Heavy metals in broiler chicken ‘far below’ tolerable limit: BARC

Infographic: TBS

A latest research has found antibiotics and heavy metals in broiler chicken "far below" the tolerable level.

Broiler chicken meat, bones and composites contain two antibiotics – oxytetracycline and doxycycline – and three heavy metals – arsenic, chromium and lead, but they were far below the tolerable level, according to the research conducted by the Bangladesh Agricultural Research Council (BARC) and funded by the agriculture ministry.

This means broiler chicken is safe for consumption and not dangerous for public health, said Agriculture Minister Md Abdur Razzaque while presenting the findings of the research at the Secretariat on Thursday.

About 315 samples prepared from 1,200 broiler chickens and 30 types of broiler chicken feeds were tested for 10 antibiotics and three heavy metals. Samples for the research conducted during January-June 2022 were collected from small, medium and large firms in Dhaka, Gazipur, Chattogram, Rajshahi and Barishal.

Antibiotics were found in 70% of the chicken meat samples and heavy metals in 90% of the samples.

Head of the research team and BARC Chief Scientific Officer (Livestock Division) Mohammad Rafiqul Islam, told TBS, "Antibiotics and heavy metals are present in most of the samples, but it is far below the acceptable level, which is not harmful to health."

A study by a group of Bangladesh Agricultural University researchers, published in the Nature journal on 25 June last year said chickens found in five key kitchen markets in Dhaka contained superbugs resistant to some of the strongest antibiotics at alarming levels. As a result, 67% of the most common and important antibiotics do not work on the human body.

According to a Chattogram Veterinary and Animal Sciences University study on 137 commercial farms in different regions of Chattogram, 38.6% of the farmers used antibiotics for better growth of chickens and 10.2% were using antibiotics to improve the quality of their chickens and eggs.

"We identified that inappropriate usage of antimicrobials (behaviour) was strongly driven by farmers' short-term goals to maintain the health of their chickens in a production cycle, rather than long-term concerns," said the researchers in the paper titled "Social and cognitive factors influencing commercial chicken farmers", published on Scientific Reports journal on 11 January this year.

Highlighting the results of BARC's research, Agriculture Minister Abdur Razzaque yesterday said broiler meat contains an average of 8ppb (parts per billion) of oxytetracycline, 9.1ppb of doxycycline, 6.2ppb of arsenic, 190.7ppb of chromium and 259.1ppb of lead, which are 12.5 times, 10.9 times, 6.5 times, 5.2 times and 23.1 times less than the maximum permissible limit respectively.

Similarly, bone samples from broiler chickens showed an average of 53.7ppb oxytetracycline, 27ppb doxycycline, 7.2ppb arsenic, 439.9ppb chromium and 464.6ppb lead, which were 1.8 times, 3.7 times, 5.5 times, 2.27 times and 12.9 times less that the permissible limits respectively.

Broiler chicken composite (combination of liver, kidney and gizzard) contained an average of 14.5ppb oxytetracycline, 17.2ppb doxycycline, 10.9ppb arsenic, 239.2ppb chromium and 307.6ppb lead, which were 6.8 times, 5.8 times, 3.6 times, 4.18 times and 19.5 times less than the maximum limit respectively.

The agriculture minister said, "Many of us have misconceptions or doubts about whether it is safe to eat broiler chicken. Many campaigns say that broiler meat contains antibiotics, heavy metals and other harmful substances, which are harmful to human health. Misconceptions about broiler meat have led people to reduce consumption, which has had a detrimental effect on the broiler industry.

"Studies have found the antibiotics oxytetracycline, doxycycline, tylosin, arsenic, chromium, and lead in broiler chicken feed, but their amounts were much lower than harmful levels."

The BARC researchers tested samples for seven of the 10 antibiotics (enrofloxacin, ciprofloxacin, neomycin, tylosin, colistin, amoxicillin and sulfadiazine) at SGS Laboratory, Chennai, India through SGS Bangladesh Ltd. The remaining three antibiotics (chloramphenicol, oxytetracycline and doxycycline) and three heavy metals (arsenic, chromium and lead) were tested at the ISO certified and accredited Quality Control Laboratory, Savar under the Department of Livestock Services.

The agriculture minister said the use of tannery waste in chicken feed is completely unfounded, because, currently the demand of poultry feed in the country is 95 lakh tonnes, and cattle feed is 145 lakh tonnes, while total tannery waste is only 85,000 tonnes.