Z. Kanacki

THE INFLUENCE OF LONG TERM SOUND STRESS ON HISTOLOGICAL STRUCTURE OF BROILER'S ADRENAL GLANDS

The aim of this paper is to examine the effect of different sound stress duration on adrenal gland of broiler chickens of different age. The experiments were conducted on 90 HYBRO broiler chickens, divided into nine groups (each group consisting of 10 birds) by different age and lenght of sound stress duration. The chickens were exposed to sound stress in sound attenuated building using a fire alarm bell (95 dB) for stress sessions lasted 120 min every day. The histological structure of adrenal gland was analyzed by light microscopy. The results indicate that adrenal gland is sensitive on this kind of stress and sound as stressor could introduce organism in stress reaction. Adrenal glands of broilers exposed to sound stress characterized by marked hyperemia, hypertrophy of interrenal cells, smaller affinity for staining of chromaffin cells compared with control groups. According to our results, degree of histological changes of adrenal gland under the influence of sound stress depends on the length of exposure and age of chickens.

Effects of Fullerenol C60(OH)24 Nanoparticles on a Single-dose Doxorubicin-induced Cardiotoxicity in Pigs: An Ultrastructural Study

Abstract Cardioprotective effects of fullerenol C60(OH)24 nanoparticles (FNP) were investigated in pigs after a single treatment with doxorubicin (DOX). Semithin and ultrathin sections of myocardial tissue routinely prepared for transmission electron microscopy were analyzed. Extensive intracellular damage was confirmed in cardiomyocytes of DOX-treated animals. By means of ultrastructural analysis, a certain degree of parenchymal degeneration was confirmed even in animals treated with FNP alone, including both the oral and the intraperitoneal application of the substance. The cardioprotective effects of FNP in animals previously treated with DOX were recognized to a certain extent, but were not fully confirmed at the ultrastructural level. Nevertheless, the myocardial morphology of DOX-treated animals improved after the admission of FNP. Irregular orientation of myofibrils, myofibrillar disruption, intracellular edema, and vacuolization were reduced, but not completely eliminated. Reduction of these cellular alterations was achieved if FNP was applied orally 6 h prior to DOX treatment in a dose of 18 mg/kg. However, numerous defects, including the inner mitochondrial membrane and the plasma membrane disruption of certain cells persisted. In FNP/DOX-treated animals, the presence of multinuclear cells with mitosis-like figures resembling metaphase or anaphase were observed, indicating that DOX and FNP could have a complex influence on the cell cycle of cardiomyocytes. Based on this experiment, further careful increase in dosage may be advised to enhance FNP-induced cardioprotection. These investigations should, however, always be combined with ultrastructural analysis. The FNP/DOX interaction is an excellent model for the investigation of cardiomyocyte cell death and cell cycle mechanisms.

Morphodynamics of embryonic development of skeletal musculature of broiler and layer chickens.

Eggs of broiler (Ross 308) and layer (Hy-Line Brown) chicken hybrids were incubated and tissue samples from the leg muscle (m. biceps femoris) and breast muscle (m. pectoralis profundus) were taken on embryonic days 9, 12, 15, 18 and 20, as well as on the first day post hatching. Histological preparations were made from the samples and the diameter of muscle cells, the volume density of connective tissue of muscles, and the nucleocytoplasmic ratio of muscle cells were recorded. Comparison of the diameter of muscle cells of leg muscle and the breast muscle between broiler and layer chicken during the period of late incubation and day 1 post hatching showed the diameter of the examined muscle cells was greater in layers, while the nucleocytoplasmic ratio of muscle cells was higher in broilers. No differences were established between these two strains in the volume density of connective tissue in both muscles examined. Such results are explained by the prolonged proliferation of myoblasts and delayed differentiation of muscle cells in broilers, which leads to a greater development of the skeletal musculature during the postnatal period. These processes in the embryonic period of development are the cause of differences in the morphodynamics of embryonic development of the skeletal musculature between broilers and layers presented in this paper.

Skeletal muscle characteristics of broiler chickens under modified incubation factors

Four groups of broiler chicken hybrid (Ross 308) eggs were incubated under different temperature and light conditions to assess the effects of both variables on musculature development. During the incubation, the first group was the control and the eggs were incubated at a temperature of 37.8 °C without light, the second group was exposed to increased temperature, while the third group was exposed to monochromatic green light. The fourth group of eggs was incubated under simultaneously changed temperature (according to the regime of the second group) and light (according to the regime of the third group) conditions. Tissue samples from the breast muscle (M. pectoralis superficialis) were taken on embryonic days 9, 12, 15, 19 and 20, as well as on days 1, 3, 7, 14, 21 and 42 after hatching. Histological preparations were used to assess muscle cell diameter, connective tissue volume density, and the nucleocytoplasmic ratio of muscle cells. Our findings indicate that thermal and light manipulations during incubation increase diameter and decrease nucleocytoplasmic ratio in postnatal skeletal muscle cells. No differences were found among groups with regard to connective tissue volume density. These results can be explained by the influence of thermal and light manipulations during incubation on prolonged myoblast proliferation, as well as on the greater postnatal development of skeletal muscle cells.

Circulation Index as a Quantitative Indicator of Angiogenesis in Chorioallantoic Membrane of Chicken Broilers

Summary Chorioallantoic membrane (CAM) is an extraembryonic membrane very frequently used for in vivo studies in various researches. Since researches require a fast method for quantifying the CAM angiogenic response, there is a need to develop a new precise and unbiased method of quantification of angiogenesis in CAM, which would be easy to perform and suitable for analysis of a large number of samples. The objective of this paper is to apply a new method of quantification of angiogenesis in investigation of the development of blood vessels in the CAM, in particular days of embryonic life considered essential for CAM development. The present research included 75 fertilized eggs of heavy hybrid Ross 308. CAM sampling for stereological analyses was in key phases of embryonic development, namely on the 12th, 15th and 19th day. The results of the present investigation show that the increase in embryonic age results in increase in circulation index, which is also an indicator of angiogenic processes developing in CAM. The lowest value of circulation index (0.1952) was recorded on the first sampling day (E12), while the highest value (0.2666) was recorded on the last sampling day (E19). This method may be applied in researching different factors which affect angiogenesis in CAM.

The Effect of Thermal Conditioning on Thyroid Hormones, Hatchability and Embrionic Mortality of Broilers during the Incubation Period

Summary The aim of this study was to examine the effect of thermal conditioning on the embryonic mortality, on the time of embryonic mortality, as well as to examine the effect of this temperature regime on hatching and on thyroid gland hormone levels. 400 fertile eggs, randomly divided into two groups with two repetitions, were used in this research. The control group was exposed to the standard temperature (37.8°C) through the whole embryonic development. The second group was incubated under the standard conditions as the control group, up to 15th day of embryonic development. During 16th, 17th and 18th day of embryonic development, the incubation temperature was increased to 39°C for 3 hours. From 19th day up to the end of the incubation period the conditions of incubation were identical to those of the control group. Results of this study show that the applied treatment leads to an increase of concentration of free T3 hormone on the day 19 of embryonic development, as opposed to a decrease of free T4 hormone in the embryo’s blood compared to the control group. The percentage of hatchability was 82.2% in the control group and 83.3% in the second group. The result shows that this way of thermal manipulation did not affect the embryonic mortality, which was 9.5% in the control group and 8.9% in the experimental group. It can be concluded that in this manner thermal conditioning may manifest the positive effect on the thyroid gland hormone levels without increasing embryonic mortality or disturbing the hatching percentage.

Influence of modified incubation factors on carcass characteristics of broiler chickens.

Incubation factors have a great influence on embryonic and postnatal development of broiler chickens. The aim of changing of incubation factors is to obtain the best possible production characteristics of broilers. In previous studies, it was determined that the application of monochromatic green light and thermal conditioning during incubation give the most satisfactory results on the postnatal development of chickens. This paper examines the effects of green monochromatic light and thermal conditioning during incubation on the carcass characteristics of broilers. In this paper four experimental groups were set. The first group was incubated under the standard conditions (37.8 ° C, no light). In the second group incubation temperature were increased, while in the third group incubation was carried out under green monochromatic light. In the fourth group temperature and light conditions of incubation were changed simultaneously. In all groups, changes of incubation factors were made at precisely defined time intervals. After hatching, chickens were grown up to day 42, when they were sacrificed and their carcass characteristics examined. Analysis of results showed that all treated groups have significant higher body weight, weight of drumsticks, thighs and toes. The fourth group have significant higher weight of breasts and wings compared to control group. These results are explained by the influence of the temperature and light changes during incubation on the increased proliferation of myoblasts, the growth of skeletal muscle cells, and the activity of satellite cells, which are reflected in changes of carcass characteristics.