Long-term population studies on the cattle tick (Boophilus microplus) on untreated cattle selected for different levels of tick resistance

1979 ◽  
Vol 30 (2) ◽  
pp. 353 ◽  
Author(s):  
RW Sutherst ◽  
RH Wharton ◽  
IM Cook ◽  
ID Sutherland ◽  
AS Bourne
Keyword(s):  
Census Data ◽  
Seasonal Pattern ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Tick Population ◽  
Population Sizes ◽  
The Mean ◽  
Highly Correlated ◽  
Tick Counts ◽  
Tick Resistance

Census data were collected at weekly intervals on tick populations on untreated cattle over a period of 6 years in central Queensland, near Rockhampton. Hereford x Shorthorn (British; HS) heifers and two herds of Africander (Zebu) x [Hereford and Shorthorn] (AX) heifers, one with animals of high resistance (AXH) and the other of medium (AXM) tick resistance, were grazed in separate paddocks. A herd of AX steers was added to the trial when the heifers commenced calving in 1972–73. Data were collected from the heifers for three years prior to their first calving and then for a further three years whilst they were breeding. There were large differences between the numbers of ticks in different years and a consistent seasonal pattern, the numbers being lowest from July to September and highest in the April to June quarter. The AXH herd had fewest ticks for most of the experiment, but after the first year there was little difference between the infestations on the AXM and HS herds. The resistance of all herds, measured by artificial infestations with larvae, increased during the first 3 years but declined after the cattle began breeding, and fluctuated from year to year. The resistance of some heifers did not stabilize until the animals were more than a year old, and that of some animals drifted up or down over long periods. The loss of resistance of a small proportion of the cattle in the AXH herd was responsible for the advantage of that herd being substantially reduced. Both the ranking for resistance of animals and the mean resistance of the herds, assessed with artificial infestations, agreed with the rankings and tick population sizes observed from tick counts on the cattle in the field. Changes in the mean resistance of the herds in spring in different years were highly correlated with concurrent field infestations, which suggests that changes in host resistance have important effects on tick populations. Tick counts on the calves up to weaning showed no correlation with concurrent counts on their dams, but the ranking of the counts on the calves was consistent over the 6 month period.

Resistance to the cattle tick, Boophilus microplus in a herd of Australian Illawarra Shorthorn cattle: Its assessment and heritability

1970 ◽  
Vol 21 (1) ◽  
pp. 163 ◽  
Author(s):  
RH Wharton ◽  
KBW Utech ◽  
HG Turner
Keyword(s):  
Reference Value ◽  
Mature Female ◽  
Boophilus Microplus ◽  
Supplementary Information ◽  
Cattle Tick ◽  
The Mean ◽  
Tick Counts ◽  
The Right ◽  
High Level ◽  
Tick Resistance

An Australian Illawarra Shorthorn herd of 24 cows was mated in three consecutive years with an AIS bull. The cows and their progeny were rated for tick resistance at frequent intervals from August 1959 to December 1965 by counting the numbers of semiengorged female ticks on the right side. The mean of log counts for all counts on a particular animal was adopted as the reference value for its degree of susceptibility. The ranking of cattle generally showed a high level of consistency with mean repeatability of counts (r = 0.47, P < 0.01). Discrimination between animals was more reliable (P < 0.01) in summer (r = 0.52) than in winter (r = 0.27). The repeatability of tick counts increased with mean count, from r = 0.27 when the mean count was 3 to r = 0.67 when it was 100. The reliability of counts on the cows decreased with age and with lactation. Supplementary information on a larger herd showed no effect of pregnancy on mean count or on discrimination between susceptible and resistant animals, but showed that there was a partial breakdown of resistance during lactation. In calves infested naturally, no effects of age or sex on tick counts or their repeatability were detected, though male calves yielded significantly larger numbers of ticks than females when infested artificially. The mean yield of mature female ticks on the cows following two artificial infestations with known numbers of larvae ranged from 0.2 to 27.4% of the potential. Natural and artificial assessments of susceptibility were closely correlated. The rank of the bull was similar to that of the more resistant cows. Mean estimates of the heritability of tick resistance based on single counts were 39 % from dam-calf correlations and 49 % from full-sib correlations. Estimates based on summer counts only were 42 and 64% respectively. These results provide strong encouragement for selecting for tick resistance.

Heritability estimates from correlations in intra-sire data. Appendix I. from - Resistance to the cattle tick, Boophilus microplus in a herd of Australian Illawarra Shorthorn cattle: Its assessment and heritability

1970 ◽  
Vol 21 (1) ◽  
pp. 181
Author(s):  
HG Turner
Keyword(s):  
Reference Value ◽  
Mature Female ◽  
Boophilus Microplus ◽  
Supplementary Information ◽  
Cattle Tick ◽  
The Mean ◽  
Tick Counts ◽  
The Right ◽  
High Level ◽  
Tick Resistance

An Australian Illawarra Shorthorn herd of 24 cows was mated in three consecutive years with an AIS bull. The cows and their progeny were rated for tick resistance at frequent intervals from August 1959 to December 1965 by counting the numbers of semiengorged female ticks on the right side. The mean of log counts for all counts on a particular animal was adopted as the reference value for its degree of susceptibility. The ranking of cattle generally showed a high level of consistency with mean repeatability of counts (r = 0.47, P < 0.01). Discrimination between animals was more reliable (P < 0.01) in summer (r = 0.52) than in winter (r = 0.27). The repeatability of tick counts increased with mean count, from r = 0.27 when the mean count was 3 to r = 0.67 when it was 100. The reliability of counts on the cows decreased with age and with lactation. Supplementary information on a larger herd showed no effect of pregnancy on mean count or on discrimination between susceptible and resistant animals, but showed that there was a partial breakdown of resistance during lactation. In calves infested naturally, no effects of age or sex on tick counts or their repeatability were detected, though male calves yielded significantly larger numbers of ticks than females when infested artificially. The mean yield of mature female ticks on the cows following two artificial infestations with known numbers of larvae ranged from 0.2 to 27.4% of the potential. Natural and artificial assessments of susceptibility were closely correlated. The rank of the bull was similar to that of the more resistant cows. Mean estimates of the heritability of tick resistance based on single counts were 39 % from dam-calf correlations and 49 % from full-sib correlations. Estimates based on summer counts only were 42 and 64% respectively. These results provide strong encouragement for selecting for tick resistance.

Resistance to Boophilus microplus (Canestrini) in different breeds of cattle

1978 ◽  
Vol 29 (4) ◽  
pp. 885 ◽  
Author(s):  
KBW Utech ◽  
RH Wharton ◽  
JD Kerr
Keyword(s):  
Beef Cattle ◽  
High Resistance ◽  
Bos Indicus ◽  
Boophilus Microplus ◽  
Supplementary Information ◽  
Cattle Tick ◽  
Tick Population ◽  
Frequency Distributions ◽  
Jersey Cattle ◽  
The Mean

Resistance to the cattle tick Boophilus microplus was assessed in heifer herds of various breeds of beef and dairy cattle in spring and summer in Queensland. All cattle had had tick experience before assessment. Resistance levels were determined as the percentage of larval ticks that failed to survive to maturity following infestations with c. 20,000 larvae. Bos indicus Brahman beef cattle were the most resistant (99%), followed by B. indicus × B. taurus (95–97%) and B. taurus British cattle (85%). In the dairy breeds, B. taurus Jersey cattle (98%) were more resistant than Guernsey (93%), Australian Illawarra Shorthorn (89%), and Friesian (85%), but not significantly different from B. indicus × B. taurus Australian Milking Zebu (96%). Cattle were classified as having high (> 98%), moderate (95–98%), low (90–95%), or very low (< 90%) resistance. The frequency distributions of resistance in B. indicus × B. taurus cattle showed that 80% had moderate to high resistance and that culling of 20% of the cattle would about halve the mean tick population. Of B. taurus cattle, 80% had low to very low resistance. Supplementary information on sibling bull herds showed that their resistance levels and frequency distributions of resistance were similar to those of the heifer herds.

Host resistance to cattle tick (Boophilus microplus) in Brahman (Bos indicus) cattle. I. Responses of previously unexposed cattle to four infestations with 20,000 larvae

1975 ◽  
Vol 26 (6) ◽  
pp. 1073 ◽  
Author(s):  
BM Wagland
Keyword(s):  
Host Resistance ◽  
Bos Indicus ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Brahman Cattle ◽  
The Mean

Four purebred Brahman and four beef Shorthorn cattle which had not previously been exposed to Boophilus microplus were infested four times with 20,000 B. microplus larvae. On first infestation, the yield of engorged female ticks on all animals was about 25% of the larvae applied. Aftcr three further infestations, the mean yield of engorged females on the Brahmans decreased to 7.5% whereas there was no decrease in the yield of ticks on the Shorthorns. On the Brahman cattle. development of larvae to engorged females took 1–2 days longer and the engorged females weighed less. However, there was no difference in the reproductive index of female ticks engorged on either Brahmans or Shorthorns. Increases in rectal temperatures occurred in all cattle 15–17 days after the first infestation and in some cattle on days 6–7 as well as on days 15–17 after reinfestation. It was concluded that resistance to B. microplus is an acquired phenomenon in Brahman cattle.

Ecological observations on the cattle tick, Boophilus microplus (Canestrini)

1957 ◽  
Vol 8 (4) ◽  
pp. 394 ◽  
Author(s):  
GJ Snowball
Keyword(s):  
Dairy Herd ◽  
Early Spring ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Late Winter ◽  
Tick Population ◽  
Parasitic Stage ◽  
Free Living ◽  
Larval Population ◽  
Low Levels

Studies were undertaken during 1948-1950 on Boophilus microplus under field conditions in southern Queensland to determine the duration of the non-parasitic stages, and to relate this information to tick incidence on cattle. In the area where the observations were made, the population of ticks on cattle is high in summer and autumn and low in minter and spring. Each week throughout the investigation engorged female ticks, freshly fallen from cattle, were placed in a pasture plot and their subsequent history recorded. Concurrently, observations were made on the changes in tick population on a dairy herd on an adjacent farm. Female ticks exposed on the plot between April and July produced virtually no progeny, and it is probable that the ticks in the pasture traversed by the dairy cattle exhibited a similar, though less severe, inhibition of reproduction. This failure to reproduce, combined with the dying out of larvae and protracted developmental periods of eggs, reduced to very low levels the larval population available to infest cattle during the months of August–October. Ticks exposed from late July to the following autumn produced progeny. There was a tendency for the progeny of ticks exposed in the late winter and early spring to hatch a t about the same time in the late spring, and this synchronous hatching was probably responsible for the 'spring rise' in tick population on cattle. It appears likely that the engorged female adults dropped in the early autumn represent the most important stage in the overwintering of the species in this area. Some of their larvae survive the adverse winter conditions, either in the free-living or the parasitic stage, and give rise to adults, which fall in the late winter and spring, and which in turn produce the larvae of the spring rise.

Selection of cattle for tick resistance, and the effect of herds of different susceptibility on Boophilus populations

1962 ◽  
Vol 13 (5) ◽  
pp. 974 ◽  
Author(s):  
PR Wilkinson
Keyword(s):  
Tick Infestation ◽  
Tick Control ◽  
Boophilus Microplus ◽  
Skin Thickness ◽  
Adult Females ◽  
Cattle Ticks ◽  
In Parenthesis ◽  
Tick Counts ◽  
Tick Resistance ◽  
Selection Of

Weekly counts of Boophilus microplus (Canestrini) on 30 Australian Illawarra Shorthorn heifers enabled the cattle to be ranked in order of tick infestation, with highly significant correlations between counts of two observers and between counts of one observer on different occasions. In May 1960, when the heifers were 1½–2 years old, 12 were selected as relatively tick-resistant and 12 as relatively tick-susceptible. Each of these groups was divided at random into herds of six, and the four herds were then allotted randomly to separate paddocks, each onequarter of the area previously grazed. A herd was sprayed with 0.5% DDT emulsion when its average count of ticks (adult females over 5 mm in length) on one side of the animals exceeded 40. During the ensuing tick season, from October 5, 1960, to June 7, 1961, the sums of average weekly tick counts, and the numbers of sprayings (in parenthesis) were: susceptible herds 4853 (5) and 5962 (6): resistant herds 718 (0) and 1073 (1). Counts of tick larvae on defined body areas showed that, in the summer after segregation, resistant herds carried fewer larvae than the susceptible herds, apparently because fewer mature ticks fell from the resistant cattle in the preceding spring and winter. As a consequence of this, counts of adult ticks were comparatively lower after than before segregation. There was little or no 'spring rise' of tick infestation on the resistant herds. There was no significant correlation between tick resistance and coat score, sweat gland dimensions, or total skin thickness, but a correlation of -0.53 with follicle depth was significant at the 1% level. There was no evidence of adaptation of cattle ticks to the resistant animals, either in the field experiment or in observations on stalled cattle. The experiment draws attention to the appreciable proportion of tick-resistant animals within the Australian Illawarra Shorthorn breed, which has largely been overlooked in past discussions on tick-resistant breeds of cattle. It also suggests a technique for estimating the improvement in tick control that may be obtained by a given degree of selection within any breed, for any given environment.

The rate of loss of DDT on cattle in relation to protection from reinfestation by the cattle tick Boophilus microplus

1972 ◽  
Vol 23 (5) ◽  
pp. 735 ◽  
Author(s):  
HJ Schnitzerling ◽  
WJ Roulston ◽  
BF Stone ◽  
JT Wilson ◽  
PG Thompson
Keyword(s):  
Laboratory Tests ◽  
Boophilus Microplus ◽  
The Other ◽  
Cattle Tick ◽  
Cyclic Change ◽  
Minimum Period ◽  
The Mean

Australian Illawarra Shorthorn cattle were sprayed with 0.5% w/v DDT on 31 consecutive occasions at intervals of 4 weeks. Spraying was rotated amongst three groups of cattle. The rate of loss of DDT was determined on the barrel for all occasions and concurrently on the flank and escutcheon for the last 16 occasions. A protective period, defined as the minimum period cattle were protected against reinfestation by the cattle tick, was determined concurrently from observations made on the flank and escutcheon. A cyclic change in the rate of loss of DDT occurred on all sites. The rate was highest in summer and lowest in winter, and was in antiphase with corresponding changes in the protective period. The magnitude of the change of rate of loss of DDT was greater on the flank than on either the barrel or the escutcheon. The rate of loss from the three sites was always in the sequence flank > escutcheon > barrel. The mean deposits of DDT present on the flank and escutcheon when protection had just ceased were respectively 0.29 mg/g hair and 0.054 mg/sq. in., and the protective periods did not differ significantly. The protective period on the barrel was not measured, but it was calculated from data on the DDT deposits to be longer than on either of the other sites, even allowing for the fact that laboratory tests showed that DDT on barrel hair was relatively less effective against larvae than similar weights of DDT on flank hair.

Trapping of larvae of the cattle tick Boophilus microplus by Stylosanthes scabra under grazing conditions

1989 ◽  
Vol 40 (6) ◽  
pp. 1301 ◽  
Author(s):  
LJ Wilson ◽  
RW Sutherst ◽  
JD Kerr
Keyword(s):  
Laboratory Tests ◽  
Seasonal Pattern ◽  
Tick Control ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Research Station ◽  
Morphological Attributes ◽  
Control Programs ◽  
Per Se ◽  
Stylosanthes Scabra

Several varieties of the leguminous genus Stylosanthes have the capacity to trap larvae of the tick Boophilus microplus. This capacity was assessed for S. scabra plants collected from grazed fields at two locations, Brian Pastures Research Station and 'The Springs' in central Queensland. Morphological attributes which may affect the capacity of plants to trap tick larvae were recorded. In laboratory tests, plants collected from Brian Pastures trapped 27% of larvae in summer and 12% in winter, whilst plants from 'The Springs' trapped an average of 12%, with no seasonal pattern discernible. The percentage of branches which were sticky was the major determinant of a plant's capacity to trap ticks. Variation in stickiness per se was less important. Frost and burning temporarily reduced tick-trapping capacity, but after four months, burnt plants trapped a higher percentage of larvae than unburnt plants due to the production of sticky regrowth. The implication of the results for the use of S. scabra in tick control programs is discussed.

Effect of cattle tick (Boophilus microplus) infestation on performance of Bos indicus cross cows and their progeny

1988 ◽  
Vol 28 (1) ◽  
pp. 1 ◽  
Author(s):  
RG Holroyd ◽  
PJ Dunster ◽  
PK O'Rourke
Keyword(s):  
Pregnancy Rate ◽  
Bos Indicus ◽  
Treated Group ◽  
Pregnancy Rates ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
First Year ◽  
The Third ◽  
Lactating Cows ◽  
Tick Counts

The effects of cattle tick infestations on liveweight and fertility of Droughtmaster (1/2 Bos indicus) cows and on calf weaning weights were determined over 3 years. Tick populations on the control (non-dipped) group of cattle fluctuated, with mean annual tick counts/side being 9.5, 8.9 and 13.6 for years 1, 2 and 3 respectively, while the treated group of cattle, which were dipped every 21 days, were free of ticks. Tick counts were not related to fertility or liveweight change in pregnant-lactating cows or to calf growtb or weaning weights. Treatment for ticks significantly (P<0.05) affected liveweight change in pregnant-lactating cows on only a few occasions, and annual liveweight changes were not significantly influenced by treatment. When lactating cow pregnancy rates were low (< 30% for control cows), treatment for ticks increased the pregnancy rate by about 100% in 2 of the 3 years, these differences being significant only in the last year. Calves in the treated group were born significantly earlier in the first year and had significantly lighter birth weights in the third year. Treated calves grew faster to weaning and had higher weaning weights (mean difference 17.9 kg) than control calves but differences were significant in the first and third years only.

Resistance to BHC in the cattle tick Boophillus microplus (Can.) in India

1964 ◽  
Vol 55 (3) ◽  
pp. 405-410 ◽  
Author(s):  
R. P. Chaudhuri ◽  
R. C. Naithani
Keyword(s):  
First Record ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Indian Veterinary Research Institute ◽  
Veterinary Research ◽  
Wettable Powder ◽  
The Mean ◽  
The Difference ◽  
The Village ◽  
Village Population

Cattle kept at the Latoli kraal of the Indian Veterinary Research Institute at Mukteswar in the Kumaon foothills of the Himalayas were heavily infested with the tick Boophilus microplus (Can.). In order to reduce the infestation, the animals were treated with BHC dusts every season for a number of years. In 1960, it was noticed that the treatment was not as effective as in the previous years. A series of concentration/response tests was therefore carried out in 1961–62 to see whether or not the tick had developed any resistance to BHC. Ticks collected from cattle in a village about five miles distant, where no acaricide had ever been applied, were used as the standard for comparison. BHC as a wettable powder was used to provide six different concentrations of γ BHC for engorged females and unfed larvae, respectively. Treatment was by appropriate dipping techniques. Analysis of the results showed that the population of B. microplus infesting cattle at the Latoli kraal had developed resistance to BHC. The LC50's of γ BHC for engorged females and unfed larvae, respectively, of the Latoli population were 0.5164 and 0.0182 per cent., and of the village population 0.0834 and 0.00069 per cent. This seems to be the first record of any species of tick developing resistance to an acaricide in India.It was found that the mean number of eggs laid per tick in the control batches was higher in the village population than in the Latoli population and that the difference was highly significant.

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