to supply 6 x 109 cfu of bacteria or yeast/g of carrier. The diet of each steer was top-dressed with blend or carrier once daily at the time of feeding (10 g/d). Both E. faecium EF212 and S. cerevisiae were supplied by Chr. Hansen Inc. (Milwaukee, WI). The viability of the preparations was tested by Chr. Hansen Inc. before beginning the experiments. Experimental diets were formulated based on the NRC requirements (1996) to meet or exceed the CP, effective fiber, mineral, and vitamin needs for cattle weighing 450 kg and gaining 1.5 kg/d (Table 1). A feed mixer was used for preparing the diet each day. The diet was fed once a day at 0900. Feed and water were available ad libitum, and orts were approximately 10% of the diet.
Blood Sampling and Laboratory Analyses
Blood samples were obtained from each steer on d 17 and 21 of each period. The reason for choosing these sampling days was the time needed for the host to respond to the feeding of DFM. At 5 h after feeding, blood samples were collected from the jugular vein into 10-mL vacuum tubes containing Naheparin (Vacutainer, Becton Dickinson, Franklin Lakes, NJ). Samples were centrifuged (5,000 x g, 20 min, 4°C) within 20 min, and plasma was collected, immediately placed on ice, transported to the laboratory, and frozen at –20°C until analysis.
Concentrations of SAA in the plasma were determined by commercially available bovine ELISA kits (Tridelta Development Ltd., Greystones Co., Wicklow, Ireland) according to the manufacturer’s instructions and as described by McDonald et al. (1991). All samples including standards were tested in duplicate. Samples were initially diluted 1:500. Optical density values were read on a microplate spectrophotometer (model Spectra Max 190, Molecular Devices Corporation, Sunnyvale, CA) at 450 nm. The intra- and interassay CV were below 10%. According to the manufacturer, the detection limit of the assay was 0.30 µg/mL.
Concentrations of haptoglobin in plasma were determined by bovine ELISA kits (Tridelta Development Ltd.), as described by Godson et al. (1996), using a pool of bovine serum as the standard. All samples including standards were tested in duplicate. Optical density values were read on the Spectra Max 190 microplate spectrophotometer at 630 nm. The intra- and interassay CV were below 10%, and the detection limit of the assay was at 0.05 µg/mL.
Concentrations of 1-AGP in plasma were measured with bovine radial immunodiffusion (RID) assay kits (Tridelta Development Ltd.). Single RID assays were prepared to measure plasma concentrations of 1-AGP. Calibrators and samples were applied to wells in 5.0-µL volumes. Plates were placed in humidified chambers at 37°C and allowed to incubate for 24 h before reading the test results. For the calibrators, a plot of the diameter squared on the y-axis and the concentration of the antigen on the x-axis, gave a linear function, as described previously by Mancini et al. (1965). On the basis of this linear function, sample concentrations were calculated. The intra- and interassay CV were below 4%, and the detection limit of the assay was at 50 µg/mL.
Concentrations of LBP in the plasma were determined with a commercially available multispecies ELISA kit that crossreacts with bovine LBP (Cell Sciences Inc., Norwood, MA). Plasma samples were initially diluted 1:1,500, and samples with optical density values lower than the range of the standard curve were diluted 1:1,200 and reassayed according to the manufacturer’s instructions. The optical density at 450 nm was measured on the Spectra Max 190 microplate spectrophotometer. The intra- and interassay CV were below 10%, and the detection limits of the assay were 1.6 to 100 ng/mL. The concentration of LBP was calculated by extrapolating from a standard curve of known amounts of human LBP.
Statistical Analyses
Data were analyzed using the MIXED procedure (SAS Inst. Inc., Cary, NC) with the first autoregressive covariance structure. For variables measured over time, the model included treatment, day, and the 2-way interaction as fixed effects. The random effects were square, steer within square, and period. Period within square was not considered in the model because both squares were conducted simultaneously, and thus the effect of period was considered to be the same for both squares. The REML method was used to estimate the variance components, and the Bayesian information criterion was used to determine the best fitting model, whereas the Kenward-Roger method was used to approximate the denominator degree of freedom. Data for sampling time were analyzed as repeated measures. Significance was declared at P < 0.05.
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RESULTS AND DISCUSSION
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Previously, we showed the metabolic and productive aspects of feeding E. faecium alone or combined with yeast in feedlot steers (Beauchemin et al., 2003). Other researchers also have investigated the productive aspects of supplementation of E. faecium and yeast in dairy cattle (Krehbiel et al., 2003; Nocek et al., 2003). To our knowledge, however, this is the first study to evaluate immunomodulatory effects of DFM in cattle.
Results of Exp. 1 showed no significant overall treatment effects of feeding feedlot steers E. faecium on plasma concentrations of SAA, LBP, haptoglobin, and 1-AGP (Table 2). No significant differences were observed in the concentrations of SAA, LBP, haptoglobin, and 1-AGP in blood collected on d 17 vs. 21 between controls and those supplemented with E. faecium. Although we did not find treatment effects in Exp. 1 for the concentrations of SAA in plasma, values were consistent with the value of 29 µg/mL that was reported recently for healthy steers (Tourlomoussis et al., 2004). The SAA values for our control steers were about 40 µg/mL and about 35 µg/mL in steers fed E. faecium (Table 2). In contrast, results of Exp. 2, in which steers were supplemented with E. faecium and yeast, showed elevated concentrations of SAA in plasma compared with control steers (P = 0.02; Figure 1). No significant day effect or treatment x day interaction was obtained for concentrations of SAA in plasma in Exp. 2 (Figure 1). Serum amyloid A is a protein produced by the liver and is associated with high-density lipoproteins in the plasma. Although the precise physiological role of SAA in the host defense mechanism is not well understood, SAA is involved in binding, neutralization, and rapid removal of endotoxin from circulation (Baumberger et al., 1991). Production and release of SAA from liver hepatocytes is stimulated by cytokines IL-1, IL-6, and TNF- secreted by activated liver macrophages after removal of endotoxin from circulation (Watanabe et al., 2000; Elam et al., 2003). The mechanism by which addition of yeast to E. faecium enhanced production of SAA by the liver is not well understood; however, some of the contributing factors might include cytokines produced locally by gastrointestinal immune cells or the translocation of yeast antigenic compounds such as glucan or mannan into the bloodstream and subsequent activation of liver macrophages. Recent research indicates that glucan and mannan derived from S. cerevisiae induce production of TNF- by monocytes (Tada et al., 2002; Majtan et al., 2005).
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Table 2. Acute phase proteins in the plasma of feedlot steers with or without Enterococcus faecium (n = 8; Exp. 1)
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Figure 1. Least squares means ± SEM (Exp. 2) of plasma serum amyloid A (SAA) in control steers supplemented with 10 g/d of calcium carbonate (solid bars) and steers supplemented with Enterococcus faecium EF212 and Sacharomyces cerevisiae (open bars; n = 8/group) at 6 x 109 cfu/d for 11 d in a 2 x 2 Latin square experiment (10-d adaptation and 11-d measurements). a,bMeans with different superscripts differ, P = 0.02.
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These data are the first reported on concentrations of LBP in feedlot steers. In clinically healthy Holstein dairy cows in midlactation, plasma LBP was reported to be approximately 37 µg/mL (Bannerman et al., 2003). The same authors reported that within 8 h of administering lipopolysaccharide into the blood of dairy cows, plasma LBP increased more than 3.5-fold, reaching average values of 137 µg/mL and remaining high during the entire 72 h of the experimental period (Bannerman et al., 2003). Feedlot steers in our experiment had LBP values greater than 20 µg/mL 21 d after feeding a diet with a high proportion of grain. Addition of E. faecium in the diet had no effect on LBP concentrations in plasma.
In contrast to results of Exp. 1, when E. faecium and yeast were fed in Exp. 2, a treatment x day interaction for plasma concentrations of LBP (P = 0.02; Figure 2) was detected. An effect also was observed for concentrations of LBP between controls and steers treated with E. faecium and yeast on d 21 of the experiment (P < 0.05). The LBP is a liver-derived acute phase protein that is implicated in modulating host responses to endotoxin from gram-negative bacteria. The protein interacts with circulatory endotoxin to form complexes that bind to CD14, which facilitates binding and activation of TLR4/MD-2 complex on cells of the monocytic lineage and neutrophils, resulting in their activation (Fitzgerald et al., 2004). This triggers release of cytokines, which are responsible for initiating the acute phase response (Moshage, 1997). Lipopolysaccharide binding protein also facilitates transferring of endotoxin to lipoproteins and its rapid removal from circulation by the liver (Kitchens and Thompson, 2003). Increased plasma concentrations of LBP in our steers support the hypothesis that feeding yeast may increase translocation of endotoxin, or yeast-derived antigenic compounds like glucans and mannans, or both. In support of this hypothesis are results showing that enhanced production of TNF- by monocytes stimulated with the S. cerevisiae membrane-product mannan required presence of LBP (Tada et al., 2002).
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Figure 2. Least squares means ± SEM (Exp. 2) of plasma lipopolysaccharide binding protein (LBP) in control steers supplemented with carrier (solid bars) and steers supplemented with Enterococcus faecium EF212 and Sacharomyces cerevisiae (open bars; n = 8/group) at 6 x 109 cfu/d for 11 d in a 2 x 2 Latin square experiment (10-d adaptation and 11-d measurements). a,bMeans with different superscripts differ, P = 0.02.
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Tourlomoussis et al. (2004) reported haptoglobin concentration of 110 µg/mL in plasma of healthy beef cattle; however, cattle under different pathological conditions had average plasma haptoglobin values of approximately 270 µg/mL. Results of Exp. 1 showed haptoglobin concentrations of about 270 µg/mL in control steers and about 225 µg/mL in steers supplemented with E. faecium (Table 2
). Elevated plasma haptoglobin values suggest translocation of bacteria into the bloodstream of feedlot steers fed high proportions of grain. In our study, E. faecium supplementation reduced plasma haptoglobin values. Further, Gozho et al. (2005) reported increased concentrations of endotoxin in the rumen of male Jersey cattle fed high-grain diets and that this was associated with elevated concentrations of haptoglobin in plasma. Endotoxin is a cell-wall component of gram-negative bacteria and, when released in great amounts, has been documented to affect gut mucosal barrier functions and subsequent translocation of bacteria and bacterial products (Deitch, 1990).
Treatment affected plasma concentration of haptoglobin in steers fed E. faecium and yeast (P < 0.01; Figure 3); however, no effect of day or treatment x day interaction was observed (Figure 3). Typically, concentrations of haptoglobin in plasma are low but increase when there is an inflammatory response and translocation of bacteria into the bloodstream (Deignan et al., 2000). By binding to hemoglobin, haptoglobin prevents utilization of iron in the hemoglobin by bacteria translocated into the bloodstream (Wassell, 2000). Thus, the greater plasma haptoglobin concentration in steers fed yeast might be due to increased translocation of bacteria into the bloodstream. The mechanism by which yeast increases translocation of bacteria is not well understood and remains to be elucidated.
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Figure 3. Least squares means ± SEM (Exp. 2) of plasma haptoglobin in control steers supplemented with carrier (solid bars) and steers supplemented with Enterococcus faecium EF212 and Sacharomyces cerevisiae (open bars; n = 8/group) at 6 x 109 cfu/d for 11 d in a 2 x 2 Latin square experiment (10-d adaptation and 11-d measurements). a,bMeans with different superscripts differ, P = 0.01.
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This is the first report on concentrations of 1-AGP in plasma of feedlot steers. In healthy dairy cows, Tamura et al. (1989) obtained plasma values of 1-AGP of approximately 283 µg/mL. In addition, cows suffering from traumatic pericarditis, arthritis, mastitis, pneumonia, and mesenteric liponecrosis had 1-AGP values at or greater than 450 µg/mL (Tamura et al., 1989). When steers were supplemented with E. faecium alone (Exp. 1), results showed values of plasma 1-AGP greater than 600 µg/mL (Table 2). Elevated concentrations of 1-AGP in control and experimental animals in our experiment suggest that feeding high proportions of grain solicits an inflammatory condition in feedlot steers.
Concentrations of the acute phase protein 1-AGP also were elevated (greater than 600 µg/mL) in plasma of all steers in Exp. 2, and again, no differences were found between controls and steers fed E. faecium and yeasts (Figure 4). Elevated concentrations of this acute phase protein are again indicative of an inflammatory response in feedlot steers fed E. faecium and yeast. As previously stated (Beauchemin et al., 2003), in Exp. 1, 6 of the 8 steers in period 1 and 5 of the 8 steers in period 2 experienced subclinical ruminal acidosis. In Exp. 2, 5 steers experienced subclinical ruminal acidosis in period 1 and 4 in period 2 (Beauchemin et al., 2003). Prolonged exposure of the ruminal epithelium to high acid concentrations (i.e., acidosis) can result in inflammation of the rumen wall (i.e., rumenitis) and then to hyperkeratosis and parakeratosis (Fell and Weekes, 1975). Alpha1-acid glycoprotein is produced by the liver to control inappropriate or extended activation of the immune system (Fournier et al., 2000).
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Figure 4. Least squares means ± SEM (Exp. 2) of alpha1-acid glycoprotein (1-AGP) in control steers supplemented with carrier (solid bars) and steers supplemented with Enterococcus faecium EF212 and Sacharomyces cerevisiae (open bars; n = 8/group) at 6 x 109 cfu/d for 11 d in a 2 x 2 Latin square experiment (10-d adaptation and 11-d measurements).
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In a previous publication involving metabolic and production aspects of the same experiments, we reported that steers supplemented with E. faecium had almost 4-fold greater total number of coliform bacteria in the feces than those of controls (16 x 106 vs. 3.8 x 106 cfu/g) (Beauchemin et al., 2003). This effect was negated, however, when yeast was provided. Interestingly, data reported in this paper showed that supplementing diets of the same feedlot steers with E. faecium alone did not elicit an acute phase response; however, supplementing E. faecium and yeast was associated with increased concentrations of acute phase proteins in the plasma. The reason for elevated production of acute phase proteins when E. faecium and yeast were fed to steers is not well understood at present and may be due to lysis of coliform bacteria when yeast is added. Yeast is known to support gram-positive bacteria, which in turn might produce bacteriocins, antibiotic-like substances that can kill certain gram-negative bacteria (Nes and Holo, 2000). Dead gram-negative bacteria release endotoxin, and the latter may transfer into the bloodstream and stimulate production of cytokines and increase gut permeability to gastrointestinal flora (Deitch, 1990). Enhanced production of proinflammatory cytokines like IL-1, TNF-, and IL-6 has been reported following intake of probiotics (Wold, 2001). The proinflammatory cytokines stimulate hepatocytes to secrete acute phase proteins (Gruys et al., 2005).
In conclusion, results reported in this study show for the first time that feeding live probiotic bacteria such as E. faecium to feedlot steers under high-grain diet for a period of 11 d had no effects on acute phase proteins measured (i.e., SAA, LBP, haptoglobin, and 1-AGP). On the other hand, feeding a combination of E. faecium and S. cerevisiae increased concentrations of SAA, LBP, and haptoglobin in the plasma of experimental animals. Our finding that combined feeding of E. faecium and yeast stimulated an inflammatory response in feedlot cattle fed high proportions of grain suggests that further research is needed to understand whether the effect is due to the yeast alone or due to a combination effect with E. faecium. Further, it would be important to understand the mechanism by which the DFM stimulate production of these proteins and whether elevated plasma concentrations of SAA, LBP, and haptoglobin are beneficial or detrimental to the host.
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Footnotes
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1 Present address: Isfahan University of Technology, Isfahan, Iran 84156. 
2 Present address: JL Microbiology Inc., Hartland, WI.
3 Corresponding author: burim.ametaj{at}ualberta.ca
Received for publication April 5, 2006.
Accepted for publication July 26, 2006.
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LITERATURE CITED
|
|---|
Ametaj, B. N., B. J. Bradford, G. Bobe, R. A. Nafikov, Y. Lu, J. W. Young, and D. C. Beitz. 2005. Strong relationships between mediators of the acute phase response and fatty liver in dairy cows. Can. J. Anim. Sci. 85:165–175.
Bannerman, D. D., M. J. Paape, W. R. Hare, and E. J. Sohn. 2003. Increased levels of LPS-binding protein in bovine blood and milk following bacterial lipopolysaccharide challenge. J. Dairy Sci. 86:3128–3137.[Abstract/Free Full Text]
Baumberger, C., R. J. Ulevitch, and J. M. Dayer. 1991. Modulation of endotoxic activity of lipopolysaccharide by high-density lipoprotein. Pathobiology 59:378–383.[Medline]
Beauchemin, K. A., W. Z. Yang, D. P. Morgavi, G. R. Ghorbani, W. Kautz, and J. A. Leedle. 2003. Effects of bacterial direct-fed microbials and yeast on site and extent of digestion, blood chemistry, and subclinical ruminal acidosis in feedlot cattle. J. Anim. Sci. 81:1628–1640.[Abstract/Free Full Text]
Benyacoub, J., G. L. Czarnecki-Maulden, C. Cavadini, T. Sauthier, R. E. Anderson, E. J. Schiffrin, and T. van der Weid. 2003. Supplementation of food with Enterococcus faecium (SF68) stimulates immune functions in young dogs. J. Nutr. 133:1158–1162.[Abstract/Free Full Text]
Bizzini, B., and M. Fattal-German. 1990. Use of live Saccharomyces cerevisiae cells as a biological response modifier in experimental infections. FEMS Microbiol. Immunol. 2:155–167.[Medline]
Canadian Council on Animal Care. 1993. Guide to the care and use of experimental animals. Vol. 1. 2nd ed. CCAC, Ottawa, ON, Canada.
Deignan, T., A. Alwan, J. Kelly, J. McNair, T. Warren, and C. O. Farrelly. 2000. Serum haptoglobin: An objective indicator of experimentally-induced salmonella infection in calves. Res. Vet. Sci. 69:153–158.[CrossRef][Medline]
Deitch, E. A. 1990. Bacterial translocation of the gut flora. J. Trauma 30:S184–S188.[Medline]
Elam, N. A., J. F. Gleghorn, J. D. Rivera, M. L. Galyean, P. J. Defoon, M. M. Brashears, and S. M. Younts-Dahl. 2003. Effects of live cultures of Lactobacillus acidophilus (strains NP45 and NP51) and Propionibacterium freudenreichii on performance, carcass, and intestinal characteristics, and Escherichia coli strain O157 shedding of finishing beef steers. J. Anim. Sci. 81:2686–2698.[Abstract/Free Full Text]
Fell, B. F., and T. E. C. Weekes. 1975. Food intake as a mediator of adaptation in the rumen epithelium. Pages 101–118 in Digestion and Metabolism in the Ruminant. W. McDonald and A. C. I. Warner, ed. Univ. of New England, Armidale, New South Wales, Australia.
Fitzgerald, K. A., D. C. Rowe, and D. T. Golenbock. 2004. Endotoxin recognition and signal transduction by the TLR4/MD2-complex. Microbes Infect. 15:1361–1367.
Fournier, T., N. Medjoubi-N, and D. Porquet. 2000. alpha1-Acid glycoprotein. Biochim. Biophys. Acta 1482:157–171.[CrossRef][Medline]
Ghorbani, G. R., D. P. Morgavi, K. A. Beauchemin, and J. A. Z. Leedle. 2002. Effects of bacterial direct-fed microbials on ruminal fermentation, blood variables, and the microbial populations of feedlot cattle. J. Anim. Sci. 80:1977–1980.[Abstract/Free Full Text]
Godson, D. L., M. Campos, S. K. Attah-Poku, M. J. Redmond, D. M. Cordeiro, M. S. Sethi, R. J. Harland, and L. A. Babiuk. 1996. Serum haptoglobin as an indicator of the acute phase response in bovine respiratory disease. Vet. Immunol. Immunopathol. 51:277–292.[CrossRef][Medline]
Gozho, G. N., J. C. Plaizier, D. O. Krause, A. D. Kennedy, and K. M. Wittenberg. 2005. Subacute ruminal acidosis induces ruminal lipopolysaccharide endotoxin release and triggers an inflammatory response. J. Dairy Sci. 88:1399–1403.[Abstract/Free Full Text]
Gruys, E., M. J. Toussaint, T. A. Niewold, and S. J. Koopmans. 2005. Acute phase reaction and acute phase proteins. J. Zhejiang Univ. Sci. B. 6:1045–1056.
Isolauri, E., Y. Sütas, P. Kankaanpää, H. Arvilommi, and S. Salminen. 2001. Probiotics: Effects on immunity. Am. J. Clin. Nutr. 73:444S–450S.[Abstract/Free Full Text]
Kitchens, R. L., and P. A. Thompson. 2003. Impact of sepsis-induced changes in plasma on LPS interactions with monocytes and plasma lipoproteins: Roles of soluble CD14, LBP, and acute phase lipoproteins. J. Endotoxin Res. 9:113–118.[CrossRef]
Krehbiel, C. R., S. R. Rust, G. Zhang, and S. E. Gilliland. 2003. Bacterial direct-fed microbials in ruminant diets: Performance response and mode of action. J. Anim. Sci. 81:E120–E132.[Abstract/Free Full Text]
Lewenstein, A., G. Frigerio, and M. Moroni. 1979. Biological properties of SF68, a new approach for the treatment of diarrhoeal diseases. Curr. Ther. Res. 26:967–981.
Majtan, J., G. Kogan, E. Kovacova, K. Bilikova, and J. Simuth. 2005. Stimulation of TNF- release by fungal cell wall polysaccharides. Z. Naturforsch. [C] 60:921–926.
Mancini, G., A. O. Carbonara, and J. F. Heremans. 1965. Immunochemical quantitation of antigens by single radial immunodiffusion. Immunochemistry 2:235–254.[CrossRef][Medline]
McDonald, T. L., A. Weber, and J. W. Smith. 1991. A monoclonal antibody sandwich immunoassay for serum ammyloid A (SAA) protein. J. Immunol. Methods 144:149–155.[CrossRef][Medline]
Moshage, H. 1997. Cytokines and the hepatic acute phase response. J. Pathol. 181:257–266.[CrossRef][Medline]
Nes, I. F., and H. Holo. 2000. Class II antimicrobial peptides from lactic acid bacteria. Biopolymers 55:50–61.[CrossRef][Medline]
Nocek, J. E., W. P. Kautz, J. A. Z. Leedle, and E. Block. 2003. Direct-fed microbial supplementation on the performance of dairy cattle during the transition period. J. Dairy Sci. 86:331–335.[Abstract/Free Full Text]
Nocek, J. E., W. P. Kautz, J. A. Z. Leedle, and J. G. Allman. 2002. Ruminal supplementation of direct-fed microbials on diurnal pH variation and in situ digestion in dairy cattle. J. Dairy Sci. 85:429–433.[Abstract]
NRC. 1996. Nutrient Requirements of Beef Cattle. 7th rev. ed. Natl. Acad. Press, Washington, DC.
Ohya, T., T. Marubashi, and H. Ito. 2000. Significance of volatile fatty acids in shedding of Escherichia coli O157 from calves: Experimental infection and preliminary use of a probiotic product. J. Vet. Med. Sci. 62:1151–1155.[CrossRef][Medline]
Suffredini, A. F., G. Fantuzzi, R. Badolato, J. J. Oppenheim, and N. O’Grady. 1999. New insights into the biology of the acute phase response. J. Clin. Immunol. 19:203–214.[CrossRef][Medline]
Tada, H., E. Nemoto, H. Shimauchi, T. Watanabe, T. Mikami, T. Matsumoto, N. Ohno, H. Tamura, K. Shibata, S. Akashi, K. Miyake, S. Sugawara, and H. Takada. 2002. Saccharomyces cerevisiae- and Candida albicans-derived mannan induced production of tumor necrosis factor alpha by human monocytes in a CD14- and Toll-like receptor 4-dependent manner. Microbiol. Immunol. 46:503–512.[Medline]
Tamura, K., T. Yatsu, H. Itoh, and Y. Motoi. 1989. Isolation, characterization, and quantitative measurement of serum alpha1-acid glycoprotein in cattle. Nippon Juigaku Zasshi 51:987–994.[Medline]
Tourlomoussis, P., P. D. Eckersall, M. M. Waterson, and S. Buncic. 2004. A comparison of acute phase protein measurements and meat inspection findings in cattle. Foodborne Pathog. Dis. 1:281–290.[CrossRef][Medline]
Wassell, J. 2000. Haptoglobin: Function and polymorphism. Clin. Lab. 46:547–552.[Medline]
Watanabe, A., Y. Yagi, H. Shiono, and Y. Yokomizo. 2000. Effect of intramammary infusion of tumor necrosis factor-alpha on milk protein composition and induction of acute phase protein in the lactating cow. J. Vet. Med. B Infect. Dis. Vet. Public Health 47:653–662.[Medline]
Wold, A. E. 2001. Immune effects of probiotics. Scand. J. Nutr. 45:76–85.
Yoon, I. K., and M. D. Stern. 1996. Effects of Saccharomyces cerevisiae and Aspergillus oryzae cultures on ruminal fermentation in dairy cows. J. Dairy Sci. 79:411–417.[Abstract]
Zhao, T., M. P. Doyle, B. G. Harmon, C. A. Brown, P. O. Mueller, and A. H. Parks. 1998. Reduction of carriage of enterohemorrhagic Escherichia coli 0157:H7 in cattle by inoculation with probiotic bacteria. J. Clin. Microbiol. 36:641–647.[Abstract/Free Full Text]
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Abstract
INTRODUCTION
