Study On The Growth Characteristics Of Winter Coat Of Male Minghua Black Mink With Melatonin Implantation

China is a big producer of mink(Mustela vison),but the quality of mink needs further improvement.By analyzing the growth and morphological characters between the melatonin-inducted mink pelage and natural grown mink pelage,It can be used as a reference to distinguish mink pelage and to obtain high quality fur after melatonin implantation,and is of great significance for improving the quality of mink pelage in China.This paper selected 5 fresh male Minghua black Mink skins from Dalian Mingwei Mink industry co.,ltd.respectively on August 15,2017(31d after melatonin implantation),September 15,2017(62d after melatonin implantation)and September 28,2017(75d after melatonin implantation)and 5 fresh skins of the same species of mink without melatonin implantation were selected On October 5,November 5 and November 27,2017.A total of 8 guard hairs and 8 underfur were selected from the belly,mid-back and buttock of each skin respectively in each.Skin samples of 1cmx1cm size were collected from the above three parts of the mink 75 days after melatonin implantation(melatonin-inducted mink pelage)and on November 27 without melatonin implantation(natural grown mink pelage),respectively,for measuring the hair density.All the sampled hairs were made into paraffin slice of skin tissues,cuticular impression organic glass and medulla pattern slide were made.Hair density of the three sites,length of underfur,diameter of medulla,length and diameter of hair,medullary index,medulla-absent region length near hair root,flat-shaped scale pattern length near hair root,ratio of length of underfur and guard hairs was measured.With the analysis of SPSS,we concluded that:1.In addition to the diameter of hair at the thickest point,there was a significant correlation between other morphological traits of guard hairs in newborn winter of mink,and the characteristics of other morphological traits could be inferred from one of the morphological traits of guard hairs in newborn winter.2.On the morphological indexes,such as the length of guard hairs,the length of underfur and the density of hair,natural grown mink pelage was slightly larger than the melatonin-inducted mink pelage,but the difference was not significant.3.There were significant differences in morphological indexes,such as diameter of underfur and underfur medulla index,which can be used to distinguish melatonin-inducted and natural grown mink pelage at micro leve.4.31 days to 62 days after the implantation of melatonin(from October 5 to November 5,2017 without melatonin implantation),the average growth rate of winter guard hairs is fast.The average growth rate of winter guard hairs of the skin decreased from 62 days to 75 days after the implantation of melatonin(from November 5 to November 27,2017 without melatonin implantation).