Document Type : Research Paper

Authors

• zahra Mostafaie ¹
• Mehran Torki ²
• Kianosh Chaghamirza ³
• Rouhallah Sharifi ⁴

¹ Corresponding Author, Animal Science Department, College of Agriculture and Natural Resources, Razi University, Kermanshah, Iran. E-mail: zmostafai@basu.ac.ir

² Animal Science Department, College of Agriculture and Natural Resources, Razi University, Kermanshah, Iran. E-mail: torki@razi.ac.ir

³ Agronomy and Plant Breeding Department, College of Agriculture and Natural Resources, Razi University, Kermanshah, Iran. E-mail: cheghamirza@ razi.ac.ir

⁴ Plant Protection Department, College of Agriculture and Natural Resources, Razi University, Kermanshah, Iran E-mail: r.sharifi@razi.ac.ir

Abstract

Introduction: Corn and wheat are the main sources of energy in poultry diets worldwide, although due to its availability, wheat can be a good substitute for corn in the diet of broilers and laying hens. However, the inclusion level of wheat is limited often because wheatbased diet contained higher levels ofsoluble non-starch polysaccharidesThe arabinoxylans are the main NSP in wheat that increasing the viscosity of the digesta and reducing nutrient digestibility of direct-fed microbial (DFM) supplements include Bacillus velezensis, Trichoderma, and Saccharomyces cerevisiae, which are used as biological control agents due to their high ability to suppress disease agents and inhibit the proliferation of intestinal pathogens.
Materials and Methods: The total number of 240 Hy-Line W-36 laying hens were randomly distributed between 40 cages, and the five experimental diets including (A) corn-soybean meal-based control diet, (B) wheat-based diet with no microbial additive, (C) wheat-based diet with 1Í10⁹ cfu/kg Bacillus velezensis, (D) wheat-based diet with 1Í10⁵ cfu/kg Trichoderma and (E) wheat-based diet with B. velezensis + Trichoderma were assigned to hens with 8 replicate cages per diet and 6 hens per each replicate.
Results and Discussion: The results showed that the addition of B. velezensis + Trichoderma to the diet led to an improvement in the feed conversion ratio (FCR),  and increased egg production (EP) and feed intake (FI; P<0.05)., Also, the pH of the contents of the jejunum, ileum and caecum was reduced in the treatments containing microorganisms(P<0.05). The DFMs enhanced the efficiency of nutrient adsorption and utilization, predominantly ascribable to the production of exogenous enzymes by the test probiotic. Prebiotics work as feed for the intestinal microflora and could stimulate the fermentation rate which increased the production of short chain fatty acids and reduced luminal pH. Hens fed microbe-added diets had higher plasma levels of calcium (Ca), phosphorus (P) and high-density lipoprotein (P<0.05). The addition of B. velezensis + Trichoderma to the diet, modulated the ileal and caecal microflora composition by decreasing the numbers of Escherichia coli and increasing the numbers of Lactobacilli. Dietary supplemented by B. velezensis and Trichoderma could increase plasma Ca and P compared to other treatments, which can be interpreted as probiotics increase the rate of fermentation and reduce intestinal pH, leads to better absorption of Ca and P from the intestine. Improved intestinal morphology characteristics were observed in hens fed the microbe-added diets (P<0.05). These beneficial effects were directly associated with decrease in total microbes, E. coli and Salmonella and enhance lactic acid bacteria of cecal. Consistently, addition of B. subtilis manipulated the gut ecosystem toward beneficial bacteria and enhanced the development and health of gastrointestinal tract. The positive effects of DFMs on eggshell quality can be attributed to the enhancement of gut health and intestinal tract microflora environment. Also, modifying the gut microflora composition by promoting the growth of beneficial microflora (such as lactic acid bacteria) and inhibiting the growth of Salmonella, E. coli, and Clostridium perfringens is beneficial effects of DFMs. The present study confirmed B. velezensis and Trichoderma enhanced the colonization of the beneficial bacteria and reduced the colonization of enteric bacteria. Maintaining a healthy intestine by probiotics and prebiotics will improve the ability of birds to overcome the disease and enhance their performance. Highest count of aerobic bacteria, lactobacilli, anaerobic bacteria, and E. coli were associated with Trichoderma reesei. 
Conclusion: Based on the results of the current study, it can be concluded that adding B. velezensis + Trichoderma to the wheat-based diets improve performance of laying hens, decrease plasma levels of cholesterol, triglyceride, and LDL and the intestinal pH and number of E. coli.

Keywords

• Bacillus velezensis: Intestinal health
• : Laying hen: Trichoderma
• : Wheat