Dr Sillence has enjoyed a diverse research career, publishing over 100 scientific papers in the fields of pharmacology, forensic chemistry, endocrinology, animal science and equine science, winning a Literary Prize from the Journal of Veterinary Science in 2004 for his scientific writing and a Vice-Chancellor's award from Central Queensland University for excellence in postgraduate student supervision. He has also served as a research consultant to major animal health companies, and has held several patents concerning the use of vaccines to improve the efficiency of food utilization in livestock.