Effect of dietary conjugated linoleic acid and monounsaturated fatty acids on productive, carcass and meat quality traits of pigs Diana Martin a , Elena Muriel a , Elena Gonzalez b , Javier Viguera c , Jorge Ruiz a, ⁎ a Tecnologia de Alimentos, Facultad de Veterinaria, Universidad de Extremadura, Avda. Universidad s/n, 10071 Caceres, Spain b Producción Animal, Escuela de Ingenierias Agrarias, Universidad de Extremadura, Ctra. Caceres s/n, 06071 Badajoz, Spain c Imasde Agropecuaria, S.L. C/ Nápoles 3, 28224 Pozuelo de Alarcón, Spain Received 12 June 2007; received in revised form 13 November 2007; accepted 5 December 2007 Abstract Three levels (0, 1 and 2%) of conjugated linoleic acid (CLA) were combined with two levels (low and high) of mono- unsaturated fatty acids (MUFA) for pig feeding. Productive, carcass and meat quality traits were studied. Large White ♂ × Landrace × Large White ♀ gilts (n = 288) weighting 70 kg were randomly allotted to 6 different feeding treatments and fed to a final average weight of 107 kg. Loins were taken from 48 animals (8 animals randomly selected from each treatment). No differences due to dietary CLA, MUFA or CLA×MUFA interaction were found on average daily gain, average daily consumption, feed conversion ratio, carcass yield, backfat thickness, loin weight, loin pH and loin colour. A significant increase in intramuscular fat content ( p =0.010) and in saturated fatty acids (SFA) ( p b 0.001), and a decrease in MUFA ( p = 0.001) and desaturase indices were found as consequence of dietary CLA, regardless the MUFA level. Therefore, dietary CLA, MUFA and their interaction did not influence productive and carcass traits of pigs. However, the use of CLA for swine feeding increased the intramuscular fat content and modified the fatty acid profile, regardless the MUFA level of the diets. © 2007 Elsevier B.V. All rights reserved. Keywords: Conjugated linoleic acid; MUFA; Pig; Fatty acid profile; Meat quality 1. Introduction Dietary supplementation with conjugated linoleic acid (CLA) has gained an increasing attention in the field of swine production last decades. CLA has been pointed out as an effective tool for improving productive and meat quality traits such as growth rate, feed conversion ratio (FCR), average daily gain (ADG) or intramuscular fat content in swine. Nevertheless, contradictory effects have been found in different studies concerning CLA-fed pigs (reviewed by Dugan et al., 2004). CLA supplementation has been also suggested as a potential strategy for obtaining meat and meat products enriched in CLA, since accumulation of CLA isomers in tissues from CLA-supplemented pigs has been reported in several studies (reviewed by Schmid et al., 2006). On the other hand, it is well known that CLA feeding leads to modifications in the fatty acid profile of different tissue lipids, increasing the proportion of saturated fatty acids (SFA), while decreasing that of monounsaturated fatty acids (MUFA) (reviewed by Dugan et al., 2004). This is a positive effect from a technological point of Available online at www.sciencedirect.com Livestock Science 117 (2008) 155 – 164 www.elsevier.com/locate/livsci ⁎ Corresponding author. Tel.: +34 927 257123; fax: +34 927 257110. E-mail address: jruiz@unex.es (J. Ruiz). 1871-1413/$ - see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.livsci.2007.12.005