Beef Cattle Tick Count Recording
3.10 Tick count recording
Management aspects
The aim with the recording of tick counts is the evaluation of the genetic variation between animals for tick susceptibility. For this reason, it serves no purpose to do tick counts on animals that are not exposed to tick infestation.
Guidelines
- Tick counts should be done on groups of animals that are kept in their natural environment (e.g. natural pastures), where they are exposed to ticks. (There is normally little or no exposure to tick infestation in feedlots, resulting in little or no variation in tick loads between animals).
- Tick-control measures:
- The ideal is not to apply dipping or other tick-control measures on the particular group of animals for the testing period. However, this is not always possible if the tick infestation is severe.
- If dipping or other tick-control measures is needed during the testing period, the following guidelines should be followed:
- Record tick counts immediately before dipping or the application of other tick-control measures. The ideal is not to dip or to use other tick-control measures on the to-be-recorded animals for at least three weeks prior to the tick count recording date.
- This period should be selected based on:
- The effective period of the particular dip or other tick-control measure(s) being used. (A minimum of two weeks for long-acting remedies and a minimum of one week for short acting remedies is recommended).
- The dominant or major tick species in the specific region/area. (The one-host blue ticks which have a three-week life cycle and a shorter than three-week dipping interval would allow only infestation of immature blue ticks. Because the immature ticks are very small, they may easily be missed during counting. An ideal dipping interval would therefore be three weeks. This is of course not always possible in situations of heavy multi-host tick challenge, but is essential if any data is to be obtained in areas where the one-host blue ticks are the only or major tick species present).
- The general degree of tick infestation of that particular group of animals at the specific location and point in time.
- Tick count recordings should preferably be done during the season or period of expected high tick infestation - usually the warm (summer) months. The reason is that heavier tick infestation will increase the expression of genetic variation in tick resistance of individual animals, which in turn will be beneficial for genetic evaluation of tick resistance.
- Tick counts should preferably be done at a minimum of three or more occasions during the test period, with ideally at least three weeks between any two consecutive dates. This will increase the accuracy of the genetic evaluations.
- Each date during the test period on which tick counts are taken, should be recorded as a separate count or record for each animal.
- All tick species and types irrespective of sex and stage of maturity at a specific counting site should be counted at each event date on which counts are done during the test period.
- Each site on the animal where tick counts are done, should be recorded as a separate count (record) per animal.
Contemporary groups
Apart from the general requirements for contemporary groups, the following is recommended. For young animals, a contemporary group should be subjected to the same tick control measures and the tick counts should be recorded at the same dates. The animals should be born within a period of maximum 100 days of each other.
For older animals (cows and breeding bulls), different birth years and seasons may be evaluated in the same group, provided they are managed alike and they are in the same production stage. (Dry cows and cows suckling calves should, for example, be handled as separate groups). The same person (recorder) should record tick counts on all animals in a contemporary group on the same date(s).
