Description: Principally between 1934 and 1940, Fred McKenzie (University of Missouri) conducted pioneering research on semen quality as it was affected by season, ambient temperature, and nutrition. He also studied methods for semen collection, the ultastructure of sperm, and the relationship between sperm abnormalities and fertility. While most of his work was with rams, he also published research on horses, mules, dogs and chickens. Lester Casida (University of Wisconsin) studied with Fred McKenzie. Photo circa 1938.