This experiment was conducted to evaluate the effect of Bacillus subtilis (BS) on broiler performance and health after intramuscular inoculation with E. coli and compare its effect with a growth promoter antibiotic. In a completely randomized design manner, 360 male Ross 308 chicks were divided into 6 treatments and 5 replicates of 12 chicks in each replicate. Experimental treatments included control diet, control + E. coli (0.5 mL of culture containing 108 CFU of E. coli/ml), control + 0.1% BS, control + 0.05% bacitracin methylene disalicylate (BMD), control + E. coli and BS, and control + E. coli and BMD in a factorial arrangement (3 × 2). Addition of BMD or BS to the control diet significantly (P < 0.01) increased body weight and decreased FCR, but E. coli challenge adversely reduced (P < 0.01) body weight and increased FCR, so that the addition of BMD or BS did not compensate growth reduction. E. coli challenged chicks had the lowest vaccine titers for ND, IB, AI, and IBD and the highest were observed in chicks fed BS. The E. coli challenge significantly (P < 0.01) increased albumin, globulin, cholesterol, triglyceride, LDL, ALT, and ALP indices. Addition of BMD and BS decreased albumin and globulin in challenged chick's plasma but had no effect on plasma lipid profile concentration. The E. coli challenge decreased villus height and increased crypt depth and goblet cell numbers significantly (P < 0.01). In birds subjected to BMD or BS, crypt depth decreased and villus height increased (P < 0.01), compared with the control diet. Challenge of E. coli significantly (P < 0.01) increased the bacterial population of E. coli, coliforms, and Salmonella in cecal parts of broilers' intestines. In challenged birds receiving BMD or BS, E. coli, coliform, and Salmonella populations of ceca showed a significant (P < 0.01) reduction. Both BMD and BS increased the digestibility of nutrients significantly (P < 0.01), but a reduction was observed in E. coli challenged groups. Results of the study suggest that spore-forming probiotics are partially effective in unsuitable rearing situations such as colibacillosis in which the load of harmful bacteria is high.

The aim of this study was to compare the effects of a new multispecies probiotic containing four Bacillus species and Saccharomyces boulardii (Microguard ® ) with a commercial probiotic (Protexin ® ) and a commonly used antibiotic in broilers. Six hundred one-day-old male Ross 308 broilers were randomized to six experimental treatments, with five replicates of 20 chicks each, for 42 days, receiving an ad libitum cornsoybean basal diet. Treatments were added to the basal diet and consisted of tetracycline as an antibiotic growth promoter (500 g/ton), three dosages of Microguard (50, 100 and150 g/ton) or Protexin (100 g/ton). The control group received the basal diet with no additive. The group fed with Microguard at 150 g/ton showed increased final bodyweight, weight gain, high density lipoprotein, triglyceride, and antibody titres against Newcastle disease (ND) and avian influenza (AI) levels. Improved feed conversion ratio, increased villus height, and villus highest crypt depth ratio, along with lower plasma gamma-glutamyl transpeptidase, alkaline phosphatase, alanine aminotransferase, were found in probiotic-supplemented broilers. Carcass yield, liver weights, breast muscle values, and abdominal fat weights were reduced in groups fed with 100 or 150 g/ton of Microguard. Caecal coliforms, Salmonella and Escherichia coli numbers decreased in groups fed with 100 or 150 g/ton of Microguard. These results show that Microguard at 150 g/ton is a promising probiotic to replace antibiotics in broiler feed as a growth-promoter while enhancing immune system responses and inducing beneficial modulations in the caecal microflora. ______________________________________________________________________________________

This study was performed to evaluate the efficacy of a herbal mycotoxin binder to overcome the adverse effects of 1.5 mg/kg of aflatoxin fed to laying quails. Results showed that addition of aflatoxin altered the performance indices of quails in terms of feed intake, FCR, egg production, and egg weight. Intestinal morphology of quails was also manipulated by inclusion of aflatoxin into the diet. The immunity of quails fed aflatoxin declined significantly. However, it could increase the population of harmful bacteria collected from the ileum of quails. The results of this study established that using herbal mycotoxin binder could bypass these adverse effects significantly and can be used in laying quails as a suitable binder when mycotoxin is present in their feed.

-The effect of a non-antibiotic growth-promoting component composed of natural phytomolecules, directfed microbials, glucomannan oligosaccharides, and organic acids on the performance, intestinal morphology and microbiology, plasma biochemistry, enzyme activities, visceral organ weights, and immune response of commercial broilers challenged with Escherichia coli was investigated. Three hundred and sixty one-day old male Ross 308 broiler chicks were randomly divided into basal diet (control, CON); control plus 0.5 mL of culture materials containing 10 8 cfu/mL of E. coli (E. coli); control with 400 mg/kg bacitracin methylene disalicylate (an antibiotic growth promoter, AGP); control plus 1000 g/t of feed of a blended mixture of natural feed additives (NAT); combination of E. coli and AGP treatments (E. coli + AGP); or the combination of E. coli and NAT treatments (E. coli + NAT). E. coli injection decreased broiler performance by lowering body weight and increasing feed intake, whereas AGP and NAT treatments improved body weight and the feed efficiency when compared to the other groups. However, feed intake was not affected by treatment. Immune response also improved with the addition of NAT, compared with control. Blood biochemistry parameters were significantly affected by the treatments. Nutrient digestibilities were increased by AGP and NAT supplementation in E. coli-challenged groups. Both AGP and NAT significantly decreased E. coli and coliform numbers in ceca. Ileal villus height was not affected by treatment, but ileal crypt depth and goblet cell counts decreased in the NAT relative to control group. Antibiotic growth promoter was somewhat more effective in improving broiler growth and health characteristics than NAT, but since NAT generally improved broiler performance compared to the control group, it can be alternatively used as an alternative to AGP in commercial broiler production.

This experiment was conducted using 192 day-old Ross 308 chicks, divided into 4 groups of 4 replicate consisting 48 birds. Group I was fed a control diet, Group II was fed control diet supplemented with 0.5 ppm T-2 toxin for 5 weeks, Group III was fed control diet supplemented with 8 × 10(8) cfu/mL of Mycoplasma gallisepticum, and group IV was fed control diet supplemented by T-2 toxin and Mycoplasma gallisepticum. Body weight and feed conversation ratio (FCR), relative organ weights, clinical signs, biochemical characteristics, and gross and histopathological lesions were recorded in the experimental groups at the end of the second and fifth weeks of age. Body weight and relative weights of bursa of Fabricius, thymus, and spleen decreased and FCR increased significantly (P ≤ 0.05), but the relative weights of liver and kidney showed no significant decrease (P ≤ 0.05) in the serum total proteins, albumin, and increase in aspartate aminotransferase and alanine transaminase were observed in T-2 toxin and T-2 accompanied with Mycoplasma fed birds when compared to the control group. Liver was enlarged, friable, and yellowish discoloration with distended gall bladder was noticed. Lymphoid organs such as bursa of Fabricius, thymus, and spleen were atrophied in group II and group IV throughout the study. Microscopically, liver showed vacuolar degeneration of hepatocytes, with increased Kupffer cell activity, bile duct epithelial hyperplasia, and infiltration of inflammatory cells. Kidney showed vacuolar degeneration of tubular epithelium along with pyknotic nuclei. Lymphoid organs showed lymphocytolysis and depletion with prominent reticuloepithelial cells. Proventriculus revealed desquamation of villous epithelial cells and lymphoid infiltration in submucosa. Heart showed mild hemorrhage with infiltration of inflammatory cells. Lung showed edema and inflammatory cells in the bronchioles. Trachea showed desquamation and erosions of mucosa. Proliferation of mucosal glands with increased mucous secretion was obvious. Air sacs showed thickening with presence of inflammatory cells and edema.

The objective of the present study was to investigate the effectiveness of a non-antibiotic growth promoter (Non-AGP) which is a combination of phytomolecules, direct-fed microbials (DFMs) and organic acids on performance, serum enzyme activities, immune response and visceral organ weights of commercial broiler chickens. A total of 375 day-old Ross 308 broiler chickens (mixed sex) were obtained from a local hatchery, weighed, and randomly allotted to 5 treatment groups with 5 replicates of 15 birds each. They received different treatments as basal diet (control); control plus 400 mg/kg bacitracin methylene disalicylate (BMD); control plus 0.05% Non-AGP (Non-AGP1); control plus 0.1% Non-AGP (Non-AGP2) and control plus 0.1% commercial probiotic (PRO). Chicks fed BMD resulted in maximum feed efficiency and a significant (P≤0.05) increase in the body weight, relative weights of liver, kidney and pancreas and Newcastle disease (ND), Infectious Bursal Disease (IBD) and Avian Influenza (AI) titers at d 42. Dietary inclusion of Non-AGP at the level of 0.1% into the basal diet proved its efficiency equal to BMD fed chicks, whereas addition of a probiotic at the level of 0.1% showed its applicability similar to the control group. It is concluded that the tested Non-AGP product at 0.1% but not 0.05% in the current study may be a suitable replacement for BMD in poultry diets.

Keywords Japanese quails, egg production, gut health, immune response. ABStRACtThe present study was carried out to determine the effects of the inclusion of a spore-forming probiotic (Bacillus subtilis) in laying Japanese quail diets as an alternative to growth-promoting antibiotics to help produce healthy eggs and meat. This experiment was conducted as a completely randomized design with three treatments (control, 0.05% bacitracin methylene disalicylate (BMD), or 0.1% Bacillus subtilis) of five replicates of 11 quails each. Feed intake and egg production were recorded daily on cage basis. Body weight was determined at the beginning and end of the trial (36 and 42 weeks). At the end of the experiment (42 weeks), antibodies against Newcastle disease and avian influenza, egg components, Haugh units, eggshell quality and breaking strength, blood parameters, cecal microbial population, villus length, and crypt depth were measured. The dietary inclusion of Bacillus subtilis and BMD significantly (p≤0.05) increased egg production and egg weight; however, eggshell thickness and breaking strength, Haugh units, and eggshell percentages were not affected. The dietary addition of both products significantly (p≤0.05) decreased plasma cholesterol levels and increased LDL levels, as well as antibody levels against Newcastle disease and avian influenza (p≤0.01). In birds fed Bacillus subtilis and BMD, crypt depth was reduced, but villus height and villus to crypt ratio were significantly increased (p≤0.001) compared with those fed the basal diet. Cecal coliforms, E. coli, and Salmonella counts were reduced (p≤0.01) in quails fed the diets containing Bacillus subtilis and BMD compared those quails fed the non-supplemented diet. The results of this study demonstrated that in absence of AGPs, the inclusion of a spore-forming probiotic partially improves the performance of laying quails.

The current study was conducted to examine the effects of an herbal compound, a probiotic and an antibiotic growth promoter (AGP) on the performance, intestinal bacterial population, antibody titers, and morphology of the jejunum and ileum of broilers. A number of 240 male Ross 308 broilers were distributed into four treatments, with five replicates of 12 bird each. The experimental period was 42 days. Treatments includes: 1) basal diet; 2) basal diet supplemented with an AGP (phospho-flavomycin at 450 mg/kg of diet); 3) basal diet supplemented with a Lactobacillus-containing probiotic (250 mg/kg of diet); and 4) basal diet supplemented with an herbal compound (containing thyme, oregano, chamomile, and peppermint essential oils at 1 g/kg of diet). Body weight (BW) and cumulative feed intake (CFI) were measured weekly. Blood parameters, intestinal morphology, vaccine immunity titers, and intestinal microbial population were measured on day 42. The results showed that probiotic and herbal compound supplementation significantly increased body weight (BW) and decreased feed conversion ratio (FCR) (p<0.05), in comparison with the basal diet. A significant increase in vaccine titers against Avian Influenza, Newcastle disease, and Infectious Bursal Disease were achieved with the treatment with herbal compound supplementation. Herbal compound significantly reduced triglycerides, cholesterol, LDL concentration and ALP, AST and ALT activities and increased the HDL levels in blood serum of chicks (p<0.05). The bacterial load of E. coli, Salmonella and coliforms of the AGP-fed group was significantly lower than those fed the control diet. Significant increases in villus height and decrease in crypt depth and goblet cells were seen in the ileum and jejunum of probiotic-fed broilers (p<0.05). In conclusion, better overall immune status and blood biochemical parameters were obtained with the herbal compound than with the probiotic; however, the performance of broilers fed the probiotic was better than that of the broilers fed the herbal compound and the AGP.