Abstract
This study evaluated the use of Mentofin,(R) a natural Eucalyptus/Peppermint essential oil-based preparation, in treatment of broilers with multiple viral and bacterial infections in their respiratory system, a condition that is prevalent in poultry industry of most parts of the world. Eighty day-old broiler chicks were divided into four treatments (two replicate pens/treatment with 10 birds/pen). Birds of the four treatments were all vaccinated with live Infectious Bursal Disease Virus (IBDV) (intra-esophageally) and with live Newcastle disease virus (intra-occularly), at 10 and 18 days of age. Each bird in treatments 1 and 2 was challenged intra-tracheally at 7 days of age, with 1.6x 104cfu / 50 mu l / bird of viable Mycoplasma gallsepticum organism.
The birds in treatments 1 and 2 were each challenged intratracheally at 28 days of age, with 0.5 ml of a mixture containing H9N2-avian influenza virus (2 HA units / bird) and intermediate Infectious Bronchitis virus (IBV) (10x log 3.6 EID50 / bird), and another intrathoracic challenge with a 0.1 ml mixture of H9N2 (2 HA units / bird) and IBV (10 x log 3.6 EID50 / bird).
Mentofin treatment was given to birds of treatments 2 (challenged) and 3 (unchallenged) in 250 ml Mentofin / liter of drinking water at 14-16 days of age (starting treatment at 7 d post the MG challenged and 4 d post the first vaccination, and ending treatment at 2d before the second vaccination).
The Mentofin treatment was repeated in birds of groups 2 and 3 in the same concentration of drinking water, at 30-32 d of age (starting treatment at 2 days post IB/H9N2 challenge). The 4th treatment group was the control, deprived of all challenges and Mentofin treatment. The Mentofin treatment reduced the mortality in challenged and unchallenged birds, improved the feed conversion in unchallenged birds, reduced specific signs and lesions, homogenized the creatinine level in challenged birds, as indicated by the low Coefficient of Variation, reduced the immune reaction to the H9N2 challenge and to IBDV intermediate strain, and boosted the vaccine immunity to the NDV vaccine.