Ramírez-Iglesia Lilido Nelson, Roman Bravo Rafael María, Díaz de Ramirez Adelina, Torres Leandro J
Centro de Investigaciones Agrícolas, Biológicas, Educativas y Sociales (CIABES), Universidad de Los Andes-Trujillo (ULA), Avenida Medina Angarita, Casa Carmona. Apartado Postal 198, Trujillo 3150, Estado Trujillo, Venezuela.
Facultad de Ciencias Veterinarias, Núcleo Agropecuario, La Universidad del Zulia, Ciudad Universitaria, Avenida Goajira, Maracaibo 4001, Estado Zulia, Venezuela.
J Vet Med. 2014;2014:404363. doi: 10.1155/2014/404363. Epub 2014 Aug 26.
The aim of this research was to compare two artificial insemination protocols (AIP): hormonal synchronization with fixed time artificial insemination (SC-FTAI) and the use of a table based on visual observation of estrus signs (VO) in order to identify cows in natural or spontaneous estrus being assigned to AI (NSE-IA). Two groups were formed: in the first group 109 cows were assigned to SC-FTAI, in which a commercial protocol is used; the second one included 108 randomly chosen cows, which were assigned to NSE-AI and in this group a modified table was used. Response variable was first service fertility rate (FSF), which was coded 1 for pregnant and 0 for empty. Predictor variables were AIP, postpartum anestrus, daily milk yield, body condition score at AI and calving number. Statistical analyses included association chi-square tests and logistic regression. Results showed an overall 41.94% FSF and a significant association was detected (P < 0.05) between FSF and daily milk yield; pregnancy rates were 42.20% and 41.67% for the SC-FTAI and NSE-IA groups, respectively (P > 0.05). The odds ratio for the effect of AIP was only 1.050, suggesting no differences in FSF between groups. The NSE-AI protocol can enhance both the technique of VO and reproductive efficiency. Further validation of the table is required.
本研究的目的是比较两种人工授精方案（AIP）：激素同步定时人工授精（SC-FTAI）和使用基于发情迹象视觉观察的表格（VO）来识别处于自然或自发发情期并接受人工授精（NSE-IA）的奶牛。组建了两组：第一组109头奶牛被分配至SC-FTAI，采用商业方案；第二组包括108头随机选择的奶牛，被分配至NSE-AI，该组使用改良表格。反应变量为首次输精受胎率（FSF），怀孕记为1，未怀孕记为0。预测变量为AIP、产后乏情、日产奶量、人工授精时的体况评分和产犊次数。统计分析包括关联卡方检验和逻辑回归。结果显示总体FSF为41.94%，且检测到FSF与日产奶量之间存在显著关联（P<0.05）；SC-FTAI组和NSE-IA组的怀孕率分别为42.20%和41.67%（P>0.05）。AIP效应的优势比仅为1.050，表明两组间FSF无差异。NSE-AI方案可提高VO技术和繁殖效率。该表格需要进一步验证。
