The objective of this study was to investigate the effect of dietary different levels of feed restriction (FR) and probiotics (PR) (Lacobacillus lactis 2.5 x 108 CUF, Bacillus subtilis 1.8 x 109 CUF/g) on productive performance and economic efficiency for growing rabbits. A total number of 54 local growing rabbits,7 weeks old were weighed and divided into six dietary treatments of 9 rabbits each (5 males+4femals) The dietary levels of FR and PR included 3x2 factorial design as follow: T1: Rabbits fed basal diet ad-libitum without PR ,T2: Rabbits fed basal diet ad libitum and supplemented with 0.4g PR/ kg diet, T3 : Rabbits fed restricted diet by 120% of the energy requirements for maintenance without PR, T4: Rabbits fed restricted diet by 120% of the energy requirements for maintenance with 0.4g PR/kg diet, T5: Rabbits fed restricted diet by 140% of the energy requirements for maintenance without PR and T6: Rabbits fed restricted diet by 140% of the energy for maintenance with 0.4g PR/kg diet.
The results illustrated that dietary ad-libitum with 0.4 g PR/kg diet were higher significantly (P≤0.05) live body weight than other treatment groups. But, the restricted diets120 or 140 % of the energy for maintenance with 0.4g PR/ kg diet did not significantly (P≥0.05) as compared to the control diet. The rabbits fed ad-libitum and supplemented with 0.4g PR/kg diet returned to the first position of daily weight gain and significantly (P≤0.05) exceeded the other treatment groups. Regarding feed conversion, rabbits fed 120% of energy for maintenance with or without PR and those received ad libitum diet with 0.4g PR /kg diet improved significantly (P≤0.05) as compared to control diet. All dietary treatments tend to have greater gastrointestinal tract and cecum% than control diet. Conversely, the rabbits fed different treatments had (P≤0.05) the lowest values of lipase and protease except for the restricted diet120% of energy for maintenance without PR as compared to the control diet. The best value of EE was found for rabbits fed 120% of the maintenance energy with 0.4g PR/kg diet.
Conclusively, these results imply an important FR strategy by 120% of energy requirements for maintenance and supplemented with 0.4g PR/ kg diet, where feed conversion, performance index, E. coli /TBC ratio and economic efficiency improved under environmental Egyptian condition.