مقایسه افزودنی‌های مختلف در جیره حاوی جو با اندازه ذرات متفاوت بر عملکرد رشد، جمعیت میکروبی سکوم و ریخت شناسی روده‌ی کوچک جوجه‏های گوشتی

نوع مقاله : مقاله پژوهشی

نویسندگان

• لیلی عبدعلی ¹
• سمیه سالاری ¹
• محمدرضا قربانی ²
• شیما حسینی فر ³

¹ گروه علوم دامی، دانشکده علوم دامی و صنایع غذایی، دانشگاه علوم کشاورزی و منابع طبیعی خوزستان، اهواز، ایران

² گروه مهندسی طبیعت، دانشکده کشاورزی شیروان، دانشگاه بجنورد، بجنورد، ایران

³ گروه علوم پایه، دانشکده دامپزشکی، دانشگاه شهید چمران اهواز، اهواز، ایران.

چکیده

کلیدواژه‌ها

• جوجه گوشتی
• ضریب تبدیل خوراک
• مدت زمان انتقال
• ویسکوزیته

موضوعات

• تغذیه دام و طیور

عنوان مقاله [English]

Comparison of different feed additives in diet containing barley with different particle sizes on growth performance, cecal microbial population and morphology of the small intestine of broiler chickens

نویسندگان [English]

• Leili Abdali ¹
• Somayyeh Salari ¹
• Mohammad Reza Ghorbani ²
• Shima Hosseini Far ³

کلیدواژه‌ها [English]

• Broiler chickens
• Feed conversion ratio
• Transit time
• Viscosity

Extended Abstract

Introduction

 Grains are the most important and widely used ingredients in poultry diet. Barley can be included in poultry feed as an energy source. The carbohydrates in barley, however, are not as easily digested as those in corn due to the presence of non-starch polysaccharides mainly beta-glucans. Beta-glucans can increase the viscosity of the intestinal contents. An increase in viscosity of the digesta adversely affects the digestion and absorption of nutrients and increase colonization of pathogenic bacteria. Autolyzed yeast is the product of cellular degradation, activated by its own enzymes, that solubilize cellular components and it can be used in broiler diet as prebiotic. The composition of autolyzed yeast varies depending on the production process, and usually autolyzed yeast Saccharomyces Cerevisiae contains 29-64% beta-glucan, 31% mannan oligosaccharide, 13% peptide and essential amino acids, and 9% lipid. Therefore, the use of autolyzed yeast in the diet of broilers provides cellular components and cell wall carbohydrates. In broiler chickens, the effects of prebiotics partially rely on blocking receptor sites of pathogen adhesion, immunomodulation, production of antimicrobial molecules by the intestinal microbiota, and shifts in the intestinal microbial structure.

Materials and methods

 An experiment was conducted with 400 one-day-old Ross 308 broiler chickens (mixture of two sexes) in completely randomized design with factorial arrangement 2×4 with 8 treatments, 5 replicates from 1 to 35 days of age. The experimental treatments included type of additive (without additive, enzyme, autolyzed yeast and autolyzed yeast with enzyme) and barley particle size (fine (2 mm) and coarse (8 mm)). Body weight gain (BWG) and feed intake (FI) of each pen were recorded. Feed conversion ratio (FCR) adjusted for mortality and it was calculated by dividing FI with BWG for total period (1-35 d). On d 35, two birds were randomly selected from each pen, weighed, and euthanised by cervical dislocation. Then, the pH of the contents from different parts of the GIT (gizzard, duodenum, jejunum, ileum, and caecum) was measured using a digital pH meter. Each of these segments was opened in the middle by an incision and split longitudinally and pH was immediately recorded by inserting the pH meter directly into the digesta. On d 35, a further two birds per replicate (i.e. eight birds per treatment) were randomly selected and euthanised by cervical dislocation. The small intestine was removed, and the digesta from the ileum (from Meckel’s diverticulum to the ileo-caecal junction) was immediately collected. The samples were placed into clean tubes and centrifuged at 9000 x g at room temperature for 10 min. The supernatant was withdrawn and viscosity was determined using a Brookfield digital viscometer. On day 30, feed was withdrawn for 2 hr and diets containing chromic oxide (3.0 g/kg) were offered. The digesta transit time was then determined as the time from the introduction of the diets to the first appearance of green‐coloured droppings. Cecal microbial population also determined at 35 days of age. On d 35, to measure the caecal microflora, one caecum from two birds in each replicate, which had been euthanised by cervical dislocation for ileal collection, was used. The caecal contents were aseptically collected in individual sterile culture tubes, kept on ice, and immediately transferred to the microbiological lab. The data obtained from the experiment were analyzed using SAS (version 9.4) statistical software and GLM procedure. To compare means, Duncan's (1955) multi-range test was used at a significant level of 5%.

Results and discussion

Enzyme addition led to a decrease in feed consumption compared to the treatment receiving the ration without additives during the growth period (P>0.05). The size of coarse barley particles caused a decrease in feed consumption compared to fine barley particles during the growth period (P<0.05). The experimental treatments did not show any significant effect on the weight gain of chickens during the experimental period (P>0.05). In the final period and the entire period of the experiment, the treatment receiving the ration without additives showed a higher feed conversion ratio than other treatments (P<0.05). In the final period, the treatment receiving autolyzed yeast with the size of large barley particles created the lowest feed conversion ratio compared to other treatments (P<0.05). Add enzyme and autolyzed yeast decreased the pH of gizzard and jejunum compared to the control treatment (P<0.05).Autolyzed yeast along with enzyme increased the number of Lactobacillus bacteria colonies and decreased the number of E. coli and coliform bacteria colonies compared to other treatments (P<0.05). Autolyzed yeast with enzyme reduced the viscosity of ileum digestive juice compared to other treatments (P<0.05). The digesta transit time in the digestive system in the treatment receiving enzyme, autolyzed yeast, autolyzed yeast with enzyme was less compared to the treatment receiving diet without additives. Additive type, size of barley particles and interaction effect of particle size and type of additive on villus height, crypt depth and villi height to crypt depth ratio of duodenum, jejunum and ileum showed a significant effect. The barley particle size had no significant effect on villus height, crypt depth and duodenal villi height to crypt depth ratio (P<0.05). Addition of autolyzed yeast along with enzyme and also the size of barley coarse particles improved the morphological characteristics of the small intestine (P<0.05).

Conclusion

 If these two additives are used in a targeted way, they can create positive effects in the formation of stable microbial flora in the intestine, which will lead to the improvement of the intestinal morphology and ultimately improve the performance of birds.

Author Contributions

Conceptualization, Somayyeh Salari

Methodology, Somayyeh Salari, Leili Abdali, Shima Hosseini Far

Investigation, Leili Abdali,  

Data curation, Leili Abdali,  

Writing—original draft preparation, Leili Abdali

Writing—review and editing, Somayyeh Salari

Supervision, Somayyeh Salari, Mohammad Reza Ghorbani

Project administration, Somayyeh Salari

All authors have read and agreed to the published version of the manuscript

Data Availability Statement

Data available on request from the authors.

Acknowledgements

We would like to thank the Honorable Vice Chancellor of Research, Agricultural Sciences and Natural Resources University of Khuzestan for their financial support, and Kawoshgar Sepehr Javan Company for providing autolyzed yeast and financial support for the project. We would also like to thank Aria Food Designers Company for providing the enzyme used in the research.

Ethical considerations

This study was approved by the Animal Ethics Committee at the Agricultural Sciences and Natural Resources University of Khuzestan, Ahvaz, Iran.

Conflict of interest

The author declares no conflict of interest.