Effect of light intensity during the breeder period on semen production of low weight and normal weight breeder turkeys.

Semen production of low weight and normal weight breeder turkeys was compared when maintained on low or high light intensities during the breeder period. A flock of Large White male breeder turkeys was raised in two houses and received 12 hr of 54 lx incandescent light from 10 to 30 weeks of age. The average body weights of the 32-week-old males in the two houses were 12.6 (low weight) and 19.4 kg (normal weight), respectively. At 30 weeks of age the males were exposed to 15 hr of 6.5 lx (LL) or 100 lx (HL) incandescent light. The semen volume of the low weight males was less than that of the normal weight males during the first few weeks (Weeks 33, 34, 35, and 37), and during the last weeks of semen collection (Weeks 45 to 49, inclusive). Semen volumes of normal weight males were comparable for LL and HL, but semen volumes of low weight males were greater with HL than LL, particularly during Weeks 33 to 42. Body weight at 32 weeks of age or light treatment during the breeder period had no effect on sperm concentration, and, therefore, sperm per ejaculate paralleled semen volume. This study demonstrated that an increase in light intensity during the breeder period did not completely overcome the delay in the onset of semen production caused by low body weight gain during the adolescent period. However, because the overall total number of sperm in the ejaculate of low weight males on HL was greater than those on LL, increased light intensity may improve the sperm production of low weight males.