Auxiliary effects of camphor on reproductive function of Japanese quail.

In recent decades, reproductive problems were raised alongside the continuous genetic selection for performance purposes in poultry. As such, a negative correlation was observed between reproductive and production performance, which may possibly imply that the high growth rate in poultry causes physiological disorders such as decreased libido and frequency of mating. A study was conducted to establish the efficacy of feeding graded levels of camphor on reproductive function of Japanese quail as a bird model. Two-hundred-and-eighty one-day-old quail chicks were randomly assigned to individual cages in 7 treatments (zero [control], 250, 500, 750, 1,000, 5,000, or 10,000 ppm of camphor). The results demonstrated that testosterone concentration displayed an uncertain attitude, as the lower dosages of camphor used (250, 500, and 750 ppm) had the highest values. Thyroxine (T) linearly increased with increasing camphor levels in male birds (P < 0.05). Triiodothyronine (T) also was increased in the groups receiving a camphor-containing diet in comparison with the control (P < 0.05). The male birds' libido behavior was linearly increased with the increase of camphor concentration (P < 0.05). Dietary camphor in 500 and 10,000 ppm caused the highest percentage of fertility (P < 0.0001) and hatchability (P = 0.0117), respectively. As well, the groups with 5,000 and 10,000 ppm of camphor accounted for the highest percentage of hatched-fertile eggs (P = 0.0055). The highest rate of sperm penetration in the yolk inner perivitelline layer (IPVL) was demonstrated by the group allotted with 10,000 ppm camphor (P < 0.05). This group also had the highest hole persistency in IPVL. Conclusively, the result indicated that camphor can be added in poultry diet for the improvement of reproductive functions.