Analyst Simon Quilty predicts a significant increase in lamb and mutton prices in Australia due to high ewe slaughter, which is expected to continue for the next 2-3 years, leading to a decrease in supply. He criticizes the lack of recent census data on sheep and cattle numbers and believes the mutton kill is a better indicator of flock size and liquidation. Quilty also believes there has been a significant exit from the sheep industry, which he believes will continue despite high prices. The article also discusses the impact of seasonal challenges and the migration of lamb production from New South Wales to Victoria.