Effects of different levels of Eucalyptus (Eucalyptus globules) leaf powder on performance, carcass characteristics and immune response of broiler chicks

Recently, many countries tended to minimize or prohibit the chemical components for their deleterious side effects on both animals and human. So, it is important to use natural promoters. Herbs and its by products were found to have useful effects, e.g., antioxidant, growth promoters (Habibi et al. 2014), Immunostimulants (Habibi et al., 2016) tonics, antiparasitic, anti-bacterial, carminative, anti-fungial, anti-microbial and antiseptic (Jafarnia et al. 2007). Medicinal plant competes with the synthetic drugs. (Habibi et al. 2014). Eucalyptus (Eucalyptus globulus) of the Myrtaceae family is an important medical herb in world and has antioxidant, anticholestrol and antimicrobial properties (Jafarnia et al. 2007). Eucalyptus leaves used to produce essential oil. Essential oil of eucalyptus leaves contain effective compounds such as 1,8 cineol, Limonene, o-Cymene and α-pinene, that main composition of its is eucalyptol (1,8 Cineole). constituting the 60–90%, that has been reported to inhibit the production and synthesis of tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), leukotriene B4, and thromboxane B2 in human blood monocytes (Serafino et al. 2008). Eucalyptus essential oil proved to be able to implement innate-cell mediated, humoral immune response and have a potent immunomodulatory effect in chickens (Awaad et al. 2010). This study was conducted to investigate the effects of different levels of eucalyptus (Eucalyptus globules) leaf powder on performance, carcass characteristics and immune response of broiler chicks.
Material and A total of 240 one day male broiler chicks (Ross-308) provided by a local commercial hatchery were randomly allocated to one of the 5 experimental treatments. Each treatment condition consisted of 4 replicate pens with 12 birds each. Experimental treatments included: Control (corn-soy meal based diet) and treatments containing diets supplemented with 0.25, 0.5, 0.75 and 1 percent of eucalyptus leaf powder. The composition of the basal diets is presented in Table 1. Chicks were provided with ad libitum access to water and feed. The birds were reared on concrete flooring covered with wood shavings as litter material. The body weight and feed consumption of the birds were recorded at 10, 24 and 42 days of experiment period. Two birds per each replicate were randomly selected and then slaughtered. Organs were removed and weighed from each bird. Weight of the organs were expressed as a percentage of live body weight. The SRBC (sheep red blood cell) test was performed to quantify the specific antibody titre for injection of SRBC, at first 30cc of phosphate buffered saline (PBS) solution with 10cc of SRBC completely mixed and 0.2 cc of the obtained solution drawn into the syringe was injected into the breast muscle 4 bird per treatment in 20 and 30 days of age. Whole sheep blood collected in solution was washed three times in PBS with pH=7.4 and diluted in PBS to 25 %. Therefore, 7 days after each sensitization (27 and 37 days) were bled for assessing haemagglutination (HA) titre against SRBC by using freshly prepared one percent SRBC. The test serum (25μl) was serially diluted 1:2 with PBS in microtiter plates. After dilution, 25 μl of 1 % SRBC was added to each well and mixed. The plate was incubated at 37°C for 1 hour and haemagglutination titre was expressed as the log2 of the reciprocal of the highest dilution showing 100 percent agglutination (Yamuna and Thangavel 2011). All data were analyzed according to GLM procedure of SAS (SAS Institute, 2004), version 9.1. The Duncan’s Multiple Range Test was used to compare means when significant effects (P Experimental treatments had no effects (P>0.05) on the amounts of weight gain, feed intake and feed conversion ratio (Table 3). There was no significant difference between treatments in carcass characteristics and relative weight of immune organs at 42 days of age (P>0.05). This results were in agreement with Yaghoobzadeh et al (2004) who observed an non significant improvement in the body weight gain of chicks fed diets supplemented with eucalyptus powder and its by products, however carcass traits relative weight was not affected by the inclusion of eucalyptus in the diet. Also, Koopaie et al (2011) reported that eucalyptus essential oil has positively influenced growth performance in broilers. Birds were received 0.5% of eucalyptus leaf powder, had highest antibody concentration versus sheep red blood cells (SRBC) and its difference was significant with control group (P0.05). At 37 days of age, treatments contained 0.5, 0.75 and 1% of eucalyptus leaf powder, had higher antibody concentration than control group (P Results of the present study indicated that usage of eucalyptus leaf powder in 0.5 percent concentration, caused improvement and reinforcement immune response, however had no significant effect on performance and carcass traits of broiler chicks.