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.
hybrid commercial chicks (Hubbard Flex) were A total of /450/
reared from 1 to 42 days of age. Chicks were distributed into five
groups; each group contained 90 birds within three replicates. Five
diets were used; the first was the traditional die
t (control group) and
the others differed in the growth promoters added and were as
following: nutritional antibiotic (Lincomycin) for the second group,
probiotic (Bacillus subtilis) for the third group, prebiotec (manna
oligosaccharide) for the forth group and finally a mixture of organic
acids for the fifth group.