Document Type : Research Paper
Authors
1 Department of Animal Science, Faculty of Agriculture, Ilam University, Ilam, Iran. E-mail: h.heydari@ilam.ac.ir
2 Corresponding Author, Department of Animal Science, Khorasan Razavi Agricultural and Natural Resources Research and Education Center, AREEO, Mashhad, Iran. E-mail: a.khatibjoo@areeo.ac.ir
3 Department of Animal Science, Faculty of Agriculture, Ilam University, Ilam, Iran. E-mail: h.shirzadi@ilam.ac.ir
4 Department of Animal Science, Faculty of Agriculture, Tarbiat Modarres University, Tehran, Iran. E-mail: karimitm@modares.ac.ir
5 Department of Animal Science, Faculty of Agriculture, Ilam University, Ilam, Iran. E-mail: j.jamali@ilam.ac.ir
Abstract
Objective: During the first week of life, body weight increases 2- to 3-fold, and there are significant changes in the weight and morphology of the gut and muscles. Gastrointestinal development is particularly important in early chick growth and delayed feeding during the first few days of life reduces final BW and probably affects gut health and immune function. Probiotics are live microbial feed additives and can be considereda functional nutritional approach, whereby adequate amounts of live beneficial microorganisms are administered to establish a healthy microbial environment and improved intestinal function in young chicks, resulting in stimulation of mucosal immunity, pathogen inhibition, improvedperformance, and modulation of intestinal microflora of young or stressed broilers. As such, probiotic seems to influence broiler growth performance and intestinal growth under late feeding challenge.
Method: The objective of this experiment was to investigate the effect of probiotic levels on performance, blood metabolites and small intestine morphology of broiler chickens subjected to late feeding challenge (LFC). The experiment was conducted using a completely randomized design and a 3×3 factorial arrangement with 3 levels of probiotic (0, 0.2 and 0.4 g/kg feed) and 3 LFD time (0-, 12- and 24-h), 450 Ross-308 broiler chickens (one-d-old, mixed sexes) were allocated to 9 treatments, 5 replicates and 10 birds in each replicate.
Results: The broiler chickens fed greater level of probiotics and immediately access to feed had the highest BW and BWG and those fed with 24h LFC and greater level of probiotic had the lowest BW at the end of the starter period; and at the end of the experiment, broiler chickens fed 0.2 g/kg probiotics with 12h LFC and those fed greater level of probiotics and immediately access to feed had the lowest FI, BW and BWG (P < 0.05). LFC time had no significant effect on the distribution parameters of chickens at 10d age and carcass parameters at 42d age. Broiler chickens fed 0.4 g/kg probiotics with 12- and 24h LFC had the lowest triglyceride and glucose concentration respectively, and at this level of probiotic with 0- LFC the lowest count of E. Coli was observed while 12 and 24h LFC decreased bifidobacteria count (P<0.05). Villous height increased with LFC time in thoese broiler chickens fed diets contatning 0 or 0.2 g/kg probiotic. The greatest villous surface area was observed in broiler chickens fed 0.2 g/kg probiotic diet with 12h LFC (P<0.05).
Conclusions: In conclusion, 12- and 24h DP decreased the performance and intestinal morphometry of broiler chickens, and double recommended probiotic supplementation could not completely ameliorate the negative effects of LFC.
Keywords
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