Effect of Adding Sodium Nitrate without or with some Feed Additives in Growing Rabbit Diets on: 2. Nutrients Digestibility, some Caecum Fermentation and some Blood Constituents

Abstract

Thirty, 14 weeks of age New Zealand White (NZW) rabbits with an average live body weight (LBW) of 2.0 Kg were divided into 10 similar groups (3 in each). The rabbits were housed in a separate cage (3 rabbits in each). Ten pelleted experimental diets were contained two levels of sodium nitrate (0 and 2%). However, the other four tested feed additives were sodium sulfate (0.2%), clay (2%), yeast (0.25 %) and prebiotic (0.2%). Diets refers to as R2, R3, R4 and R5 were without sodium nitrate, but with feed additives, sodium sulphate, clay, yeast and prebiotic, respectively. While, diets R6, R7, R8, R9 and R10 were with sodium nitrate and R6 without feed additives but R7, R8, R9 and R10 were with the same feed additives, sodium sulphate, clay, yeast and prebiotic, respectively. The DMI g/d was higher with feeding on R1 and R8 than feeding on the other diets, but the DM digestibility was higher with feeding on R1 and R7 than the others. The DCP % was higher with feeding on R1, R2 and R7, DCF with R2, R5 and R8, DEE with R1, DNFE with R1, R3, R4, R6 and R9, TDN % was higher with feeding with R1, DCPI g/d with R1, R5 and R7, TDNI g/d with R1, DE Kcal/Kg was higher with feeding on R4 and R9, DEI Kcal/d with R1 and R4, DEI/DCPI increased with feeding on R4, R6 and R9­. The effect of the feed additives, also showed that the total VFA increased (p < 0.05) without feed additives or with added Na2SO4 or clay (2.85, 2.98 and 2.63 ml. eq/100ml, respectively) than added prebiotic (2.37 ml. eq/100ml). The highest values were observed with feeding on R1­ (3.3 ml. eq/100ml), R2 (3.07 ml. eq/100ml) and R7 (2.90 ml. eq/100ml). The highest values of NH3 concentrations were observed with feeding on R3 and R8 diets (32.20 and 32.85 mg/100ml respectively) than the feeding on the other experimental diets. There was no significant effect on the blood constituents as the effect of the experimental diets. The glucose concentration was higher (130 mg/100ml) with feeding on R9 than other diets. Protein concentration was higher with feeding on R4 or R10 (6.73 and 7.00 g/100ml, respectively) than the others. Urea - N concentration was the highest with feeding on R7 (60.83 mg/100ml), while the creatinine concentration was increased (2.60 mg/100ml) with feeding on R9 compared with the other diets. The foregoing results, it was clear that the DCPI g/d was higher with feeding on R1, R5 and R7, TDNI g/d was higher with R1, DE Kcal/Kg was higher with feeding on R4 and R9, DEI Kcal/d with R1 and R4, DEI/DCPI increased with feeding on R4, R6 and R9­.