No abstract

Over the recent years, there has been an increasing interest in improving pork quality, which at present often fails consumer requirements. Nutritional regime is one of the key environmental factors affecting fattening results, slaughter value and meat quality. The technological and organoleptic properties of pork can be modified through feeding. Numerous studies have been conducted to determine the effect of diet composition on meat quality.Consumers prefer lean pork with a bright reddish-pink color, and they object to muscles that are too pale or too dark. An excess amount of meat juice in the package is also considered unacceptable.The role of vitamins, minerals and feed additives in animal nutrition is an important consideration. Animal production efficiency is dependent upon an adequate supply of nutrients and minerals. Nutrient availability from feedstuffs is a principal factor in improving animal productivity and health as well as meat quality. Organic forms of minerals have been proven to have high bioavailability.Since the magnesium content of standard diets satisfies the needs of animals, pigs are usually not provided with supplemental magnesium. However, research results show that magnesium compounds have a beneficial influence on selected aspects of pig production. Dietary magnesium supplementation positively affects the behavior of animals, decreases their stress sensitivity and improves pork quality by enhancing meat color, reducing drip loss and increasing acidity.

The experimental materials comprised cooked coarsely-ground and finely-ground sausages. The sausages were packaged in vacuum (V) and in modified atmospheres with the following composition: 20 % CO2, 80 % N2 (A1); 50 % CO2, 50 % N2 (A2); 80 % CO2, 20 % N2 (A3). The samples were stored at around 4 °C for 15 days. The measurements were repeated 8 times: at the completion of the production process and at 3-day intervals (day 0, 3, 6, 9, 12, 15) during storage. Drip loss changes in the package were analyzed during storage. Meat products were subjected to a sensory evaluation. The obtained results show that changes in the quality of meat products packaged under modified atmosphere are significantly influenced by the composition of the applied atmosphere. A wider range of quality changes were noted in vacuum-packaged products. Changes in the quality of modified atmosphere packaged products were less significant.

The aim of the study was to determine changes in nitrogen fractions during the ensiling of lucerne and red clover herbage in bales. Protein nitrogen and non-protein nitrogen compounds in herbage and silage were distinguished. Furthermore, buffer soluble nitrogen compounds (BSN) were determined and divided into buffer soluble protein and non-protein nitrogen (BSPN and NPBSN, respectively). In addition, peptide nitrogen and amino acid nitrogen were distinguished within the NPBSN fraction, while nitrogen compounds were divided into those of low solubility (NDIN) and completely insoluble (ADIN). The research findings confirmed the effect of a legume plant species on changes in the content of nitrogen fractions during the ensiling in round bales. The ensiling of lucerne herbage grossly decreased the protein nitrogen fraction while raising the total soluble fraction of nitrogen. Nitrogen in the form of soluble proteins, NDIN and ADIN was the least affected. The study demonstrated a different response of the two legume plant species to ensiling with respect to all fractions. A high proportion of protein nitrogen in round bale wilted red clover silage was accompanied by a large contribution of insoluble nitrogen fractions. A large share of the protein nitrogen fraction in red clover silage does not necessarily mean a higher nutritional value of the protein because it may contain a large amount of protein compounds that are non-hydrolysable by bacterial and intestinal enzymes.

Badano wpływ sezonu produkcji mleka na zawartość kwasów tłuszczowych w tłuszczu mlekowym. Materiałem badanym był tłuszcz mlekowy pozyskany metodą ekstrakcyjną z niepasteryzowanej 30 % śmietanki. Próbki do badań pobierano 12 razy w miesiącu przez cały rok. Profil kwasów tłuszczowych w tłuszczu mleka określano metodą chromatografii gazowej. Przeprowadzone badania wskazują, że sezon produkcji mleka wywiera istotny wpływ na profil kwasów tłuszczowych tłuszczu mlekowego oraz proporcje kwasów tłuszczowych nienasyconych (UFA, w tym MUFA i PUFA) do nasyconych (SFA) oraz zawartość kwasów tłuszczowych o działaniu hipocholesterolemicznym (DFA) i hipercholesterolemicznym (OFA).