|Jacob sheep eating hay during snow cover|
Jacob sheep are piebald, with black-and-white faces and spotted bodies. Both males and females can have 2-6 horns. They are an unimproved (primitive) sheep breed of unknown origin and antiquity. They have a medium fine fleece and no outer hairy coat, unlike other primitive breeds which typically have a fine inner coat and hairy outer coat. More info: www.jsba.org.
In cold climates, alternative fodder sources must be provided to grazing animals during periods of snow cover. In the past, this has typically been summer vegetation, cut and stored as hay, but it might include straw, chaff and spoiled grain. Additional 20th/21st century options are silage (fermented cut vegetation) and commercial ‘cake’.
Isotopically speaking, this means that animals are consuming summer vegetation in winter. This is likely to affect their tissues’ isotope values, because plant species availability and plant isotope values vary seasonally in response to temperature, humidity and growth rates. Mean tissue values for animals receiving fodder may therefore be shifted overall towards a summer signal when compared to other species which do not.
Many thanks to Punkin's Patch for permission to use the photo!