González-Maldonado Juan, Rangel-Santos Raymundo, Rodríguez-de Lara Raymundo, García-Peña Oswaldo
Posgrado en Producción Animal, Departamento de Zootecnia, Universidad Autónoma Chapingo, Estado de México, 56230, Mexico.
Posgrado en Producción Animal, Departamento de Zootecnia, Universidad Autónoma Chapingo, Estado de México, 56230, Mexico.
Anim Reprod Sci. 2017 Jun;181:57-62. doi: 10.1016/j.anireprosci.2017.03.015. Epub 2017 Mar 28.
This study evaluated the effect of injecting trace minerals on reproductive performance in over-conditioned Holstein cows before synchronized estrus. Multiparous non-lactating, over-conditioned repeat breeder cows (n=20) were assigned randomly to one of two treatments: 1) control (n=10), and 2) supplementation with an injectable trace mineral complex 25days before expected synchronized estrus (n=10). Follicular waves were synchronized by intravaginal insertion of a CIDR for eight days and an intramuscular (i.m.) injection of a GnRH analogue. Estrus was induced at CIDR removal by an i.m. injection of PGF. Blood samples were collected before and after synchronized estrus. The response variables were follicle population (FP), diameter of the preovulatory follicle at CIDR removal (DFP0) and at estrus detection (DFP1), time of estrus after CIDR removal (TE), area of corpus luteum (ACL), pregnancy rate and copper and zinc serum concentrations. The statistical analysis of the variables was carried out with SAS. The FP, DFP0, DFP1, TE, ACL and serum concentrations of copper and zinc were not affected by the trace mineral injection (P>0.05). Even though pregnancy rate at 40 (77.78±13.46 vs 44.44±16.56%) and 60days after AI (66.67±15.71 vs 33.33±15.71%) was numerically higher for cows injected with trace minerals than for the control group, the differences were not significant (P>0.05). In conclusion, while follicular and corpus luteum development were not affected by trace mineral injection, it may be a feasible way to increase the pregnancy rate in over-conditioned cows.
本研究评估了在同步发情前对体况过肥的荷斯坦奶牛注射微量矿物质对繁殖性能的影响。将多胎非泌乳、体况过肥的屡配不孕奶牛（n = 20）随机分为两种处理之一：1）对照组（n = 10），2）在预期同步发情前25天补充可注射的微量矿物质复合物（n = 10）。通过阴道插入孕酮释放装置（CIDR）8天并肌肉注射促性腺激素释放激素（GnRH）类似物来同步卵泡波。在取出CIDR时通过肌肉注射前列腺素F诱导发情。在同步发情前后采集血样。反应变量包括卵泡数量（FP）、取出CIDR时（DFP0）和发情检测时（DFP1）排卵前卵泡的直径、取出CIDR后的发情时间（TE）、黄体面积（ACL）、妊娠率以及铜和锌的血清浓度。使用SAS对变量进行统计分析。微量矿物质注射对FP、DFP0、DFP1、TE、ACL以及铜和锌的血清浓度没有影响（P>0.05）。尽管注射微量矿物质的奶牛在人工授精后40天（77.78±13.46对44.44±16.56%）和60天（66.67±15.71对33.33±15.71%）的妊娠率在数值上高于对照组，但差异不显著（P>0.05）。总之，虽然微量矿物质注射不影响卵泡和黄体的发育，但它可能是提高体况过肥奶牛妊娠率的一种可行方法。
