Effect of Nigella sativa seeds and Mentha pulegium mixed with coated formic acid on performance, blood characteristics, ileal morphology, and ileal and cecal microbial population of broilers fed mash or pellet diets

The prevalence of antibiotic resistant pathogens has resulted from the use of sub-therapeutic concentrations of antibiotics delivered in poultry feed (Sandra Diaz-Sanchez etal. 2015). The ban on the use of antibiotic feed additives as growth promoters caused researchers for exploring the future utility of other alternatives (Hamid etal. 2018). Furthermore, there are a number of consumer concerns regarding the use of antibiotics in food animals including residue contamination of poultry products and antibiotic resistant bacterial pathogens. These issues have resulted in recommendations of reducing the use of antibiotics as growth promoters in livestock around the world (Sandra Diaz-Sanchez etal. 2015). Now a days conventional and organic productions have been limited to use antibiotics. Thus, both conventional and organic poultry production need alternative methods to improve growth and performance of poultry. Organic acids, herbs, spices, and various other plant extracts are being evaluated as alternatives to antibiotics and some do have growth promoting effects, antimicrobial properties, and other health-related benefits (Sandra Diaz-Sanchez etal. 2015 and Hamid etal. 2018). Current study was designed for further elucidation of the effects of the organic acid combined with phytogenic plant on gut healt in chicks fed with mash or pellet diets, therforecurrent trial was conducted to evaluate the effects of Phytocid (a plant-organic acid complex) on performance, immune response, and gut health of broiler chicks.

Experiment was done as a completely randomized design with 8 treatments (4 mash and 4 in pellet form), 4 replicates of 7 chicks in each pen. Treatments included control, control+1 or 2 g/kg Phytocid and control+ Salinomycin (0.5g/kg). Two basal diets were formulated for starter (1 to 21) and grower (22 to 42) period and Phytocid (1 and 2g/kg) and Salinomycin were added to the basal diet. For each treatment, a batch of 100 kg of each ration was mixed by using a Twin-Shaft Paddle Mixer and batches of the resulting ratins then were divided into two portion. The first portion was fed in mash form and the second portion was pelleted. The birds were reared in floor pens having wood shavings as litter material over a concrete floor. The room temperature was thermostatically set by automation systems using the two heaters and one fogger. Bell drinkers from the same polyethylene tank were used and water was provided ad libitum. Body weight and cumulative feed intake were measured on d 7, 21, and 42 for each pen and the feed conversion ratio (FCR) was calculated. Antibody titer aginst Newcastel and and Avian Influenza were measured at 36 d of age. Plasma triglyceride, cholesterol, LDL, VLDL, HDL, heamatocrit, and heamaglobin concentration was measured at 42 d of age. Gastrointestinal pH was measured at 42 d of age. On d 7 and 21, two chicks from each pen were slaughtered by neck cutting for extraction of cecal contents. The cecal contents of each bird were pooled for serial dilution. Microbial populations were determined by serial dilution (10−4 to 10−6) of cecal samples in anaerobic diluents before inoculation onto petri dishes of sterile agar as described by Bryant and Burkey (1953). Salmonella was grown on Salmonella Shigella agar (Merck, Germany) and Coliforms were grown on McConkey agar (Darmstadt, Germany). Plates were counted between 24 and 48 h after inoculation. Colony forming units were defined as distinct colonies measuring at least one mm in diameter. On d 42, a 2-cm segment of the middle of the ileum was washed in physiological saline solution and fixed in 10% buffered formalin and formalin was changed three times for fixation. A single 0.5-cm sample was cut from each ileal section, dehydrated using increasing ethanol concentrations, cleared with xylene, and placed into polyfin embedding wax. Tissue sections (2 µm) were cut by microtome (model; Easy cut 202, Italy), floated onto slides, and stained with hematoxylin (Gill number 2; Sigma, St. Louis, MO) and eosin (Sigma Aldrich, Darmstadt, Germany). For each sample, villus height and crypt depth were measured using a digital camera that had light microscopy (Motic-SMZ-140, Germany). Twenty-five images from 15 tissue sections of each ileal section were taken and villus heights and crypt depths were measured by imaging software.

Supplementing diet with Phytocid increased body weight gain, feed intake, and reduced feed conversion ratio significantly throughout the experimental period (P<0.05). Phytocid did reduce ileum and jejenum pH significantly (P<0.01). Supplementation of pellet and also mash diets with Phytocid did decrease Salmonella, coliform, and E-Coli population of ileum and ceca at 7 and 21 d of age significantly (P<0.05). Ileal villus length and crypt depth was increased by addition of Phytocid to basal diets.

Results of current trial showed that Phytocid have beneficial effect on gastrointestinal health and improved weight gain and feed intake and feed conversion ratio in broiler chickens and could be a possible replacing agent to antibiotics in poultry.