Karolina Kot vel Ławecka, Dorota Banaszewska, Barbara Biesiada-Drzazga
Abstract. The aim of the study was to determine the effect of selected meat packaging systems on certain quality attributes based on the example of breast muscles of broiler chickens. The research material consisted of 120 breast muscles of Ross 308 broiler chickens slaughtered at 36 days of age. The muscles were divided into four groups of 30 each, including one control group. The other three groups were packaged individually in three different packaging variants in accordance with the procedures used at meat processing plants: MAP, on a shrink-wrapped EPS tray and a vacuum. Analyses were performed of the following physical characteristics in the control samples (day 0, before packaging) and experimental samples (after seven days of storage): pH, WHC, EC, drip loss, composition of the mixture in the case of MAP packaging and colour measurement in the CIE L*a*b* system. The meat packed using various systems undergoes some changes during storage. The research confirmed significant differences in the quality characteristics of meat packed by different methods after seven days of storage. Vacuum-packed chicken breast muscles had a lighter colour and the highest electrical conductivity. These muscles also showed a higher drip loss, which may be of importance in processing.
Abstract. The aim of the study was to analyze various mating systems, mating dates, and the number of matings applied for farmed American mink in relation to resulting litter sizes. The observations were carried out on yearling females of two color varieties, Perl (P) and White Hedlund (WH), as well as yearling males belonging to four color varieties, namely P, WH, White Regal (WR) and Black Cross (BC). The color of the males was chosen so as to easily discern, which male sired which litter and what was the litter size resulting from the particular copulation date. The breeders were mated according to various mating schemes. The analysis revealed that if two matings were the case, most embryos conceived on the first date died.
Urszula Kaczor, Maria Płotkowska, Elżbieta Martyniuk
Abstract. The aim of the study was to identify a potential occurrance of c.*1232G>A polymorphism in the 3'-UTR region of the myostatin gene (MSTN) in sheep of meat breeds: Pomeranian sheep, Suffolk and Berrichon du Cher. The populations of Suffolk and Berrichon du Cher breeds turned out to be monomorphic, whereas in the native Pomeranian sheep, the occurrence of polymorphism in the region of the MSTN gene was demonstrated. The Pomeranian sheep were characterized by a higher frequency of the mutated A allele (0.41), the frequency of genotypes AA and GA was 0.18 and 0.46 respectively. The effect of polymorphism c.*1232G>A on the body weight of ewes on the day of license has not been observed.