Field study of monochromatic light effect on Bursal Body Weight ratio and spleen weight

Lighting is a critical parameter in poultry breeding controlling many behavioral and physiological functions effectively. Measuring bursa of fabricius as the most important lymph node of the birds and setting the ratio of the bursa weight to the total body weight are also important parameters to assess the health and functionality of the immune system. To do so, 34700 day-old chicks were selected from a 26-week Ross 308 breeder farm randomly. The chicks were free from congenital mycoplasma and salmonella infections. They were divided into three groups according to the capacity of the poultry house randomly. The only difference among the groups was the lighting wavelengths. On days 1, 24 and 46; 10 chicks were weighed in gram and euthanized each time; following the bursa of fabricius and spleen was weighed separately in 0.001 g to make the ratio of it with the total body weight. In case of measuring the spleen, there was no significant difference between the green and yellow lights in day 24 but both were less than the blue one while in day 46, there were no significant differences (P>0/05) among the groups. In day 24, the weight of bursa of fabricius was not significantly different between the yellow and green lights but both were more than the blue light; also, it was true for the ratio of bursa of fabricius weight to the total body weight. In day 46, the analyses indicated that there were no significant differences (p>0.05) in the ratio among the groups but the total body weight of the chicks breeding in blue light was a little more than the green one.