Carcass quality, physico-chemical parameters, muscle fibre traits and myosin heavy chain composition of m. longissimus lumborum from Puławska and Polish Large White pigs Dorota Wojtysiak a, ⁎, Katarzyna Połtowicz b a Department of Reproduction and Animal Anatomy, Agricultural University of Krakow, Al. Mickiewicza 24/28, 30-059 Kraków, Poland b Department of Animal Genetics and Breeding, National Research Institute of Animal Production, Balice, Poland abstract article info Article history: Received 12 June 2013 Received in revised form 11 March 2014 Accepted 14 March 2014 Available online 20 March 2014 Keywords: Pigs Carcass quality Meat quality Myosin heavy chain Muscle fibres In 54 Puławska pigs and 60 Polish Large White pigs (PLW), slaughtered at 30 and 100 kg body weight, carcass and meat quality of m. longissimus lumborum were studied. Analysis revealed that in both examined body weight groups, hot carcass weight, carcass yield percentage, meat content, and weight of ham and carcass ham percentage were significantly lower and backfat thickness higher for Puławska pigs compared to PLW pigs, while PLW pigs exhibited significantly longer carcasses, greater loin eye area, and, in the case of lighter pigs, smaller proportion of loin in the carcass. Muscles of Puławska pigs, in the lighter group, had higher IMF content and a* value, while in the heavier group they exhibited higher pH 45 , pH 24 and a* values, lower L*, drip loss, WHC, and thermal loss compared with PLW pigs. PLW pigs had higher WB and hardness values and more glycolytic muscles characterised by higher TNF. © 2014 Elsevier Ltd. All rights reserved. 1. Introduction Pork is highly popular in Poland and its consumption represents about 60% of total meat consumption in this country. Saturation of the market with meat products causes that consumers are increasingly demanding higher quality. For many years high carcass lean content has been one of the main targets of pig breeders. On the other hand, such a heavy emphasis on animal production has also affected meat quality. The lower quality of meat from highly productive pigs is due to frequent quality defects associated with excessive exudation of meat juices, and the decreased amounts of intramuscular fat (Kim et al., 2008; Park, Kim, Lee, & Hwang, 2007; Serra et al., 1998; Wood et al., 2004). In large-scale commercial farms, however, the high meat content in pigs together with high production intensity have a positive effect on reducing animal maintenance costs and the price of the end product. At the same time, an increasing group of consumers are looking for high quality, often regional meat products obtained from animals maintained under less intensive conditions. Previous studies showed that the native and local pig breeds have interesting meat quality com- pared to improved pigs (Bocian et al., 2012; Fortina et al., 2005; Jiang, Zhu, Li, & Li, 2012; Renaudeau & Mourot, 2007). Moreover, these animals represent a valuable genetic reserve to utilise for recovering some properties of meat, which have been lost in modern breeding as a result of intensive selection. Of the Polish native breeds of pigs (Złotnicka Spotted, Złotnicka White, Puławska), the latter is the oldest, has the largest population and is one of greatest economic importance. Puławska pigs have a gentle disposition, are undemanding in feed, and show good fertility, prolificacy and maternal responsiveness (Szyndler-Nędza, Blicharski, & Bajda, 2008). They adapted very well to local, often extensive conditions of management without losing valuable traits inherited from their ancestors, such as resistance to disease and stress. For these reasons, Puławska pigs can and in many cases are successfully kept in organic farms (Blicharski, 2001; Kasprzyk & Walkiewicz, 2004; Kondracki, 1999; Szyndler-Nędza, Szulc, & Blicharski, 2012). Today, the Puławska breed is a transitional form between fat and lean type pigs. The meat of these pigs is partic- ularly valuable in terms of flavour, quality and nutritive value (Florowski, Pisula, Adamczak, Buczyński, & Orzechowska, 2006) and, according to Blicharski (2001), it provides the perfect raw material for making unique regional products of high quality. In 2009, the Puławska breed was enrolled in Poland in the genetic resources conservation pro- gramme, the aim of which is to increase the population and to maintain productive traits at a constant level while keeping within-population diversity so as to prevent inbreeding from accumulating. It is well known that an important component in the quality assessment of meat, in addition to analysis of physico-chemical parameters, is to un- derstand muscle microstructure. Evidence from the literature (Chang et al., 2003; Gil et al., 2003; Kang et al., 2011; Ryu & Kim, 2005, 2006) Meat Science 97 (2014) 395–403 ⁎ Corresponding author. Tel.: +48 12 662 40 93; fax: +48 12 633 33 07. E-mail addresses: wojtysiakd@wp.pl (D. Wojtysiak), katarzyna.poltowicz@izoo.krakow.pl (K. Połtowicz). http://dx.doi.org/10.1016/j.meatsci.2014.03.006 0309-1740/© 2014 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Meat Science journal homepage: www.elsevier.com/locate/meatsci