A. S. Abd El-Hakim and Hemat A. Abd El-Magied

[email protected]

Depart. of Poult. Nut., Anim. Prod. Res. Inst. Dokki, Giza, Egypt.

ABSTRACT

 Two hundred and ten unsexed Arbor Acres broiler chicks of 7 days old were used in the present work to investigate the effect of liquorice extract (sap) supplementation through different feeding systems on broiler performance during summer season.  Three different feeding systems and three levels of liquorice sap supplementation were used in the study. Thirty chicks were  fed on the 1st  feeding system (ad libitum with no liquorice sap supplementation)  and used as a control treatment. The other 180 chicks were distributed into  two different feeding systems;  2nd  feeding system: fasting for 6 hours daily (from 11:00 am to 5.00 pm), and 3rd  feeding system fasting for 12 hours daily (from 7:00 am to 7:00 pm). Chicks of the 2nd and the 3rd  feeding systems were fed on diets supplemented with three levels of liquorice sap (zero, 0.25% and 0.50%) in 2*3 factorial design. All diets contained 23% CP and 3100 Kcal ME anddiet contained ges of this study nditions 22% CP and 3000 Kcal ME/Kg for the first 7- days /Kg, for grower period (7-28 days) and 20% CP with 3200 Kcal ME anddiet contained ges of this study nditions 22% CP and 3000 Kcal ME/Kg for the first 7- days /Kg, for finisher periods (29-49 days).

Results obtained clear that using the 2nd feeding system during summer season improves significantly the chicks performance during grower and overall period. liquorice sap supplementation at either 0.25 or 0.50% to broiler diets significantly improved  the live body weight gain compared to those fed unsupplemented diet during the grower period. Supplementation of liquorice sap  at 0.25% or 0.50% significantly improved dry matter, crude protein and organic matter digestibility coefficients. Chicks reared under the 3rd feeding system significantly recorded the lowest rectal temperature. Also supplementation of liquorice sap decreased the  respiration rate than unsupplemented group. The lowest values of T3 and T4 hormones were recorded for chicks reared under the 3rd feeding system.

It could be concluded that using liquorice sap at either 0.25% or  0.50% as a supplement to diets of broilers reared under systems based on fasting for 6 and    somewhat 12 hours will improve the  growth performance, economical  efficiency and will act to decrease effects of heat stress during summer season.