(appeal of summary judgment motion in case involving multiple parties after unidentified cow in highway caused injuries to plaintiff after striking cow with automobile; defendant contracted with power company to install power lines along the highway on which accident occurred four months before plaintiff’s injuries; defendant was successful in having claim severed from remaining claims in suit then moved for summary judgment claiming plaintiff had no evidence to establish claim against defendant; appellate court upheld grant of summary judgment due to lack of non-speculative evidence that defendant actually cut fence or that if fence was cut, it was proximate cause of cow wandering onto highway four months after work was finished).