[1] Texas A&M Univ, Coll Vet Med, Dept Vet Anat & Publ Hlth, College Stn, TX 77843 USA
[2] Texas A&M Univ, Coll Vet Med, Dept Vet Pathobiol, College Stn, TX 77843 USA
[3] Texas A&M Univ, Coll Liberal Arts, Dept Psychol, College Stn, TX 77843 USA
[4] Texas A&M Univ, Coll Agr, Dept Anim Sci, College Stn, TX 77843 USA