Zhang B R, Larsson B, Lundeheim N, Rodriguez-Martinez H
Department of Obstetrics & Gynecology Swedish University of Agricultural Sciences Uppsala, Sweden.
Theriogenology. 1997 Jul 15;48(2):221-31. doi: 10.1016/s0093-691x(97)84069-1.
Frozen-thawed bull semen with > 50% post-thaw motility from 40 batches (21 bulls, 2 consecutive ejaculates per batch) was used for fertilization (IVF) and embryo development in vitro to assess the relationship between field and laboratory fertility using a retrospective approach. Each frozen batch was tested in 3 or 4 replicates with 30 oocytes per replicate. Field fertility, quantified as the 56-d nonreturn rate and based on 89 to 441 artificial inseminations per frozen batch, ranged between 46.2 and 74.8%. The cleavage and blastocyst rates after IVF varied from 29.0 to 81.9% and from 1.8 to 32.0%, respectively, with significant differences among frozen batches. Rates of cleavage and blastocyst formation were significantly related to the nonreturn rate (r = 0.59, P < 0.001; r = 0.35, P < 0.05, respectively). The interaction between cleavage and blastocyst rate was 0.69 (P < 0.001). Significant variations (P < 0.05) among frozen semen batches within 15 bulls with >/= 2 different semen batches were found for the nonreturn rate (13.3%) of 2 bulls, for cleavage rates (26.7%) in 4 bulls and for blastocyst rates (20.0%) in 3 bulls. Significant differences (P < 0.05) among replicates within the 40 frozen semen batches were only found in 3 batches (7.5%) for the cleavage rate and in 7 batches (17.5%) for blastocyst rate. Overall, bull and frozen semen batch were the greatest sources of variation in the cleavage rate (30.6 and 29.4%, respectively), while testing date was the greatest source of variation in the blastocyst development rate (21.7%). The results indicated that in vitro fertilization and, to a lesser extent, culture to the blastocyst stage could be useful in estimating the potential fertilizing ability of frozen-thawed semen from dairy bulls.
使用来自40个批次（21头公牛，每个批次2次连续射精）解冻后活力>50%的冻融公牛精液进行体外受精（IVF）和胚胎发育，以回顾性方法评估田间和实验室生育力之间的关系。每个冷冻批次进行3或4次重复试验，每次重复使用30个卵母细胞。田间生育力以56天不返情率量化，基于每个冷冻批次89至441次人工授精，范围在46.2%至74.8%之间。IVF后的卵裂率和囊胚率分别在29.0%至81.9%和1.8%至32.0%之间变化，不同冷冻批次之间存在显著差异。卵裂率和囊胚形成率与不返情率显著相关（分别为r = 0.59，P < 0.001；r = 0.35，P < 0.05）。卵裂率和囊胚率之间的相互作用为0.69（P < 0.001）。在15头有≥2个不同精液批次的公牛中，发现2头公牛的不返情率（13.3%）、4头公牛的卵裂率（26.7%）和3头公牛的囊胚率（20.0%）在冷冻精液批次之间存在显著差异（P < 0.05）。在40个冷冻精液批次中，仅在3个批次（7.5%）的卵裂率和7个批次（17.5%）的囊胚率中发现重复试验之间存在显著差异（P < 0.05）。总体而言，公牛和冷冻精液批次是卵裂率变化的最大来源（分别为30.6%和29.4%），而检测日期是囊胚发育率变化的最大来源（21.7%）。结果表明，体外受精以及在较小程度上培养至囊胚阶段可用于估计奶牛冻融精液的潜在受精能力。
