Tick resistance in cattle

Working in the Northern Fontier District

After my FAO Fellowship ended and I joined the ICIPE and my work shifted towards the understanding of the resistance that some cattle have against ticks. Some colleagues there were working on a tick vaccine while I was given the task of exploring the natural resistance that is observed among cattle in the field.

At the time there were reports of animals that were refractory to ticks while the opposite also happened, a few animals in the herd carried most of the ticks and culling them was recommended to reduce tick populations in the long term. We needed tp prove this in Kenya, in an area free of Theileriosis as the work demanded to stop the application of chemicals to kill the ticks.

Boran bull Mutara copy

Beautiful Boran bull.

After discussions with colleagues and with the agreement of the Government of Kenya’s veterinary authorities it was agreed that we would focused our work on Mutara Ranch in Laikipia District where the Agricultural Development Corporation had the National Boran Stud. They were prepared to let us work on a group of one hundred young bulls to determine their resistance status.

After the trial preparation period we started with the work that lasted for six months. We got a number of interesting results that confirmed the hypothesis that tick distribution in the herd was normally distributed with a few bulls carrying few and lots of ticks while most were somewhere in between.

mutara

Working. From left to right Mark, Henry, Joseph, Bushsnob, Gitau and the other Henry.

So, we decided to compare our list of best ranked bulls for tick resistance with those of the Farm Manager for physical quality and body built. Our best animals for tick resistance did not match those regarded as best by the Manager! Although this was not what we expected and a disappointment as it was clear that selection would take a longer route than anticipated, the geneticists and statisticians unanimously agreed that the consistency of the results merited continuation[1].

We then entered in collaboration discussions with geneticists from Texas’ A&M University in the United States to expand the work and, with them, planned a series of follow-up trials. Unfortunately, the research group dispersed and myself and another of the collaborators departed from Kenya and the work stopped there.

In addition to doing very interesting work, my regular visits to Mutara gave me a great opportunity to explore some areas of the Northern Frontier District, a fascinating area that I mentioned in my previous post. These safaris follow next!

 

[1] Results of the work are published and those of you with a scientific mind can access the publication. See:https://www.researchgate.net/publication/337857245_Towards_the_selection_of_cattle_for_tick_resistance_in_Africa