Uticaj dugotrajnog zvučnog stresa na histološku građu nadbubrežne žlezde brojlera

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.Cilj ovog rada je da ispita uticaj različite dužine trajanja zvučnog stresa na histološku građu nadbubrežnih žlezda brojlerskih pilića u različitim uzrastima. Ogled je izveden na 90 HYBRO brojlerskih pilića, podeljenih u 9 grupa u skladu sa uzrastom i dužinom izlaganja stresu. Pilići su zvučnom stresu bili izlagani u zvučno izolovanim objektima uz korišćenje požarnog alarmnog zvona (95dB) u trajanju od 120 min svakog dana. Histološka građa nadbubrežnih žlezda je analizirana svetlosnim mikroskopom. Rezultati ukazuju da je nadbubrežna žlezda osetljiva na ovu vrstu stresa i da zvuk, kao stresor, može da uvede organizam u stresnu reakciju. Nadbubrežne žlezde pilića izlaganih zvučnom stresu karakteriše značajna hiperemija, hipertrofija interrenalnih ćelija, manji afinitet prema bojenju hromafinih ćelija u odnosu na kontrolnu grupu. U skladu sa ovim rezultatima, stepen histoloških promena nadbubrežne žlezde pod uticajem zvučnog stresa zavisi i od dužine izlaganja i uzrasta pilića

The effects of thermal and light exposure on the development of broiler chicken leg musculature

Modified incubation factors affect skeletal musculature development of broiler chickens during embryonic and postnatal periods of development. These changes appear to have great influence on the proliferation of myoblasts and muscle growth after hatching. In this study, the histomorphological and -morphometric parameters of broiler chicken leg musculature, after thermal and light treatments during embryogenesis, were examined. The applied treatments included thermal manipulation (exposure of fertilized eggs to increased temperature), light manipulation (exposure of fertilized eggs to monochromatic green light) and simultaneous thermal and light manipulations. Following the specific parameters that were observed, it was determined that in the late postnatal period of development, treated groups have a larger diameter and smaller nucleocytoplasmic ratio of muscle cells compared to those of the control group, in which fertilized eggs were incubated at a constant temperature of 37.8°C, without light. Diameter was increased by 4.20%, 3.77% and 4.55% on day 42 after hatching in thermal, light and combined thermal and light treated groups, respectively, compared to the control. The nucleocytoplasmic ratio was increased by 37.5% on day 42 after hatching in the control group compared to all treated groups. The volume density of the muscle connective tissue was approximately at the same level between the groups. It can be concluded that thermal and light treatments stimulate the proliferation of myoblasts and enhance development and growth of leg muscles in broiler chickens. [Projekat Ministarstva nauke Republike Srbije, br. TR 31033i br. OI173009