الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 100 |  |  |
| | | from | 100 | | |
Abstract
The current study was performed at a private commercial broilers farm located in Samhoud, Aboutisht, Qena, Egypt throughout 5 successive weeks of season 2018 from July to August. The experiment was designed aiming to investigate whether Cre-AMINO supplementation (either at 0.6 or 1.2 g/kg diet) can overcome the adverse effects of dietary energy reduction (lower by either 50 or 100 kcal/kg than the standard commercial diet) on the productive performance, carcass and blood characteristics as well as economic efficiency of broiler chicks. A total number of 630 one-day old unsexed Arbor Acers chicks, were randomly distributed into 7 equal treatments with similar average body weight, each of these groups was divided into three replicates with 30 birds each, they were reared up to 35 days. The assembly of each pen included a bell drinker and tube feeder as well as provided an appropriate heat and ventilation. Birds were offered feed ad libitum, and clean fresh water was also available all over the experimental period. A constant illumination of 24 h of light for the first week of age was provided, then 23 h of light and one hour of dark for the rest of the experimental period. The studied dietary treatments were distributed on 7 experimental groups: the control basal diet (included the commercial standard ME containing 3050 and 3150 kcal/kg during starter and finisher period, respectively), the next three diets contained ME reduction by 50 kcal/kg in each growing period than the control diet and supplemented with either 0, 0.6 or 1.2 g/kg Cre AMINO, whereas the last three diets contained ME reduction by 100 kcal/kg than the control diet either with 0, 0.6 or 1.2 g/kg Cre-AMINO supplementation. The most important results obtained from this study could be summarized in the following points: 1- The group of birds received diet lower by 50 kcal ME/kg and supplemented with 1.2 g/kg Cre AMINO had significantly the highest final BW at 35 days of age with 2.4% higher than the control group, followed by those fed diet of -50 kcal ME/kg and supplemented with 0.6 g/kg Cre-AMINO which recorded 0.87% improvement compared to the control group, on the other hand, reducing ME of experimental diets by 100 kcal/kg than the control diet with either 0.6 or 1.2 g/kg Cre-AMINO supplementation resulted in significant decrement in final BW compared with the control group by 7.8 or 6.2%, respectively.
2- Exactly the same trend was observed for BWG, where the highest BWG was obtained by birds fed diets decreased in ME by 50 kcal/kg with 1.2 g/kg Cre-AMINO supplementation (with 2.5% higher than the control group), while the group of -50 kcal ME/kg and supplemented with 0.6 67 g/kg Cre-AMINO had an intermediate BWG value (with only 0.93% improvement compared with the control group), but those received diets reduced by 100 kcal ME/kg and supplemented with either 0.6 or 1.2 g/kg Cre-AMINO recorded significantly the lowest values of BWG compared with the control group (with 7.9 or 3.5% reduction, respectively).