In order to investigate the effects of organic acids, prebiotics and probiotics on broiler chickens, a total of 288 day-old male Cobb chicks were distributed in a completely randomized design according to a 2 × 4 factorial, consisting of two levels of crude protein (recommended or low (85% of recommended)) and a four feed additive programme. The basal diet without any feed additive served as control and the basal diet one of the following additives; organic acid, a prebiotic and a probiotic. Starter and finisher diets were offered from 1 to 21 and 22 to 42 d of age, respectively. Birds were reared in an open-sided house system under natural tropical conditions with the same housing and general management practices. Lowering dietary protein level significantly decreased bird performance throughout the experiment. Additives had no significant effects on body weight, body weight gain and feed intake. Dietary supplementation with the prebiotic resulted in significant improvements in feed efficiency during 22 – 42 d and 1 – 42 d of age. At 21 and 42 d of age birds fed diets containing the prebiotic had the longest duodenum villi compared to other treatments. Jejunum villi and duodenum and jejunum crypt depth were not influenced by additives. At 21 d of age the dietary addition of the prebiotic and organic acids significantly increased antibody titres against Newcastle disease compared to control group. It could be concluded that under condition of current study, the prebiotic affected performance, small intestinal morphology and immunity of broiler chickens significantly.
Effects of non-antibiotic feed additives on performance, immunity and intestinal morphology of broilers fed different levels of
Author: M. Houshmand, K. Azhar, I. Zulkifli, M.H. Bejo & A. Kamyab
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