This experiment was carried out at the Poultry Research Farm of Animal Production Department, Faculty of Agriculture at Moshtohor, Benha University, during a period of 42days started from 9 October to 19 November 2013. The chemical analysis and microbiological studies were conducted at the laboratories of each of Animal Production and Botany Departments, Faculty of Agriculture at Moshtoher, Benha University and Food Analysis Center, Faculty of Veterinary Medicine belong to the same University.
This study aimed to evaluate the effect of an antibiotic and some medicinal and aromatic feeds (oregano essential oil and garlic powder) as natural growth promoters on growth performance of Japanese quails (Couturinx couturinx japanico).
The experimental design used in this study include two levels of the antibiotic (Oxytetracyclin), 0.5 and 1.0 g / kg diet, three levels of the oregano essential oil (OEO), 0.5, 1.0 and 1.5 g / kg diet, and three levels of the garlic powder (GP), 0.1, 0.2 and 0.3 g / kg diet. The response of the previous feeds was measured as growth performance, carcass traits, meat quality, microbial count of small intestine, blood plasma parameters, economical efficiency and digestibility of quail birds.
A total number of 540 unsexed one week old Japanese quails of nearly similar live body weight were chosen randomly and distributed into nine experimental treatments each of 60 chicks in three replicates (20 chick/each).The average live body weight of chicks of different treatments at the start of the experiment ranged between 31.60 and 32.60g without significant differences.
Chicks in all experimental treatments were kept under similar management, hygienic and environmental conditions. Artificial lighting was provided over the 23 hours daily during the whole experimental period.
Quails were fed nine experimental diets contained about 24% CP and 3000 kcal ME/kg diet.
The control (basal) diet was fed either without any supplementation (control, treatment 1) or supplemented with 0.5 or 1.0 g Oxytetracyclin 20% /kg diet (treatments 2 and 3, respectively) or supplemented with 0.5, 1.0 or 1.5 g OEO /kg diet (treatments 4, 5 and 6, respectively), or supplied with 0.1, 0.2 or 0.3 g GP (Garlin) /kg diet (treatments 7, 8 and 9, respectively. Accordingly a total of 9 experimental diets including control, 2 levels of antibiotic, 3 levels of OEO and 3 levels of GP, were studied. The natural growth promoters were used to substitute the total feed mixture of the control diet, mainly yellow corn. Feed and water were provided ad-libitum throughout all the experimental period.
Birds of each experimental treatment were individually weighed to the nearest gram at the start of the experiment (one week of age) then weighed weekly up to the end of the experimental period (6 weeks of age). Weight gain and growth rate between each two successive periods were individually calculated. Feed intake by all chicks was weekly recorded for each treatment. It was then averaged and expressed in gram per chick per day. Thereafter, feed conversion was calculated as the ratio between feed intake (g) and weight gain (g). Performance index was individually calculated. Mortality rate was also estimated. At the end of the experimental period (6 weeks of bird's age), a slaughter test was performed to determine carcass traits and microbial count in the digestive track of quails. Also, meat quality and meat microbial count were carried out. Blood parameters, plasma protein fractions, hemoglobin, red blood cells, total white blood cells, asparatate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, uric acid, cholesterol and triglycerides were determined and economical efficiency for meat production of quails was calculated. Also, at the end of the experimental period, digestibility trials were under taken to study the effect of the experimental treatments on the digestibility of different feed nutrients of the experimental diets.
Results obtained could be summarized as follows:
All treatments applied had significant (P