Short communication. The effect of oestrus at slaughter on carcass and meat quality of gilts intended for dry-cured ham production

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1 Instituto Ncionl de Investigción y Tecnologí Agrri y Alimentri (INIA) Spnish Journl of Agriculturl Reserch (4), Avilble online t ISSN: X eissn: Short communiction. The effect of oestrus t slughter on crcss nd met qulity of gilts intended for dry-cured hm production S. Clvo 1, G. Ripoll 1, J. A. Rodriguez-Snchez 1 nd M. A. Ltorre 2 * 1 Centro de Investigción y Tecnologí Agrolimentri de Argón (CITA). Avd. Montñn, Zrgoz. Spin 2 Fcultd de Veterinri. Universidd de Zrgoz. Avd. Miguel Servet, Zrgoz. Spin Abstrct On the dy previous to slughter, totl of 467 Duroc (Lndrce Lrge White) gilts with pproximtely 130 kg body weight nd 242 ± 3 dys of ge intended for Teruel hm production were observed to detect oestrus. The behviourl mnifesttions described in the literture were used for this. A totl of 24 gilts were positively detected nd individully identified (O gilts). From the sme gilts observed, totl of 24 tht clerly did not mnifest oestrus were lso individully identified (NO gilts). Therefore, totl of 48 gilts were used to study the effect of the presence of oestrus t slughter on crcss nd met qulity. No crcss chrcteristics were ffected by oestrus t slughter. However, ll the crcsses (100%) from NO gilts were suitble for cured hm while 12.5% of crcsses from O gilts were not suitble becuse of the lck of the minimum bckft thickness required (16 mm) (p = 0.09). The influence of oestrus t slughter on met chrcteristics ws scrce. Under our experimentl conditions, it cn be concluded tht voiding the slughter of gilts in oestrus might be recommendble when minimum covering ft in crcss is needed to improve the qulity of the end product. However, new trils would be needed to confirm this. Additionl key words: loin qulity; pig femles; stress. Resumen Comunicción cort. Efecto de l presenci de estro en el momento del scrificio sobre l clidd de l cnl y l crne de cerds destinds l producción de jmón curdo El dí previo l scrificio, se observron un totl de 467 cerds Duroc (Lndrce Lrge White), con proximdmente 130 kg de peso vivo y 242 ± 3 dís de edd destinds l producción de Jmón de Teruel, pr detectr l presenci de estro medinte ls mnifestciones descrits en l bibliogrfí. Un totl de 24 cerds fueron detectds positivmente e identificds individulmente (cerds O). Entre ls cerds observds, un totl de 24 que clrmente no mnifestbn celo fueron tmbién identificds individulmente (cerds NO). Por tnto, se usron 48 cerds pr estudir el efecto de l presenci de estro durnte el scrificio sobre l clidd de l cnl y l crne de cerds destinds Jmón de Teruel. Ningun crcterístic de l cnl se vio fectd por l presenci de estro. Sin embrgo, tods ls cnles (100%) de ls cerds NO fueron pts pr l producción de jmón curdo, mientrs que un 12,5% de ls cnles de cerds O no lo fueron por no cumplir el mínimo espesor de grs de cobertur requerido (16 mm) (p = 0,09). El estro en el scrificio pens fectó ls crcterístics de l crne. Podemos concluir que podrí ser recomendble evitr el scrificio de cerds en estro cundo se exige un mínimo de grs de cobertur en l cnl pr mejorr l clidd del producto finl. Sin embrgo, se necesitrín más ensyos pr confirmrlo. Plbrs clve dicionles: clidd del lomo; estrés; hembrs porcins. Spin is the world leder in dry-cured hm nd shoulder production with totl of 46 million pieces in 2008 (MARM, 2010). Currently, the only Protected Designtion of Origin (PDO) of dry-cured hm from crossbred commercil pigs (not utochthonous) ccepted by the Spnish government is «Teruel hm». The * Corresponding uthor: mltorr@unizr.es Received: ; Accepted: Abbrevitions used: * (redness), b* (yellowness), BW (body weight), C* (chrom), DFD (drk, firm nd dry), H* (hue ngle), L* (lightness), m. GM (gluteus medius muscle), NO (not oestrus gilts), O (oestrus gilts), p (sttisticl significnce level), PDO (Protected Designtion of Origin), PSE (ple, soft nd exhudtive), SE (stndrd error of the men).

2 982 S. Clvo et l. / Spn J Agric Res (2010) 8(4), production of Teruel hm hs incresed drsticlly in recent decdes from 2,000 pieces in 1985 to 700,000 in 2009 (CRPDO Jmón de Teruel, 2010). The Regultion of PDO Teruel hm estblishes minimum of 84 kg for crcss weight, of 16 mm for ft thickness over the gluteus medius muscle (m. GM) nd of 11.3 kg for fresh hm to improve the uniformity nd qulity of the end product (BOA, 1993). In recent study, Ltorre et l. (2008) recommended n verge slughter weight of 130 kg to optimize the growth performnce nd crcss qulity of these pigs. However, t this slughter weight, ll the crcsses from brrows were suitble for Teruel hm but third of the crcsses from gilts were rejected becuse of the limited mount of covering ft depth (Ltorre et l., 2009). There re severl fctors tht cn ffect the production nd qulity of Teruel hm from gilts (weight/ge t slughter, helth sttus, feeding or stress). Among cuses of stress, the presence of oestrus t slughter might be importnt. Trditionlly, the slughter of gilts in oestrus ws voided becuse it ws believed tht it negtively ffected met qulity. Currently, the Regultion of PDO Teruel hm prohibits the slughter of gilts in oestrus (BOA, 1993). Also, Iberin gilts which re slughtered t 160 kg of body weight (BW) re usully cstrted to void possible negtive effects of oestrus on growth performnce or met qulity (Serrno et l., 2008). However, to our knowledge, there is no reserch study tht justifies the effect of oestrus t slughter on met chrcteristics of gilts. A totl of 467 Duroc (Lndrce Lrge White) gilts of pproximtely 130 kg BW nd 242 ± 3 dys of ge intended for Teruel hm production were observed t frm during the previous dy of the slughter to detect oestrus. The behviourl mnifesttions described in the literture (Whittemore, 1998) were used: jw chmping, frothing t the mouth, erect ers nd immobiliztion. A totl of 24 gilts resulted positive (in oestrus; O gilts) nd were individully identified. The sme number (24) of gilts tht resulted clerly negtive (no oestrus; NO gilts) were lso individully identified. Therefore, totl of 48 gilts were used to study the effect of the presence of oestrus t slughter on crcss nd met qulity. The feeding progrm ws common to ll of the nimls nd ws bsed on whet, brley, mize nd soyben mel. A growing diet from 20 to 70 kg BW (2,210 kcl NE kg 1, 16.9% CP nd 1.00% lys) nd finishing diet from 70 kg BW to slughter (2,340 kcl NE kg 1, 14.4% CP nd 0.86% lys) were provided. When nimls chieved pproximtely 130 kg BW, they were strved for 7 h nd, on the sme dy, trnsported 130 km to commercil bttoir plnt (Jmones y Embutidos Alto Mijres, S.L., Teruel, Spin). At the bttoir, pigs were rested for 10 h with ccess to wter but not to feed. Hot crcss weight ws individully recorded becuse it is the first criterion used to identify those crcsses suitble for the production of Teruel hm. Therefore, crcsses tht weighed less thn 84 kg re not cceptble. At 45 min postmortem, ph nd temperture in the semimembrnosus muscle using ph-meter equipped with glss electrode (model 52-00, Crison Instruments S.A., Brcelon, Spin), crcss length from the posterior edge of the symphysis pubis to the nterior edge of the first rib, hm length from the nterior edge of the symphysis pubis to the hock joint, nd hm circumference t its widest point were mesured on the left side of ech crcss. In ddition, ft depth over the m. GM, nd bckft thickness between the 3 rd nd 4 th lst ribs on the midline of the crcss (skin included) were mesured, with ruler with precision of 0.5 mm, becuse it is the second criterion used to identify those crcsses suitble for Teruel hm production; crcsses with ft depth over the m. GM less thn 16 mm re not cceptble. After 2 h t 2 C, crcsses were processed ccording to the simplified EC reference method (Brnscheid et l., 1990). Loins, hms, nd shoulders were then trimmed of externl ft nd weighed to clculte trimmed loin, hm, nd shoulder yield. Hm weight is the third criterion used to identify those crcsses suitble for Teruel hm production; crcsses with fresh hm weight less thn 11.3 kg re not cceptble. At 24 h postmortem, ph ws mesured s described before nd hms were weighed gin to clculte hm shrink losses. The incidence of ple, soft nd exudtive met (PSE, s % crcsses with ph t 45 min < 5.8) nd of drk, firm nd dry met (DFD, s % crcsses with ph t 24 h > 6.2) were clculted. A section of 300 ± 20 g of longissimus thorcis muscle ws excised t the level of the lst rib from ech left loin of crcss. Met smples were stored in individul plstic bgs nd vcuum-pckged t 20 C until subsequent nlyses. Thwing nd drip losses were determined s described by Ltorre et l. (2003). Met colour ws evluted with chrommeter (model CM 2002, Minolt Cmer, Osk, Jpn) using objective mesurements (CIE, 1976). Lightness (L*), redness (*) nd yellowness (b*) were recorded nd chrom (C*) nd hue ngle (H*) were clculted s C* = (* 2 +b* 2 ) nd s H* = tn 1 (b*/*) 57.29, respectively. Chrom is relted to the quntity of pigments nd high vlues represent more vivid color denoting lck of gryness

3 Oestrus t slughter on crcss nd met qulity in gilts 983 while Hue is the ttribute of color perception denoted by blue, green, yellow, red, purple, etc. relted to the stte of pigments (Wyszecki nd Stiles, 1982). Cooking losses were determined by the method described by Honikel (1998) using wter bth (Precisterm, J.P. Select S.A., Brcelon, Spin) nd hndheld temperture probe (model HI 9063, Hnn Instruments, Woonsocket, RI). Afterwrds, tenderness ws determined by Wrner-Brtzler device ttched to n Instron Universl testing mchine ttched to computer (Instron model 5543, Instron Ltd, Buckinghmshire, UK). Dt were nlyzed using the GLM procedure of SAS v (SAS, 1990). The tretment (presence or not of oestrus t slughter) ws included t the model s min effect. Ech tretment ws replicted 24 times. The incidence of PSE nd DFD met were nlyzed by χ 2 test. p vlues lower thn 0.05 were clssified s significnt difference nd p vlues between 0.05 nd 0.10 were clssified s trend. A totl of 857 pigs were observed t frm, 54.4% being brrows nd 45.6% gilts. From ll the femles, totl of 24 mnifested oestrus which is 6.14% of the totl gilts. The proportion of O gilts ws lower thn expected. The reson could be tht only femles with cler oestrus symptoms were identified, not tking into ccount those tht were t the beginning or t the end of the oestrus period, or delys in the puberty nd silent oestrus (without cler symptoms) (Tummruk et l., 2007). Crcss prmeters (weight, covering ft depth nd yield of priml len cuts) were similr to those reported by Ltorre et l. (2009) for similr gilts slughtered t 130 kg BW nd lso intended for dry-cured hm (Tble 1). The presence of oestrus t slughter did not modify ny crcss chrcteristics of gilts. However, tretment ffected the percentge of crcsses suitble for Teruel hm (Tble 2). No effect of the presence of oestrus t slughter ws detected on the proportion of suitble crcsses with the minimum crcss nd hm weights required for PDO Teruel hm. In fct, 100% of the crcsses fulfilled those requirements. However, NO gilts tended to show higher proportion of finl crcsses suitble for Teruel hm (crcsses tht fulfill the three nmed requirements) thn O gilts (91.6 vs. 84.4%; p = 0.09) becuse of lck of bckft thickness t m. GM (100 vs. 87.5%; p = 0.09 for NO nd O gilts, respectively). This might be due to reduction in feed intke during oestrus dys s consequence of stress. Some uthors hve mentioned tht oestrus could led to lower feed consumption (Zeng et l., 2002; Serrno et l., 2008) but it hs been not scientificlly demonstrted. Le Bellego et l. (2002) reported reduction in dily feed intke nd in bckft thickness in growing pigs under stress sitution; housed t high (29 C) vs. thermoneutrl (22 C) temperture. However, these effects could be due to the hot temperture nd/or to the stress cused by hot temperture. In fct, Morrison et l. (2003) detected reduced bckft depth under Tble 1. The effect of oestrus t slughter on crcss chrcteristics of gilts intended for dry-cured Teruel hm Oestrus No oestrus SE p b Crcss weight, kg NS Bckft depth t 3 rd -4 th lst ribs, mm NS Ft depth t m. gluteus medius, mm NS Crcss length, cm NS Hm length, cm NS Hm perimeter, cm NS Weight of trimmed len cuts, kg Shoulder NS Loin NS Hm NS Totl c NS Yield of trimmed len cuts, % crcss Shoulder NS Loin NS Hm NS Totl c NS Hm shrink losses,% NS SE: stndrd error of the men. b p: significnce. NS: not significnt (p > 0.05). c Shoulder + Loin + Hm.

4 984 S. Clvo et l. / Spn J Agric Res (2010) 8(4), Tble 2. The effect of oestrus t slughter in gilts on suitble (%) crcsses intended for dry-cured Teruel hm Requirements for Teruel hm Oestrus No oestrus SE b p c Crcss weight 84 kg NS Ft depth t m. gluteus medius 16 mm Fresh hm weight 11.3 kg NS All d According to BOA (1993). b SE: stndrd error of the men. c p: significnce. NS: not significnt (p > 0.05). +: p < d Crcsses fulfill ll the bove requirements. other stress sitution ( reduced pen spce) but the uthors concluded tht it ws not ssocited with chnges in feeding behviour but with socil stress. Irrespective of the oestrus presence t slughter, 87.5% of the gilts studied were suitble for Teruel hm. Similr results were reported by Ltorre et l. (2008) who found tht 84.2% of gilts slughtered t 130 kg BW were suitble. The influence of the presence of oestrus t slughter on met chrcteristics of gilts ws scrce (Tble 3). Met prmeters (color, wter holding cpcity nd tenderness) were similr to those showed by Ltorre et l. (2009b) for similr gilts slughtered t 130 kg BW nd lso intended for dry-cured hm. Possible differences in met between O nd NO gilts were expected for ph, temperture or DFD/PSE met incidence becuse oestrus is stressful to the gilt. A mrked increse in socil ctivities ws demonstrted in gilts in oestrus which includes snout contcts between pigs, no-genitl sniffing, flnk nosing nd mounting (Pedersen, 2007). Met from O gilts tended to show higher lightness (p = 0.08) nd hd yellower (p < 0.01) nd more intense (p < 0.01) colour thn met from NO gilts. This could be relted to stress. It hs been widely reported tht stress sitution just before slughter results in low ph vlues t 45 min postmortem nd higher lightness nd moisture losses (Wrris, 2000). However, no nmed vrible ws ffected by tretment. In fct, lthough O gilts showed numericlly higher incidence of PSE nd DFD met thn NO gilts (20.8 vs 18.2% for PSE nd 16.6 vs 9.0% for DFD), the differences were not significnt (p>0.05). Also, wter holding cpcity ws not ffected by the presence of oestrus. Perhps, higher number of replictes per tretment might hve permitted the detection of significnt Tble 3. The effect of oestrus t slughter on met chrcteristics of gilts intended for dry-cured Teruel hm Oestrus No oestrus SE p b Mesurements postmortem t m. Semimembrnosus ph 45 min NS ph 24 h NS Temperture 45 min, C NS Mesurements t m. Longissimus thorcis Color L* * NS b* ** C* ** H* NS Wter holding cpcity, % Drip losses NS Thwing losses NS Cooking losses NS Totl losses NS Sher force, kg NS SE: stndrd error of the men. b p: significnce. NS: not significnt (p > 0.05). +: p < **: p < 0.01.

5 Oestrus t slughter on crcss nd met qulity in gilts 985 differences in some of these trits. In ddition, sensoril nlysis would be interesting becuse possible differences in flvour might be found. However, the «sexul odour in femles» is only hypothesis nd it hs not been demonstrted. Under our experimentl conditions, it my be concluded tht low proportion of gilts were in oestrus when femles were slughtered t 130 kg BW, lthough the result might hve been underestimted. The presence of oestrus in gilts t slughter hd scrce effect on crcss nd met chrcteristics. It did not ffect the proportion of PSE/DFD met but incresed yellowness nd intensity in met colour. It lso tended to reduce the proportion of suitble crcsses intended for PDO Teruel hm production becuse of lck of bckft depth. However, new trils (with higher proportion of replictes nd lso sensoril nlysis) would be needed before recommending the industry to void the slughter of gilts in oestrus if minimum covering ft is needed to improve the qulity of the end product. Acknowledgements This reserch ws supported by the Ministry of Science nd Technology (CDTI Project ). The uthors thnk L. Ariño nd stff of the slughterhouse for help with smple collection. References BOA, Orden del Deprtmento de Agricultur, Gnderí y Montes por l que se prueb el Reglmento de l Denominción de Origen Jmón de Teruel y su Consejo Reguldor. Boletín Oficil de Argón 29/07/1993. [In Spnish]. BRANSCHEID W., DOBROWOLSKI A., SACK E., Simplifiction of the EC-reference method for the full dissection of pig crcsses. Fleischwirtsch 70, CIE, Colorimetry: Officil Recommendtions of the Interntionl Commission on Illumintion. Publiction CIE No. 15 (E-1.3.1). Commission Interntionl de l Eclirge, Pris. CRPDO JAMÓN DE TERUEL, Dt bse. Consejo Reguldor of the Protected Designtion of Origin of Teruel hm. Avilble in [25 Jnury, 2010]. [In Spnish]. HONIKEL K.O., Reference methods for the ssessment of physicl chrcteristics of met. Met Sci 49, LATORRE M.A., MEDEL P., FUENTETAJA A., LÁZARO R., MATEOS G.G., Effect of gender, terminl sire nd ge t slughter on performnce, crcss chrcteristics nd met qulity of hevy pigs. Anim Sci 77, LATORRE M.A., GARCÍA-BELENGUER E., ARIÑO L., The effects of gender nd slughter weight on growth performnce nd crcss trits of pigs intended for drycured hms from Teruel (Spin). J Anim Sci 86, LATORRE M.A., RIPOLL G., GARCÍA-BELENGUER E., ARIÑO L., The increse of slughter weight in gilts s strtegy to optimize the production of Spnish high qulity dry-cured hm. J Anim Sci, 87, LATORRE M.A., RIPOLL G., GARCÍA-BELENGUER E., ARIÑO L., 2009b. The effect of gender nd slughter weight on loin nd ft chrcteristics of pigs intended for Teruel dry-cured hm production. Spn J Agric Res 7, LE-BELLEGO L., VAN MILGEN J., NOBLET J., Effect of high temperture nd low-protein diets on the performnce of growing-finishing pigs. J Anim Sci 80, MARM, Anurio de Estdístic Agrri. Dt bse. Ministerio de Medio Ambiente y Medio Rurl y Mrino. Avilble in [17 Jnury, 2010]. [In Spnish]. MORRISON R.S., HEMSWORTH P.H., CRONIN G.M., CAMPBELL R.G., The effect of restricting pen spce nd feeder vilbility on the behviour nd growth performnce of entire mle growing pigs in deep-litter, lrge group housing system. Appl Anim Behv Sci 83, PEDERSEN L.J., Sexul behvior in femle pigs. Hormones Behv 52, SAS, SAS Institute user s guide: sttistics. Sttisticl Anlysis Systems. Version 6, 4 th ed. Cry, NC, USA. SERRANO M., VALENCIA D.G., NIETO M., LÁZARO R., MATEOS G.G., Influence of sex nd terminl sire line on performnce nd crcss nd met qulity of Iberin pigs rered under intensive production systems. Met Sci 78, TUMMARUK P., TANTASUPARUK W., TECHAKUMPHU M., KUNAVONGKRIT A., Age, body weight nd thickness t first observed in crossbred Lndrce Yorkshire gilts, sesonl vritions nd their influence on their subsequent performnce. Anim Reprod Sci 99, WARRIS P.D., Met science: n introductory text. CABI Pub Inc, NY, USA. 310 pp. WHITTEMORE C., Cienci y práctic de l producción porcin. Ed Acribi. 800 pp. [In Spnish]. WYSZCECKI G., STILES W.S., Color science. Concepts nd methods: quntittive dt nd formul, 2 nd ed. John Wiley, NY. ZENG X.Y, TURKSTRA J.A., TSIGOS A., MELOEN R.H., LIU X.Y., CEN, F.Q., SCHAAPER W.M.M., OONK H.B., GUO D.Z., VAN DE WIEL D.F.M., Effects of ctive immuniztion ginst GnRH on serum LH, inhibin A, sexul development nd growth rte in Chinese femle pigs. Theriogenology 58,