Slaughter traits of dual purpose (meat-fat) pigs derived from current rearing on small-scale farms

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1 Animal Science Papers and Reports vol. 24 (2006) Supplement 1, 2733 Institute of Genetics and Animal Breeding, Jastrzębiec, Poland Presented at the Conference Genetic and Breeding Research on Pigs with Special Reference to Indigenous Breeds organized to commemorate the 10 th anniversary of the death of Professor Stefan Alexandrowicz 2021 October 2005, Poznań, Poland Slaughter traits of dual purpose (meatfat) pigs derived from current rearing on smallscale farms Karol Borzuta, Eugenia Grześkowiak, Jerzy Strzelecki, Dariusz Lisiak, Janusz T. Buczyński Meat and Fat Research Institute in Warsaw, Raw Materials and Engineering Unit, Głogowska 239, Poznań, Poland Slaughter evaluation was performed on 168 porker carcasses from 90 purebred Puławska pigs (Pul) and 78 Pul Polish Landrace (Pul PL) hybrids. All animals were derived from smallholder farms, Lublin region. It was found that the hybrids were characterized by 3.7 per cent points (pp) higher meat content of carcass and smaller subcutaneous fat than the pure Pul porkers. Normal meat was recorded in 75% carcasses of hybrid porkers, whereas in P pigs the respective value was 87.2%. KEY WORDS: carcass / hybrid pigs / meat faults / porkers / slaughter value Currently, commercial pig production is dominated by fatteners of the meat type. The introduction into commercial production of breeds characterized by high meat content, e.g. Hampshire, Pietrain or their crosses as well as imported hybrid pigs contributed to a significant increase of meat content of carcass and reduction of carcass adiposity [Grześkowiak et al. 2002, Borzuta et al. 2003, Krzęcio et al. 2003, Lisiak and Borzuta 2003]. 27

2 K. Borzuta et al. Dual purpose (meatfat) pigs constitute a small proportion of all slaughtered pigs and can be found only in certain regions of Poland, primarily in Lublin, Świetokrzyskie and Podkarpackie provinces. The raw material of this sort is sold to, among others, Italian and Spanish companies for the manufacture of fermented hams. Puławska pigs represent a typical example of the abovementioned type of animals and occur mainly in the region of Lublin, where they are also bred [Bzowska et al. 2003]. However, animal selection and proper feeding have elevated the meat content of Pul pig carcass and in consequence the mean meat content in boars derived in 2002 from the Regional Animal Breeding Centres reached 56.8% and that of sows 54.9%. According to Kamyk et al. [2001], in years the meat content of carcass of Pul pigs increased by 4.13 per cent points (pp) whereas the thickness of backfat decreased by 7.6 mm. Nevertheless, there are still numerous farms in this country where Pul pigs are still fed traditional carbohydraterich diets. Their carcasses contain more fat and correspond to the dualpurpose type. The aim of investigations presented here was to compare the slaughter traits of the pure Pul pigs with those of Pul Polish Landrace hybrids derived from the current commercial smallscale farms. Material and methods The material comprised 168 porkers, including 90 of the Puławska pure breed (Pul) and 78 upgraded with the Polish Landrace (Pul PL). All animals were derived from smallholding farms in the region of Lublin. Meat content was determined of hot, hanging, left carcass sides, using the CGM apparatus. The thickness of backfat was measured on the back over the last rib, on the shoulder, and on the ham in points KI, KII, and KIII. Moreover, measured were the carcass length and width [Borzuta 1998]. After cooling, the carcasses were cut on the level of last rib, and height and width of longissimus dorsi (LD) muscle were measured in order to calculate the loin eye area [Borzuta 1998]. Fortyfive minutes after stunning, ph 45 was measured in the LD muscle at the last rib using the Radiometer PHM 80 phmeter equipped with a combined electrode. On the basis of the ph 45 measurements, the proportion of carcasses with meat quality defects was estimated as follows: ph 45 up to 5.8 PSE; ph 45 from 5.81 to 6.30 partly PSE, and ph 45 > 6.3 normal meat [Kauffman 1997, Kortz 2001, KoćwinPodsiadła and Krzęcio 2004]. Results were evaluated statistically calculating means and their standard deviations and identifying the significance of differences between means with the Tukey s test. In addition, correlation coefficients were calculated among selected slaughter traits [Stanisz 1998]. 28

3 Genetic and Breeding Research on Pigs with Special Reference to Indigenous Breeds Results and discussion Table 1 presents results of the evaluation of the slaughter value of porkers. The carcasses of hybrids (Pul PL) were characterized by better muscling and less fattening than those of purebreds (44.85% and 41.14% meat of carcass, respectively) KoćwinPodsiadła et al. [1993], Kulisiewicz et al. [1996]. Carcasses from the latter group were also found to have a significantly thicker backfat over the shoulder and on ham (KI and KIII) by 4.6 mm, 3.64 and 5.61 mm, respectively. Table 1. Mean indicators of carcass quality and standard error means (SEM) Trait Pure Pulawska breed Pulawska Polish Landrace hybrids SEM Hot carcass weight (kg) Meat content of carcass (%) A B 4.06 Backfat thickness (mm) over shoulder on the back on cross I (KI) on cross II (KII) on cross III (KIII) A A A B B 30, B Mean fom 5 backfat thickness measurements (mm) A B 6.48 Loin eye area (cm 2 ) Carcass length (cm) Carcass width (cm) AB Within rows means bearing different superscripts differ significantly at P In comparison with similar raw material of similar carcass weight but derived in year 1984 from the same Lublin region [Borzuta et al. 1986], porkers with the Pul breed share derived from small farms are now only less fattened as the backfat is by about 2 mm thinner over the shoulder, by about 6 mm thinner on the cross II and similar on the back. On the other hand, the mean meat content of carcass of that raw material was 41.1%, being similar to the Pul porkers analysed in this study and by 3.71 pp lower than in the Pul x PL hybrids. Studies conducted by Eckert and Blicharski [2001] on similar Pul PL hybrids, showed by 2.4 pp higher meat content of carcass and by mm thinner backfat over the last rib. However, those hybrids were lighter than those examined in the current study. In addition, the authors failed to identify significant differences in the carcass muscling and fattening between Pul pigs and Pul crosses with Polish Large White and 29

4 K. Borzuta et al. PL breeds. Thinner backfat in Pul x PL hybrids was also reported by Walkiewicz et al. [1994] who found the mean backfat thickness from five measurements to reach 26.1 mm, whereas in carcasses of similar hybrids examined in this study it was by mm thicker. The large area of the loin eye deserves special attention as it amounted to about 53 cm 2 (Tab. 1) in both compared groups. This is related to the high weight of the examined carcasses, uncommon in slaughter houses. Table 2. Mean physical traits of meat and share of carcasses with different meat quality Item ph 45 ph 24 EC 3h PSE meat (%) Partly PSE meat (%) Normal meat (%) Pure Pulawska breed Pulawska Polish Landrace hybrids Table 2 shows that in the examined population of Pul pigs, PSE meat was found in 5.98% of carcasses, while in the carcasses of hybrids only in 1.3%. This phenomenon indicates a clearly negative effect of environmental factors on meat quality as both the purebred Pul and the PL pigs are not genetically susceptible to stress [Koćwin Podsiadła et al. 1993]. Normal quality meat was recorded in 87.18% of Pul carcasses and in 75% of the Pul PL hybrids. Many more carcasses with PSE meat are recorded in other pig genotypes, e.g. in hybrids with the Pietrain pig the frequency of PSE meat varies from 8 to 25% of carcasses [KoćwinPodsiadła 1996, Rybarczyk et al. 2002]. Table 3 presents correlation coefficients among selected slaughter traits of the carcasses examined. A low and negative correlation was found between the carcass weight and meat content of carcass (r = 0.143) and a significantly higher between the carcass weight and the backfat thickness measured at different carcass points (r = from x to xx ). Also the highly significant correlation between the meat content of carcass and the backfat thickness deserves attention as it was found the highest on K II (r = 0.884). Summing up the results presented here on porkers derived from the current rearing on small farms in the region of Lublin, it can be concluded that the Pulawska x Polish Landrace hybrids were characterized by higher meat content of carcass and smaller fattness than purebred Pulawska pigs. In Pul PL hybrid porkers 75% of carcasses were found to contain normal meat, while in the pigs of the Puławska breed the respective per cent was

5 Genetic and Breeding Research on Pigs with Special Reference to Indigenous Breeds Table 3. Correlation coefficients between selected carcass traits Item Hot carcass weight (kg) over shoulder on back Backfat thickness (mm) on cross I (KI) on cross II (KII) on cross III (KIII) Hot carcass weight (kg) 0,328 x 0,439 xx 0,445 x 0,366 x 0,515 xx Meat content of carcass (%) 0,143 0,674 xx 0,820 xx 0,832 xx 0,884 xx 0,767 xx Backfat thickness (mm) over shoulder on the back on cross I (KI) on cross II (KII) on cross III (KIII) 0,328 x 0,439 x 0,445 x 0,366 x 0,515 xx 0,586 xx 0,644 xx 0,723 xx 0,499 xx 0,586 xx 0,871 xx 0,861 xx 0,725 xx 0,644 xx 0,871 xx 0,862 xx 0,836 xx 0,723 xx 0,861 xx 0,863 xx 0,782 xx 0,499 xx 0,725 xx 0,836 xx 0,782 xx x Significant at P xx Significant at P

6 K. Borzuta et al. 32 REFERENCES 1. BORZUTA K., 1998 Badania nad przydatnością różnych metod szacowania mięsności do klasyfikacji tusz wieprzowych w systemie EUROP. Roczniki Instytutu Przemysłu Mięsnego i Tłuszczowego. Rozprawy 35, 2, BORZUTA K., BORYS A., GRZEŚKOWIAK E., WAJDA S., STRZELECKI J., LISIAK D., 2003 Zmienność wartości rzeźnej i jakości mięsa tuczników ze skupu rynkowego 2002 r. Roczniki Instytutu Przemysłu Mięsnego i Tłuszczowego 40, BORZUTA K., MĄDEREK R., STRZELECKI J., CEJROWSKI K., 1986 Analiza wartości rzeźnej tusz wieprzowych tuczników ze skupu rynkowego. Cz. IV. Tuczniki rasy puławskiej, skład tkankowy i charakterystyka technologiczna półtusz. Gospodarka Mięsna 7, BZOWSKA M., PTAK J., KARPOWICZ R., 2003 Wyniki oceny trzody chlewnej w 2002 r. Krajowe Centrum Hodowli Zwierząt, Warszawa. 5. ECKERT R., BLICHARSKI T., 2001 Comparing the growth and slaughter value of Puławska gilts and barrows and their crosses with Polish Large White and Polish Landrace breeds. Annals of Animal Science Suplement 1, GRZEŚKOWIAK E., BORZUTA K., STRZELECKI J., WAJDA S., LISIAK D, 2002 Badania zmienności stopnia umięśnienia i otłuszczenia surowca wieprzowego w wybranych zakładach mięsnych kraju (Investigations on the degree of musculature and fat centent variability of pork raw material in some selected meat processisng plants in Poland). In Polish, summary in English. Roczniki Instytutu Przemysłu Mięsnego i Tłuszczowego 39, KAMYK P., WALKIEWICZ A., BAJDA Z., BABICZ M Population development and performance level of puławska pigs in Annals of Animal Science Supplement 1, KAUFFMAN R.G., 1997 Odkrycia dotyczące jakości mięsa u świń. Trzoda Chlewna 10, KOĆWINPODSIADŁA M., KRZĘCIO E Nowe trendy w badaniach jakości wieprzowiny (New trends and the porcine meat research a rewiew). In Polish, summary in English. Prace i Materiały Zootechniczne Zeszyt Specjalny 15, KOĆWINPODSIADŁA M., KURYŁ J., PRZYBYLSKI W., 1993 Fizjologiczne i genetyczne tło występowania wad wieprzowiny indukowanych stresem. Prace i Materiały Zootechniczne 44, KOĆWINPODSIADŁA M., PRZYBYLSKI W., KACZOREK S., KRZĘCIO E., ENGIEL M., 1996 Efekt krzyżowania dwu i trójrasowego świń z udziałem rasy wbp, pietrain i linii pbz23 w zakresie cech mięsności i jakości mięsa (The effect of two and three breed crossing with share of Polish Large White (PLW) Pietrain and Polish Landrace 23 line (PL23) on carcass and meat qulaity). In Polish, summary in English, Zeszyty Naukowe Przeglądu Hodowlanego KORTZ J., 2001 The chief defects of meat and methods of detection Polish Journal of Food and Nutrition Science 10/51, 3 Supl., KRZĘCIO E., SIECZKOWSKA H., ZYBERT A., ANTOSIK K., PRZYBYLSKI W., KOĆWIN PODSIADŁA M., 2003 Quality of raw material of twobreed fatteners originating from crossing of imported breeds. Annals of Animal Science Supplement 1, KULISIEWICZ J., SOKÓŁ J., REKIEL A., WIĘCEK J., 1996 Wyniki tuczu trzech typów mieszańców żywionych do woli mieszankami o zróżnicowanym poziomie energii, lizyny i aminokwasów siarkowych (The fattening results of three types sof crossbred pigs fed ad libitum diets with different levels of lysine, sulphuric amino acids and energy). In Polish, summary in English. Zeszyty Naukowe Przeglądu Hodowlanego 26, LISIAK D., BORZUTA K., 2003 Wyniki monitoringu mięsności tusz wieprzowych poddanych ubojowi w 2002 r. Trzoda Chlewna 2, RYBARCZYK A., KORTZ J., CZARNECKI R., PIETRUSZKA A., KARAMUCKI T., JAKUBOWSKA M., 2002 Normal and defective meat frequency in hybrid fatteners sired by Pietrain boars or by Pietrain Duroc line 900 boars.

7 Genetic and Breeding Research on Pigs with Special Reference to Indigenous Breeds STANISZ A., 1998 Przystępny kurs statystyki w oparciu o program STATISTICA PL na przykładach z medycyny. Startsoft Polska, Sp. z o.o., Kraków. WALKIEWICZ A., WIELBO E., STASIAK A., 1994 Prace badawcze dotyczące świni puławskiej. Przegląd Hodowlany 1, Karol Borzuta, Eugenia Grześkowiak, Jerzy Strzelecki, Dariusz Lisiak, Janusz T. Buczyński Cechy rzeźne świń typu mięsnotłuszczowego pochodzących z aktualnego chowu drobnotowarowego S t r e s z c z e n i e Dokonano rzeźnej oceny tusz 168 tuczników, w tym 90 rasy puławskiej (Pul) i 78 mieszańców rasy Pul z polską białą zwisłouchą (Pul PL). Zwierzęta pochodziły z chowu drobnotowarowego z rejonu lubelskiego. Mieszańce charakteryzowały się wyższą o 3,7 pp mięsnością i mniejszym otłuszczeniem podskórnym w porównaniu z tucznikami rasy puławskiej. Tusze z mięsem normalnym stwierdzono u 75% mieszańców i u 87,2% tuczników rasy puławskiej. 33

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