Antimicrobial compounds have been used for decades in poultry diets to increase
performance and decrease morbidity particularly in broiler chickens. However, consumer
pressure related to the potential development of antibiotic-resistant bacteria ha
s resulted in
the development of non-antibiotic feed additives that may also improve broiler erformance.
In recent years, aromatic plants and their extracts have received attention as growth and
health promoters. Such products have several advantages over commonly used commercial
antibiotics since they are residue free and they are also, generally recognized as safe and
commonly used items in the food industry. The antimicrobial properties of medical plants
and their extracts have been widely reported because they consist of many active
ompounds such as carvacrol, eugenol,which partition lipids in the bacterial cell wall and
mitochondria, disturbing the structures and rendering them more permeable.
Generally,medical plants are slightly more active against Gram-positive than Gramnegative
bacteria. Medical plants are well known for their antioxidant activity and show a
considerable effect on increasing the antioxidant capacity of chicken meat because they
consist of many of active compounds such as tocopherol, carvacrol. Spices or their active
principles have been reported to stimulate digestive secretions such as lipase, amylase and
proteases.because they consist of many active compounds such as anothol, eugenol.
Variable effects of medical plants and their extracts on the productive performance of
broiler have been reported. The majority of experimental results indicate improved body
weight gain or final body weight and feed conversion ratio.
The effect of some essential oils taken from Cinnamomum zeylanicum, Citrus
limonum and Rosmarinus Officinalis was investigated in relation to the growth of bacteria
Paenibacillus larvae which causes American Foulbrood disease that affects world hon
ey
bees Apis mellifera L. The study was carried out in the laboratories of the Faculty of
Agriculture, Damascus University from 2012 till 2013. This is in order to contribute to
preparing an integrated pest management program for American Foulbrood disease. The
oils were extracted from the plants using steam distillation. The effects of the
concentrations of oils on the growth of P. larvae were tested between (3.90625 - 500
μg/ml) using agar disc diffusion in petri plates. Results showed that the essential oils used
stop the growth of P. larvae in some of their concentrations. The minimal inhibitory
concentrations which stop the growth of P. larvae of the oils of Cinnamomum zeylanicum,
Citrus limonum and Rosmarinus officinalis were recorded at 31.25 μg/ml, 62.5 μg/ml, 125
μg/ml respectively.
A morphological , anatomical and chemical study was carried out on Salvia viridis
L. (Lamiaceae) . The results showed presence of two types of trichomes :
- Glandular hairs with four or eight celled globular heads or with oval heads .
- Eglandular
hairs which are unicellular or multicellular , in addition to presence of
candle shaped eglandular hairs .
The palynological study revealed that the pollen grains were prolate and they had six
germination lines , exine appeared reticulate .
The extraction of volatile oils have been done by dry evaporation using GC/MS
technique , chromatographic analysis of these extracts have showed the presence of
complex of carboxylic acids , hydrocarbons , terpenes , esters and aldehydes .
Essential oils from peels of 6 citrus species were extracted. The species were
lemon (Citrus limon), orange (C. sinensis), grapefruit (C. paradisi), pomelo
(C. maxima), mandarin (C. reticulata) and bitter lemon (C. aurantium) using
hydro-distillat
ion (Clevenger type).
In general Gram-positive bacteria were more sensitive to the oil
extracts tested than Gram-negative bacteria, and P. aeruginosa was the most
sensitive within the Gram-negative group.
