IFNAR1 and protozoa infectious disease: While some biallelic knockout sheep have survived for long periods of time under farm conditions, the longest surviving individual being a ram who lived to about 4.5 years of age and produced over 80 offspring, 60% of our IFNAR knockout sheep born in 2017 through 2021 have died between 1 and 12 months of age due to viral, bacterial, or protozoal infections compounded by weight loss and emaciation.