Evaluation of bacteriophage supplementation on growth performance, blood characteristics, relative organ weight, breast muscle characteristics and excreta microbial shedding in broilers.

A total of 720 1-d-old male broilers (Arbor Acres) with the initial BW = 45+/-2 g were used in a 32-d experiment. Birds were randomly allotted into 1 of 4 treatments according to a completely random block design. Dietary treatments included: i) CON (basal diet), ii) ANT (CON+0.5 g antibiotics/kg feed (bacitracin methylene disalicylate)), iii) BP1 (CON+0.25 bacteriophage/kg feed), and iv) BP2 (CON+0.5 g bacteriophage/kg feed). The BWG and FT were not affected by dietary treatments throughout the whole experiment, whereas BP2 treatment reduced (p<0.05) the feed conversion ratio compared with the CON treatment during 0 to 14 d. The birds fed bacteriophages at the level of 0.25 g/kg increased (p<0.05) the relative liver weight. The inclusion of antibiotic and bacteriophage significantly reduced (p<0.05) the Escherichia coli and Salmonella concentration in the excreta compared with the NC group. Broilers fed the BP2 treatment had higher (p<0.05) lactobacillus counts compared with those fed NC and PC treatments. In conclusion, dietary supplementation of 0.5 g/kg bacteriophages increased feed efficiency and liver weight without effects on the breast muscle properties; also pathogens were inhibited by addition of bacteriophages.