The effect of using a mixture of Cinnamomum verum, Origanum vulgare and Capsicum annuum extracts on performance, weight and relative length of gastrointestinal tract, enzymes and blood minerals in broilers

Industrial poultry farming on a large scale and intensively has increased the possibility of disease outbreaks. Studies have shown that the use of antibiotics, in addition to environmental threats, causes microbial resistance in the body (Yakhkeshi et al. 2011). The presence of chemical residues in poultry products and its impact on human health was one of the reasons for the ban on the use of antibiotics in 2006 (Garcia et al. 2007). Much research has been done to find suitable alternatives to antibiotics. Essential oils and plant extracts with a variety of biological and physiological compounds have a very high potential for their use as new medicinal compounds (Hussain et al. 2008). Useful properties of medicinal plants are related to the presence of secondary metabolites in them (Efterpi et al. 2012). In addition to improving bird growth and production, medicinal plants have positive effects on health status parameters (Grashorn, 2010), intestinal microbial population (Bolukbasi et al. 2008), serum concentration of antibodies to viral diseases (Toghyani et al. 2010) and biochemical and hematological parameters (Toghyani et al. 2010). Among the medicinal plants, cinnamon, marjoram and pepper are aromatic herbaceous plants that are of great importance and have effective healing properties. In some studies, consumption of cinnamon in the diet has caused weight gain, decreased feed conversion ratio and improved liver function in broilers and mice (Mehdipour et al. 2013; AL-Kassie, 2009). Giannenas and Et al. (2005) reported that consumption of marjoram extract improves the performance of broilers. Capsaicin in pepper increases intestinal and bile secretions, increases the activity of pancreatic enzymes, slows the passage of substances in the intestine, and increases the absorption of nutrients (Farrell, 1978). Platel and Srinivasan (2003) reported that consumption of capsaicin by 0.15% in the diet increased salivary amylase secretion in mice; it also increased gallic acid salts by 17%. It has been reported that the consumption of several medicinal plants simultaneously has a greater effect on the production, functional and health parameters than the consumption of one medicinal plant alone (Mehdikhani, 2015). Farrokhnia et al. Reported in 2020 that the consumption of a mixture of Thymus vulgaris and Echinacea angustifolia extracts was reduced due to a reduced conversion ratio of broilers compared to separate consumption. According to the above, the aim of this study was to investigate the effect of consumption of a mixture of cinnamon, marjoram and pepper extracts on performance, weight and relative length of gastrointestinal tract, enzymes and blood minerals in broilers.
Material and Methods: This experiment was performed using 192 Ross 308 broilers in a completely randomized design with 4 treatments, 6 replications and 8 broilers per replication in a 42-day breeding period. Experimental treatments are: (1) base diet, (2) base diet + 50 mg/kg mixture of plant extracts, (3) base diet + 100 mg/kg mixture of plant extracts and (4) Base ration + 200 mg/kg mixture of plant extracts. Functional parameters of feed intake, weight gain and feed conversion ratio were measured at the end of 42 days of rearing. On the last day of the experiment, 3 chickens were selected from each replicate for blood sampling. Samples were transferred to the laboratory to measure the activity of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase; These parameters were measured by an autoanalyzer and commercial kits of Pars Azmoun Company. Also, the amount of calcium, phosphorus, magnesium and iron elements in the blood were measured by autoanalyzer by spectrophotometry (Biowave model S2100 made in England) by commercial kits of Biochemistry Company. Then the birds were slaughtered and after filling, separating the ventricular contents and separating the components, the relative weights of different parts of the gastrointestinal tract were calculated in terms of body weight, and the relative lengths of the duodenum, jejunum, ileum and cecum were measured (Daneshyar et al. 2012). Experimental data were statistically analyzed in a completely randomized design by SAS statistical software (2003) using GLM linear procedure. Mean comparisons were performed using Tukey-Kramer test at 5% level.
Results and Discussion: The results showed that feed intake and feed conversion ratio were not affected by experimental treatments (P>0.05). However the treatments receiving 100 and 200 g/ton of mixed plant extracts had more body weight gain than the control treatment (P<0.05). Consumption of all three levels of plant extracts resulted in a significant increase in the length of jejunum and ileum of chickens (P<0.05). On the other hand, duodenum and cecum length were not affected by experimental treatments (P>0.05). There was no significant difference between the relative weights of the duodenum, jejunum, ileum and cecum between the experimental treatments (P>0.05). The results showed that the levels of liver enzymes aspartate, transaminase and alkaline phosphatase were not affected by experimental treatments (P>0.05). However, consumption of 100 and 200 g/ton of plant extracts reduced the amount of alanine aminotransferase and lactate dehydrogenase in comparison with the control treatment (P<0.05). The results showed that the consumption of a mixture of plant extracts had no significant effect on the amount of phosphorus and iron in the blood serum of broilers (P>0.05). On the other hand, consumption of 200 g/ton of mixed plant extracts compared with the control treatment increased the amount of calcium and magnesium in the blood of broilers (P<0.05).
Conclusion: From this study, it is concluded that up to 150 g/t of a mixture of Cinnamomum verum, Origanum vulgare and Capsicum annuum extract in broiler diet without changing feed intake led to improved weight gain and increased relative length of ileum and jejunum in broilers. Liver enzymes were at normal levels and even showed a decreasing trend; The blood calcium and magnesium levels of broiler chickens also increased. Therefore, up to this level, a mixture of cinnamon, marjoram and pepper extract can be used in broiler diets.