The current indiscriminate use of antibiotics in poultry production systems raises safety concerns. To avoid this, farmers need to apply good agricultural practices that include deployment of bio-security measures and use of recommended vaccines. Here is how to do it:
Across the world, poultry meat and eggs are some of the most popular livestock products.
Poultry meat consumption rose significantly from 34.6 million metric tonnes (MT) in 1990 to 130 MT in 2020, according to the Food and Agriculture Organization (FAO).
In 2022, consumption of chicken meat, the most popular poultry product, is expected to hit 98 million MT, double the volumes eaten in 1999, the Organization for Economic Cooperation and Development notes in its latest report. And in less than a decade, adds the organisation, chicken will become the most consumed source of animal protein.
Affordability, worldwide production, low fat content and few religious and cultural barriers are some of the things that contribute to the high preference for poultry products.
However, the current indiscriminate use of antimicrobials in the poultry production systems raises safety concerns to animals, humans and the environment.
The main one is anti-microbial resistance (AMR). To overcome this challenge that has the potential to wipe out gains made in the poultry trade, farmers should familiarise themselves with the dangers of arbitrary application of antimicrobials.
Second, they need to know and apply good agricultural practices (GAPs) that will curb use of antimicrobials. These include deployment of bio-security measures and use of vaccines. Others are control of external and internal parasites, proper housing and feeding and environmental hygiene. Regulations should also be put in place to curb use antibiotics as preventive drugs, growth promoters and egg production enhancers.
Antimicrobial resistance (AMR)
AMR occurs when microbes/germs such as bacteria, viruses, fungi and parasites change over time and no longer respond to medicines, making infections harder to treat and increasing the risk of disease spread, severe illness and death. The main drivers of AMR are misuse and overuse of antimicrobials.
Further, lack of clean water, proper sanitation and inadequate disease control promote spread of drug resistant disease-causing pathogens, which are currently referred to as superbugs. AMR is a global health and development concern and the World Health Organization (WHO) has declared that it is one of the top 10 global public health threats facing humanity.
Misuse and overuse of antimicrobials in chicken production is common in Kenya. In a study carried out in Kiambu County, whose findings were published in the Pubmed Journal in January 2021, researchers from FAO, Kenya’s Ministry of Agriculture and College of Sciences in Makerere, Uganda, investigated the challenges of small-scale layer farms. They found out that 62 per cent of farmers were constantly using antimicrobials, some of which were referred to as magic drugs. These included tetracycline and tylosin. Misuse of antibiotics was done through treatment of all birds when only one of them in a flock was ill and use of the drugs to prevent diseases.
The study further showed that only 47.5 per cent of farmers had heard about withdrawal period, which implies that they continued selling and consuming meat and eggs that had traces of the drugs used to treat the birds. Further, it was found that the farmers were using antibiotics as growth promoters and egg boosters. This implies that the antibiotics were being used throughout the lifecycle of a bird. Here is how to avoid misuse of antiobiotics.
These include putting foot and or vehicle baths at the entry of the farm or from one poultry house to another to control spread of diseases from farm to farm, unit to unit. A footbath is a shallow trough that has a disinfectant that kills most germs on the feet and wheel of vehicles passing through it. This important disease control measure is rarely utilised. In the Kiambu study, the researchers found out that only 51 per cent of the respondents had footbaths at the entrance of their layer houses.
Out of those who had indicated that they had footbaths, 51 per cent described theirs as sponges/mats soaked in plain water (without soap or disinfectant), 33 per cent had mats soaked in disinfectant, 13.4 per cent had concrete troughs with plain water and 2.6 per cent had added disinfectant to the concrete troughs.
For this important tool to control diseases perfectly, it must have a broad-spectrum disinfectant that should be of the correct strength as indicated by the manufacturer’s label.
The chemical should also be changed regularly as it undergoes bio-degradation with time thus becoming ineffective. If possible, install troughs in a series so that the initial ones contain only clean water for removing dirt and the one next to the door has the disinfectant. You see, dirt dilutes the strength of the disinfectant.
Ensure that the trough or container is protected from environmental effects such as rainwater that is likely to dilute the disinfectant and direct sunlight, which evaporates the water necessitating frequent addition.
Other biosecurity measures include installing a perimeter fence on the poultry farm or house and use of personal protective equipment (PPE), regular cleaning and disinfection of feed and water equipment as well as regulating human traffic to the poultry establishments.
Vaccines have been able to transform traditional poultry keeping into thriving enterprises, attracting people of all ages through the income offered by the agribusiness. However, disease outbreaks continue to be experienced among vaccinated and unvaccinated birds despite the high effectiveness of vaccines. This leads to use of antimicrobials to control the diseases thus leading to AMR. For vaccines to work, here are the dos and don’ts:
Cold storage: Always use cool boxes/ice packs to transport vaccines that require low temperatures.
High percent coverage: Ensure that you administer a vaccine to all birds in a flock using an appropriate route. For example, whereas it is easy to administer Newcastle Disease (NCD) vaccine through drinking water to layers and broilers because they consume dry feeds and thus take a lot of water, it is advisable to administer NCD vaccine though the eye or nose route to free-range or unconfined birds as they might not consume water within the stipulated time.
Constitute the vaccine with the recommended amount of water so that the birds finish it in one hour. Thereafter, you can add more water. Water with reconstituted vaccine should be placed in a cool environment as high temperatures inactivate the drug.
Hygiene: The vaccine handler should ensure that his hands are clean and any equipment or tool used for vaccine administration is also clean. Administer vaccines early in the morning or late afternoon to minimise handling and weather stress.
For injectable vaccines, use sterile non-expired vaccine diluents issued by the manufacturer of the drug.
Mature and trained personnel should do the vaccine administration. For vaccines that are administered through drinking water, withdraw water for not more than one hour before provision of the vaccine water so that birds get thirsty.
Have an assistant to restrain the birds when administering vaccines that are not applied through drinking water.
Vaccination schedule: Diseases commonly controlled through vaccines are NCD, infectious bursal disease (Gumboro), infectious bronchitis (IB), fowl typhoid and fowl pox. Commercial producers are normally issued with a vaccination schedule upon purchase of chicks, thus, all you need to do is follow the schedule judiciously for effective vaccination.
For producers of local/improved indigenous chickens, a likely vaccination schedule includes administration of Gumboro at Day 10 and a booster at Day 18; NCD and fowl pox at three weeks and fowl typhoid at eight weeks.
NCD boosters should be administered after six weeks and, thereafter, every 3-6 months depending on disease challenges in the area. The early NCD vaccines should be the ones combined with IB. Vaccine manufacturers need to produce vaccine packs of 25 and 50 doses for Gumboro, fowl typhoid and fowl pox, just like in the case of NCD. This is because most indigenous birds farmers have less than 50 birds.
Use treated (chlorinated) or borehole water, which is too salty to reconstitute the vaccine. Instead, use rainwater or nose, eye drop preparations instead of those that are administered through drinking water.
Vaccinate stressed birds or those showing signs of disease.
Administer vaccines in metal drinkers as they are likely to react with the vaccine
Dr Mwirigi is a livestock production specialist. [email protected]