Starting time and distribution of different physiological stages of the musk secretion period in captive forest musk deer (Moschus berezovskii)

The musk response is a unique physiological function of the musk deer, which is directly expressed in the secretion and formation of musk. This study aimed to reveal the relationship between the musk secretion start-up time, different physiological stages and age distribution of musk deer in order to elucidate the mechanism of musk, explore factors influencing musk yield and quality, and provide scientific feeding and breeding management techniques for musk deer. Genealogical records were collected for 50 musk deer from six age groups (1-, 2-, 4-, 5-, 7- and 9-year-old). Observations of feeding intake, behavior, defecation frequency, texture, color and smell of pellets were used to classify the entire musk period into three stages. Complete data for 39 musk deer were recorded. All data were analyzed using Excel 2003 and SAS 9.0 software. Two peaks in the age group were dominated by the adult (> 2-year-old ) and bred group (≤ 2-year-old). The start-up time of the adult group was earlier than that of the bred group (approximately 15 days), and the whole physiological period lasted longer and the change was relatively flat. Younger the musk deer, later the start up time of musk secretion; However, the musk physiological period was more concentrated. The duration of every physiological stage in the 6 age groups was not significantly different, and the duration of variation was bigger. A T-test of non-paired samples was carried out to compare the differences in 3 stages between the adult and bred group. The prime musk-secreting stage was not significantly different (T = –0.68, P = 0.499 2). The vigorous musk secreting stage of the bred group (2.89 d, n = 18) and adult group (4.10 d, n = 21) was significantly different (T = –2.59, P = 0.013 5), whilst the later musk secreting stage was not significantly different (T = –0.26, P = 0.799 7). The total musk physiological period of the bred group (8.67 d, n = 18) and adult group (10.24 d, n = 21) was significantly different (T = –2.05, P = 0.047 0). These results show that the time of vigorous musk secreting stage, total time and musk yield, and quality need to be further explored. The results of this study can lay the foundation for scientific feeding and breeding management techniques and clarify the relationship between the duration of different physiological stages of the musk-secreting period and the yield and quality of musk.