| Summary: | 碩士 === 國立屏東科技大學 === 畜產系 === 94 === In the cervids in the temperate zone, changes of the reproductive activity are mainly controlled by the photoperiodism. It is very little documents concerning the breeding biology of tropical-subtropical cervids. For example, there is quite a few information for the reproductive activity of the muntjac (Muntiacus reevesi). The Formosan Reeves’ muntjac (Muntiacus reevesi micrurus) bucks farmed in southern Taiwan (22.5。N, 120.5。E) were allotted to investigate the effect of semen collection methods on the semen quality (Study 1), annual changes of semen characteristics and serum testosterone concentration (Study 2). Effects of sex maturity on the gross morphometry related to breeding characteristics, semen characteristics and serum testosterone concentration (Study 3). Results showed that the adult bucks (>2y) were in hard antler stage (HAS) from the 3rd triplet in October to the 1st triplet in May in next year and in velvet antler stage (VAS) from the 2nd triplet in May to the 2nd triplet in September. The values of semen volume, sperm motility score and sperm concentration collected by EE were significant better than it collected by artificial vagina (350 vs. 170 μl; 5 vs. 2 score and 252.39 vs. 90.24 × sperm 107/ml, respectively; P < 0.05) (Study 1). Annual Changes of the testosterone concentration were ranged in 3.73 ± 2.90 ng/ml, and the semen containing sperm could be collected by electro-ejaculation (EE) throughout the year. The testicular volume (TV) in HAS was significantly higher than that in VAS (29.76 ± 4.25 vs. 25.40 ± 2.97 cm3, P < 0.05). The scrotal circumference, TV and serum testosterone concentration were significantly higher in winter, but it were reversed in summer (respectively, 10.74 ± 0.62 vs. 9.89 ± 0.46 cm, 31.62 ± 3.56 vs. 25.95 ± 2.51 cm3 and 4.55 ± 4.02 vs. 1.92 ± 2.16 ng/ml, P < 0.05). The value of gross morphometry related to breeding characteristics and semen characteristics during the HAS were better than that in VAS. Furthermore, the other gross morphometry related to breeding characteristics and semen characteristics were also highest during winter. Changes of body weight, neck girth, TV and serum testosterone were positively and significantly correlated to each other (P < 0.05) (Study 2). Pedicle growth was appeared at age of 7-8 months in the juvenile muntjacs (≦2y). Semen containing sperm could be first collected by EE at the age of 10-11 months when the velvet initiated, and then the testosterone concentration was maintained in 3.96 ± 2.94 ng/ml throughout the year. The semen characteristics of the adults, both in VAS and HAS were better than it in the juveniles (semen: 305, 216 vs. 273, 239 μl and sperm concentration: 235.4, 259.8 vs. 217.0, 200.2 sperm ×107/ml, respectively; P > 0.05). The gross morphometries related to breeding characteristics were also high in the adults (Study 3). In conclusion, the semen collected by electro-ejaculation method exhibit better quality than by artificial vagina method in hard antler stage. The year-round sperm production ability in the Formosan Reeves’ muntjac was first proved by the direct observations of the live animals in the studies. The muntjac bucks developed their first velvet at the age of 10-11 months, and the capability of sperm production at the same time, when they maintained the serum testosterone concentration both in HAS and VAS in the range of 1 ~ 6 ng/ml throughout a year.
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