The good, the bad and the ugly of antibiotics in birds

10th Aug, 2019
The good, the bad and the ugly of antibiotics in birds
Molecular Geneticist and Animal Biotechnology group leader, Dr Sheila Cecily Ommeh (left) with biotechnology students at Molecular Genetics Laboratory at JKUAT's main campus on Thursday, May 09 2019. JKUAT has embarked on efforts to kick-start invention of improved vaccine for indigenous chicken through sustained scientific research. [David Njaaga, Standard]

Elijah Musyoka nearly lost an entire flock of 500 layers when he started poultry farming in 2014.

He had bought a large number of chicks unaware they could not fit in the structure that measured 24 by 14 feet which he had constructed for his venture in Kwale.

As the chicken grew, the breeding space became smaller and the stressed birds began pecking and tearing into each other’s flesh. In no time, the cannibalism had spread and he was losing more than 10 birds a day.

Give your birds space

Musyoka, who studied accounting, admits the miscalculation is the worst mistake he ever made in poultry farming. “When I just started, I never knew each bird required a breeding space of 2 by 2 feet and I instead bundled them up in a small space,” says Musyoka.

A novice in the venture then, Musyoka tried several drugs before calling a veterinary officer who revealed that the stressed birds were only venting on each other and didn’t need medication.

Philip Murunga, a PhD student at Jomo Kenyatta University of Agriculture and Technology (JKuat), says overcrowding in breeding spaces exposes poultry to stress and diseases.

Antibiotic use in poultry farming

He says to keep birds off viral and bacterial diseases in these crowded spaces and to ensure the chicken stay healthy even in deplorable conditions, feed manufacturers have been adding little amounts of antibiotics to the feeds. They also do this to entice farmers into buying their feeds.

“Due to the increased demand for poultry and poultry products, attempts have been made to intensively raise poultry in large numbers while using smaller floor space in confinements. This makes birds stressed and vulnerable to poultry diseases, especially those caused by bacterial infections,” says Murunga.

He adds: “To counter this and make their feeds more appealing to farmers, some animal feed manufacturers add antibiotics in therapeutic doses to prevent disease outbreak, increase feed utilisation and boost growth.”

Studies indicate that little amounts of penicillin, streptomycin and bactrican and a variety of other antibiotics used to treat bacterial diseases are common additives in feed for livestock and poultry.

Effects of misuse of antibitotics

Mr Murunga says feeding chicken that are not sick on antibiotics has led to an increase in resistance to the drug.

In a survey released in April, the World Health Organization found out that more than 50 per cent of antibiotics in many countries are used inappropriately. “Antibiotics in many countries are used inappropriately such as for treatment of viral diseases which are otherwise meant for bacterial pathogens, or even using a wrong antibiotic against a particular bacterial disease,” read the WHO report.

Dubbed ‘Securing The Future from Drug-resistant Infections’, the report warned that misuse of antibiotics was contributing to the spread of antimicrobial resistance in poultry, animals and even humans.

And in his research supervised at JKUAT’s Institute of Biotechnology Research (IBR), Murunga is surveying inappropriate use and misuse of antibiotics among poultry farmers. He has interviewed farmers in the coastal counties and Nairobi who he says misuse antibiotics when they treat their chicken without proper guidance from extension experts.

“We observed that some low income poultry farmers keeping backyard poultry under free range also use antibiotics indiscriminately for treating any poultry that shows a disease sign without seeking the input of veterinary experts,” says Murunga.

In a past interview, Dr Sheila Ommeh, a molecular geneticist at IBR said desperate farmers do the unthinkable to manage Newcastle disease and other poultry diseases. “The farmers we have are those I describe as impatient optimists. They are farmers who will do anything but sit and watch their chicken die. I have seen farmers who gave their chicken paracetamol and other painkillers when they saw signs of Newcastle disease in their birds,” said Dr Ommeh.

Murunga’s study also found out that many farmers who kept backyard poultry battled poultry diseases such as fowl pox, infectious coryza and New castle disease. Other poultry diseases in these regions included infectious bursal disease, fowl cholera and fowl typhoid.

Adulterated poultry feed

Farmers who bought the commercial feeds risked falling prey to unscrupulous manufacturers who added antibiotics to the feeds to attract the unsuspecting farmers.

Musyoka, who rears more than 2,000 layers, suspects he once bought feeds that were contaminated.

He recalls experiencing one of his biggest losses in poultry farming in May when some of his birds stopped laying eggs. On May 1, Musyoka collected only 18 trays from 2,000 chicken. This was a major drop given that he had collected 36 trays the previous day.

In the few days that followed, the yield plunged from 80 per cent and he was now collecting less than 15 per cent from the birds. This significant plunge in production worried the Kwale farmer who says he had done everything possible to ensure that the birds’ yield was high.

He had kept all the biosafety requirements in the coop including washing his feet with disinfectant before he entered the coop. This, he did to prevent any possible infections to the birds. He had ensured the aeration and heat conditions in the chicken space were also at optimum levels. But still, the birds could not lay as they were expected.

It wasn’t until other farmers started complaining about the plunge in production at their own farms that Musyoka suspected the feeds he bought were contaminated by the manufacturer.

“We knew the feeds were contaminated because all affected farmers had bought the feeds from the same manufacturer. Nothing had happened to poultry farmers who bought feeds elsewhere,” says Musyoka, adding that everything went back to normal shortly after he started buying from a different feeds manufacturer.

Antibiotic resistance

Even then, other farmers do not strictly adhere to the withdrawal period recommended for poultry that are on antibiotics before selling their products such as meat and eggs to the unsuspecting consumers and exposing them to antibiotics.

This use of low doses of antibiotics, the researcher says, is the primary cause of antibiotic resistance to some pathogenic bacteria. “Antibiotic resistance can be transferred to the consumer and create resistance to common antibiotics treating human infections. This is of great concern to the poultry industry and the consumer alike,” says Murunga.

Statistics by WHO indicate that because of abuse of antibiotics, drug-resistant diseases are accounting for at least 700,000 deaths globally a year. WHO further estimates that this could increase to 10 million deaths globally per year by 2050 if no action is taken.

Regulating use of antibiotics

The JKUAT researcher says clear policy on the inclusion of antibiotics by manufacturers in poultry feeds will prevent misuse of these drugs.

He urges animal nutritionists and veterinary experts to consider encouraging farmers to use probiotics and prebiotics in the place of antibiotics. Probiotics are live feed supplements such as bacteria that promote growth and health in poultry. These supplements also boost productivity and quality of poultry meat.

“Probiotics inhibit the spread of intestinal pathogens by competing for nutrients, producing antimicrobial conditions, lowering intestinal pH and stimulating the immune system in poultry,” he says.

Additionally, he says, there is need to sensitise poultry farmers on the importance of making use of extension services for advice on correct diagnoses of poultry diseases and on the need to get proper drug prescriptions for poultry diseases.

Dr Ommeh says new technologies in chicken rearing have led to over-reliance on commercial feeds. “In the past, people allowed their chicken to scavenge for their own food and while at it, the chicken picked things that were medicinal. But with the increasing commercialisation of poultry products where chicken are reared in controlled spaces, farmers have continually relied on manufactured feeds. Some of these feeds have antibiotics added to them,” says Dr Ommeh.

She blames mistakes made by farmers who administer drugs blindly on the declining extension services where the number of extension officers has dropped.

Dr Ommer says Murunga’s research is timely. 

“The study will establish the status of misuse of antibiotics among poultry farmers. Hopefully, it will be picked up by policy makers who will in turn regulate the use of antibiotics to safeguard human health and improve agricultural productivity.” 

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