EVALUATION OF USING PROPIONIC ACID AND LIVE YEAST IN DIETS LOW IN PROTEIN AND ENERGY ON BROILER PERFORMANCE

Abstract

The aim of the present study was to determine the effect of dietary supplementation of either propionic acid (PA), live yeast (Saccharomyces cerevisae) (Sc) or their combination on the performance, carcass characteristics, some blood traits and economical efficiency (EEf) of broiler chicks. Two hundred and fourty unsexed day-old Cobb commercial broiler chicks were distributed randomly into eight treatments, each having three replicates of 10 chicks each. Eight dietary treatments were conducted including, (T1) control group which were fed the basal diet, (T2) control +0.2% (PA), (T3) control + 0.2% (Sc), (T4) control + (0.2% PA + 0.2% Sc), (T5) Control – low by 1.5% protein and 200 Kcal ME /Kg (LPLE), (T6) LPLE + 0.2% (PA), (T7) LPLE + 0.2% (Sc) and (T8) LPLE + (0.2% PA + 0.2% Sc). Results showed that birds fed diets with all additions achieved higher body weight gain BWG compared to control or LPLE. Results of feed intake (FI) showed significantly (P≤0.01) higher values in group T4 compared to all treatments. While, the lowest feed intake (P≤0.01) values were in groups T5, T6 and T7 compared to control. Feed conversion ratio (FCR) improved in all supplemented diets compared to those without supplementation. No significant effect was observed in the average values of giblets (liver, heart, gizzard), and abdominal fat, while all additions significantly (P≤0.01) increased the dressing percentage and total edible parts compared to control or LPLE. Dietary supplements of either PA, Sc or (PA + Sc) increased RBCs, Hb, PCV, WBCs, as compared to control group, but LPLE with different supplements insignificantly affect all hematological parameters as compared to LPLE. Total protein and globulin were significantly (P≤0.01) increased by using all supplements compared to control or LPLE. Total cholesterol and total lipids significantly (P≤0.01) reduced of the chicks fed supplements compared to control or LPLE. Addition of PA, SC and combination of them had significantly (P≤0.01) higher ND titers than control or LPLE. Addition PA, Sc and combination of them to LPLE recorded the best values of (EEf) and (REEf) compared to the other groups. In conclusion, the addition of PA or Sc either alone or in combination to LPLE broiler diet, could improve the performance, carcass characteristics and some blood traits and enhanced the immunity and proved to be a good substitute to antibiotic growth promoters in improving the performance of broiler chicken.