Effects of dill powder (Anethum graveolens dhi) on performance and biochemical traits, immune response, blood cells and microbial population of cecum broilers after stress induced with dexamethasone were investigated. Two hundred and forty broilers were arrayed in completely randomized design with six experimental groups, five replications and eight broilers per replication. The experimental groups consisted of G1: control diet without additives, G2: control diet supplemented with 1.5% dill powder, G3: control diet supplemented with 1.5% dill powder under dexamethasone stress, G4: control diet supplemented with 3% dill powder, G5: control diet supplemented with 3% dill powder under dexamethasone stress, and G6: control diet under dexamethasone stress. After 31, 33, 38 and, 40 days, 2 mg/kg bodyweight (BW) dexamethasone was injected in right chest muscle in groups 3, 5, 6, and samples were taken after 35 and 42 days. Use of 3% dill powder reduced cecum microbial population significantly. Under dexamethasone oxidative stress conditions dill powder improved biochemical traits and the number of white blood cells significantly. Without stress induced by dexamethasone injection, use of 3% dill powder improved internal organs, increased the length of the digestive tract, improved weight gain, reduced FCR and improved antibody titers to Newcastle disease (ND) and avian influenza (AI) viruses. All levels of dill powder prevented negative impacts of dexamethasone on functional and biochemical traits. Thus, 3% dill powder has beneficial effects on performance, immune response, blood cell and microbial population, and could be used as a growth promoter and to prevent oxidative stress.

ABSTRACT The 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.

In order to estimate the crude protein (CP) equivalence value of Natuzyme-p (NP) enzyme by using regression response equations, two experiments were carried out using Ross (308) broiler chicks. Graded levels of dietary CP (while amino acids levels were kept constant) and NP enzyme were used to derive the regression equation in the first experiment. Four levels of dietary CP and NP enzyme were fed to 160 feather-sexed male broiler chicks during the starter (0-28 d of age) and grower (28-42 d of age) period. Each diet was offered to four replicates of five chicks in a completely randomized design. Results obtained in experiment one failed to fit a regression equation between BW, dietary CP levels and NP enzyme. In experiment two, graded levels of CP changed along with the levels of lysine (Lys), Met+Cys and threonine (Thr). Regression equations between BW and dietary CP and NP enzyme were derived. Nonlinear and linear equations were generated for enzyme and CP. Based on an assessment of r² and P value, nonlinear equations were used to determine enzyme equivalence. The derived regression equations of body weight for CP were set to be equal with those obtained for NP and were solved; enzyme equivalence value for CP was calculated by subtracting the obtained value from CP content of basal diet. Crude protein equivalence value of NP at 28 and 42 d of age was estimated to be 0.96 and 0.38 %, respectively.