Trecentocinque suini pesanti sono stati sottoposti a stordimento elettrico (146 soggetti) o con CO2 (159 soggetti) per valutare l’effetto del metodo di stordimento sull’incidenza del difetto di venatura delle cosce, sul valore del pH, sul colore dei muscoli SM e BF e su alcuni parametri ematici. Nei suini sottoposti a stordimento con CO2 si è osservata una più alta percentuale di cosce con il difetto di venatura e valori più elevati di HCT, PT e PTT. I suini storditi mediante elettronarcosi hanno presentato un pH1 più basso e un colore più chiaro nel SM 

LO FIEGO, Domenico Pietro

Nanni Costa L.

Russo V.

Tassone F.

English

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Full Terms & Conditions of access and use can be found athttps://www.tandfonline.com/action/journalInformation?journalCode=tjas20Italian Journal of Animal ScienceISSN: (Print) 1828-051X (Online) Journal homepage: https://www.tandfonline.com/loi/tjas20Effect of different stunning methods of pigs onsubcutaneous veining defect and meat quality ofraw hamD.P. Lo Fiego, L. Nanni Costa, F. Tassone & V. RussoTo cite this article: D.P. Lo Fiego, L. Nanni Costa, F. Tassone & V. Russo (2003) Effect ofdifferent stunning methods of pigs on subcutaneous veining defect and meat quality of raw ham,Italian Journal of Animal Science, 2:sup1, 370-372To link to this article:  https://doi.org/10.4081/ijas.2003.11676014© 2003 Taylor & Francis Group LLCPublished online: 07 Mar 2016.Submit your article to this journal Article views: 80View related articles Effect of different stunning methods of pigs on subcutaneous veining defect and meat quality of raw hamD.P. Lo Fiego1, L. Nanni Costa2, F. Tassone2, V. Russo21 Dipartimento Interdisciplinare di Scienze Agrarie, Formazione Primaria e Programmazione Sanitaria– Università di Modena e Reggio Emilia, Italy.2 Dipartimento di Protezione e Valorizzazione Agroalimentare – Università di Bologna, Italy.RIASSUNTO – Effetto del metodo di stordimento sul difetto di venatura e sulla qualità della carnedelle cosce fresche di suino – Trecentocinque suini pesanti sono stati sottoposti a stordimento elettrico (146soggetti) o con CO2 (159 soggetti) per valutare l’effetto del metodo di stordimento sull’incidenza del difet-to di venatura delle cosce, sul valore del pH, sul colore dei muscoli SM e BF e su alcuni parametri emati-ci. Nei suini sottoposti a stordimento con CO2 si è osservata una più alta percentuale di cosce con il difet-to di venatura e valori più elevati di HCT, PT e PTT. I suini storditi mediante elettronarcosi hanno pre-sentato un pH1 più basso e un colore più chiaro nel SM.KEY WORDS: ham, veining defect, stunning method, meat quality, heavy pig.INTRODUCTION – In the last 20 years, the incidence of veining defect on pigs raw hams has pro-gressively risen, up to reach worrying levels. Excluding the research by Gallo et al. (1999) regarding theheritability, the literature does not report scientific data about the cause of this defect. This investiga-tion is part of a larger research programme aimed at studying some of the causes which may determinethe appearance and gravity of the problem (Russo et al., 2003). Particularly, its main objective is to inves-tigate on the effect of the type of stunning method on the incidence of the subcutaneous veining defect,on pH value and colour of semimembranosus (SM) and biceps femoris (BF) muscles of raw hams and onsome blood parameters.MATERIAL AND METHODS – A number of 305 heavy pigs, all coming from the same farm andslaughtered in the same slaughterhouse on 8 different days, have been submitted to two stunning meth-ods: 146 pigs have been put under electrical stunning (at 250 V, 1.25 A, 50 Hz) by using Stork equipment(Netherlands), while 159 of them have been subject to CO2 stunning (82% of CO2 on air), by using Butinaequipment (Denmark). During bleeding, samples of blood have been taken from 103 pigs of the firstgroup and from 110 of the second one to determine the hematocrite (HCT), the prothrombin time (PT)and the partial thromboplastin time (PTT). About 40 minutes after slaughtering, the pH (pH1) value ofSM muscle has been measured in all left raw hams. After chilling at a temperature of 0-4°C for 24 hours,in both hams of each carcass a subjective examination of veining defect has been carried out by using anevaluation scale of 4 classes, previously elaborated, where 1=no defect or barely observable, 2=light,3=evident, 4=heavy (Russo et al., 2003). In addition, in the SM and BF muscles of left raw hams, pH (pHu)value and colour have been measured (Minolta Chromameter CR 300, diameter of 8 mm, illuminantD65). Data from the subjective examination of veining defect have been subject to the analysis of vari-ance according to the type of stunning, by using a model for non-parametrical data and by using the testof Kruskal-Wallis for comparison of means (SAS, 1996). In the evaluation, the frequency of raw hamsbelonging to veining classes 1 and 2, generally considered with no defects for commercial purposes, andto classes 3 and 4, normally excluded from the transformation in DOP Parma and San Daniele hams, hasbeen measured, together with χ2 value in accordance with the method of stunning. Data related to HCT370 ITAL.J.ANIM.SCI. VOL. 2 (SUPPL. 1), 370-372, 2003* ASPA - Atti corretti  27-12-2005  16:39  Pagina 370and PTT, as to be adapted to normal distribution, have been squared and subject to logarithmical trans-formation, respectively. Finally, all data have been processed with an analysis of variance according tothe stunning method (SAS, 1996).RESULTS AND CONCLUSIONS – CO2 stunning has increased the subcutaneous veining defect.As a matter of fact, the mean value has resulted to be significantly higher in the raw hams of swine sub-mitted to this type of stunning (Table 1).The negative effect of CO2 stunning on the veining defect is even more obvious in Table 2, whichshows the distribution of hams into the different classes of veining. In particular, it is possible to observean appreciable reduction of frequency in the raw hams of classes 1 and 2, while in classes 3 and 4 fre-quency is doubled under this method of stunning.In swine subject to CO2 stunning, values found out are significantly higher for HCT, PT and PTT(Table 3). Yet there not seem to be a relation between these parameters and the higher incidence of vein-ing defect for this group. The differences for the two stunning typologies concern both hams with nodefects and those with defects. The method of stunning used has not significantly altered the pH valueand colour of BF muscle (Table 3). But, in the SM muscle, swine subject to electrical stunning have pre-sented a lower pH1 value and a higher value of L* at 24h p.m., although these parameters are to be con-sidered as normal for both groups. These results agree with those of Channon et al. (2002), with respectto the muscle longissimus thoracis for swine under electrical stunning, although the latter was appliedby a different methodology. On the whole, results achieved in this research suggest that stunning withCO2 may determine an increased incidence of veining defect. The conclusion must however find furtherscientific confirmation.Table 1. Effect of stunning type on mean value (1) of ham veining (Mean ± s.d.).Electrical stunning CO2 stunning Kruskal-Wallis (no. = 146) (no. = 159) test significanceRight ham 1.57 ± 0.72 1.80 ± 0.76 **Left ham 1.49 ± 0.68 1.70 ± 0.77 **Average of both hams 1.53 ± 0.60 1.75 ± 0.65 **(1):scale of 4 classes: 1 = no defect or barely observable, 2 = light, 3 = evident, 4 = heavy. **: P< 0.01. Table 2. Distribution (%) of hams into the different classes of veining defect in relation to the stunning method*.Veining class Electrical stunning CO2 stunning(no.=292) (no.=318)1+2 91.43 83.333+4 8.57 16.67*=χ2 significant stunning effect per P< 0.001.PROC. 15th CONGR. A.S.P.A., PARMA, ITALYITAL.J.ANIM.SCI. VOL. 2 (SUPPL. 1), 370-372, 2003 371* ASPA - Atti corretti  27-12-2005  16:39  Pagina 371PROC. 15th CONGR. A.S.P.A., PARMA, ITALYACKNOWLEDGEMENTS – Research supported by Emilia-Romagna Region (Coordinated by CRPAReggio Emilia) and by funds of University of Bologna (RFO ex 60%).REFERENCES – Channon, H.A., Payne, A.M., Warner, R.D., 2002. Meat Sci. 60:63-68. Gallo, L.,Padoan, D., Bondesan, V., Penzo, N., 1999. Proc. 13th Nat. Congr. A.S.P.A., Piacenza, Italy, 689-691.Russo, V., Lo Fiego, D.P., Nanni Costa, L., Tassone, F., 2003. Riv. Suinicoltura XLIV (5): in press. SAS,1996. “SAS Inst. Inc”. Cary, NC, USA.Table 3. Effect of stunning type on some haematic parameters and on pH value and colour of semimembranosus (SM) and biceps femoris (BF) muscles.Electrical stunning CO2 stunning EMS(1)(303 D.F.) HCT (%) 45.75 47.31 ** 19.118aPT (sec.) 8.28 9.19 ** 1.589bPTT (sec.) 36.46 38.46 ** 46.221cpH1 SM 6.31 6.38 ** 0.057pHu SM 5.61 5.68 n.s. 0.048pHu BF 5.60 5.62 n.s. 0.016L*24h p. m. SM 47.13 45.96 ** 13.233a* 24h p. m. SM 9.20 9.00 n.s. 7.587b* 24h p. m. SM 6.32 6.16 n.s. 9.400L*24h p. m. BF 42.80 42.10 n.s. 18.484a* 24h p. m. BF 10.85 10.67 n.s. 7.629b* 24h p. m. BF 7.93 7.52 n.s. 7.922**: P< 0.01, n.s.: not significant. a: D.F.( degree of freedom) 211; b: D.F. =203,c: D.F.= 201. (1) EMS = Error mean square.372 ITAL.J.ANIM.SCI. VOL. 2 (SUPPL. 1), 370-372, 2003* ASPA - Atti corretti  27-12-2005  16:39  Pagina 372

Effect of different stunning methods of pigs on subcutaneous veining defect and meat quality of raw ham

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Effect of different stunning methods of pigs on subcutaneous veining defect and meat quality of raw ham

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