Comparison between rosemary and commercial antioxidant blend on performance, caecal coliform flora and immunity in broiler chickens fed with diets containing different levels of poultry fat
2017
Khazaei, Roshanak | Esmailzadeh, Ladan | Seidavi, Alireza | Simões, João
The aim of the present study was to evaluate the effects of a commercial antioxidant blend (CAB; Loxidan ® TD100) and rosemary powder (RP) on performance, caecal microflora and humoral immunity of broilers fed with two different dietary poultry fat (PF) levels. Using a 3 × 2 factorial experiment, 180 male Ross 308 broiler chicks were assigned to 6 groups with 3 replicates per group, during a 42-day production cycle according to each following treatment: 3.5% (Treatment 1, T1) or 6% (Treatment 2, T2) PF without antioxidants; 0.1% CAB to 3.5% (Treatment 3, T3) or 6% (Treatment 4, T4) PF; and 0.1% RP added to 3.5% (Treatment 5, T5) or 6% (Treatment 6, T6) PF. All birds were vaccinated against Newcastle and infectious bursal disease virus. During starter, grower or finisher periods the weight gain was higher in T2 than T1. Feed efficiency was also improved during the first two periods at 6% PF level. On day 42, a lower number of Escherichia coli colonies on caecal contents were observed when 6% PF and CAB or RP were added. Plasma antibody titre against infectious bursal disease virus was higher in T2 than T1 and in groups T6 and T5 than T2 or T1. Both additives showed advantages, mainly in broilers fed with 6% PF.
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