Medycyna Wet. 62 (4), 411-415, 2006
Graczyk S., Kuryszko J., Orda J., Pliszczak-Król A., Zawadzki W., Janaczyk B.
Influence of feeding on the reactivity of lymphatic spleen structures in chickens
The study was carried out to evaluate the influence of feed restriction on the reactivity of lymphatic structures of the white spleen pulp in chickens; it lasted 49 days and used Leghorn breed chickens. During the last period of the study some of the chickens received the same diet as earlier, but were also subjected to skip-a-day regimen (chicken were deprived of feed 1 day and consumed feed on the alternate day). The material was taken on the 49th day of the experiment, after 14 or 21 days of feed restriction and body weight, relative weight of the spleen, Bursa of Fabricius and adrenal glands were evaluated. The number of germinal centres was analysed on the spleen sections as well as the reaction to acid phosphates (APh) which was evaluated in the mature and newly formed germinal centres (I and II type) and in the periellipsoidal (PEL) and periarterioral (PAL) lymphatic tissue. It was determined that feed access restriction causes not only a decrease in body weight but also, through its action as a stressor agent, leads to a decrease in the weight of the lymphatic organs (spleen and Bursa of Fabricius). The APh reaction analysis showed its diversified intensity in the investigated structures of the spleen. The feed deprivation period lasting 14 days resulted in a change in the mutual relations of both types of germinal centres (increase in the number of newly formed centres in comparison to the number of mature centres). This was accompanied by the activation of APh reactions in II type centres and in the PAL. The mature germinal centres (I type) and periellipsoidal lymphatic tissue (PEL) appeared to be less sensitive to the applied experimental factor. However, prolonging fodder access restrictions up to 21 days, led to a weakening of the APh reaction in all the examined spleen structures. The obtained results indicate the essential role that nutritional factors play in the lymphatic system’s reactivity, as well as displaying the complexity of the mechanisms of lymphatic system activity disorders in birds exposed to stressors.
Keywords: chickens, feed restriction, spleen