Reproductive Rates of Merino Ewes and Offspring Quality under AI Program

Abstract

Reproductive wastage is a major economic burden in sheep production globally, especially within Australia as livestock production systems face increased pressure from climatic variability (e.g. prolonged droughts or flooding). Sheep are sensitive to acute changes in their environment such as heat stress, which if not adequately monitored will result in significant production losses such as reproductive failure, increased parasite and worm burden, morbidity and mortality risks. Through basic and applied research in the areas of stress and reproductive physiology our team has made significant advancements in the understanding of sheep behaviour and physiological responses to acute and chronic stressors. Using minimally invasive hormone monitoring technology in combination with field based assessment of sheep health and productivity traits, our team has delivered new knowledge on how sheep react to acute environmental stress and how it impacts on sheep reproduction. In this chapter, we evaluated the fertility rates and embryo quality of Merino ewes under AI breeding program. We discuss factors such as heat stress that can impact on ewe and offspring quality.