Effects of creatine and vitamin E on muscle energetic metabolism, antioxidant stability and meat quality of pigs

LAHUČKÝ, R. , BUČKO, O. , HAŠČÍK, P., LIPTAJ, T. : Eff ects of creatine and vitamin E on muscle energetic metabolism, antioxidant stability and meat quality of pigs. Acta univ. agric. et silvic. Mendel. Brun. , 2012, LX, No. 5, pp. 151–160 The eff ects of supplementing the diet of pigs with creatine monohydrate (CMH) and vitamin E on blood plasma creatine concentration, vitamin E level in muscle, muscle energy metabolism, antioxidant capacity and meat (musculus longissimus dorsi) quality of pigs (DNA tested and negative on malignant hyperthermia) were investigated. Two treatments were used: supplementation with CMH alone (2 g.kg−1 of feed, 10 days before slaughter); and supplementation with both vitamin E (500 mg -tocopherol.kg−1 of feed for minimum of 30 days) and CMH (2 g.kg−1 of feed, 10 days before slaughter). Pigs supplemented with CMH alone showed elevated plasma creatine concentration (P ≤ 0.05). Phosphorus nuclear magnetic resonance (31P NMR) measurements on post mortem (15 min.) muscle samples showed the highest phosphocreatine levels and ratio PCr/Pi (P ≤ 0.05) in CMH supplemented pigs alone and in combination with vitamin E. Dietary supplementation with vitamin E signifi cantly (P ≤ 0.05) increased the concentration of -tocopherol in meat. Supplementation with CMH alone or in combination with vitamin E resulted in higher (P = 0.07) a values of loin chops at 5 days of storage. Antioxidative capacity (measured as MDA production a er incubation of longissimus muscle homogenates with Fe2+/ascorbate) was substantially improved by vitamin E and somewhat by CMH supplementation. meat quality, pork, creatine monohydrate, vitamin E Previous research has examined the eff ects of supplementing swine fi nishing diets with creatine. Some studies suggested a positive eff ect (Berg and Alle, 2001; James et al., 2002; Young et al., 2004, 2005), but others found little or no eff ect on meat quality parameters (O’Quinn et al., 2000; Maddock et al., 2002; Berg et al., 2003; Stahl and Berg, 2003; Rosenvold et al., 2007; Stahl et al., 2007; Young et al., 2007). Dietary creatine (mainly as creatinemonohydrate, CMH) supplementation has been studied extensively in humans since creatine (phosphocreatine, PCr) functions in maintaining cellular adenosinetriphosphate (ATP) homeostasis (Harris et al., 1992). Increasing and maintenance the PCr/Pi ratio and thus the amount of available energy for resynthesis of ATP could also improve some meat quality parameters, as indicated by studies of the metabolism of phosphorus compounds using phosphorus nuclear magnetic resonance spectroscopy, both ante mortem (Lahucky et al., 1993, 2002; Kohn et al., 1999) and post mortem (Miri et al., 1992; Shen et al., 1992; Moesgaard et al., 1995; Scholz et al., 1995; Lahucky et al., 2000; Bertram et al., 2002). Muscle metabolism around the time of slaughter has a major eff ect on pork quality. An important genetic factor that alters muscle metabolism is the presence of mutations in the ryanodine receptor gene (RYR1) as was shown in many studies (Lahucky et al., 1993, 2002; Fiedler et al., 152 R. Lahučký, O. Bučko, P. Haščík, T. Liptaj 1999; Maddock et al., 2002). Carriers (heterozygotes, Nn) produce lower quality meat and it was proposed that carriers should be excluded from the breeding population (and also from welfare point of view). Results of experiment using 25 g CMH per pig and per day for 5 days before slaughter (Maddock et al., 2002) do not provide convincing evidence for an increase the quality of fresh pork of normal and halothane carrier genotypes but some positive data indicated a need for further studies. Young et al. (2007) found the plasma content of creatine higher and the phosphorylation of creatine more effi cient in Duroc and Landrace pigs but a stronger and more homogenous response to CMH supplementation was seen in the responding Duroc breed compared to the quasi-responding Landrace breed. Lower cooking loss and higher redness (a value) were found on crossbred barrows when 0.92 % CMH supplemented in diet (Stahl et al., 2007). Together with widely used antioxidants such as vitamin E (both natural and synthetic forms) alone or in combination with selected plant extracts (Buckley et al., 1995; Lauridsen et al., 1999; Lahucky et al., 2000, 2010; Bolere et al., 2009; Trefan et al., 2011) it seems be supplementation by CMH could also positively infl uence antioxidant capacity of muscle (Lawler et al., 2002). The objective of the present experiment was further to evaluate the eff ects of creatine monohydrate supplementation alone and together with vitamin E on muscle phosphorus metabolism, antioxidant capacity and meat quality parameters of growth-fi nishing pigs. MATERIAL AND METHODS Animal and sample preparations 36 pigs originating from lines of Slovak White Meaty pigs were used in this experiment. The RYR-1 genotype (Fujii et al., 1991) of these animals was determined by a DNA based test (Malignant hyperthermia syndrome; MH) and only homozygous negative (NN) pigs were used. The experiment was conducted in accordance with the institutional guidelines for animal care (Slovak Agriculture Research Centre, Research Institute of Animal Production, RIAP, Nitra, 1999). The animals were divided into a control group (12 pigs, 6 barrows and 6 gilts) and two experimental groups (12 pigs in each group: 6 barrows and 6 gilts). The pigs were penned in double boxes at the institute facilities. The control group received a standard diet (Tab. I). The fi rst experimental group (group CMH) received supplemental creatine monohydrate (CMH, Sigma, 2 g.kg−1 of feed, 10 days before slaughter) and the second experimental group (group CMH+E) received supplemental vitamin E (ROVOMIX® E-50 SD, 500 mg a-tocopherol.kg−1 of feed for minimum of 30 days) plus supplemental creatine monohydrate (again Sigma, 2 g.kg−1 of feed, 10 days before slaughter). The levels of -tocopherol in the diets are shown in Tab. I (Protocol 12221223/2007, Central Control Institute of Agriculture, Bratislava). The animals were stunned, slaughtered and exsanguinated in the slaughter house of RIAP Nitra (transportation about 200 m) with an average live weight of 105 ± 6 kg. Blood was collected in heparinized tubes for creatinine estimation. 15 min a er slaughter a sample of approx. 1 g was taken from the longissimus muscle (last rib) on the right side using a biopsy instrument (Biotech, Slovakia), immediately frozen, and stored in liquid nitrogen until analysed. A er chilling the carcass at 3–4 °C for 24 h, the entire musculus longissimus thoracis (MLD) was removed from the carcass (right side, 13/14 rib) and then sliced into chops (2.5 cm thick). One wrapped sample was stored in a refrigerator for 5 days at 4 °C.