Artificial insemination field data on the use of sexed and conventional semen in nulliparous Holstein heifers
Artificial insemination field data on the use of sexed and conventional semen in nulliparous Holstein heifers
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DOI：
10.3168/jds.2012-5465
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发表时间：
2013-03-01
影响因子：
3.5
通讯作者：
Thomson, P. C.
中科院分区：
文献类型：
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作者：
Healy, A. A.;House, J. K.;Thomson, P. C.
本研究调查了2004年1月至2009年4月在新南威尔士州中西部的澳大利亚商业奶牛群中，使用性和常规精液对未产荷斯坦小母牛进行人工授精（AI）的受孕率和其他生殖结果。采用多种混合模型分析了4456头小母牛9870次人工授精记录的回顾性数据，以评估养殖环境温度和湿度、授精成功率、人工授精技术人员、服务次数、小母牛体重和养殖年龄对生殖性状（受孕率、性别比例、妊娠期长短、流产和死胎率）的影响。使用的精液来自15个有性雄性和41个无性雄性。性别精液主要用于第一次和第二次服务。有性别和无性别的精液的经验受孕率分别为31.6和39.6%，而基于模型的预测则较低，分别为21.3和32.1%。受精率受授精率、性别分选、母牛龄、养殖环境温湿度、服务次数和at技术人员的影响显著。与传统精液的48%相比，性别精液的产出率为86%。犊牛性别的重要预测因子包括精液性别、妊娠期长短和人工授精。两种精液类型的双胞胎率都很高，为3.6%，妊娠期长度和母牛体重是双胞胎的显著预测因子。有性受孕和无性受孕的流产率相似，分别为6.1%和6.5%，并受母牛繁殖年龄的影响。死产率受犊牛性别、双胞胎、妊娠期长短和AT技术人员的影响；精液分选、繁殖年龄、温度和湿度是边际显著的预测因子。在后代的发育中没有观察到异常，除了性别小牛的死产率略高，这一发现需要进一步调查。许多变量影响与商业奶牛场应用性别分类精子相关的育种结果。对这些变量的认识和管理将增加投资于性别分类精子的经济回报。
This study investigated conception rates and other reproductive outcomes achieved with artificial insemination (AI) of nulliparous Holstein heifers using sexed and conventional semen in a commercial Australian dairy herd in central western New South Wales from January 2004 to April 2009. Retrospective data from on-farm records of 9,870 inseminations of 4,456 heifers were analyzed using several mixed models to assess the effect of temperature and humidity surrounding breeding, insemination sire, artificial insemination technician, service number, and heifer weight and age at breeding on reproductive traits (conception rates, sex ratios, gestation length, and abortion and stillbirth rates). Semen was used from 15 sexed sires and 41 unsexed sires.. Sexed semen was primarily used at first and second service. Empirical conception rates of 31.6 and 39.6% were achieved for sexed and unsexed semen respectively, whereas model-based predictions were lower, at 21.3 and 32.1%. Conception rates were significantly affected by insemination sire, sex-sorting, heifer age at breeding, temperature and humidity surrounding breeding, service number, and AT technician. Sexed semen yielded 86% heifers, compared with 48% for conventional semen. Significant predictors of calf sex included semen sexing, gestation length, and insemination sire. Twinning rate was high, at 3.6% for both semen types, and gestation length and heifer weight at breeding were significant predictors of twinning. Abortion rates for sexed and unsexed conceptions were similar at 6.1 and 6.5%, respectively, and were affected by heifer age at breeding. Stillbirth rate was affected by calf sex, twinning, gestation length, and AT technician; semen sorting, age at breeding, and temperature and humidity were marginally significant predictors. No abnormalities were observed in the development of offspring, except for a marginally higher stillbirth rate for sexed calves, a finding that needs further investigation. Many variables influence the breeding outcomes associated with the application of sex-sorted sperm on commercial dairy farms. Recognition and management of these variables will increase the economic return from the investment in sex-sorted sperm.