Veterinary drugs have been extensively used in animal production for the prevention and treatment of animal diseases. The imprudent use of these drugs could lead to presence of residues in animal-derived food like meat and eggs This cross-sectional study was conducted to determine the presence of antibiotic residues in eggs collected from seven-layer farms in Nueva Vizcaya. A total of 120 eggs were collected and tested.

Using the six-plate microbiological assay, 17.5% (21/120) of the egg samples were detected to contain antibiotic residues. Of the six antibiotics tested in eggs, sulfonamides class ranked highest in occurrence with 10.83% (13/120), followed by aminoglycosides at 9.61% (11/120) and penicillin at 0.83% (1/120). The result correlates significantly (P<0.0000001) with the antibiotic that is commonly being used in the positive farms Macrolides, quinolones and tetracycline residues have not been detected on all of the egg samples tested Four of the positive egg samples contain two types of residues, three (14.28%) has both sulfonamides and streptomycin while one (4.76%) has both penicillin and sulphonamide residues At the farm level, three of the seven (42.85%) farms have samples positive for residues Survey results however, showed that all of the seven farms were using veterinary drugs during the laying period of chickens Results of this study are very relevant as this indicated the imprudent use of antibiotics in layer chickens and therefore a need for mandatory testing of eggs intended for human consumption and to an intensified monitoring and surveillance to ensure food safety.
 

Thesis (Doctor of Veterinary Medicine)

includes appendices and bibliographical references.