Antibiotics are largely used in poultry production whether for their therapeutic effect or as growth promoters. The effectiveness of antibiotics has been proven in different countries by the reduced mortality rates and increased productivity. HOWEVER, residues are real concern and the present a real threat for human health. Reducing antibiotic residues in meat and eggs is essential and has to be the objective of all professionals involved in poultry industry.
Bacterial respiratory diseases represent one of the most reason for using antibiotics.
Fowl cholera, caused by infection with Pasteurella multocida (PM), is a disease of many avian species. Chickens, turkeys, ducks, and quail are the most important domestic avian species involved and the disease is of economical significance. Although PM may induce lesions in multiple organ systems, respiratory pathology is the most important facet of the disease.
Infectious coryza is an upper respiratory disease of chickens caused by infection with Haemophilus paragallinarum (HPG). The disease is characterized by swollen infraorbital sinuses, nasal discharge, and depression. The disease is seen most commonly in adult chickens and can cause a very significant reduction in the rate of egg production.
Respiratory colibacillosis is a respiratory disease caused by secondary infection with pathogenic Escherichia coli. Escherichia coli is a ubiquitous organism in poultry production. Any insult to the respiratory tract of chickens and turkeys creates a climate for potential colonization of the respiratory tract by E. coli.
Ornithobacterium rhinotracheale causes a potentially severe disease in turkeys characterized by respiratory distress, facial edema, and swelling of infraorbital sinuses. The most striking lesion is unilateral or bilateral fibrinopurulent pneumonia. .
Bordetellosis is an upper respiratory disease, primarily seen in young turkeys, caused by infection with Bordetella avium. The disease is characterized in young turkeys by sneezing, oculonasal discharge, mouth breathing, tracheal collapse, and stunted growth. The disease is most commonly referred to as turkey coryza because its clinical appearance is somewhat similar to the clinical signs of infectious coryza in chickens.
One such class of comparable alternative is. In the last decade, alternatives such as natural source of herbs and medicinal plants have been increasingly used in broiler, layer and Japanese quail diets.
Poultry performance have been reported to be enhanced using these medicinal plants such as ''thyme'' (Thymus vulgaris) that may be an effective alternative to antibiotics in poultry production.