The study was aimed to find out the effect of different light intensities (wattages) on weight gain, feed consumption feed conversion ratio, dressing percentage, mortality and abnormalities in broiler chicks. 120, one day old chicks were selected and divided randomly in four groups of 30 chicks each. The following light treatments were provided to the chicks of the Groups A,B,C and D. (A) 40 watt bulb at night and natural day light (B) 25 watt bulb at night and natural day light (C) 15 watt bulb at night and natural day light (D) Spot-lighted feeders with 5 watt bulb at night and natural day light. Each chick was given 0.8 sq. ft. floor space. Feeding and watering were provided ad.lib. under indentical managemental conditions.
Weekly data starting from 4th week onwards revealed that at 4th week of age there wa non-significant difference in weight gain, feed consumption and feed convertion ratio among the four treatment groups. Significant differences in weight gai and feed conversion ratio and non-significant differences in feed consumption were noticed among the groups at 8th week of age.
The results indicate that birds of Group A due to more activities under high wattage gained least weight i.e. 1.6937 Kg and sonsumed more feed i.e. 4.8017 Kg and showed poorest feed conversion ratio i.eo 2.84 as compared to the birds of rest of three groups, i.e. B, C and D. The birds of Group B gained less weight i.e. 1.7343 Kg, consumed more feed i.e. 4.7983 Kg and showed poorer feed conversion ratio i.e. 2.77 than the birds of Group C and D. The birds of Group C gained less weight, i.e. 1.8293 Kg consumed more feed i.e. 4.6733 Kg and showed poor feed conversion ratio i.e. 2.55 when compared with the birds of Group D but showed better performance tha the birds of Group A and B. The birds of Group D gained significantly more weight (P<0.05) i.e. 1.8567 Kg, at low feed intake i.e. 4.6510 Kg and showed significantly better feed conversion ratio (P<0.05) i.e. 2.50 as compared to the birds of Group A and B, as the light intensity (wattage) available to the birds of Group D was very low, hence there was less activity due to less movement, as compared to Group A,B and C. Therefore, the birds of Group D converted more available energy into weight gain and showed best performance as compared to other three groups i.e. A, B and C.
Dressing percentage recorded after 8th week of age was 61.85% 62.24% 62.86% and 63.11% for Group A, B, C and D respectively. A non-significant difference was observed among all the groups.
There was no mortality throughout the experimental period and apparently no considerable abnormality was observed.