A cow does not have two stomachs as Martinius Jacobson says to the children in the barn.
A cow actually has four stomachs. The Rumen, The Reticulum, The Omasum, and the Abomasum.
In the opening scene, during the two-shot of Selma Jacobson and Arnold Hanson, he can be seen mouthing her lines as she says them.
The cars/trucks have no windshields. Studio lights can be seen reflected off vehicle bodies but not where the glass would be. Additionally, this movie was filmed/set during World War II when gas was rationed; since there's no windshields, there are also no rationing stickers visible.
When Arnold and Selma are heading out from the barn in the tub, you can see a wire pulling it along.