Abstract
SUMMARY: The concentrations of maternal immunoglobulin in 2-day-old lambs born to Scottish Blackface ewes which had been mated when 6 to 7 mo old were significantly lower than in lambs born to these ewes a year later. But the mortality rates were almost identical. The concentrations in lambs born to the same ewes in successive years were significantly more highly correlated than the concentrations in lambs born to older females in successive years, examined in a previous study.