The Effect of organic and inorganic selenium on productivity and meat quality of fattening pigs

Abstract

Selenium has been established as an essential trace element that is important in many biochemical and physiological processes. Research has shown that the organic and inorganic forms of Se vary in tissue retention and that organic Se is deposited in greater concentrations in many tissues compared with inorganic Se (Behne et al., 2009; Juniper et al., 2009). Inorganic form of selenium has a role of prooxidant, but given in great quantities (< 5 mg/kg diet) can be very toxic (Todorovic et al., 1998). Selenium is a part of many hormones and enzymes, a part of the ferment of glutathione peroxidase in particular, which forms complexes with peroxides and prevents the development of oxidative stress (Bertinato and Hidiroglou, 2007). Antioxidant vitamins are essential in the animal dief for normal health (Fiego et al., 2004). Supplementation of the swine diet with vitamin E during the growing and finishing periods may improve pork quality. Vitamin E is a potent antioxidant and has been demonstrated to decrease lipid oxidation, improve average daily gain and feed efficiency of pigs (Cannon et al., 1996). So the aim of this study was to determine the productivity, lean and fat thickness, amount of accumulated selenium and vitamin E concentration in M. longissimus dorsi of fattening pigs feeding diets supplemented with inorganic and organic selenium. Materials and Methods The pigs for fattening were kept in the stalls and its keeping condition accorded with the Council Directive 2008/120/EC of 18 December 2008 laying down minimum standards for the protection of pigs. The feeding trial was performed with sixty 62-d-old Landrace x Yorkshire (mother) and Pietrain x Duroc (father) pigs for fattening which were individually weighed and were randomly assigned to 5 dietary treatments with 4 replicate stalls of 30 pigs each. The pigs were fed for 13 weeks ad libitum with a standard wheat-barley-soybean meal compound diet (Control group) supplemented \vith 0.5 mg/kg Na2Se03 and 70 mg/kg vit. E and with 0.5 mg/kg Se-methionine and 70 mg/kg vit. E (Experimental group). The diet was formulated to meet the nutrient and energy requirements for pigs for fattening (NRC, 1998). The data recorded during the feeding phase were live weight (LW) at 62, 90, 118 and 150 day from the start of the study, average daily gains (ADG) and feed: gain ratio (F:G) during the periods 62-90, 90-118, 1 18-150 and from the start of the study (62-150). Before pigs slaughtering, fat thickness and muscularity (two measurements of fat thickness and thickness of the M. longissimus dorsi) was measured by ultrasound equipment ,,Piglog-105"(SFK Technology, 1991). At the end of the trial (150 days) from each group 8 pigs for fattening (8 pigs x 2 groups = total of 16 pigs) were selected and slaughtered according to standard procedures. The samples for the analysis of a, y tocopherols (vit. E) and selenium were taken from the M longissimus dorsi between 12 and last rib. The accumulation of Se was determined with the atomic absorption spectrometric method (Neugebauer et al., 2000) and vitamin E with the AOAC Official Method 975.43 by HPLC. Statistical analysis. Data were analyzed using one-way analysis of variance (ANOVA) with Statistica software package version 8.0 (StatSoft Inc., 2007). Means were compared with a PLSD Fisher's test. The differences between the control and experimental groups were considered to be statistically significant for P < 0.05. Results and disscussion The results of growth performance of pigs for fattening, fed wheat-barley-soybean meal compound diet supplemented with 0.5 mg/kg Se-methionine and 70 mg/kg vit. E, are presented in Table 1 and 2. [...].