Great ideas.
I have used in the past get paper a trace out the pig,chicken,sheep,horse
To color in the pig we used shaving cream and brown paint and when the picture dried it looks like a muddy pig
We used feathers for the chicken( my daughter used some cotton LOL)
For the lamb/sheep we used cotton
For the cow which used grass clipping
The last picture we used straw/hay for a paint brush with any color paint we had.
Happy Farmers Day