Tenhagen B A, Drillich M, Surholt R, Heuwieser W
Clinic for Reproduction, Section of Production Medicine and Quality Management, Free University of Berlin, 14163 Berlin, Germany.
J Dairy Sci. 2004 Jan;87(1):85-94. doi: 10.3168/jds.S0022-0302(04)73145-8.
A timed artificial insemination (TAI) protocol using OvSynch was compared to artificial insemination (AI) at detected estrus in 2 large dairy herds differing in reproductive management. Cows were synchronized for TAI starting at 62 and 42 d in milk in herds 1 and 2, respectively. The OvSynch regimen included: GnRH (buserelin) at 0.02 mg (i.m.) on d 0; PGF2alpha (tiaprost) at 0.75 mg (i.m.) on d 7; buserelin at 0.02 mg (i.m.) on d 9; and TAI 16 to 20 h later. After TAI, cows seen in estrus received AI, whereas cows diagnosed not pregnant were resynchronized for TAI. Control cows received AI based on detected estrus after voluntary waiting periods of 72 d in herd 1 and 50 d in herd 2. An economic analysis included costs associated with days open, culling, AI, synchrony products, treatment, and examinations. A sensitivity analysis of those variables determined effects on total costs per pregnancy. Use of OvSynch reduced intervals to first AI and days open in both herds and reduced culling for infertility in herd 2. Conception rates for first AI at detected estrus were significantly higher compared to TAI in both herds and for overall AI at estrus in herd 2. For groups assigned to AI at estrus, mean 21-d submission rates over 200 d for AI were higher in herd 1 than in herd 2 (55.6 vs. 28.6%). Days open and culling were the major cost factors. Although OvSynch improved reproduction in both herds, AI based on detected estrus was economically superior in herd 1, whereas OvSynch was superior in herd 2. This was consistent across ranges of cost factors evaluated. Evaluation of synchrony protocols should include reproductive performance along with appropriate costs associated with treatments. Such costs may offset benefits to reproduction in herds with good estrous detection rates.
在两个繁殖管理方式不同的大型奶牛场中，将使用OvSynch定时人工授精（TAI）方案与在检测到发情时进行人工授精（AI）作比较。在牛群1和牛群2中，分别在产犊后62天和42天开始对奶牛进行同步化处理以进行TAI。OvSynch方案包括：在第0天肌肉注射0.02毫克戈那瑞林（布舍瑞林）；在第7天肌肉注射0.75毫克前列腺素F2α（噻前列素）；在第9天肌肉注射0.02毫克布舍瑞林；并在16至20小时后进行TAI。TAI后，发情的奶牛接受AI，而诊断未怀孕的奶牛重新进行同步化处理以进行TAI。对照奶牛在牛群1自愿等待72天、牛群2自愿等待50天后，根据检测到的发情情况接受AI。经济分析包括与空怀天数、淘汰、AI、同步化产品、治疗和检查相关的成本。对这些变量进行敏感性分析，确定其对每次怀孕总成本的影响。使用OvSynch缩短了两个牛群首次AI的间隔时间和空怀天数，并减少了牛群2中因不育而被淘汰的情况。在两个牛群中，检测到发情时首次AI的受孕率均显著高于TAI，在牛群2中发情时总体AI的受孕率也显著高于TAI。对于分配在发情时进行AI的组，在200天内AI的平均21天提交率在牛群1中高于牛群2（55.6%对28.6%）。空怀天数和淘汰是主要成本因素。尽管OvSynch在两个牛群中均改善了繁殖情况，但在牛群1中基于检测到发情进行的AI在经济上更具优势，而在牛群2中OvSynch更具优势。在评估的成本因素范围内，情况均如此。对同步化方案的评估应包括繁殖性能以及与治疗相关的适当成本。这些成本可能会抵消发情检测率高的牛群在繁殖方面的益处。
