Effects of Photoperiod and Age: RESULTS(2)
In trial 2, changes in hormone concentrations and semen production confirmed and extended the results from trial 1. The concentrations of LH were not different between lighting treatments from 12 to 15 wk of age (Fig. 1C). The level of LH was then higher in the LL group until 29 wk of age, when the level of LH increased sharply in the SL birds by 2 days after the switch to LD, at which time LH became higher in the SL group. The level of LH then remained higher in the SL group until the trial was terminated at 35 wk of age. Levels of T increased at 17 wk of age in both groups and were then sustained (Fig. 1D). Levels of T were higher in the LL group until 29 wk of age, but increased sharply in the SL group by 2 days after the switch to LD, in agreement with results from trial 1. buy yasmin online
The level of T then remained higher in the SL group until the trial was terminated at 35 wk of age. Semen production was first detected in an individual bird in the LL group at 20 wk of age; 7 of 8 birds produced semen at 26 wk of age, and 8 of 8 birds did so at 35 wk of age (Fig. 2C). Semen was first detected in an individual bird in the SL group at 22 wk of age; 5 of 9 birds were producing semen at 29 wk of age, and 9 of 9 birds at 35 wk of age, or 6 wk after the switch from SD to LD lighting. Overall mean semen volume was significantly greater (0.29 ± 0.02 g/ejaculate, n = 16) from the LL birds than from the SL birds (0.21 ± 0.02 g/ejaculate, n = 14). Mean weekly semen volumes are presented in Figure 2D.
Category: Semen Production
Tags: Luteinizing Hormone, Male, Semen Production, Testosterone