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New Caledonia is a major livestock producing country in the Southwest Pacific where cattle raising for beef production is a primary agricultural activity. The cattle tick, Rhipicephalus australis, is the most economically important ectoparasite of livestock in New Caledonia. Blood feeding by the parasitic stages of R. australis limits the productivity of tick-susceptible European cattle breeds, which are preferred by livestock farmers. Methods that consider the interplay between tick biology and ecology of pastured cattle provide an opportunity for integrated tick management approaches to mitigate the deleterious effects of R. australis on cattle health and production. Research to implement a Pasture and Cattle Management (PCM) method for integrated control of R. australis in New Caledonia is presented here. Principal aspects of the PCM are described. Optimizing the use of long-acting acaricides contributes to these efforts. Its agroecological foundation affords versatility in the strategic application of practices that follow the PCM method at the farm and agricultural landscape levels. This allows the incorporation of other control technologies like the use of a vaccine against R. australis. Research recommendations to refine integrated R. australis control involving the PCM method for sustainable cattle production in New Caledonia are discussed. Continued research on the biology and ecology of R. australis across the changing agricultural landscape of its geographic range will inform science-based adaptations of the PCM method, which could facilitate its implementation as part of integrated cattle tick management efforts in other semi-extensive cattle management settings. [ABSTRACT FROM AUTHOR]

Multi-species livestock grazing is a common practice in the Edwards Plateau of Texas. Winter demands on livestock are high because of forage quality and quantity limitations and stresses of tick parasitism. Our objective was to assess winter-active tick burden on livestock and gauge effectiveness of a pour-on synthetic pyrethroid acaricide. At the Sonora AgriLife Station, 26 Bos taurus crossbred heifers (260 ± 6 kg) and 28 Dorper ewes (42 ± 1 kg) were maintained on 97.125 hectares of rangeland. Tick burden was assessed by individual animal inspection on: 12-18-2017, 01-05-2018, 01-122018, 01-26-2018, 02-09-2018, 02-16-2018, 02-23-2018, and 03-08-2018. Trial 1 acaricide treatment was applied 01-05-2018 on heifers and ewes chosen randomly to serve in the non-treated control (13 heifers; 14 ewes) or acaricide-treated (13 heifers; 14 ewes) groups. Trial 2 acaricide treatment was applied 02-16-2018 using a switchback design. Tick species included Amblyomma americanum, Dermacentor albipictus, and Ixodes scapularis. Tick burden differences were determined by analysis of variance procedures. There were no differences in tick burden on heifers or ewes prior to acaricide application for Trial 1 nor Trial 2 (P > 0.276, 0.002 ± 0.46; P > 0.354, 0.002 ± 0.11 and P > 0.606, 0.002 ± 0.05; P > 0.705, 0.001 ± 1.34, respectively). There were no differences (P > 0.149) between acaricide-treated (0.519 ± 0.05) and non-treated control (0.644 ± 0.07) heifers in Trial 1 nor Trial 2 (0.759 ± 0.07 and 0.404 ± 0.04, respectively). Similarly, there were no differences (P > 0.997) between acaricide-treated (2.964 ± 0.31) and non-treated control (2.965 ± 0.3) ewes in Trial 1 nor Trial 2 (1.015 ± 0.13 and 5.563 ± 0.45, respectively). We conclude ticks challenge the well-being and production in overwintering livestock in the Edwards Plateau. Alternative acaricides should be evaluated for efficacy and efficiency in these production systems [ABSTRACT FROM AUTHOR]

The Edwards Plateau region of Texas is largely used for grazing cattle and small ruminants. Tick parasitism in range livestock can occur year-round with direct production losses manifested as body weight or condition. The objective was to assess two acaricide treatments on the active tick burden on livestock within two forage growing seasons (winter through summer). At the Sonora AgriLife Station, 22 Bos taurus crossbred heifers (248 ± 47 kg) were maintained on 97 hectares of rangeland. Tick burden was assessed by individual animal inspection every two wk from 18-Dec-2019 to 11-May-2020 (Season 1) and from 8-Jun-2020 to 3-Aug-2020 (Season 2). Acaricide treatment was applied each date to heifers chosen randomly to serve in the nontreated control (control: 11 heifers) or acaricide-treated (treatment: 11 heifers) groups. Season 1 acaricide treatment was a pour-on synthetic pyrethroid (11 dates) and Season 2 was a diluted synthetic pyrethroid wholebody spray (5 dates). Tick species observed included Amblyomma americanum and Dermacentor albipictus. Tick burden (total counts) and body condition score differences were determined by analysis of variance procedures. For tick burden, there were significant differences (P < 0.0012) between treatment (0.528 ± 0.06) and control (0.819 ± 0.06) heifers in Season 1 (0.673 ± 10.44), and no differences (P > 0.11) between treatment (0.642 ± 0.07) and control (0.799 ± 0.07) heifers in Season 2 (0.721 ± 2.64). For body condition score, there were no differences (P > 0.72) between treatment (5.61 ± 0.04) and control (5.59 ± 0.04) heifers in Season 1 nor Season 2 (5.51 ± 0.005 and 5.80 ± 0.47, respectively). Season 1 acaricide treatment was effective in controlling tick burden (efficacy = 3-4 wk) as compared to Season 2 (efficacy = 1-2 wk). Tick burdens observed under the conditions of this study had no effect on body condition. [ABSTRACT FROM AUTHOR]

Bovine babesiosis, a highly fatal tick-borne disease of cattle, was eliminated from the United States in the last century through tick eradication programs against 2 species of cattle fever ticks. The threat to the U.S. cattle industry continues through tick introductions from Mexico. The standard method of detecting Cattle Fever Ticks [Rhipicephalus (B.) annulatus and R. (B.) microplus] in the state-federal tick eradication program is physical examination of restrained cattle to find attached ticks. New methods of detecting tick-infested cattle could improve reliability and reduce animal stress. The objective of this study was to determine whether changes in fecal chemistry induced by tick infestation was detectable using near-infrared reflectance spectroscopy (NIRS). Fecal samples were collected daily from 6 stanchioned Bos taurus yearling heifers (initial mean weight 163.3 kg +/- 4.7 kg) at the USDA Cattle Fever Tick Research Laboratory, Edinburg, TX, before, during, and after an infestation of 5000 R. (B.) microplus larvae. Cluster analyses were conducted using GRAMS IQ for NIR spectra in the 576–1126 nm range to test for fecal chemistry changes different from pre-infestation condition, and coincident with the biological phases of the tick infestation. The first three factors of spectral variation accounted for 87.87% of spectral variation among all samples. Factors 1, 2, and 3 had F-Ratios for the Reduced Eigenvalues of 941.59, 387.44, and 221.79, respectively. Three-dimensional analysis for these 3 factors shows shifts in sample clusters away from pre-infestation and coincident with progressive tick blood-feeding and post-infestation recovery. We conclude that fecal NIRS may provide a tool for detection of tick-infested cattle; however, further testing is needed to determine the sensitivity of detection on cattle with varying levels of tick burden, and a protocol developed and evaluated for fecal sampling under field conditions [ABSTRACT FROM AUTHOR]