Effects of light source on growth rate, behavior and biogenic amines in brain of broilers

Present study was conducted to observe the effect of incandescent and tluorescent light on the growth rate, feed conversion ratio, activity behaviors and cortical brain biogenic amines in broilers. The day old chicks were exposed to continuous incandescent light of 30–45 lux (group I) and tluorescent light of 35–40 lux (group II) for first three days. From day 4 to 7^th week, chicks in both of the groups were exposed to 60–80 lux and the photoperiod was maintained as Ll8: D6. The results indicated that the tluorescent light showed increment in growth rate and improved feed conversion ratio compared to the birds exposed to incandescent light. Crouching behavior in birds exposed to tluorescent light was higher (80–85%) compared to birds exposed to incandescent light (30–40%), whereas desultory activity was observed less (22–30% vs 45–52%) in birds exposed to tluorescent light compared to incandescent light. Serotonin, epinephrine and nor-epinephrine concentration in brain cortical region was significantly higher in birds exposed to tluorescent light indicating that birds experiencing a state of comfort compared to incandescent light.