II Feb of pale, soft and exudative (PSE) ning procedure (Althen et al. 1977), re-

Transcription

1 EFFECT OF DANTROLENE SODIUM ON PORK QUALITY FROM PIGS STUNNED BY CAPTIVE-BOLT T. S. YANG'2, Z. J. HAWRYSH3, M. A. PRICE2, and F. X. AHERNE, 2Department of Animal Science, and 3Department of Foods and Nuftition, University of Alberta, Edmonton, Alta. T6H 2HI. Received t5 July 1982, accepted II Feb YeNc, T. S., Hewnysn, Z. J., PnrcE, M. A. enoahbnne, F. X Effect of dantrolene sodium on pork quality from pigs stunned by captive-bolt. Can. J. Anim. Sci. 63: Three groups, each consisting of six crossbred pigs weighing approximately 100 kg, were used to determine the effects of three preslaughter stunning methods on certain quality characteristics of the longissimus, semitendinosus and biceps femoris muscles. The three methods of stunning were captive-bolt, electric shock and oral dantrium (dantrolene sodium, a muscle relaxant) followed by captivebolt. The three muscles were significantly different to each other in some of the quality traits, but the responses to treatments were similar in the three muscles. Without dantrium, captive-bolt stunning resulted in reduced muscle ph at 45 min postmortem and a greater water exudation in muscles at either I h or 24 h postmortem compared to electrically stunned pigs. Dantrium treatment followed by captive-bolt stunning eliminated these differences. Key words: Pigs, PSE, stunning, muscle relaxant, dantrolene [Effet du dantroldne sodium sur la qualit6 de la viande de porcs 6tourdis au pistolet d percuteur.l Titre abr6g6: Qualit6 de la viande de porcs 6tourdis au pistolet percuteur. Trois groupes de porcs, chacun form6 de 6 crois6s, d'un poids moyen de 100 kg, ont 6t6 utilis6s pour 6valuer les effets de trois m6thodes d'6tourdissement pr6alable d I'abattage sur certains caractbres qualitatifs des muscles longissimus, semltendinosus et biceps femoris. Les trois m6thodes 6taient: pistolet d percuteur, 61ectronarcose et administration orale de dantrium (dantrolbne sodium, relaxant musculaire) suivi du pistolet d percuteur. Les trois muscles diff6raient significativement par I'un ou I'autre des caractdres, mais leur r6action aux m6thodes d'6tourdissement 6tait la mome. L'emploi du pistolet sans administration de dantrium a abaiss6 le ph musculaire 45 min aprds I'abattage et a cause une plus abondante exsudation dans les muscles I h ou 24 h aprds l'abattage que 1'6lectronarcose. L'administration de dantrium suivie d'6tourdissement au pistolet a 61imin6 ces diff6rences. Mots cl6s: Porcs, viande exsudative IPSE), 6tourdissement, relaxant musculaire, dantrolbne Captive-bolt stunning is designed to cause pork than electrical stunning (van der Wal an immediate and irreversible suppression 1978). The deleterious effects of captiveof consciousness. This stunning method bolt stunning on meat quality are thought when applied to pigs, however, results in to result from the violent muscle contraca lower muscle ph value at 45 min post- tion and the continuous elevated secretion mortem (pht) and a more frequent occur- of catecholamines associated with the stunrence of pale, soft and exudative (PSE) ning procedure (Althen et al. 1977), re- Lpresenr address (T.S.y.): physiology Division, pig sulting in rapid postmortem glycolysis and Research rnsrirure, p.o. B; z:, i'unu", rui*ui ph fall. Bendall (1966) showed that 350. administration of the muscle relaxant cu- Can. J. Anim. Sci (June 1983) rare before slaughter resulted in high initial 299

2 300 CANADIAN JOURNAL OF ANIMAL SCIENCE (45 min) postmortem ph followed by a slow rate of ph fall compared with pigs electrically stunned and slaughtered in the normal manner. Dantrolene sodium (l-(5-p-nitrophenylfurfurylidene-amino) hydantoin sodium) is also a muscle relaxant which acts by interfering with calcium release from the sarcoplasmic reticulum inhibiting the excitation-contraction system (Ellis and Carpenter 1974). This interference with calcium flux also blocks catecholamine release (Cohen and Grotman 1979). It is likely, therefore, that by administration of dantrolene sodium before captive-bolt stunning the mechanisms responsible for the development of PSE may be attenuated or reversed. This was tested in the following experiment by examining some quality characteristics of porcine longissimus, semitendinosus and biceos femoris muscles. MATERIALS AND METHODS A total of 18 crossbred (Yorkshire x Lacombe) pigs (approximately 100 kg liveweight) were evenly divided into three groups. Dantrium (Norwich-Eaton Ltd., Paris, Ontario) capsules were administered (5 mg dantrolene sodium/kg liveweight) to one group of six pigs 18 h and 4 h before slaughter by using a stomach tube while the animals were restrained. The tube was flushed with 200 ml water to ensure the complete intake of the drug. The remaining 12 pigs were also dosed with 200 ml of water by stomach tube 4 h before slaughter. Feed and water were withheld after the 4 h antemortem drug or sham treatment. Captive-bolt stunning was used for the six dantrolene-treated pigs and for six of the untreated pigs. Electrical stunning (125 V; 60 Hz) was applied to the remaining six pigs. After stunning, the animals were slaughtered by exsanguination. At 30 min postmortem, the left longissimus muscle was exposed, cut transversely at the 5th rib and a section of the muscle, posterior to the cut (25 cm in length) was removed as described by Bendall (1966). A similar procedure was subsequently employed to remove the whole semitendinosus (ST) and biceps femoris (BF) muscles, respectively, from the left hindquarter. At 45 min postmortem, a transverse cut was made through the longissimus muscle at the position corresponding to the 7thl8th rib interface. A portion of meat (about 5 cm) was removed from the anterior end of the ST and BF muscles. For each of the muscles, temperature and ph values were subsequently recorded. The temperature was measured by inserting a Mackson temperature meter thermistor probe (10 cm) into the cut surface center of the remaining muscle. Muscle ph was determined using an Ingold (no ) probe-type electrode attached to a Fisher Accument Model 230 ph/ion meter. The electrode was inserted (3 cm) in each of four areas surrounding the temperature probe. At I h postmortem, another portion (5 cm) of meat was removed from each of the muscles for color determination. A photoelectric reflectance meter (Criterion Instruments, CG-6), equipped with a green filter, was used to measure meat color, expressed as percent reflectance, on a scale of 0 (total absorption) to 100 (total reflectance). Each of these muscle samples was carefully wrapped and stored at loc for 24 h postmortem color determinations using a Hunter Color Difference Meter. The instrument was standardized using the white standard tite (C2-8692) with values of L:92.'l, a: - 1.0, b:0.3. Duplicate determinations were made. Three samples, each weighing about 0.5 g and taken from the center of each of the muscles, were used to determine water-holding capacity as described by Hawrysh and Berg,1'9'76). Water-holding capacity (WHC) was calculated according to the method of Miller and Harrison (1965). A sample was removed from each of the muscles, frozen (-70'C in a solution of methanol and dry ice) and stored at -25'C for subsequent measurement of R-value according to the method of Honikel and Fischer (19'7'l). At 24 h postmortem. measurements of temperature, ph, color and WHC, as described above, were made (in the same locations) on the longissimus, semitendinosus and biceps femoris removed from the right side of the carcass which had been stored at 1"C. The differences among muscle types, the effects of stunning methods and their interaction were tested by two-way analysis of variance. Student-Newman-Keuls test was used to compare means (Steel and Torrie 1980). RESULTS AND DISCUSSION Analysis of the results showed no significant interaction between muscle types and

3 YANG ET AL. - PORK QUALITY FROM PIGS STUNNED BY CAPTIVE-BOLT 301 stunning methods for any of the quality characteristics measured. It was found (Table 1) that ph, values for longissimus and semitendinosus muscle were similar and lower (P<0.05) than that for biceps femoris. Although phro values for the three muscles differed significantly, all ph.o values were indicative of "normal" meat. R- values were similar for longissimus and semitendinosus but lower (P<0.05) for biceps femoris. The three muscles were different for both C, and Cr1 (P<0.001). WHCr values were similar for longissimus and biceps femoris and lower (P<0.05) than the value for semitendinosus. However WHC'* values showed no differences among the three muscles. Of the three muscles the longissimus is known to contain the least number of red fibers and the biceps femoris the most (Cassens and Cooper 1971). These differences in fiber content, as would be expected, were indicated by the differences in light reflectance (C, and Cro, Table 1). It is not fully understood, however, whether the ratio of fiber content (red, intermediate and white) would influence postmortem exudation. The similarity in WHC.. and the differences in WHCI among the three muscles suggests that the ultimate equilibrium between extracellular and intracellular fluid (WHCr4) was similar but the time required to reach the final equilibrium may have varied with the fiber-type content. When compared to electrical stunning, captive-bolt stunning resulted in a higher rate of postmortem glycolysis (indicated by a significantly (P<0.05) lower muscle ph, and ph2a; Table 1). This agrees with other studies (van der Wal 1978). Captive-bolt stunning had little effect on muscle color at either I or 24 h postmortem but caused a greater exudation in muscles at both t h and 24 h postmortem (Table 1). There was no significant difference in any of the quality characteristics determined in muscles obtained from either pigs stunned by electrical shock or from dantrolene-treated pigs stunned by captive-bolt (Table l). This similarity shows that the deleterious effects of captive-bolt stunning on the quality characteristics of porcine muscle could be prevented by preslaughter treatment with dantrolene. In pigs, dantrolene has been successful in preventing and treating succinylcholinehalothane-induced malignant hyperthermia (Harrison 1977). The oral dosage of dantrolene required to provide a prophylaxis for muscle rigidity that occurs with the development of malignant hyperthermia varies from two doses of 5 mglkg.24 h (Harrison 1977) to two doses of ll mglkg.24 Table 1. Effects of stunning methods and dantrolene treatments on quality characteristics of pork muscle Muscle longissimus semitendinosus biceps femoris SEM Significance Stunning method Electric shock Captive-bolt Dantrolene/captive-bolt SEM Significance PHr 5.76a 5.80a 6.35b 0.06 Absom- -r.;'' Color ^ (qo reflectance) Water-holding capaclty ratto phzr (R-value) Cr Cro whcl WHC c.21a 29.00a 5.73a 1.22a 25.88b 5.64b 0.98b 19.l9c *** *** *** 6.02a 5.67a 1.l4ab b 5.61b.20b a 5.63ab.O9a **+*NS 49.94a 38.41b 30.44c NS *P<0.05, **p<0.01, **+p<0.001, NS, p>0.05. c-c Means in the same column bearing different letters are different (P<0.05) a b a ** NS 0.07 a 0.31a 0-24b 0.45b O.O2a 0.35a **+ *

4 302 CANADIAN JOURNAL OF ANIMAL SCIENCE h (Kerr et al. 1978). In the present study dantrolene treatment levels similar to those suggested by Harrison (191'7) failed to prevent muscle contraction induced by captive-bolt stunning; pigs still showed violent kicking, although the actual muscle spasticity may have been significantly depressed. Muscle contraction per se would induce a hyperlactacidemia as a consequence of anaerobic glycolysis. But this glycolysis of muscle contraction cannot be blocked with B-sympathiocolytic drugs and this is in contrast to the glycolysis provoked by catecholamines (Chapler 197 2). Phosphorylase activation is the main control of postmortem glycolysis (Kastenschmidt et al. 1968). Dantrolene is known to inhibit catecholamine secretion (Cohen and Grotman 1979). Thus, it is suggested that the effect of dantrolene on quality characteristics of pig meat was mainly due to the inhibition of catecholamine secretion which subsequently prevented rapid glycolysis. The retardation of glycolysis is indicated by the similarity in ph and R-values of muscles obtained from pigs stunned by electric shock and those from pigs stunned with captive-bolt but treated with dantrolene (Table 1). The results of this work indicate that careful preslaughter handling of pigs would be insufficient to prevent the occurrence of PSE since the stunning method itself can influence postmortem muscle glycolysis. Dantrium (dantrolene sodium) was used in this work as an aid in the study of PSE occurence; it is not suggested that the substance could be used in commercial management. No attempt was made in this study to follow the metabolism of dantrium in the body or to establish residue levels of it, or any of its metabolites. ACKNOWLEDGMENTS Financial support provided by the Alberta Agriculture Research Trust and the Alberta Pork Producers' Marketing Board is gratefully acknowledged. Appreciation is especially expressed to Ms. A. M. Chovelon and Ms. S. R. Gifford for their technical assistance. ALTHEN. T. G.. ONO, K. and TOPEL' D. G. 19'17. Effect of stress susceptibility or stunning method on catecholamine levels in swine. J. Anim. Sci BENDALL, J. R The effect of pre-treatment of pigs with curare on the post-mortem rate of ph fall and onset of rigor mortis in the musculature. J. Sci. Food Agric. 17: CASSENS, R. G. and COOPER, C. C' l97l' Red and white muscle. Adv. Food Res. 19: r-t+, CHAPLER, C. K Effects of propranolol and epinephrine infusion on glycogenolysis in dog skeletal muscle in situ. Can. J. Physiol. Pharmacol. 5O 47 l COHEN. J. and GROTMAN, Y Effects of verapamil, dantrolene and lanthanum on catecholamine release from rate adrenal medulla. Br. J. Pharmacol. 65: ELLIS. K. O. and CARPENTER, J. F Mechanism of control of skeletal muscle contraction by dantrolene sodium. Arch. Phys. Med. Rehabil HARRISON, G. G The prophylaxis of malignant hyperthermia by oral dantrolene in swine. Br. J. Anaesth. 49: HAWRYSH, Z. I. and BERG, R T Studies of beef eating quality in relation to current Canada Grade Classifications. Can. J. Anim. Sci. 56: HONIKEL, K. O. and FISCHER, C' A' raoid method for the detection of PSE and DFD oorcine muscles. J. Food Sci. 42: kastenscsmldt, L. L., HoEKSTRA, w. G. and BRISKEY, E. J Glycolytic intermediates and co-factors in "fast-" and "slow-glycolyzing" muscles of the pig. J. Food Sci. 33: KERR, D. D., WINGARD, D. W' and GATZ, E. E Prevention of porcine malignant hyperthermia by oral dantrolene. Pages in J. A. Aldrete and B. A. Britt, eds. Int. Symp. on Malignant Hyperthermia. Grune and Stratton. New York. MILLER, E. M. and HARRISON, D. L Effect of marination in sodium hexametaphosphate solution on the palatability of loin steaks. Food Tech. 19: STEEL. R. G. D. and TORRIE, J. H Principles and procedures of statistics; A biometrical approach. 2nd ed. McGraw-Hill, New York. VAN DER WAL, P. G Chemical and physiological aspects of pig stunning in relation to meat quality - A review. Meat Sci' 2:

5 This article has been cited by: 1. S. Bjurström, J. Carlsten, L. Jönsson The Reduction of Skeletal Muscle Lesions after Experimental Stress in Stress-susceptible Pigs Protected with Dantrolene. Journal of Veterinary Medicine Series A 42:1-10, [Crossref]