No, it isn't; "I am" refers to the verb "breed" in the previous sentence, so it means "I'm breeding, and wasn't prepared for it." But even that rather unusual usage isn't the same as what Michel erroneously thinks is a correctly formed sentence. The abbreviation "I'm" is invariably followed by a complement; it never refers back to an earlier sentence [1]. If someone wanted to do so, in current usage they would always separate it out into "I am" in the manner of Michel's Googled example.
Dave
[1] And even if it was trying to, it could only be referring to a transitive verb, of which there isn't one anywhere else in the post to refer back to.