Ferraz P A, Burnley C, Karanja J, Viera-Neto A, Santos J E P, Chebel R C, Galvão K N
Escola de Medicina Veterinária, Universidade Federal da Bahia, Salvador, BA, Brazil.
Southern Embryo, Athens, Georgia, USA.
Theriogenology. 2016 Oct 15;86(7):1834-41. doi: 10.1016/j.theriogenology.2016.05.032. Epub 2016 Jun 2.
The objectives of this study were to evaluate factors affecting in vivo embryo production and pregnancy per embryo transfer (P/ET) in Holstein cattle in the southeast region of the United States. Data from a total of 516 embryo collections and 10,297 ETs performed from 2011 to 2014 were available. For embryo production, the effects of donor parity (nulliparous [N], primiparous [P], multiparous [M]), average temperature-humidity index (THI) at embryo collection, days in milk at embryo collection, occurrence of calving problems, and occurrence of metritis postpartum were evaluated. For P/ET, the effects of donor parity (N or parous), recipient parity (N, P, and M), embryo type (fresh, frozen, IVF, and IVF-frozen), embryo developmental stage (4-7), embryo quality (1-3), recipient estrous cycle day at ET (6-9), average THI at ET, days in milk at ET, milk yield at ET, occurrence of calving problems (abortion, dystocia, twins, fetal death, or retained placenta), and occurrence of metritis postpartum were evaluated. Pregnancy was diagnosed at 41 ± 3 days of gestation. Continuous and binary data were analyzed using the MIXED and GLIMMIX procedures of SAS, respectively. Parity affected embryo production; M had greater number and percentage of unfertilized embryos and lesser percentage of viable embryos than P and N. Recipient parity, embryo type, embryo stage, embryo quality, estrous cycle day at ET, and THI at ET affected P/ET. There was an interaction between recipient parity and THI at ET. P/ET was greater for N than P and greater for P than M, greater for fresh embryos than others, greater for stage 7 than others, greater for quality 1 than 2 and greater for quality 2 than 3, and greater for ET on estrous cycle Day 7 and 8 than 6. P/ET was decreased for THI ≥80 in N and THI ≥72 in P and M. Calving problems and metritis also affected P/ET in P and M and was lesser for cows that had calving problems and metritis. In conclusion, embryo production was affected by donor parity, and P/ET was affected by embryo type, embryo stage, embryo quality, recipient estrous cycle day at ET, THI, calving problems, and metritis.
本研究的目的是评估影响美国东南部地区荷斯坦奶牛体内胚胎生产以及每次胚胎移植妊娠率（P/ET）的因素。可获取2011年至2014年期间总共516次胚胎采集和10297次胚胎移植的数据。对于胚胎生产，评估了供体胎次（未产 [N]、初产 [P]、经产 [M]）、胚胎采集时的平均温度 - 湿度指数（THI）、胚胎采集时的泌乳天数、产犊问题的发生情况以及产后子宫炎的发生情况的影响。对于P/ET，评估了供体胎次（N或经产）、受体胎次（N、P和M）、胚胎类型（新鲜、冷冻、体外受精、体外受精 - 冷冻）、胚胎发育阶段（4 - 7）、胚胎质量（1 - 3）、胚胎移植时受体的发情周期天数（6 - 9）、胚胎移植时的平均THI、胚胎移植时的泌乳天数、胚胎移植时的产奶量、产犊问题（流产、难产、双胞胎、胎儿死亡或胎盘滞留）的发生情况以及产后子宫炎的发生情况的影响。在妊娠41 ± 3天时诊断妊娠。连续数据和二元数据分别使用SAS的MIXED和GLIMMIX程序进行分析。胎次影响胚胎生产；与P和N相比，M的未受精胚胎数量和百分比更高，而存活胚胎的百分比更低。受体胎次、胚胎类型、胚胎阶段、胚胎质量、胚胎移植时的发情周期天数以及胚胎移植时的THI影响P/ET。胚胎移植时受体胎次和THI之间存在交互作用。N的P/ET高于P，P高于M；新鲜胚胎的P/ET高于其他胚胎；发育阶段7的高于其他阶段；质量1的高于质量2，质量2的高于质量3；发情周期第7天和第8天进行胚胎移植时的P/ET高于第6天。当N的THI≥80以及P和M的THI≥72时，P/ET降低。产犊问题和子宫炎也影响P和M的P/ET，有产犊问题和子宫炎的奶牛的P/ET较低。总之，胚胎生产受供体胎次影响，而P/ET受胚胎类型、胚胎阶段、胚胎质量、胚胎移植时受体的发情周期天数、THI、产犊问题和子宫炎影响。
