P.PSH.0798 - Cattle tick & buffalo fly host genetics, susceptibility to buffalo fly lesions and biomarkers for resistance

Summary

There are known to be heritable differences in susceptibility to cattle tick, buffalo fly and lesions. Phenotyping of animals is however labour intensive and often inaccurate. This project will develop more practical methods of assessing tick and fly numbers, identifying of indirect criteria such as biomarkers and immunological indicators, and determination of genomic markers, for more cost effective selection for resistance.

Objectives

This project aimed to provide efficient and practically feasible methods for accurately phenotyping cattle for tick, BF and lesion resistance, including better methods for direct measurement of tick, and buffalo fly numbers and the use of biomarkers, immunological indicators, host proteomics and ultimately genomic markers for breeding increased resistance to ticks, buffalo flies and lesions. The tools developed in this research will assist beef producers in northern Australia to incorporate selection for resistance to ticks, BF and lesions into traditional breeding plans and performance based plans such as BREEDPLAN, reducing production costs and the welfare impacts of ectoparasites and lesions and reliance on chemical methods for control.

Key findings

This project developed more practical methods of assessing tick and fly numbers and skin lesions for phenotyping of resistant/susceptible animals, and identified biomarkers for these traits which could be used in genomic estimated breeding values (EBVs).

Benefits to industry

Buffalo flies are now the most costly health issue in the Australian beef cattle industry with cattle ticks second. Buffalo fly lesions are often mentioned as a welfare issue in producer surveys and affected cattle often bring lower prices at market. In addition, resistance to chemical parasiticides compromises the effectiveness of control and there is a demand for beef produced in low chemical, ethical production systems. Despite that there is good evidence that that the underlying heritability of resistance to ticks and buffalo flies is high, selection for resistance, is seldom included in breeding programs because of the difficulty and cost of direct phenotyping and a lack of indicator characters or genomic methods for selecting resistance.

MLA action

An online summary and final report for this project will be published on the MLA R&D website.

Future research

• Practical adaptation of race mounted, motion activated cameras for estimating buffalo fly numbers.
• Validation of biomarkers in industry herds.
• Further development of algorithms for ear tags for estimating BF numbers.
• Use of improved phenotyping methods and project outcomes to develop accurate genomic methods for parasite and lesion resistance prediction.

MLA is currently running a project that investigates a targeted approach to improve the control of cattle tick and buffalo fly (P.PSH.1485). The outcomes of this research will provide a strong position to enable the establishment of collaborative agreements with industry partners to translate the research to a commercial setting. A successful outcome from this project will provide proof-of-concept for a generic approach for the development of safer and more environmentally friendly insecticides.