IntroductionThe Norwegian White Sheep is a productive and prolific sheep breedfor meat production and constitutes 80% of the nearly one million ewes inthe Norwegian sheep population. Stillbirths and postnatal lamb mortalityup to 30–40 days of age have increased the last years, reaching 9.2% in2013 (Animalia, 2013). Stillbirths constitute approximately half of theselosses. Triplet and higher order litters are associated with increased riskof stillbirths and neonatal mortality (Everett-Hincks and Dodds, 2008).Average litter size at birth of the Norwegian White Sheep has increasedfrom 1.9 to 2.2 from 2000 to 2013 (Animalia, 2008, 2013).The factors causing stillbirths are complex (Binns et al., 2002