[1] [1] XIN Qingwu. On the characteristics of semen and artificial insemination of quality medium-sized meat of ducksand artificial insemination methods of high quality medium meat ducks［D］. Wuhan:Huazhong Agricultural University, 2011: 1-2.

[2] [2] ZHANG Yong. Investigation on the cryopreservation of cock semen in various diluents［D］. Yinchuan:Ningxia University, 2014.

[3] [3] ZHU Liqin, LIU Lu, HE Changqing, et al. The comparison of spectrophotometer and hand-held sperm density detector for determining sperm density［J］. China Poultry, 2017, 39(23): 60-63.

[4] [4] ZHANG Liang, GUO Zongyi, PAN Hongmei. Rapid estimation on the sperm concentration in boar semen by spectrophotometric method［J］. Guangdong Agricultural Sciences, 2012, 39(05): 103-105, 108.

[5] [5] WU Mi. The sperm density of bulls was determined by 7230 spectrophotometer［J］. Journal of Yellow Cattle Science, 1994, 67(02): 39-41.

[6] [6] ROU Zihan, RE Heman, RE Ziya. The experiment of measuring the semen density of ram by 721 spectrophotometer ［J］. Xinjiang Animal Husbandry, 2002, (4): 20-21.

[7] [7] ZHANG Tao, ZHANG Longzhen, ZHUANG Ping. Determination on the sperm concentration standard of russian sturgeon (Acipenser gueldenstaedtii)by means of spectrophotometric method［J］. Mariner Fisheries, 2009, 31(1): 87-91.

[8] [8] WANG Kun, JIANG Jun, ZHU Lijun, et al. Detection methods of sperm density in roosters［J］. China Poultry, 2014, 36(12): 12-14.

[9] [9] YAN Jialai, CHEN Yujing, ZHANG Fasu. Common methods of cell counting in the course of basic clinical examination［J］. Journal of Baotou Medical College, 2016, 32(6): 157-158.

[10] [10] ZHANG Youqing. Error analysis of nuclear polyhedrosis virus quantities determined by hematology counter plate［J］. Microbiological Bulletin, 1982, 3: 142.

[11] [11] HAN Weijie, HUANG Xiaofeng, LIU Xiaohua. Studies on artificial semen collection and semen quality of anas poecilorhyncha［J］. Hubei Agricultural Sciences, 2013, 52(07): 1611-1612.

[12] [12] LIJING Haosi, ZHANG Hong, translation. Artificial insemination of ducks ［J］. Animal Science Abroad, 1998, 25(3): 36-37.

[13] [13] SONG Weitao, LI Huifang, XU Wenjuan, et al. Semen quality assessment of SuyouⅠducks［J］. Journal of Domestic Animal Ecology, 2017, 38(5): 49-53.

[14] [14] GUO Haining, CHEN Kaifeng, SU Hongwei, et al. Optimum semen collection frequency and insemination parameters of cage-rearing ShanMa ducks［J］. Acta Agriculture Universitis Jiangxiensis, 2018, 40(02): 350-357.

[15] [15] CHEN Zhangyan, DU Wenxing, DUAN Xiujun. Artificial insem ination of the Cherry Valley ducks with Muscovy dukes［J］. Journal of Anhui Agricultural Sciences, 2009, 37(33): 16733-16735, 16737.

[16] [16] WEI Wendong, ZHANG Liang, ZHANG Wei. Accuracy comparison test of pig sperm density measured by different sperm densitometer［J］. Swine Industry Science, 2012, (10): 70-71.

[17] [17] XIE Xingyi, FANG Jianyuan, HE Kunyi, et al. Comparison of two dilutions in semen analysis of high sperm density［J］. Experimental and Laboratory Medicine, 2014, 32(4): 438-439.