Did some further reading and sounds relatively common to add garlic or sulphur to cattle feed at sufficient rate to create a body odor which deters biting insects.
Seems like it could be effective on a captive deer population but dubious on wild deer herd. To create and maintain body odor deterrent would require frequent or constant feeding on garlic-infused feed or minerals. Garlic/sulphur concentration has to be high enough to have an impact without being so strong as to make unappealing to wild deer with other food options. One might smell like an Indian trucker within a few hours after a visit to the Clay Oven lunch buffet but that is resolved by the following day.
As the root cause is cattle which are much more feasible to manage, treating cattle is likely a better bet.