HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Berg, E. P. Articles by Linville, M. L. Search for Related Content PubMed PubMed Citation Articles by Berg, E. P. Articles by Linville, M. L.

Creatine monohydrate supplemented in swine finishing diets and fresh pork quality: III. Evaluating the cumulative effect of creatine monohydrate and alpha-lipoic acid^1,2

Department of Animal Science, University of Missouri, Columbia 65211-5300

	Abstract

Top Abstract Introduction Materials and Methods Results and Discussion Implications Literature Cited

 
The objective of this study was to evaluate short-duration supplementation of -lipoic acid (ALA) and creatine monohydrate (CMH) to improve fresh pork quality. Forty-eight commercial hybrid barrows were blocked by BW and randomly allotted to one of four treatments: 1) no CMH or ALA; 2) supplementation of 24 g of CMH^-1•pig^-1•d^-1; 3) supplementation of 600 mg ALA^-1•pig^-1•d^-1; or 4) combined CMH and ALA supplements. Twelve pigs per treatment were individually penned with ad libitum access to water and a finishing diet. Treatments were hand-fed to individual pigs daily (divided into three equal doses) for 5 d before slaughter at 113 kg BW in two separate groups of 24 pigs each. Intramuscular pH was recorded at 45 min postmortem and again at 24 h in the ham semimembranosus (SM) and the longissimus muscle (LM) between the 10th and 11th rib. A Meatcheck (SFK Technology, Peosta, IA) conductivity probe was inserted in the same anatomical locations as pH measurement, providing an index value (PY) from 0 to 100 (a higher index value indicates more intact muscle cells and higher water-holding capacity). Color (L, a, b values) measurements were obtained at 24 h postmortem on the ham gluteus medius (GM), SM, and LM. Two 2.54-cm-thick loin chops were removed from the loin for determination of Warner-Bratzler shear force and glycolytic potential. The intact SM and the posterior portion of the boneless loin were vacuum-packaged and stored for 7 d to determine purge loss. Creatine-supplemented pigs had a higher (P = 0.03) PY value in the SM (66.67) at 45 min postmortem than either ALA, singularly (63.50), or in the combined CMH/ALA (62.27) treatments. (A higher PY index indicates superior water-holding capacity.) Lipoic acid supplementation resulted in the highest pH at 45 min (P = 0.029). These results justify further evaluation of the potential positive influence of supplementing -lipoic acid to improve pork quality.

Key Words: Creatine • Lipoic Acid • Meat Quality • Pork

	Introduction

Top Abstract Introduction Materials and Methods Results and Discussion Implications Literature Cited

 
Pale, soft, and exudative (PSE) lean is the most studied quality problem associated with fresh pork and is associated with rapid pH decline caused by an accumulation of lactic acid due to anaerobic glycolysis occurring while carcass temperature is high. Previous research has examined the effects of supplementing creatine monohydrate (CMH) in swine finishing diets as a means of improving fresh pork quality (Berg and Allee, 2001; Stahl et al., 2001; Maddock et al., 2002). These studies suggest that further investigation of supplementing CMH is needed to accurately determine its effects on pork quality.

A study by Greenhaff (1996) showed that supplementation of CMH in humans at a rate of 20 g/d for 5 d increased intramuscular creatine by 20%. Intramuscular creatine uptake was shown to increase by 60% when consumed with a potent insulin-releasing carbohydrate, such as dextrose (Green et al., 1996). Lipoic acid has been shown to be effective in stimulating glucose uptake into the muscle (Pagliaro, 1957). The main objective of the current trial was to reduce the number of days necessary to supplement CMH for improving fresh pork quality.

Based on previous research by Pagliaro (1957), -lipoic acid (ALA) enhances the function of insulin by increasing intramuscular deposition of glucose as glycogen. Improving the actions of insulin on the muscle cell membrane will also enhance amino acid deposition; therefore, creatine uptake into the muscle would also be enhanced. The additional intramuscular creatine should then serve as a lactic acid buffer to improve fresh pork quality (Berg and Allee, 2001; Stahl et al., 2001; Maddock et al., 2002). The present trial was conducted to determine whether the combination of carbohydrates, CMH, and ALA would promote rapid deposition of creatine and glucose into the muscle cell, and to determine whether loading CMH before slaughter would reduce the effects of rapid pH decline.

	Materials and Methods

Top Abstract Introduction Materials and Methods Results and Discussion Implications Literature Cited

 
Forty-eight commercial hybrid market hogs (approximately 107 kg) were placed in individual pens with ad libitum access to water and a traditional corn-soybean meal finishing diet containing 15% CP, 0.5% lysine, and 2% added choice white grease. An ADG of 1.15 kg/d was assumed to allow the pigs to reach 113 kg (market weight) in 5 d. Pigs were housed in an environmental chamber, held at thermoneutral temperatures, and allowed to acclimate to the new environment for 5 d before receiving the experimental treatments. During this 5-d acclimation period, the pigs were trained to eat a 40-g "doughball" of a semipurified, high-starch pig starter diet. Treatments (n = 12 pigs per treatment) were administered as follows: 1) pigs hand-fed supplemental creatine monohydrate (CMH) in three 8-g doses per day mixed with the starter diet dough ball; 2) pigs hand-fed supplemental -lipoic acid (ALA) in three 200-mg doses per day mixed in starter diet dough ball; 3) pigs hand-fed three combinations of doses of CMH (8 g) and ALA (200 mg) each day mixed with the starter diet dough balls; and 4) control (CON) pigs hand-fed three starter diet doughballs devoid of CMH or ALA. All treatments were administered for 5 d before slaughter, and final dietary treatments were administered at 1800 the day before slaughter. Pigs were slaughtered on d 6 of the experiment at approximately 113 kg in two separate groups of 24 pigs.

Slaughter
Live weight and hot carcass weight were obtained on the day of slaughter. Muscle pH measurements were taken at 45 min and 24 h after exsanguination in the inside ham (semimembranosus; SM) muscle and through the intercostal space into the longissimus muscle (LM) at the 10th- and 11th-rib interface using a PH-Star probe (SFK Technology, Peosta, IA). The Meatcheck probe (SFK Technology) was used to obtain an index value (PY) and temperature reading taken in the ham SM and LM at 45 min and 24 h postmortem. The Meatcheck PY reading provides an indication of intact muscle cells based on an index of electronic conduction through lean tissue between two stainless steel probe points. A low PY reading indicates higher conduction as a result of a greater amount of free intracellular moisture and a lower proportion of intact muscle fibers.

Measurements Taken During Fabrication
Ham Fabrication and Analysis.
The rough ham was removed by making a cut at a point half the distance between the anterior edge of the aitchbone and the posterior edge of the last lumbar vertebra, perpendicular to the outer skin surface, and to a line perpendicular to the shank. Light reflectance readings (L, a, and b values) were recorded on the cut lean surface of the exposed gluteus medius (bloom time 10 min) using a Minolta colorimeter (Minolta Corp., Ramsey, NJ; model CR-310 standardized to a white and black tile using D65 illuminant). The SM was removed from the ham and faced perpendicular to the muscle fiber orientation on the large end of the SM, exposing enough surface area to accommodate the 50-mm Minolta head to record colormetric L, a, and b values. The remaining large portion of the SM was weighed, vacuum-packaged, and placed in the cooler for 7 d at 2.8°C. After 7 d, the SM was removed from the vacuum package, patted dry, and reweighed to reveal whole muscle purge. Light reflectance and muscle pH measurements were repeated on the SM on a fresh cut lean surface after 7 d of storage.

Loin Fabrication and Analysis.
The loin was separated at the 10th- and 11th-rib juncture, and a two-rib section (9th and 10th-rib) was removed with the subcutaneous fat and skin remaining intact for determination of 10th-rib fat depth and LM area. Light reflectance readings (L, a, and b values) were recorded on the cut lean surface of the exposed 10th-rib LM using a Minolta colorimeter (Minolta Corp., model CR-310). The sirloin portion was then removed from the posterior section of the loin at the last lumbar vertebra (leaving the last lumbar vertebra attached to the sirloin). All bones and cartilage were removed and the loin was trimmed of all external fat. One 2.54-cm-thick chop was fabricated from the two rib loin section, trimmed of all external fat, packaged, and frozen for determination of glycolytic potential (Monin and Sellier, 1985). An additional 2.54-cm-thick chop was removed from the LM (9th rib), external fat removed, and an approximate 50-g muscle sample was used to determine drip loss. Loin samples were weighed to the nearest 0.1 g, suspended from a stainless steel hook, covered, placed in a cooler at 4°C for 24 h, and then reweighed. Percentage of moisture lost was calculated by dividing 24-h sample weight by the original sample weight, subtracting from 1.00 and multiplying by 100. A second pair of chops was removed from the LM (10th rib) for analysis of crude fat (ether extraction; AOAC 960.39 official procedure; AOAC, 2000).

A single 2.54-cm-thick chop was removed adjacent to the 11th rib for determination of Warner-Bratzler shear force (WBSF). Chops were placed on a Farberware Open Hearth Grill (Model 455N, Walter Kidde, Bronx, NY), cooked to 35°C, flipped, and cooked to a final temperature of 70°C. Temperature was monitored using a 12-channel thermometer (Cole-Parmer Instrument Co., Vernon Hills, IL). After reaching their end point temperatures, cooked chops were placed on a tray, and covered with oxygen-permeable clear plastic wrap to reduce moisture loss, and cooled for approximately 24 h (4°C). Six 1.27-cm-diameter cores (AMSA, 1995) were excised from each loin chop parallel to the muscle fiber and sheared perpendicular to the fiber orientation on the Warner-Bratzler shear instrument (G. R. Electric, Manhattan, KS).

Determination of Glycolytic Potential.
The frozen 2.54-cm chops removed from approximately the eighth rib were delivered to the University of Illinois Meat Science laboratory for determination of intramuscular glycolytic potential. Glycolytic potential (expressed in micromoles per gram of wet tissue weight) was calculated according to Monin and Sellier (1985) as follows: glycolytic potential = 2([glycogen] + [glucose] + [glucose-6-phosphate]) + [lactate]. A complete description of the procedures for determination of glycolytic potential is provided by Miller et al (2000).

Statistical Analyses
Data were analyzed using the General Linear Models of SAS (SAS Inst., Inc., Cary, NC). Least squares means were evaluated for least significant differences in a general linear model for all dependent variables associated with pork quality and carcass composition using dietary treatment as the lone fixed effect and pig as the experimental unit. Analysis of intramuscular hydrogen ion concentration was evaluated before logarithmic conversion. The harvest day interaction with dietary treatment was tested and found to be nonsignificant (P > 0.10), and consequently removed from the model.

	Results and Discussion

Top Abstract Introduction Materials and Methods Results and Discussion Implications Literature Cited

 
Creatine monohydrate is an amino acid derivative that has become a popular sports supplement used to increase muscle performance (Greenhaff et al., 1993) in humans. This increase in performance has been shown to also include an increase in lean body mass (Balsom et al., 1995), possibly due to the increased ability to do work resulting from a rise in the phosphocreatine concentration in muscle. As creatine is taken into the muscle, it is converted to phosphocreatine, which supplies the phosphate needed for the rephosphorylation of ADP, allowing for a delay in the onset of fatigue (Casey et al., 1996).

Balsom et al. (1995) showed that human athletes consuming 20 g of CMH/d for 6 d increased body mass by 1.1 kg. In the present study, feeding CMH, ALA, or CMH + ALA for 5 d had no (P > 0.92) effect on carcass weight (Table 1). Although LM area was largest for CMH-supplemented hogs, the tendency (P = 0.081) for treatment to influence LM area suggests that the -lipoic acid treatments (singularly or in combination with CMH) actually decreased LMA, and CMH had only a slight advantage over CON. Thus, the "trend" may reflect a negative influence of short-duration supplementation of ALA rather than a positive effect of CMH. Berg and Allee (2001), Stahl et al. (2001), and O’Quinn et al. (2000) reported a numeric increase in LMA of pigs supplemented CMH. Maddock et al. (2002) found supplementation of CMH for 5 d before slaughter increased body weight gain (6.6 kg vs. 4.4 kg) but did not increase LM area. Given the genetic type of pigs used in the present trial, 5 d of CMH supplementation may not have been a sufficient length of time to realize body weight gain or an increase in muscle size. Furthermore, the decrease in LM area associated with the ALA treatments is difficult to explain. Unpublished results from our laboratory indicated that pigs consuming ALA for 30 d before harvest at a level of 8 and 16 mg/kg of BW experienced an increase in LMA (as determined by serial ultrasound analysis) and predicted percentage carcass lean compared to untreated controls.

View this table: [in this window] [in a new window]   Table 1. Least squares means, standard errors, and level of significance for carcass measurement associated with 5-d supplementation of creatine monohydrate, -lipoic acid, and a combination of creatine monohydrate and -lipoic acid

Creatine supplementation has been reported to improve muscle performance by reducing lactic acid accumulated during high-intensity exercise (Balsom et al., 1993; Prevost et al., 1997), suggesting a reduced reliance on glycolysis for the production of ATP. One of the potential causes of the PSE condition in pork is a rapid, early postmortem pH decline due to the accumulation of lactic acid from anaerobic glycolysis. If the rate of pH decline was buffered, due to more available ATP from other sources besides glycolysis, development of PSE meat would occur less frequently.

The pH value of the LM from ALA-supplemented pigs was higher (P = 0.029) initially (45 min) than that of CON, CMH, and the combined CMH + ALA-treated pigs (Table 2). Furthermore, the LM from hogs supplemented with CMH had higher (P = 0.03) PY values in the SM at 45 min than ALA, singularly, or the combination of CMH and ALA. The higher loin pH would suggest that pork from the ALA treatment would have a high water-holding capacity. The numeric advantages observed early postmortem by ALA disappeared by 24 h and did not help predict drip loss or 7-d purge loss. Although carcasses of ALA-supplemented hogs had the lowest (P = 0.223) numerical concentrations of lactic acid, neither the concentrations of lactic acid and muscle carbohydrates (glycogen, glucose-6-phosphate, and glucose) nor glycolytic potential were affected (P > 0.38) by dietary treatments (Table 3). Furthermore, dietary treatment had no effect (P > 0.05) on hot carcass weight, 10th-rib fat depth, intramuscular fat, SM pH, 24-h LM pH, 24-h LM and SM PY, objective color (L, a, and b values), drip, purge and cooking loss percentages, or WBSF.

View this table: [in this window] [in a new window]   Table 2. Least squares means, standard errors, and level of significance for intramuscular pH, light reflectance (L, a, b), moisture loss, and Warner-Bratzler shear force relative to 5-d supplementation of creatine monohydrate, -lipoic acid, and a combination of creatine monohydrate and -lipoic acid

View this table: [in this window] [in a new window]   Table 3. Least squares means, standard errors, and level of significance for glycolytic potential parameters associated with 5-d supplementation of creatine monohydrate, -lipoic acid, and a combination of creatine monohydrate and -lipoic acida

-Lipoic acid is a powerful biological antioxidant (Packer et al., 1995) and has been shown to improve whole-body and skeletal glucose disposal in insulin-resistant animal models (Jacob et al., 1996) and humans (Jacob et al. 1995). Henriksen et al. (1997) found that ALA enhanced insulin action and increased the uptake of 2-deoxyglucose by 55% in lean rat muscle and 33% in obese rat muscle. One objective of the present study was to determine whether the combination of supplementing CMH and ALA would increase the beneficial effects of creatine on pork quality. The results of the current study did not demonstrate any beneficial effects on pork quality of the combination of these two supplements. Yet the supplementation of ALA, singularly, resulted in a higher 45-min LM pH than any other treatment group.

	Implications

Top Abstract Introduction Materials and Methods Results and Discussion Implications Literature Cited

 
Creatine monohydrate supplementation tended to affect loin muscle area relative to the other treatment diets, but not compared with control. Loin muscle 45-min pH was highest for pigs provided short-duration supplementation of -lipoic acid. Supplementation combining -lipoic acid and creatine monohydrate in the late-finishing diet did not differ from supplementing creatine monohydrate alone, nor was it different from the control treatment. Future research evaluating the unique antioxidant -lipoic acid as a dietary means of improving fresh pork quality is warranted.

	Footnotes

 
¹ This research was, in part, supported by the Missouri Agric. Exp. Stn. Project No. 0569 and the Missouri Pork Producers Association, on behalf of the National Pork Board.

² The authors wish to thank F. K. McKeith and B. S. Bidner from the University of Illinois Muscle Biology Lab for determination of glycolytic potential; J. Spencer, J. Berkemier, D. Kemp, and D. Rhoades for technical assistance; and Wilke International, Inc. (Lenexa, KS) and Ferro Phanstiehl Laboratories (Waukegan, IL) for supplying creatine monohydrate.

⁴ Present address: Iowa State University, 214 Meat Lab, Ames, IA.

³ Correspondence: S138 Animal Science Research Center, 920 East Campus Drive (phone: 573-882-3176; fax: 573-882-6827; E-mail: BergEP{at}missouri.edu).

Received for publication October 21, 2002. Accepted for publication June 27, 2003.

	Literature Cited

Top Abstract Introduction Materials and Methods Results and Discussion Implications Literature Cited

 


AMSA. 1995. Research Guidelines for Cookery, Sensory Evaluation and Instrumental Tenderness Measurements of Fresh Meat. American Meat Science Association and National Live Stock and Meat Board, Chicago, IL.

AOAC. 2000. Official Methods of Analysis. 17th ed. Vol. II. Assoc. Offic. Anal. Chem., Washington, DC.

Balsom, P. D., K. Soderlund, B. Sjodin, and B. Ekblom. 1995. Skeletal muscle metabolism during short duration high-intensity exercise: influence of creatine supplementation. Acta Physiol. Scand. 154:303–310.[Medline]

Balsom, P. D., B. Ekblom, K. Soderlund, B. Sjodin, and E. Hultman. 1993. Creatine supplementation and dynamic high-intensity intermittent exercise. Scand. J. Med. Sci. Sports 3:143–149.

Berg, E. P., and G. L. Allee. 2001. Creatine monohydrate supplemented in swine finishing diets and fresh pork quality: I. A controlled laboratory experiment. J. Anim. Sci. 79:3075–3080.[Abstract/Free Full Text]

Casey, A., D. Constantin-Teodosiu, S. Howell, E. Hultman, and P. L. Greenhaff. 1996. Creatine ingestion favorably affects performance and muscle metabolism during maximal exercise in humans. Am. J. Physiol. 271:E31–E37.

Green, A. L., E. Hultman, I. A. Macdonald, D. A. Sewell, P. L. Greenhaff. 1996. Carbohydrate ingestion augments skeletal muscle creatine accumulation during creatine supplementation in humans. Am. J. Physiol. 271:E821–826.

Greenhaff, P. L. 1996. Creatine supplementation: Recent developments. Br. J. Sports Med. 30:276–277.[Medline]

Greenhaff, P. L., A. Casey, A. H. Short, R. Harris, K. Soderlund, and E. Hultman. 1993. The influence of oral creatine supplementation on muscle torque during repeated bouts of maximal voluntary exercise in man. Clin. Sci. 84:565–571.[Medline]

Harris, R. C., K. Soderlund, and E. Hultman. 1992. Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. Clin. Sci. 83:367–374.[Medline]

Henriksen, E. J., S. Jacob, R. S. Streeper, D. L. Fogt, J. Y. Hokama, and H. J. Tritschler. 1997. Stimulation by alpha-lipoic acid of glucose transport activity in skeletal muscle of lean and obese Zucker rats. Life Sci. 61:805–812.[Medline]

Hultman, E., K. Soderlund, J. A. Timmons, G. Cederblad, and P. L. Greenhaff. 1996. Muscle creatine loading in men. J. Appl. Physiol. 81:232–237.[Abstract/Free Full Text]

Jacob, S., R. S. Streeper, D. L. Fogt, J. Y. Hokama, H. J. Tritschler, G. J. Dietze, and E. J. Henriksen. 1996. The antioxidant alpha-lipoic acid enhances insulin-stimulated glucose metabolism in insulin-resistant rat skeletal muscle. Diabetes 45:1024–1029.[Abstract]

Jacob, S., E. J. Henriksen, A. L. Schiemann, I. Simon, D. E. Clancy, H. J. Tritschler, W. I. Jung, H. J. Augustin, and G. J. Dietze. 1995. Enhancement of glucose disposal in patients with type 2 diabetes by alpha-lipoic acid. Arzneimittelforschung. 45:872–874.[Medline]

Maddock, R. J., B. J. Bidner, S. N. Carr, F. K. McKeith, E. P. Berg, J. W. Savell. 2002. Creatine monohydrate supplementation and the quality of fresh pork in normal and halothane carrier pigs. J. Anim. Sci. 80:997–1004.[Abstract/Free Full Text]

Miller, K. D., M. Ellis, D. S. Sutton, F. K. McKeith, and E. R. Wilson. 2000. Effects of live-animal sampling procedures and sample storage on the glycolytic potential of porcine longissimus muscle samples. J. Muscle Foods 11:61–67.

Monin, G., and P. Sellier. 1985. Pork of low technological quality with a normal rate of muscle pH fall in the immediate post-mortem period: The case of the Hampshire breed. Meat Sci. 13:49–56.

O’Quinn, P. R., B. S. Andrews, R. D. Goodband, J. A. Unruh, J. L. Nelssen, J. C. Woodworth, M. D. Tokach, and K. Q. Owen. 2000. Effects of modified tall oil and creatine monohydrate on growth performance, carcass characteristics, and meat quality on growing-finishing pigs. J. Anim. Sci. 78:2376–2382.[Abstract/Free Full Text]

Packer, L., E. H. Witt, and H. J. Tritschler. 1995. alpha-Lipoic acid as a biological antioxidant. Free Radical Biol. Med. 19:227–250.[Medline]

Pagliaro, L. 1957. Action of thioctic acid on liver and muscle glycogen of normal rabbits. Patol. Sper. 45:177–188.

Prevost, M. C., A. G. Nelson, and G. S. Morris. 1997. Creatine supplementation enhances intermittent work performance. Res. Q. Exer. Sport 68:233–240.

Stahl, C. A., G. L. Allee, and E. P. Berg. 2001. Creatine monohydrate supplemented in swine finishing diets and fresh pork quality: II. Commercial applications. J. Anim. Sci. 79:3081–3086.[Abstract/Free Full Text]

This article has been cited by other articles:

				D. C. Kendall, A. M. Gaines, B. J. Kerr, and G. L. Allee True ileal digestible tryptophan to lysine ratios in ninety- to one hundred twenty-five-kilogram barrows J Anim Sci, November 1, 2007; 85(11): 3004 - 3012. [Abstract] [Full Text] [PDF]

				Q. W. Shen, K. R. Underwood, W. J. Means, R. J. McCormick, and M. Du The halothane gene, energy metabolism, adenosine monophosphate-activated protein kinase, and glycolysis in postmortem pig longissimus dorsi muscle J Anim Sci, April 1, 2007; 85(4): 1054 - 1061. [Abstract] [Full Text] [PDF]

				Q. W. Shen, C. S. Jones, N. Kalchayanand, M. J. Zhu, and M. Du Effect of dietary {alpha}-lipoic acid on growth, body composition, muscle pH, and AMP-activated protein kinase phosphorylation in mice J Anim Sci, November 1, 2005; 83(11): 2611 - 2617. [Abstract] [Full Text] [PDF]

				J. T. Yen, J. E. Wells, and D. N. Miller Dried skim milk as a replacement for soybean meal in growing-finishing diets: Effects on growth performance, apparent total-tract nitrogen digestibility, urinary and fecal nitrogen excretion, and carcass traits in pigs J Anim Sci, November 1, 2004; 82(11): 3338 - 3345. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Berg, E. P. Articles by Linville, M. L. Search for Related Content PubMed PubMed Citation Articles by Berg, E. P. Articles by Linville, M. L.