Histochemical analysis of chicken meat: M. Korzeniowska and T. Smolinska

The aim of the study was an evaluation of the influence of chicken feed supplementation with plant oils contain high amount of polyunsaturated fatty acids on histochemical characteristics of meat. Chickens Vedetta were divided into three experimental groups and they were fed with feed DKA-SFA; control group and with the addition of rapeseed oil of 2.75% and vitamin E 0.015%, as well as of 8.25% of rapeseed oil and 0.03% vit. E. Two weeks before slaughter levels of added plant oils were adjusted to 5.0% in each experimental blocks. Samples were cut from randomly assigned chicken carcasses. M. pectoralis thoracica and M. pectoralis abdominalis breast, and M. iliotibialis thigh were used for trial. During microstructure analyses the number of muscles fibre, minimal diameter, area of muscles fibre and roundness ratio were measured. Measurements were done on 20 different places of the surface of the muscles with an enlarging ratio of 40x10 on the microscope Kontron Elektronik. Supplementation of 8.25% of plant oils to chicken feed caused significant increase of muscles fibre diameter. It was probably caused by muscles fibre hypertrophy phenomena. No significant differences in muscles fibre diameter were observed for smaller amount of supplemented oils. Countable number of muscle fibres was 1.5 times higher in thigh than in breast muscles. Breast muscles were mainly formed by fibres of 40 – 50 μm diameter. Thigh muscles were characterised by smaller diameter of muscles fibre (30 – 40 μm). Along with increasing of the addition of rapeseed oil to the chicken feed increase of fibres area and fibres diameter were observed. Moreover, connective tissue content was diminished. Histochemical analyses of chicken muscles proved that implementation of higher amount of rapeseed oil to the feed had a negative effect on the structure of muscle tissue, and it can be connected with decreasing of sensory and technological characteristics of chicken meat.