This study aimed to explain the possibility of partial replacement of genetically-modified soybean meal (SBM GM) with pea seeds and rapeseed meal (RSM) in complete feed mixtures for growing-finishing pigs and to determine its impact on meat quality and health-promoting indices. The pigs (n = 50) were randomly divided into five groups, 10 animals each (gilts and barrows, 1:1, 3-breed: ♀ (landrace × yorkshire) × ♂ duroc), including the control group (C) and four experimental groups (E1, E2, E3, E4), and fed complete feed mixtures. The SBM GM was the only protein source in feed mixtures for control pigs. In feed mixtures for E1–E4 groups, it was partially replaced with pea seed doses of 5.0%, 10.0%, 15.0%, and 17.5% in groups E1, E2, E3, and E4, respectively. The feed mixtures were iso-energetic and iso-protein. After completed fattening, the animals were slaughtered. M. longissimus lumborum was sampled for analyses of the chemical and physical traits. The fatty acid profile determined in intramuscular fat (IMF) was used to compute the values of the health-promoting indices. The chemical and physical characteristics of meat were comparable in all groups. The study showed a dietetically-beneficial decrease in the values of atherogenicity index (AI), thrombogenicity index (TI), and saturation (S/P) in the meat of the experimental pigs vs. control group. The values of most of the analyzed quality attributes of pork justify using alternative protein sources as partial SBM GM replacers in diets for growing-finishing pigs in sustainable animal production.

Duckweed is a plant with high phytoremediation abilities, which is why it is used in the process of cleaning the aquatic environment. The present study aimed to determine the effect of various concentrations of pig slurry added to the growth media used to produce duckweed (Lemna minor) (laboratory Warsaw University of Life Sciences—SGGW) (experimental groups 1–9, pig slurry concentration (%): 1—2.00, 2—1.50, 3—1.00, 4—0.75, 5—0.50, 6—0.25, 7—0.12, 8—0.06, 9—0.03, control group 0—0.00). The contents of nutrients in the growth media could be classified as high (gr. 1–3), optimal (gr. 4–6), and deficient (gr. 7–9). Analyses were conducted for duckweed yield and growth medium parameters (pig slurry concentration, pH, salinity, temperature, TDS, and EC) on days 0, 10, 20, and 30 of the experiment. No growth or poor growth of duckweed were noted in groups 1, 6–9, and 0. In turn, satisfactory yields of duckweed green mass were recorded in groups 3–5, which allowed choosing them for further observations and analyses, including proximate composition (including protein content); contents of Ca, Mg, K, Na, Zn, Cu, Cd, Pb, Al, Cr, and α-tocopherol; and carotenoids—β-carotene, α-carotene, violaxanthin, zeaxanthin, lutein, amino acids, fatty acids as well as N-NH₄ and N-NO₃. The plant material had an acceptable proximate composition and nutritionally safe analyzed component contents. Appropriate, stable growth medium conditions allowed the production of satisfactory duckweed yields. The study results allowed us to conclude that it is feasible to obtain feed material meeting basic quality standards by maintaining a closed circuit of duckweed culture, and use in the agricultural environment is possible through harnessing pig slurry for its production and ensuring its optimal growth conditions.

Weakened growth and development of embryos as well as of fetuses or their organs (IUGR) show a relationship with increasing sow fertility. When aiming to increase birth weight in piglets and reduce within-litter variation in piglet body weight, efforts should be made to maintain a favourable maternal environment (uterus-placenta-embryo). Intrauterine undernutrition can be limited through the hormonal and/or nutritional treatment of pregnant sows. This has an effect on prenatal myogenesis, resulting in better development of skeletal muscles, higher birth weight of piglets, and progression in postnatal growth rate.

Piglet birth weight is determined by the maternal environment, intrauterine crowding, and nutrition, which influence embryonic and fetal survival and, as a result, fertility. The internal environment regulates prenatal myogenesis and muscle fibre number nutritionally and hormonally. The growth and metabolic differentiation of muscle fibres take place during the postnatal period. The effect of intrauterine undernutrition on myogenesis and on fetal growth and development (IUGR) is reflected in the low piglet birth weight and its high within-litter variation. Slaughter traits are determined by many factors, including genetic (breed), environmental (nutrition) and preslaughter handling. Slaughter traits and the physico-chemical and sensory characteristics of meat are dependent on prenatal myogenesis and neonatal weight. Optimized body weight of newborn piglets is conducive to improving quantitative traits (meatiness, fatness) and qualitative traits. However, slaughter traits are also influenced by many other differentiating factors, which is reflected in research results. Muscle fibres become metabolically differentiated during postnatal development, and one of the factors of large variation in pig meat quality traits is variation in the proportions of different fibre types in mature muscle. Considering the divergent opinions among scientists about the effect of prenatal myogenesis and piglet birth weight on slaughter value and pork quality, as well as the existence of areas that have received little investigation, it is justified to continue research in this area.

In an experiment with 56 pigs, the effects of feeding level and linseed oil supplement on fattening and slaughter parameters, the weight of internal organs, the concentration of hormones and indicators of protein and lipid metabolism, and the fatty acid profile of m. semimembranosus and backfat were investigated. During the growing period, all animals received a feed supplemented with 4 % linseed oil. At the end of the growing period (23–61 kg body weight), compared to semi-ad libitum fed animals, animals that were fed restrictively (25 % less feed) during this period were characterized by lower daily gains (P≤0.001), greater meatiness (P≤0.01), lower weight of internal organs, higher level of growth hormone (P≤0.05), lower levels of thyroid-stimulating hormone and blood urea nitrogen (P≤0.05), and dietetically more beneficial profile of fatty acids (more polyunsaturated fatty acids [PUFA]). During realimentation (61–104 kg body weight), when all animals were fed semi-ad libitum diets with 0 or 4 % linseed oil, daily feed intake and daily weight gains of the pigs that had previously been restrictively fed, were greater than in animals fed semi-ad libitum throughout fattening. Compensatory growth was found for the internal organs. Animals that received linseed oil diets throughout fattening were characterized during the finishing period by a higher rate of growth (P≤0.001), higher concentrations of triiodothyronine (T₃) and insulin (P≤0.05), and a greater proportion of n-3 PUFA in the fatty acid profile of m. semimembranosus and backfat (P≤0.001).