The primary focus of Dr. Kastelic’s research is on animal reproduction, primarily cattle. He has published extensively on the use of ultrasonography for imaging the reproductive tract, including diagnosis of pregnancy and fetal gender, assessment of ovarian structures, and the testes. He was involved in early studies utilizing ultrasonography to monitor ovarian follicular development and has many publications regarding synchronization of estrus and ovulation. In the male, he has published extensively on scrotal/testicular thermoregulation, breeding soundness (and other methods of predicting fertility) and on the effects of nutrition on testicular development, puberty, and sperm production. He has collaborated with numerous colleagues in Canada and internationally.