Tushabe was fighting the urge to wake up when he finally opened his eyes and heard cows mooing, this time not from his kraal, but a distant homestead. The usual poignant smell of cow dung was absent and he wondered why. As he stepped into the grey morning, he shrieked so loudly that the entire village woke up. Only three out of 20 cattle were left standing. The rest had died in the night.
Men huddled by his kraal, smoking tobacco. His family stood in dismal doorways in the compound, waiting for whoever could name this catastrophe in spite of the fact that the 20 heads of cattle had recently been sprayed with a tick-control drug.
Since 2012, cattle deaths due to tick-borne diseases (TBD’s) in Uganda have been on the rise due to escalating tick resistance to acaricides.
With the future of chemical tick control under serious threat due to reports of emergence of multiple acaricide resistance, the latest innovation on herbal acaricide provides farmers with hope for a lasting solution, given its prolific efficacy in killing ticks. The overall efficacy of the herbal acaricide in killing acaricide resistant ticks ranges between 80.7 to 92.6 per cent, more effective than the chemical types currently available.
According to the lead researchers, Dr. Moses Walijjo and Mr. Amuza Nshabaruhanga from the Pharmacy Department at Makerere University, “the herbal acaricide is a product that will kill ticks that are not responding to the available medicine”.
The making of the herbal acaricide:
The herbal acaricide is made from bioactive extracts of Albizia Coriaria, whose biggest component is within the stem of the plant, also referred to as Mugavu in Luganda. It is believed that local communities in Karamoja use it to eliminate ticks.
During the research, the plant stem and barks were obtained from Rakai district and authenticated by botanists at the Department of Chemistry. These were left to dry for three weeks before being ground to obtain an extract. With the current acaricides being water based, the researchers used 70 per cent ethanol to obtain the extract, which was then stored in amber bottles that provide protection from light.
The researchers employed freeze drying to obtain the component without subjecting it to heat.
While sampling three farms in Kiruhura district, the researchers found that farmers were using insecticides used in plants to treat livestock, which posed a different risk to the animals. The ticks collected from these farms were incubated at the College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB) for two weeks to provide a larva, which was then subjected to the herbal acaricide.
Results
Ethanoic extract and herbal acaricide of the stem barks of Albizia Coriaria was found to have a significant acaricide activity against the larvae of acaricide resistant Rhipicephalus ticks from the three farms in Kiruhura district.
When researchers used a concentration of 200mg/ml for both ethanolic extracts and herbal acaricide, it recorded a high mortality/efficacy of 81 to 92 per cent. The level of tick resistance ranged from 7.4 to 19.3 per cent.
The researchers, however, pointed out the need to conduct further study on the herbal acaricide. “We have so far been successful with 23 tests out of the 26 being conducted at COVAB. We would also like to explore the possibility of manufacturing its bioactive component from the laboratory,” said Dr. Walijjo, one of the lead researchers.
He added that more studies are ongoing to determine whether the herbal acaricide can be effective when applied and the animal is exposed to direct sunlight. Dr. Walijjo said they were committed to developing novel products from plant extracts, because it would be a promising alternative to failing synthetic acaricide.
The new research, funded by the Government of Uganda through the Makerere University Research and Innovations Fund (MAKE-RIF), will help in responding to the unprecedented level of acaricide failure due to the emergence of multi-acaricide resistant ticks ravaging the country.
The breakthrough is also expected to improve livestock production, an integral part of the household food and income security in Uganda, with a nine per cent GDP contribution from livestock.
By Geroge Bush Ocen
