Influence of Different Selenium Forms on Productive Performance and Pork Chemical Composition in Fattening Pigs

Selenium is an essential trace element fundamental to the nutritional physiology of both humans and animals. Its metabolism in swine is markedly influenced by the bioavailability and physiological effects of various organic and inorganic forms. A comprehensive understanding of these selenium sources is imperative for optimising swine productivity and enhancing meat quality traits. So, the objective of this study was to evaluate the effects of different selenium forms on productivity and meat quality in fattening pigs. A total of sixty 62-day-old pigs (Landrace × Yorkshire as the maternal line and Pietrain × Duroc as the paternal line) were individually weighed and randomly assigned to two dietary treatments (n = 30 pigs per group) across four replicate stalls. Over a period of 13 weeks, the pigs were fed ad libitum with a standard compound diet composed of wheat, barley, and soybean meal, which was supplemented with either 0.3 mg/kg of Na2SeO3 and 0.2 mg/kg of Se-methionine (SeI group) or 0.5 mg/kg of Se-methionine (SeII group). During the feeding trial, the following productivity traits were recorded: individual body weight, average daily gain (ADG), and feed conversion ratio (FCR). Muscle and fat characteristics in live pigs were measured using ultrasonic equipment (Piglog 105). After slaughter, samples were taken from the M. longissimus dorsi, between the 12th and last rib, for further analysis of selenium accumulation and chemical composition of the pork. Throughout the entire trial period, the weight, ADG, and FCR of the fattening pigs did not differ significantly between groups. However, the fattening pigs in the SeII group exhibited thicker fat thickness, while the SeI group had thicker muscles (mm) and a higher muscularity (%). When comparing selenium accumulation in the muscles, the SeII group showed higher concentration by 0.799 μg/g dry matter (DM) when organic selenium was used, compared to the SeI group, which used a mixture of organic and inorganic selenium. Analysis of the chemical composition revealed that the SeII group's muscles had higher levels of DM, proteins, and ash, while the SeI group contained more fat. In conclusion, the recent study indicates that while the choice of selenium form significantly affects some meat quality traits and fat thickness in fattening pigs, it does not have a significant impact on overall productivity.