Influence of garlic (Allium sativum) feed inclusion on production performance and health of commercial chickens


The use of antibiotic growth promoters in poultry production has been banned in many parts of the world.  Synthetic antibiotic growth promoters are banned because of prevalence of antibiotic-resistant bacteria in both human and animal populations which has proved to be a challenge to effective therapy when infections occur. Furthermore, the detection of antibiotic residues in poultry meat and table eggs in Nigeria has turned consumers into passive users of these antibiotics with potential risk of ineffectiveness when the antibiotics are indicated for therapy.  These unpleasant side-effects of the use of antibiotics as growth promoters prompted the search and underscore a need for alternatives, preferably organic sources of growth promoters in poultry. Garlic (Allium sativum) has been shown to exhibit antimicrobial, antioxidant, and anti-hypertensive properties and could therefore serve as an alternative.


This University of Ibadan research project is designed to evaluate the potentials of garlic as a growth promoter in chickens through the assessment of production performance; markers of immune status and disease tolerance. The active components (allicin and alliin) of the different varieties of garlic available in Nigeria will be quantitatively assessed to determine the most potent variety which will be used in the preparation of garlic meal. Groups of commercial layers will be fed graded levels of garlic meal as inclusion in feed from day-old. Production parameters and markers of health status (immunity, haematology and serum biochemistry) in the layers will be evaluated. Organoleptic properties of the poultry meat will also be assessed.


Groups of commercial broilers placed on garlic inclusion (in feed) will be experimentally infected with infectious bursal diseases virus, Salmonella gallinarum and oocysts of Eimeria spp. (representing three classes of economically important poultry pathogens in Nigeria). The influence of garlic on the  clinical and pathological effects of infection in these  broilers will be assessed. Organoleptic properties of uninfected broiler meat will be assessed and compared.


A benefit-cost analysis of the inclusion of garlic meal in feed of commercial layers will be carried out to determine its profitability. Once the presumed advantages of the use of garlic as a growth promoter in chicken has been confirmed, the product will be introduced for poultry farming and promoted for commercial use.


This project is expected to:

  • Provide empirical information on the potentials of garlic as a growth promoter.
  • Encourage the replacement of antibiotics with garlic as an organic growth promoter with consequent reduction in production cost and availability of more wholesome meat and table eggs for human consumption.
  • Ultimately reduce the occurrence of antibiotic-resistant bacteria associated with poultry and protect human health.


The garlic meal can be packaged and sold to poultry farmers as an organic growth promoter with specific recommendation about in-feed inclusion rate and expected outcome.




Research Leader


    Dr. Omolade A. Oladele, MCVSN   DVM., MVSc. (Clinical Pathology), Ph.D (Avian Medicine)

    Consultant, Poultry Medicine,     Avian Diseases Unit

    Department of Veterinary Medicine,

    University of Ibadan.



Collaborating Research Leaders:


Dr. O.A. Abu       BSc, MSc, PhD (Animal Science)

     Department of Animal Science,

     University of Ibadan.


Dr. Olufunke O. Ezekiel     BSc, MS, Ph.D (Food Technology)

     Department of Food Technology,

     University of Ibadan.




Dr. O.O. Esan      DVM., MVSc.( Avian medicine),

     Lecturer, Avian Diseases Unit

     Department of Veterinary Medicine,

     University of Ibadan.




Dr. Olutola Oyedele      BSc, MSc. (Horticulture), Ph.D (Agricultural Extension)

     Assistant Director (Research)

Team Leader, multidisciplinary team on capacity building, extension communication and women in horticulture.

Extension Research Programme

     Department of Farming Systems and Extension Research

     National Horticultural Research Institute,




Mrs. Oluyemisi Adewale     BSc (Agronomy)

     Senior Research Officer, Spices Research Programme

 National Horticultural Research Institute,



Dr. S. O. Oyebode    DVM.

 Postgraduate Student & University Scholar

Avian Diseases Unit,

    Department of Veterinary Medicine,

    University of Ibadan.