What an interesting piece. I wonder if they still raise buffalo. I looked on Google and there is a listing for a tree nursery business owned by Lynn. I couldn't find anything when I looked up the Reeds.
There used to be a buffalo farm on Route 60 near Mundelein. I remember seeing it when my family would drive to Hawthorn mall.
My guess is that this was probably produced around 1979, and it was played around the 1979-1980 period.
I remember on a field trip to a cider mill. While riding on our school bus going there, some of the kids on our bus, young as 7 years old (I didn't join in, but I did enjoy it) were singing the chorus of this jingle over and over, for approx. 10 minutes. And this was in the fall of 1979.
We never went to McDonald's on the trip, however.
Before this, it was:
"At McDonald's, You're the Only One,"
"At McDonald's, We Do It All for You"
and of course,
"You Deserve a Break Today, at McDonald's.