Study On Cortisol And Minerals In Hair Of Captive Male Forest Musk Deer

The artificial breeding of musk deer(Moschus berezovskii)in China has been over 70 years,but the captive musk deer population has been growing slowly,therefore,it is of great significance to explore the stress state of captive male forest musk deer.At the same time,individual cultivated male musk deer secrete abnormal musk,so it is necessary to explore the physiological characteristics of this part of male musk deer.In our study,from late February to March when the forest musk deer was in a physiologically stable period in 2019,180 male musk deer hairs were collected from forest musk deer breeding bases of different scales and with different housing crowding in the Baoji area of Shaanxi Province.The concentrations of cortisol in hairs were measured by ELISA.The effects of age,field size and enclosure crowding degrees on stress state of male musk deer were evaluated.ICP-MS was used to determine the levels of macroelements calcium(Ca),magnesium(Mg)and trace elements manganese(Mn),iron(Fe),copper(Cu),zinc(Zn),and lead(Pb)in hair of Musk with abnormal secretion versus those with normal secretion,the difference of mineral content in the hair of the two types of forest musk deer were evaluated.The main results are as follows,(1)Curve estimation analysis of the relationship between age and male musk hair cortisol concentration,the results show that age(X)has a significant effect on hair cortisol concentration(Y),the regression equation is In Y=6.025+0.339/X.There was no significant difference in hair cortisol concentration between the age groups of 3 to 9 years.The results of these studies indicate that the cortisol concentration of the young forest male musk deer decreases with age and tends to be stable,and the adult male musk deer shows the relative stability of the physiological state under artificial feeding conditions.(2)The stress intensity of 3-9-year-old adult male musk deer was grouped based on the concentration of hair cortisol,and the distribution differences of the two groups in different feeding scale and feeding environment were analyzed and compared,the results show that the high hair cortisol group accounted for 8.45% of the total number of samples.The distribution of high cortisol group(low sensitivity)and low cortisol group(high sensitivity)in different scale male musk deer farms had no significant difference.High cortisol group(low sensitivity)accounted for a larger proportion in the smaller feeding space,while low cortisol group(high sensitivity)accounted for a larger proportion in the larger feeding space.The results showed that the cortisol content in hair could reflect the physiological stress state of male musk deer,and could be used to monitor the general physiological stress state of musk deer during the growth period of several months.The content of cortisol in the hair of male forest musk deer and its grouping can indicate the effect of feeding mode and management mode on physiological stress of forest male musk deer,and provide scientific basis for adjusting feeding and management mode.(3)The results of non-parametric test showed that the contents of magnesium(P = 0.017 < 0.05)and calcium(P = 0.027 < 0.05)in the hair of the male musk deer with abnormal musk were significantly lower than those secreting normal male musk deer.There was no significant difference in other trace elements manganese,iron,copper,zinc and lead(P > 0.05).It indicates that the abnormal aroma secretion of male forest musk deer may be related to the insufficient absorption of magnesium and calcium.The results of the study can provide scientific basis for the study of the physiological characteristics of male forest musk deer.