|Pregnant Katahdin ewes. Image: Suzanne Cox via grit.com|
Katahdin are a breed of sheep developed in the 20th century in Maine, USA. They are a hair sheep, which means they do not produce a woolly fleece but instead have a coarser hairy coat which moults naturally every year. These types of breeds are more common in hot climates. They are becoming more popular in temperate climates because wool is not as profitable as in the past. More info: www.khsi.org/.
Pregnancy will affect the isotopic composition of ewes’ tissues because of two separate factors: (1) different routing of nutrients through the ewe’s body towards the growing lamb, and (2) changes in the ewe’s diet during pregnancy.
Farmers may choose to provide additional feed to pregnant ewes, especially during the last month of pregnancy when lambs are growing very quickly. Because sheep fertility varies with day-length, late pregnancy is likely to be in late winter/spring. Ewes’ tissues may therefore acquire more of a winter feeding signal (see January 2014) than other sheep which receive less supplementary feeding.