Justyna Batkowska

Quality of Laying Hen Eggs During Storage Depending on Egg Weight and Type of Cage System (Conventional vs. Furnished Cages)

Abstract The aim of the study was to demonstrate the relationship of egg weight and egg quality traits with storage time and type of cages in which the laying hens were kept. The material consisted of 960 eggs from same age Hy-Line Brown hens kept in conventional and furnished cages at the same time in one building. The eggs were randomly collected, sorted by weight (S, M, L and XL), and stored under controlled temperature and humidity conditions. All eggs were weighed on days 1 (day of laying) and 28 of the experiment. During the same time they were candled to determine depth of the air cell, and 60 eggs from each subgroup were chosen to evaluate quality traits (egg weight and egg specific gravity), shell characteristics (shell strength, weight, thickness and density), and interior quality of eggs (albumen height and pH, yolk colour, weight and pH). The eggs (especially those from the heavier weight classes, XL and L) from hens reared in furnished cages were characterized by significantly smaller quality changes (egg weight loss, yolk proportion, albumen height, Haugh units) due to storage time in relation to those from hens kept in conventional cages. This fact could point to their better suitability for consumption. In addition to the housing system, changes occurring in eggs during storage should also be considered in terms of their weight class. Economically important egg traits (e.g. egg weight, shell strength) were better in eggs from furnished compared to conventional cages.

Slaughter traits and skin colour of newly crossed chicken broilers dedicated for extensive rearing system as a criterion of product identification and meat quality

Abstract The influence of genotype, rearing conditions (intensive vs. extensive) and fattening duration (9 vs. 12 weeks) on slaughter traits of chicken broilers including skin colour and meat quality were evaluated. The Cobb chickens with hybrids (C × GP or C × Sx) from mating cocks for fast-growing broilers production (C) and Greenlegged Patrigenous (GP) or Sussex (Sx) hens were compared. The evaluation of meat technological indices involved pH and electrical conductivity (EC), water-holding capacity, drip loss and cooking loss measurements. Shape and colour of carcasses skin allow to distinguish different genetic groups of chickens without optical instruments to constitute a marker allowing the identification of carcasses from extensively reared broilers. For slow-growing chickens, carcass traits such as better skin and meat colour saturation, more balanced and lower EC and pH were recorded. Variability of meat quality traits resulted from various genotypes, age and the interaction between the two factors.

Impact of lymphocyte culture media on the number of metaphases and chromosome band resolution

A special type of differential staining of chromosomes is replication banding. This staining technique reveals the band pattern characteristic of each homologous pair of chromosomes, which is a reflection of heterogeneous euchromatin structure. Banding enables identification of homologous chromosomes and detection of chromosomal aberrations, both structural and numerical. Slide preparation requires knowledge of many techniques, and the procedure is often different for each laboratory. The aim of the study was to determine the effect of selected media for lymphocyte cultures on the number of metaphases and the band resolution of chromosomes. The study was carried out using cell cultures from whole peripheral blood. The slides were stained by the GTG method. After their removal from the water bath they were immersed in trypsin solution, then rinsed in PBS solution and stained in Giemsa solution. After staining they were rinsed again and left to dry. The study confirmed the effect of selected commercially available cell media on the number of metaphases and band resolution of chromosomes, which have not previously been described. In all of the tests performed, the cell culture, fixation, slide preparation (automatic method), staining, and number of reagents were identical.