Abstract
The objective of this study was to evaluate the efficacy of a Nutrient Synergy (NS; Blend of nine nutrients) in maintaining the performance and alleviating the pathologic effects in broilers challenged with a high and a low dose-E. coli, following a primary challenge with H9N2-avian influenza virus. Six groups of broilers were included (19 birds/group). Each bird in group 1-4 received at an age of 20 d. a primary intratracheal challenge of 2 HA Units of H9N2 virus. At the age of 23 days, birds of groups 1 and 3 received a high dose-E. coli challenge in the right thoracic air sac (1.5x 10 9 cfu/0.5ml/bird), while birds of groups 2 and 4 received-E. coli challenge in the same,I low close route (1.5 x 106 cfu/ml). The initiation of a NS-daily administration, intraesophageally. was according to the manufacturer instructions (Epican Forte (R)) (976 mg/Kg of body weight). The treatment was restricted to birds in groups 3, 4, and 5, effective the age of 17 days and Until 28th day of age. Birds of group 6 were unchallenged and Untreated.However, the average weight and feed conversion at 28 days of age was significantly improved (p<0.05) in the NS-treated group compared to NS-deprived group, with similar low dose-E. coli challenge. The frequency of ocular exudates-sign and diarrhea at 2 days post the E. coli challenge dropped significantly (p<0.05) in the NS-treated groups in comparison to deprived birds, with a similar dose of E. coli challenge. The frequency of diarrhea was kept low at 5d. post-challenge, with the high dose of E. coli in birds treated with NS (P<0.05). The frequencies of the right and left thoracic airsacculitis, and the frequency of pancreatitis were reduced significantly in NS-treated birds with low-dose E. coli in comparison to similarly challenged birds, deprived of NS (p<0.05). However in the high-dose E. coli. challenge groups, the NS treatment lowered only the frequency of abdominal airsacculitis (P<0.05).