Semen Production of Cockerels as Related to Their Subsequent Capacity to Fertilize Hens in Flock Matings

FERTILITY of eggs from flock matings of chickens is generally highest in the winter and spring months and decreases in the summer and fall as shown by Upp and Thompson (1927) and numerous other investigators since. It has also been reported by Parker and McSpadden (1943) and Wheeler and Andrews (1943) that chicken semen volumes decline during the summer and fall months. The above observations lead to the speculation that fertility in flock matings may be related to the volume of semen produced by the males. Malmstrom (1943) observed that fertility in flock matings declined when temperatures exceeded 47°F. and stated that this decline was probably because of reduced semen production in the males. Jones and Lamoreux (1942) observed that White Leghorn cockerels of a high-fecundity strain produced greater volume of semen than those of a low-fecundity strain. They also observed that fertility from natural matings was higher in the…