|
|
||||||||

* Department of Animal Science, University of Arkansas, Fayetteville 72701 and
and
Alltech, Nicholasville, KY 40356
Correspondence:
B-106A Animal Science phone: (479) 575-2111; fax: (479) 575-7294; E-mail:
cmaxwell{at}uark.edu.
| Abstract |
|---|
|
|
|---|
Key Words: Copper Growth Mannans Pigs
| Introduction |
|---|
|
|
|---|
Mannan oligosaccharides (MOS) derived from yeast cell wall material may provide an alternative to feeding pharmacological levels of Cu, because MOS has been reported to improve growth response when added to the diets of poultry (Kumprecht et al., 1997) and pigs (Pettigrew, 2000). Like pharmacological additions of Cu, MOS has the ability to influence the microbial population in the intestinal tract. This modification is accomplished by the ability of MOS to attach to mannose binding proteins on the cell surface of some strains of bacteria, thereby preventing these bacteria from colonizing the intestinal tract by interfering with the binding of carbohydrate residues on epithelial cell surfaces (Spring et al., 2000). Also, both Cu and MOS have been reported to alter lymphocyte response in vitro (Muchmore et al., 1990; Pocino et al., 1991).
The objectives of this study were to 1) assess the efficacy of MOS and pharmacological additions of Cu in the form of CuSO4 for improving growth and efficiency in weaned and growing-finishing pigs and 2) to determine whether MOS acts to modulate the cell-mediated immune response of the weaned pig.
| Materials and Methods |
|---|
|
|
|---|
Experiment 1. A total of 216 weanling barrows (Hampshire x Duroc sires mated to Yorkshire x Landrace females) averaging 18 d of age and 6 kg BW were obtained from a single source (The Pork Group, Inc., Rogers, AR) and transported to the University of Arkansas off-site nursery facility. Pigs were blocked into nine weight groups, and each weight group was further divided into four subgroups of six pigs per pen. Pigs were housed in an environmentally controlled off-site nursery facility in pens (1.63 m x 1.19 m) with two nipple waterers, a five-hole feeder, and Maxima nursery flooring (Agra Flooring Int. Ltd., Calgary, Alberta, Canada). Pigs were allowed ad libitum access to feed and water. For the first week of the trial, the ambient temperature was maintained at 29°C and decreased 0.5°C each week of the experiment.
Experiment 2. A total of 144 crossbred barrows and gilts (average initial BW of 20 kg) were moved from the nursery to growing-finishing facilities at the University of Arkansas Swine Research Unit, sorted by weight, and divided into six weight blocks with 24 pigs per block. Pigs within each weight group were allotted into four equal subgroups (six pigs per pen) with stratification based on sex and litter. Pigs were housed in a curtain-sided growing-finishing barn with a positive airflow ventilation system. Pens with partially slatted floors measured 1.5 m x 4.0 m and contained a single space, wet-dry feeder. Pigs were allowed ad libitum access to feed and water.
Diets
In both experiments, dietary treatments were arranged as a 2 x 2 factorial and were randomly assigned to pens within each of the weight blocks. In Exp. 1, basal diets (Table 1
) fed during the nursery period contained 20 ppm Cu from d 0 to 10 after weaning and 27 ppm Cu from d 10 to 38 after weaning. Basal diets were supplemented with 0 or 175 ppm Cu and 0 or 0.2% MOS (Bio-Mos, Alltech, Nicholasville, KY) to provide four dietary treatments. The four dietary treatments were fed during phase 1 (d 0 to 10 after weaning), phase 2 (d 10 to 24 after weaning), and phase 3 (d 24 to 38 after weaning).
|
|
Data Collection
In both experiments, pig BW and feed intake were determined at the initiation and termination of each phase and were used to calculate ADG, ADFI, and gain:feed (G:F). In Exp. 1, a 15-mL blood sample was obtained in heparinized tubes via vena cava puncture from two randomly selected pigs in each pen for a total of 72 pigs sampled (18 pigs per treatment). Blood samples were obtained at approximately 0800 on d 28, 30, 32, and 34 of the experiment, so that 25% of the pens were sampled (18 pigs from 9 pens) on each of the 4 d. In vitro immune response was measured using a lymphocyte blastogenesis assay with methods adapted from Blecha et al. (1983). Briefly, peripheral blood mononuclear cells were isolated by gradient centrifugation using Ficoll gradient (Histopaque 1077, density = 1.077g/mL; Sigma Chemical Company, St. Louis, MO). Any remaining erythrocytes were lysed by adding 1 mL of sterile water to the isolated cell pellet for 20 s. Cells were resuspended in RPMI 1640 (Sigma) at 2 x 106 cells/mL and plated in triplicate in 96-well round bottom plates in 100-µL aliquots. Phytohemagglutinin (PHA, Sigma) and pokeweed mitogen (PWM, Sigma) were administered to each well at a concentration of 50 and 25 µg/mL, respectively, to stimulate lymphocyte proliferation. Incubation, labeling with tritiated-thymidine, and cell harvesting followed procedures outlined by van Heugten and Spears (1997). Cells were incubated for 48 h at 37°C. Following the 48 h incubation, tritiated-thymidine was added to each well, and the cultures were incubated for an additional 18 h. Cells were harvested on glass fiber mats and the radioactivity was measured as counts per minute (cpm) on a liquid scintillation analyzer (TRI-CARB 2200CA, Packard Instrument Company, Downers Grove, IL).
Statistical Analysis
In both experiments, data were analyzed as a randomized complete block design with pen as the experimental unit and blocks based on initial BW. Analysis of variance was performed using the GLM procedure of SAS (SAS Inst. Inc., Cary, NC). The effects of Cu, MOS, and Cu x MOS interaction were evaluated, as well as the effect of sampling day when analyzing lymphocyte proliferation data. When a significant interaction was observed, treatment means were separated using the PDIFF option of the LSMEANS statement in PROC GLM. Main effect means were evaluated when the interaction was not significant.
| Results |
|---|
|
|
|---|
During phase 1, ADG and G:F increased with the addition of MOS to diets containing the basal level of Cu, but were similar when MOS was added to diets containing 175 ppm supplemental Cu (interaction, P < 0.01 and P < 0.05, respectively; Table 3
). Pigs fed diets supplemented with 175 ppm Cu during phase 2 and phase 3 had greater ADG (P < 0.01) and ADFI (P < 0.05) than pigs fed diets containing the basal level of Cu (Table 4
). The addition of MOS to phase 3 diets resulted in greater ADG (P < 0.05) and G:F (P < 0.10) compared to pigs fed diets devoid of MOS. In the overall experimental period (d 0 to 38), pigs fed 175 ppm supplemental Cu had greater (P < 0.02) ADG, ADFI, and G:F than pigs fed diets containing the basal level of Cu. Moreover, during the overall experiment, pigs fed diets containing MOS had greater (P < 0.05) ADG and G:F than pigs fed diets without MOS addition. Immune response, as measured by lymphocyte proliferation in vitro, was not affected by dietary treatments (Table 5
).
|
|
|
During the starter phase, ADG and G:F improved (P < 0.05) when pigs were fed diets supplemented with 175 ppm Cu compared to pigs fed diets containing the basal level of Cu (Table 6
). Average daily gain tended to be greater (P < 0.07), and G:F improved (P < 0.05) when pigs were fed diets containing 175 ppm supplemental Cu compared to pigs fed diets containing the basal level of Cu during the grower phase. During the finishing phase, a Cu x MOS interaction (P < 0.05; Table 7
) was observed, in which ADG increased with the addition of MOS when pigs were fed the basal level of Cu but decreased when MOS was added to diets supplemented with 125 ppm Cu. In the overall experiment (20 to 106 kg BW), pigs fed pharmacological concentrations of Cu throughout the study had greater (P < 0.05) ADG, G:F, and BW at the end of the starter, grower, and finisher phases than pigs fed diets containing the basal diet level of Cu.
|
|
| Discussion |
|---|
|
|
|---|
The improvement in pig performance that accompanies pharmacological additions of Cu in swine diets is often attributed to its enteric antimicrobial action (Fuller et al., 1960). When added to the diets of nursery pigs, pharmacological levels of Cu increased feed intake in most cases (Cromwell et al., 1989; Zhou et al, 1994b; Dove, 1995) presumably from the reduction in intestinal damage caused by pathogens ensuing from its antimicrobial action. Because feed intake is a factor limiting growth in young pigs, weight gain accompanies the improvement in feed intake. Copper supplementation may also act systemically to improve performance, as evidenced by an observed increase in gain when pigs were injected intravenously with Cu (Zhou et al., 1994a). The authors indicated that intravenous injection of Cu would bypass any antimicrobial effect that copper has in the intestinal tract, since the amount of Cu injected was small and any Cu released into the intestinal tract via bile excretion would be too minute to significantly increase the intestinal Cu content. Response to intravenous injection of Cu suggests that Cu supplemented at pharmacological levels acts systemically to improve performance. The systemic effect from increased dietary Cu is likely a result of the many functions it serves in the body. For instance, Cu is necessary for cellular respiration, cardiac function, and central nervous system function and is a component of many enzymes of metabolic importance, such as cytochrome c oxidase, superoxide dismutase, lysyl oxidase, and tyrosinase (McDowell, 1992). With its many physiological functions, it is possible that the improvement in growth response observed when Cu is supplemented beyond the amount required may be attributed to the use of the mineral systemically, in addition to antimicrobial function in the intestinal tract.
Although serum Cu concentrations were not evaluated in this study, Lou and Dove (1996) reported that serum Cu concentrations were increased on d 3 after weaning from 137 µg/dL to 162 µg/dL when basal diets were supplemented with 250 ppm CuSO4. Serum Cu has been reported to range from 96 to 130 µg/dL 15 d following weaning when pigs were fed basal diets compared to 143 to 151 µg/dL when pigs were fed 250 ppm CuSO4 (Dove and Hayden, 1991; Luo and Dove, 1996). In addition, Lillie et al. (1977) observed an increase in plasma copper from 1.4 ppm when 60-kg pigs were fed a basal diet compared to 1.51 and 1.48 ppm plasma Cu when pigs were supplemented with 125 and 250 ppm CuSO4, respectively.
Although much of the research that assesses coppers effect on immune function has been conducted from the perspective of Cu deficiency (Davis et al., 1987; Arthington et al., 1995; Ward et al., 1997), very little work has been done to determine the effects on immune responses during excess Cu administration. In an experiment conducted with mice, lymphoctye proliferation in response to concanavalin A was suppressed when mice were fed excess Cu, but was increased in response to Escherichia coli lipopolysaccharide stimulation (Pocino et al., 1991). In addition, Ward et al. (1997) reported a decrease in lymphocyte proliferation when cattle lymphocytes were administered Cu in vitro. In our study, lymphocyte proliferation did not respond to pharmacological additions of dietary Cu. However, much of the reported responses in lymphocyte proliferation occurred when animals were challenged by disease, weaning, or other stressors (Blecha et al., 1983; Arthington et al., 1996; van Heugten et al., 1996; Hicks et al., 1998; Bassagany-Riera et al., 2001). Because the pigs in this experiment were not administered a direct disease challenge and the measurements were obtained several weeks after weaning, the effects of Cu on lymphocyte proliferation may not have been evident.
Although the growth promoting effects of Cu are well documented, particularly in the weanling pig, the effect of supplementation with MOS in swine diets has not been extensively investigated. In this study, we observed a response to MOS addition at the end of the 10-d period after weaning and in the overall experiment (d 0 to 38 after weaning), in which MOS improved gain and efficiency compared to pigs fed the control diet. However, these responses were not as great compared to the responses achieved with pharmacological levels of Cu. Research evaluating the effect of MOS supplementation administered to young calves resulted in improved gain (Newman et al., 1993; Jacques and Newman, 1994) and increased intake (Dvorak et al., 1997). Stanley et al. (1996) reported that broiler chicks fed diets supplemented with MOS had greater BW compared to chicks fed diets without MOS supplementation, although the response was not statistically significant. Others (Kumprecht et al., 1997; Savage et al., 1997) observed that weight gain and feed efficiency improved when poultry were fed diets supplemented with MOS. In a series of experiments evaluating growth parameters of weanling pigs in response to MOS supplementation, response to MOS addition was most evident during the second and third week after weaning (LeMieux et al., 2001). While pigs in our study responded with greater gain during the late nursery phase, we also observed an improvement in gain and efficiency when MOS was added to diets containing the basal level of Cu during the 10-d period following weaning.
Evidence indicates that MOS inhibits the colonization of some strains of bacteria in the intestinal tract, such as Escherichia coli and Salmonella. Research using human mucosal cells indicated that mannose inhibited bacterial adherence and acted as a receptor for Escherichia coli binding (Ofek et al., 1977). It has been reported that mannose inhibited the in vitro colonization of the chicken small intestine by Salmonella typhimurium (Oyofo et al., 1989b) and reduced cecal colonization by Salmonella typhimurium following oral inoculation (Oyofo et al., 1989a; Spring et al., 2000). Bacterial adherence that results in the alteration of the intestinal microflora, much like the action of antibiotics or pharmacological additions of copper, may be one mechanism by which MOS improves growth performance in swine. The suggestion that MOS may alter the intestinal microflora may explain the lack of an additive effect in this study when feeding MOS and pharmacological levels of Cu in concert. Whereas MOS increased pig performance when supplemented to diets in the absence of additional Cu, there was no benefit when supplementing MOS and pharmacological levels of dietary Cu concurrently, suggesting that the mechanisms by which both additives improve pig growth performance are similar.
Mannan oligosaccharides may also impact gain and efficiency by altering immune responsiveness to an antigen. Although in this experiment, lymphocyte proliferation response to mitogens administered in vitro was not impacted by dietary treatments, there is some evidence that MOS may have an inhibitory effect on lymphocyte function (Muchmore et al., 1990; Podzorski et al., 1990). Suppression of immune function could also be a means by which MOS improves gain and efficiency. Immune activation is accompanied by an alteration in metabolic activity so that resources are shunted away from growth and reallocated to support the organisms defense against foreign antigen (Spurlock, 1997). Although the mechanism by which MOS improves growth performance in livestock can only be speculated, the results of this study show that it does have a positive impact on gain and efficiency when added to weanling pig diets. Because weanling pigs in this study originated from a commercial farm and were moved to a relatively clean off-site nursery facility that would presumably improve the health status of the herd, the effects of MOS on growth performance may not have manifested to as great a magnitude. The greater improvement observed in Cu-supplemented pigs in a relatively healthy environment compared to those supplemented with MOS is most likely a result of the additional effects that Cu elicits systemically. As for providing an alternative to the addition of Cu at growth-promoting levels in swine diets, MOS did not increase gain or efficiency to as great an extent as pharmacological additions of Cu in either of the two experiments. However, MOS did increase performance compared to pigs fed diets devoid of MOS or additional Cu and may provide a viable alternative should levels of trace mineral addition to swine diets become restricted as a result of possible environmental regulations.
| Implications |
|---|
|
|
|---|
Received for publication February 13, 2002. Accepted for publication July 19, 2002.
| Literature Cited |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
T. M. Hill, H. G. Bateman II, J. M. Aldrich, and R. L. Schlotterbeck Oligosaccharides for Dairy Calves Professional Animal Scientist, October 1, 2008; 24(5): 460 - 464. [Abstract] [PDF] |
||||
![]() |
M. Castillo, S. M. Martin-Orue, J. A. Taylor-Pickard, J. F. Perez, and J. Gasa Use of mannanoligosaccharides and zinc chelate as growth promoters and diarrhea preventative in weaning pigs: Effects on microbiota and gut function J Anim Sci, January 1, 2008; 86(1): 94 - 101. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Zhao, A. F. Harper, M. J. Estienne, K. E. Webb Jr., A. P. McElroy, and D. M. Denbow Growth performance and intestinal morphology responses in early weaned pigs to supplementation of antibiotic-free diets with an organic copper complex and spray-dried plasma protein in sanitary and nonsanitary environments J Anim Sci, May 1, 2007; 85(5): 1302 - 1310. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. C. Brown, C. V. Maxwell, G. F. Erf, M. E. Davis, S. Singh, and Z. B. Johnson Ontogeny of T lymphocytes and intestinal morphological characteristics in neonatal pigs at different ages in the postnatal period J Anim Sci, March 1, 2006; 84(3): 567 - 578. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. T. Franklin, M. C. Newman, K. E. Newman, and K. I. Meek Immune Parameters of Dry Cows Fed Mannan Oligosaccharide and Subsequent Transfer of Immunity to Calves J Dairy Sci, February 1, 2005; 88(2): 766 - 775. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. E. Davis, C. V. Maxwell, G. F. Erf, D. C. Brown, and T. J. Wistuba Dietary supplementation with phosphorylated mannans improves growth response and modulates immune function of weanling pigs J Anim Sci, June 1, 2004; 82(6): 1882 - 1891. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. E. Burkey, S. S. Dritz, J. C. Nietfeld, B. J. Johnson, and J. E. Minton Effect of dietary mannanoligosaccharide and sodium chlorate on the growth performance, acute-phase response, and bacterial shedding of weaned pigs challenged with Salmonella entericaserotype Typhimurium J Anim Sci, February 1, 2004; 82(2): 397 - 404. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. E. Davis, D. C. Brown, C. V. Maxwell, Z. B. Johnson, E. B. Kegley, and R. A. Dvorak Effect of phosphorylated mannans and pharmacological additions of zinc oxide on growth and immunocompetence of weanling pigs J Anim Sci, February 1, 2004; 82(2): 581 - 587. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. M. LeMieux, L. L. Southern, and T. D. Bidner Effect of mannan oligosaccharides on growth performance of weanling pigs J Anim Sci, October 1, 2003; 81(10): 2482 - 2487. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |