EFFECT OF LIGHT SOURCE AND DIETARY ENERGY LEVEL ON CARCASS CUTS DISTRIBUTION OF BROILER CHICKENS

The present trial aimed to study the effect of light source and dietary energy level on some carcass cuts distribution of male and female broilers. One hundred and eighty one-day-old, male and female, Hubbard broiler chicks, were distributed in a factorial design. Experimental treatments were assigned by applying 3 metabolizable energy (ME) levels [standard recommendation (SR); SR + 100 kcal/ kg diet and SR + 200 kcal/ kg diet, for both starter and grower feeding phases], and 2 light sources [fluorescent; light-emitting diodes, LED] in 6 treatments, 3 replicates per treatment and 10 birds / replicate. The results indicated that all composition parameters of breast, thigh and drumstick (skin and subcutaneous fats, muscles and bone percentages), were not significantly affected by different dietary energy levels, light sources or bird sex. Additionally, there were no significant differences between treatments on skin and subcutaneous (SC) fats distribution of carcass parts, but LED had increased fats percentages than fluorescent. In addition, this parameter increased with birds fed medium level of dietary energy than other treatments. Furthermore, there were no significant differences between fluorescent and LED treatments or bird sex on muscles percentage of carcass parts, but there were significant differences between dietary energy levels. In addition, chicks fed high dietary energy diets had significantly higher percentages of drumstick muscles. Likewise, there were no significant differences between treatments on bone percentages of carcass parts, but LED decreased total percentage compared with that of fluorescent. Also, mid and high dietary energy level decreased total percentage of bone distribution compared with that of the low dietary energy. Overall results of the present trial, declared that LED light source and low dietary energy had improved carcass composition compared to other treatments. Therefore, it could be advice to use LED lighting in farms to reduce costs of broiler production and to improve physiological status of birds.