TY - JOUR T1 - Comparison of the Effects of Antibiotic Alternative Feed Additives on Prevention of Subclinical Necrotic Enteritis in Broilers TT - مقایسه اثرات افزودنی های خوراکی جایگزین آنتی بیوتیک در پیشگیری از آنتریت نکروتیک تحت بالینی در جوجه های گوشتی JF - rap JO - rap VL - 12 IS - 34 UR - http://rap.sanru.ac.ir/article-1-1147-en.html Y1 - 2021 SP - 11 EP - 20 KW - Necrotic enteritis KW - Organic acid KW - Phytogenic KW - Prebiotic KW - Probioticiotic N2 - Extended Abstract Introduction and Objective: Antibiotics have been widely used in animal production for decades to promote growth. Although there is a trend toward reducing antibiotics in diets and now in Europe new laws have been passed to ban their use. As a result, economically important diseases such as enteritis necrosis (NE), which is caused by Clostridium perfringens in chickens, have become more prevalent. The alternatives to antibiotic growth promoters could affect gut health and performance by their impact on intestinal microflora. The purpose of this experiment was to compare the efficacy of some feed additives as alternatives to antibiotic for preventing of subclinical necrotic enteritis in broilers. Material and Methods: The study was conducted using 336 one-day-old male broiler chicks in a completely randomized design with 7 treatments, 4 replicates and 12 chicks per replicate. The treatments included: 1) Negative control (NC, corn-soybean meal-based diet without any feed additive); 2) Positive control (PC, diet containing wheat and fish-meal without any feed additive); 3) Antibiotic (PC diet + zinc-bacitracin); 4) Probiotic (PC diet + probiotic); 5) Prebiotic (PC diet + prebiotic); 6) Phytobiotic (PC diet + phytobiotic); and 7) Organic acid (PC diet + organic acids). Results: The results indicated that addition of antibiotic or its alternatives to the PC diet did not affect average daily feed intake, average daily gain, feed conversion ratio and relative weight of internal organs (p>0.05). Evaluation of cecal bacterial population at d 41 showed that chickens were infected by subclinical necrotic enteritis. The count of Clostridium perfringens was significantly lower in broilers fed either phytobiotic or antibiotic than in broilers recieved either NC or PC treatments. Broilers fed probiotics, prebiotics or organic acid in their diet had lower counts of Clostridium perfringens in cecal contents than those fed PC diet (p<0.05), however the difference was not significant when compared to NC treatment (p>0.05). Conclusions: According to the sampling results on days 29 and 41, addition of phytobiotic compared to antibiotic, increased the number of lactobacilli while reduced the count of Clostridium perfringens and coliforms. Therefore, phytobiotic can be a suitable alternative for antibiotic to promote gastrointestinal health and prevent subclinical necrotic enteritis in broilers. M3 10.52547/rap.12.34.11 ER -