Vet on call: Be wary of the visitors on your livestock farm

Elizabeth Akinyi feeds her six month old pigs at Green Estate in Elburgon, Nakuru County. She is working on increasing her herd through good feeding and maintaining high standards of hygiene to curb diseases

Photo credit: John Njoroge | Nation Media Group

What you need to know:

  • External biosecurity is a raft of measures that a farmer implements on the farm to prevent diseases from outside from reaching the livestock.
  • When you embrace external biosecurity, you focus on the critical areas of contamination of the farm from the outside world and execute measures to prevent disease-causing organisms from entering or leaving the farm
  • Visitors bring pathogens or disease-causing organisms to your farm on their hands, clothes and feet.
  • Animals such as dogs, cats, birds, insects and reptiles should be kept out of livestock houses. They carry a lot of pathogens that may cause diseases in your animals.

Peter from Kajiado County called me this week to report that he was happy with the disease control plan I prescribed for his pig farm.

He said he had come to appreciate the concept of external biosecurity. The farmer added he had kept his pigs of all ages healthy with very little use of drugs since 2019.

External biosecurity is a raft of measures that a farmer implements on the farm to prevent diseases from outside from reaching the livestock.

I met Peter in 2018 when he wanted to exit pig farming. His herd had been struck by what he termed a strange disease that killed any pig that got infected.

When I visited him, only a few pigs remained. I diagnosed the deadly African swine fever (ASF) and advised him to destroy the surviving pigs.

When ASF affects a farm, all the sick and apparently healthy animals have to be destroyed and the farm rested for three to six months before restocking.

Peter’s dilemma was whether he could really go back to pig farming or he should just abandon the whole idea despite the heavy investment.

After a lot of discussions, he decided to restart his project and follow professional veterinary medical advice.

The farmer had a big challenge since he had to also heavily disinfect his piggery and redesign it to be hygienic.

“Am I building a hospital or a piggery doctor?” he asked when I explained what he needed to do.

Treated like visitors

You see, Peter like many other farmers had neglected external biosecurity measures. One big mistake stood out, but the intention had been well-meant as a cost reduction measure.

He had teamed up with other pig farmers in the area for a single feed delivery service. The truck would go round the farms dropping the feeds once per week.

Unfortunately, it also picked up the virus somewhere on its circuit and distributed to all the farms, with devastating consequences.

When you embrace external biosecurity, you focus on the critical areas of contamination of the farm from the outside world and execute measures to prevent disease-causing organisms from entering or leaving the farm.

The measures taken depend on the type of livestock and farm. However, there are certain interventions that are common to all livestock farms.

Visitors, vehicles, live animals and dead animals are the main causes of biosecurity failure in most farms.

Visitors bring pathogens or disease-causing organisms to your farm on their hands, clothes and feet. You should limit the number of visitors to your facility and minimise their contact with your animals.

All should wash their hands with soap or sanitise, wear gloves, clean coveralls and boots before touring your facility.

You should keep a register of all visitors. Anyone who has been in contact with sick animals should not interact with your animals. 

All visitors should disinfect their feet before entering the farm and the animal compound. Farm workers should be treated like visitors any time they step out of the animal houses or the farm.

Disinfected and cleaned thoroughly

Transport of farm inputs and services is often overlooked as a disease vector. Ensure all vehicles enter through a good disinfection bath. The vehicles should also be sprayed with an authorised disinfectant.

Animals introduced into the farm should be kept in a quarantine area for 10-14 days before being mixed with the resident stock.

During the quarantine period, they should be cleaned with pesticides and dewormed. They should also be examined for signs of diseases and treated.

Scientifically, it is known that most diseases will show signs between 10 and 14 days from the date of infection.

Animals such as dogs, cats, birds, insects and reptiles should be kept out of livestock houses. They carry a lot of pathogens that may cause diseases in your animals.

I recall a farmer who had repeated coccidiosis in her chickens. When I visited the farm, I found she had introduced two cats in the chicken house to deal with rats. Both the cats and the rats were contributing to her coccidiosis problems.

Most people do not treat dead animals as a source of infections on the farm. Remember, most animals die of disease whether diagnosed or not.

Carcasses of animals from different units of the farm should be promptly removed and properly disposed of before they start decomposing.

I have seen workers dragging carcasses through the corridors of livestock houses. That is a very efficient way of spreading diseases.

Carcasses should be wrapped with waterproof material such as plastic and carried out of the facilities.

If the whole carcass cannot be wrapped, then the head and the back end should be wrapped to prevent leakage of body fluids.

Areas where carcasses laid should be disinfected and cleaned thoroughly.