The aim of this study was to determine the possibility of using duckweed in sustainable livestock production and aquaculture. Duckweed is a small plant which grows in water and is exploited in biotechnology, dietetics, phytotherapy, and ecotoxicology. It is also used for biological waste-water treatment, and for biogas and ethanol production. This study provides the characteristics of duckweed and presents results indicating its applicability in livestock feeding. Duckweed is a rich source of proteins and amino acids, and contains many macro- and micronutrients as well as vitamins and carotenoids. Unfortunately, it accumulates considerable amounts of toxic metals and compounds from the aquatic environment, which may limit its use as a feed ingredient. Fresh or dried duckweed is willingly consumed by animals (poultry – laying hens, broiler chickens, ducks; cows, sheep, goats, swine, fish) and is a valuable protein source to them. It has been scientifically demonstrated that its use in moderate amounts or as a partial replacement of other protein feed materials, including soybean meal, has a beneficial effect on the productivity, fattening, and slaughter performance of livestock and poultry as well as on the quality of their meat and eggs. Research addressing duckweed use as a feed ingredient should focus on developing various growth media technologies, including the use of slurry digestate, to obtain high biomass yields. Another research direction should be to determine risks in the production chain (collection, processing), which limit its use in monogastric and ruminant diets.

ABSTRACT:The effect of feed additives: antibiotic (group C), probiotic (group E1) and prebiotic (group E2) on the results of fattening and selected slaughter and pork meat quality traits of two genotypes of pigs (PLW × PL) × BL and (PLW × PL) × Dur, gilts and hogs, was determined. The results obtained for the examined traits in the feeding groups under comparison were slightly differentiated. The growth rate and feed conversion differed between the genetic groups in favour of crossbred fatteners with the proportion of Dur breed (P ≤ 0.01). The mean backfat thickness from 5 measurements and loin "eye" area in fatteners derived from Dur sires as compared to hybrids coming from BL sires were significantly lower (P ≤ 0.01) while the length of carcass was higher (P ≤ 0.01). The gilts were characterized by better meatiness than boars: loin "eye" area, loin weight without backfat and skin, ham weight without backfat and skin differed on the level of P ≤ 0.05, and meatiness of carcass and meatiness of basic cuts at P ≤ 0.01. Significant (P ≤ 0.05) or highly significant (P ≤ 0.01) differences in the proportions of acids: C 18:2 , C 18:3 , C 20:4 , C 22:4 and PUFA in the lipid fraction of MLD were found between the feeding groups. The proportion of the above-mentioned acids was lower in group E2 and higher in group E1 as compared to C. The proportion of the acid C 18:1 was significantly higher (P ≤ 0.05) in group E2 as compared to E1. The demonstrated differences indicate the need of further studies in this respect. In pig fattening there is a possibility of effectively replacing feed antibiotics with other additives. The application of biostimulators -probiotic Bactocell or oligosaccharide Bio-Mos instead of the antibiotic flavomycin appeared to be favourable. From the production aspect it seems to be justified to supplement the feed rations for fatteners during the first stage of fattening with feed additives from the group of probiotics or prebiotics.

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.

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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). Keywords