Manjarin R, Dominguez J C, Castro M J, Alegre B, Driancourt M A, Kirkwood R N
Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, MI 48824, USA.
Reprod Domest Anim. 2010 Jun;45(3):555-7. doi: 10.1111/j.1439-0531.2008.01299.x. Epub 2008 Oct 30.
Gilt oestrus and ovulation responses to injection of a combination of equine chorionic gonadotrophin (eCG) and human chorionic gonadotrophin (hCG) (PG600) can be unpredictable, possibly reflecting inadequate circulating LH activity. The objective of this study was to determine the effect of PG600 followed by supplemental hCG on gilt ovarian responses. In experiment 1, 212 Hypor gilts (160 day of age) housed on two farms in Spain received intramuscular (i.m.) injections of PG600 (n = 47), or PG600 with an additional 200 IU hCG injected either concurrently (hCG-0; n = 39), or at 24 h (hCG-24; n = 41) or 48 h (hCG-48; n = 45) after PG600. A further 40 gilts served as non-injected controls. Ovulation responses were determined on the basis of initial blood progesterone concentrations being <1 ng/ml and achieving >5 ng / ml 10 d after the PG600 injection. The incidence of ovulating gilts having progesterone concentrations >30 ng/ml were recorded. During the study period, 10% of control gilts ovulated whereas 85-100% of hormone-treated gilts ovulated. There were no significant differences among hormone groups for proportions of gilts ovulating. The proportions of gilts having circulating progesterone concentrations >30 ng/ml were increased (p < or = 0.02) in all hCG treated groups compared with the PG600 group. In experiment 2, a total of 76 Hypor gilts at either 150 or 200 days of age were injected with PG600 (n = 18), 400 IU eCG followed by 200 IU hCG 24 h later (n = 20), PG600 followed by 100 IU hCG 24 h later (n = 17), or 400 IU eCG followed by 300 IU hCG 24 h later (n = 21). Blood samples were obtained 10 days later for progesterone assay. There were no effects of treatment or age on incidence of ovulation, but fewer 150-day-old gilts treated with PG600 or 400 IU eCG followed by 200 IU hCG had progesterone concentrations >30 ng / ml. We conclude that hCG treatment subsequent to PG600 treatment will generate a higher circulating progesterone concentration, although the effect is not evident in older, presumably peripubertal, gilts. The mechanism involved and implications for fertility remain to be determined.
后备母猪对注射马绒毛膜促性腺激素（eCG）和人绒毛膜促性腺激素（hCG）的组合制剂（PG600）的发情和排卵反应可能不可预测，这可能反映了循环促黄体生成素（LH）活性不足。本研究的目的是确定PG600后补充hCG对后备母猪卵巢反应的影响。在实验1中，西班牙两个农场饲养的212头海波尔后备母猪（160日龄）接受肌肉注射PG600（n = 47），或PG600并同时注射额外的200 IU hCG（hCG-0；n = 39），或在PG600后24小时（hCG-24；n = 41）或48小时（hCG-48；n = 45）注射200 IU hCG。另外40头后备母猪作为未注射的对照。根据PG600注射后最初血液孕酮浓度<1 ng/ml且在10天后达到>5 ng/ml来确定排卵反应。记录孕酮浓度>30 ng/ml的排卵后备母猪的发生率。在研究期间，10%的对照后备母猪排卵，而85 - 100%的激素处理后备母猪排卵。激素处理组之间排卵后备母猪的比例没有显著差异。与PG600组相比，所有hCG处理组中孕酮浓度>30 ng/ml的后备母猪比例均有所增加（p≤0.02）。在实验2中，总共76头150或200日龄的海波尔后备母猪分别注射PG600（n = 18）、400 IU eCG随后24小时注射200 IU hCG（n = 20）、PG600随后24小时注射100 IU hCG（n = 17）或400 IU eCG随后24小时注射300 IU hCG（n = 21）。10天后采集血样进行孕酮测定。处理或年龄对排卵发生率没有影响，但接受PG600或400 IU eCG随后200 IU hCG处理的150日龄后备母猪中，孕酮浓度>30 ng/ml的较少。我们得出结论，PG600处理后进行hCG处理会使循环孕酮浓度更高，尽管这种效果在年龄较大、可能处于青春期前后的后备母猪中不明显。其中涉及的机制及其对繁殖力的影响仍有待确定。
