Objective: To investigate the effect of antibiotics and/or probiotics on broiler performance, some serum metabolites, cecum microflora composition, and ileum histomorphology under the Egyptian conditions.
Design: Randomized controlled experimental study.
Animals: Two hundred forty 1-day-old Ross (308) chicks were reared till 35 days of age.
Procedures: The birds were randomly allocated into four main groups: a control diet without additives (CON); probiotic (Lactobacillus acidophilus) supplemented diet (PRO); antibiotic (Avilamycin) supplemented diet (ANT) and a mix group (AP) that received antibiotic in the diet form 1 to 4 days of age and treated during the rest of the experimental period with probiotics.
Results: Chickens fed on probiotic or antibiotic diets had linear improvement in live body weight (LBW) and feed conversion ratio (FCR) compared with the control group, while the best LBW and FCR were in the AP group. An improvement in the nutrient digestibility was observed in the probiotic added groups (PRO and AP). Serum cholesterol and low-density lipoprotein cholesterol contents decreased when antimicrobial (probiotic or antibiotic) supplementations were used, while there was an increase in high-density lipoprotein cholesterol contents, serum total protein, and albumin levels. Among all groups, cecum Clostridium perfringens and Escherichia coli counts decreased; however, there was an increase in Lactobacillus count compared to the control group. In probiotic supplemented groups (PRO and AP), a significant (P<0.05) improvement in ilea architecture.
Conclusion and clinical relevance: Using probiotic after initial treatment with an antibiotic in broiler diets had a positive effect on broiler growth performance, gut health (improved cecum microbial populations and ileum histomorphology), and nutrient digestibility.
Phytase dose effects in practically formulated diets that vary in ingredient composition on feed manufacturing and broiler performance
