Abstract
Practicing proper biosecurity prevents the disease spreading, occurrence and also reduces
the use Of antibiotics in poultry farms. Improper dosages, neglecting withdrawal period and
indiscriminate use Of antimicrobial drugs in poultry birds cause drug residues having
adverse effects on public health. The objectives of this study were to determine the frequency
Of antibiotic usage in the flocks, to detect antibiotic residues and resistant bacteria in edible
tisues and to measure the biosecurity status of meat producing poultry farms. A cross
sectional study was undertaken including 496 farmers and 1046 edible samples during
April 2015 to 2018 from 21 upazilas Of districts in Bangladesh. The frequency
of antibioüc usage in the farms and the three hierarchies Of biosecurity practices were
determined through questionnaire survey. Thin Layer Chromatography and Ultra-high
performance liquid chromatography were used to screen and quantify selective antibiotic
residues in edible tissues. Isolation of organism and antibiotic sensitivity were performed
using established techniques. Twenty eight antimicrobials were used for 4-6 times per cycle
by the farmers. Of them 16 antimicrobials were used to treat human illness. The most
commonly used antimicrobials were oxytetrtacycline (76%), amoxicillin (75%), ciprofloxacin
(71.2%), sulfa drugs (64.3%) and enrofloxacin (633%). The highest mean concentration of
ciprofloxacin, enrofloxacin, oxytetracycline and amoxicillin were 26.84 mg/ kg wt. in
liver Of live bird market; 0.15 mg/ kg body wt. in muscle and liver samples of live bird market
and farm; 19.34 mg/ kg body wt. in liver Of farm; 612.7 mg/ kg body wt. in liver of farm
samples, respectively. However, in cooked tissues the highest mean concentration Of
ciprofloxacin, enrofloxacin, oxytetracycline and amoxicillin were 0.72 mg/ kg body wt. in
liver; 4.45 mg/ kg body wt. in breast & leg muscle; 0.42 mg/ kg body wt. in breast muscle,
68.54 mg/ kg body wt. in leg muscle, respectively. About 64 to 97.8% positive raw edible
tissues of different sources, 16.67 to 57.1 % cooked muscles and 77.3% cooked liver samples
exceeded the MRL of ciprofloxacin. Only 2.2% to 20% live bird market raw liver and kidney
tissue samples were exceeded the MRL Of enrofloxacin. The proportion of MRL exceeded
ciprofloxacin positive super shop breast and leg muscle declined from 64.0 to 46.7% and 68
to 27.3%, respectively after cooking. Similarly, the proportion of MRL exceeded
oxytetracycline positive super shop leg and breast muscle declined from 23.0 to 9.09% and
37.5 to 13.3%, respectively after cooking. About 50 to I(WÆ of the isolates Of the S. aureus,
Salomonella spp. and E. coli were found to resistant to at least 6 out Of 10 tested antibiotics.
The conceptual, structural and operational level biosecurity status were observed to be bad
to worst in 92 to 97% farms. There was a significant (psO.05) inverse relationship of frequency
of drug usage and the level of biosecurity practices. Empowering farmers in right decision
making to operate their farms through training and motivation may reduce the usage of
antibiotics and thereby reduces the odds of causing the drug residues in edible
tissues