When looking through the 942 "Pasture" images at Acclaim Images.com this A Sheep with Two Lambs with Barns and Fence in the Background was a favorite.
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Description:
A Sheep with Two Lambs with Barns and Fence in the Background
Stock photo of a sheep with two little black lambs in an enclosed fenced pasture with lush green grass and red barns in the background. A public park that is also used as a petting zoo in the summer. The sheep is looking at the two young black lambs.

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