Proc. Aust. Soc. Anim. Prod. (1972) 9: 412
SOME ASPECTS OF TICK CONTROL IN NORTH QUEENSLAND
A. C. HASSALL*
Summary
This paper reports the methods used to control the cattle tick (Boophilus microplus) on a commercial property. Pasture spellings and infusion of Brahman blood have both contributed to the control. .
The author is unaware of any published material dealing with tick survival on unstocked pastures in this area, and therefore has come to the conclusion, as a result of year to year experience, that a spell period of three months markedly reduces the larvae population, and that a four month period provides stock with a tick free period of up to six months, and sometimes even longer, depending on seasonal conditions.
The capital expenditure required to provide the subdivision for this control was spread over a wide range of management activities, beneficial to the economic pro- duction of beef cattle in the area.
I. INTRODUCTION
The cattle tick (Boophilus microplus) occurs over a large area of the North Queensland Statistical Division. The area of infestation is in excess of 250,000 km2 including the Gulf country, Cape York Peninsula, and the eastern and western slopes of the Great Divide, north of 22” South latitude. This region is devoted principally to the breeding of beef cattle, and cattle tick infestation is a serious problem. It has been estimated that the economic loss to the cattle industry due to tick infestation is in excess of $20 million per annum, representing costs for labour and medicaments, but excluding the wastage incurred from failure to thrive due to tick worry. This situation is intolerable, especially when efficiency of pro- duction is of paramount importance in all rural industries.
Since the cattle tick is an obligate, one-host parasite, its control should be relatively simple. During the non-parasitic stage, the larvae are under the influence of local microclimatic conditions. Legg (1930), Hall and Wilkinson (1960) and Harley (1966) have shown that there is a limit to the length of time larvae will survive on pasture. This has resulted in the development of biological methods of tick control. The concept of pasture spelling aims at keeping areas unstacked for periods, thus depriving tick larvae of a host, so that the majority of larvae die.
The efficacy of this method of tick control has been reported by many authors (Wilkinson 1957; Harley and Wilkinson 1964; and Wharton et aZ. 1969).
This paper reports the effects of pasture spelling and introduction of Brahman blood on tick populations on a commercial property and on property management.
II. PROPERTY MANAGEMENT
The property involved was “Meadowbank”, which is situated in country infested with the cattle tick, 240 km north-west of Townsville. A description of
*“Meadowbank” via Mount Garnet, Queensland, 4870.
the property has been given by Rankine and Donaldson (1968). Until 1956, the main enterprise carried out was the growing of male cattle, as attempts to run breeders were unsuccessful, since facilities were not available to control ticks. On one area of black soil flats containing a spring, breeder losses were high during the latter end of the dry season as a result of tick worry and boggy conditions.
In 1950, the owner fenced off this area to make a 4,000 ha paddock, the first large paddock to be provided on the property of 21,250 ha. All stock were removed from this area to prevent deaths. About four months later, the area was carrying abundant fresh feed, although seasonal conditions had deteriorated. It was decided to restock the area with a group of Shorthorn breeders which had been acquired recently and which showed signs of stress due to the deteriorated pastures elsewhere on the property. The animals were dipped before entering the paddock, and remained there until after the summer rains. During this period they remained visibly tick-free, and were not mustered. The animals improved in con- dition, probably due to the benefit of the spelled pasture, and the absence of tick worry. Elsewhere on the property, dipping was carried out at monthly periods, or as time allowed.
From this practical demonstration of the value of spelling of pasture, the property has been progressively sub-divided and watered, and every paddock undergoes a period of spelling.
Brahman bulls were introduced into the Shorthorn herd about 1952, and the proportion of Brahman blood in the herd was steadily increased and has been stabilised at approximately 1% Brahman, 1% Shorthorn. These animals appear to possess a greater resistance to the cattle tick than the original Shorthorn herd.
The tick problem is now of very limited importance on the property. It is considered that the combination of pasture spelling and infusion of Brahman blood have been responsible for this situation.
Whilst the Brahman influence has been established as a viable factor in lessening the tick problem elsewhere in Queensland, this factor alone does not provide adequate tick control. This was demonstrated on Meadowbank over the years from 1952, when we commenced producing Brahman/Shorthorn cross cattle, up to the time when our programme of subdivision allowed spelling of sufficient paddocks, in 1959; for during this transition period, the tick was certainly evident, in numbers, on the cross breeds, though to a lesser extent than on the Shorthorns.
Those stock that were, during this period, subject to paddock controlled facilities, remained clean, for periods of five to seven months.
III. INTEGRATION OF TICK CONTROL WITH PROPERTY MANAGEMENT
The results obtained on Meadowbank have been a practical demonstration of the results of research studies on tick control. Tick control has been possible without disrupting the normal property management.
The number of paddocks necessary to gain control of both stock and the cattle tick depends on the level of control required and the nature of the country.
The simplest property design would be two large paddocks. Tick control could be achieved by rotating animals between the two paddocks with a spelling period of about four months, provided “clean musters” were obtained, and all stock were
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dipped at change of paddocks. However, good herd management requires herd segregation, into possible six classes of stock. Therefore, to allow an adequate pasture spelling programme to be undertaken, we have completed our twelfth paddock, and reduced dipping from twelve to two or three a year.
With adequate herd segregation, management procedures such as controlled mating and supplementary feeding can be put into operation successfully. Feeding of supplements without segregation results in uneven distribution and inefficient utilization of the supplement.
It has been suggested that subdivision and provision of water points for each paddock entails a large capital outlay, beyond the means of most commercial breeding units. On this property, the subdivision programme has been spread over a period of years, and each additional paddock has allowed for reduced running costs, thus providing finance for further development.
IV. CONCLUSIONS
(i) From the experience outlined above, it can be concluded that British breeds of cattle would respond to similar measures of tick control, as is now routine prac- tice on Meadowbank with our Droughtmaster herd. This was demonstrated with the first group of cattle in 1950, when these Shorthorn breeders remained tick free for a period of six months, while elsewhere on the property and with no paddocks for control, cattle required dipping at normal intervals.
(ii) It is also concluded that eradication of the cattle tick in Queensland would be quite feasible if and when, similar facilities were provided on all properties, and
covering all breeds of cattle.
On Meadowbank, we cannot afford to exploit to the full our potential for a tick free property, as the cattle would lose their immunity to Tick Fever; therefore we aim only for tick control, as an economic measure, and must necessarily con- tinue along these lines, until full control is made possible through district co- operation, and eventual eradication.
V. REFERENCES
Francis, J. and Little, D. A. (1964). Australian Veterinary Journal, 40: 247.
Hall, W. T. K., and Wilkinson, P. R. (1960). Queensland Journal of Agricultural Science, 17: 9 1.
Harley K. L. S., and Wilkinson, P. R. (1964). Australian JournaZ of Agricultural Research, 15: 841.
Harley, K. L. S. (1966). Australian Journal of Agricultural Research, 17: 387.
Legg, J. (1930). Proceedings of the Royal Society of Queensland, 41: 121.
Rankine, G., and Donaldson, L. E. (1968). Proceedings of the Australian Society of Animal Production, 7: 13 8.
Riek, R. F. (1962). Australian Journal of Agricultural Research, 13: 532.
Wharton, R. H., Harley, K. L. S., Wilkinson, P. R., Utech, K. B. and Kelley, B. M. (1969).
Australian Journal of Agricultural Research, 201= 783.
Wilkinson, P. R. (1957). Australian Journal of Agricultural Research, 8: 414.
Wilkinson, P. R. (1962). Australian Journal of Agricultural Research, 13: 974.
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