|Soay ewe and newborn lamb. Image: Woodland Creek Farm|
The Soay breed is descended from a feral population of sheep on the island of the same name in the Western Isles of Scotland. They are about a third of the size of most modern sheep breeds, are very agile, and show a wide variety of coat colourings. Their fine wool is shed naturally every year and does not need to be sheared, but can be plucked (‘rooed’) instead. Soays are thought to resemble British prehistoric sheep breeds. More info: soaysheep.biology.ed.ac.uk/.
Lambs live on their mothers’ milk alone for at least the first two-three weeks after birth. Ewes produce an extra rich milk called colostrum for the first 24 hours or so after lambing. Adequate consumption of colostrum is very important for lamb survival as it is rich in both nutrients and antibodies. Ewe milk quality depends on the ewe’s nutrition in late pregnancy.
Suckling is detectable isotopically. For this period the lambs are consuming their mothers' tissue, and are effectively a trophic level higher than she is. All the tissue they grow in this period will show this signature, reflecting both the mother’s diet and the lamb’s consumption of milk.